Merge pull request 'Site: the developer docs (phase 4), Debug Builds and the Debug Console first' (#66) from site-dev into main

Reviewed-on: #66

.gitea/workflows/ci.yml

@@ -0,0 +1,114 @@
+# CI and releases (docs/milestones/R1.md).
+#   A push to main:    the host tests, with their coverage of lib/, and the README's badges
+#                      published to the branch `badges`.
+#   A pull request:    the same tests and coverage, then the release firmware and the Debug Build.
+#                      A branch's pushes run nothing by themselves: its pull request runs, once.
+#   A tag v*:          all of it, then a Gitea release with the signed Update File.
+#   Run by hand:       the release of a tag that exists already (the ones from before CI).
+#
+# The job runs in a plain Python image, as scripts/ci.sh does on a developer's machine, with the
+# toolchains in a Docker volume the runner allows (container.valid_volumes: roro9stack-pio): that
+# volume is the cache. No JavaScript actions, so the image needs no Node: the checkout is git.
+name: CI
+on:
+  push:
+    branches: [main]  # other branches are tested by their pull request: one run, not two
+    tags: ['v*']
+    # A change that touches nothing but the site and the documents it is built from runs the Site
+    # workflow only (a tag always runs this one: Gitea doesn't apply path filters to tags).
+    paths-ignore: ['site/**', 'docs/**', 'README.md', 'CONTEXT.md']
+  pull_request:
+    paths-ignore: ['site/**', 'docs/**', 'README.md', 'CONTEXT.md']
+  workflow_dispatch:
+    inputs:
+      tag:
+        description: An existing tag to build and publish as a release
+        required: true
+
+jobs:
+  build:
+    runs-on: ubuntu
+    # A pull request from a fork would run someone else's code on our runner: not without us (Q154).
+    if: github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name == github.repository
+    container:
+      image: python:3.12-slim
+      volumes:
+        - roro9stack-pio:/pio
+    env:
+      PLATFORMIO_CORE_DIR: /pio
+      RORO_NO_DOCKER: 1
+    steps:
+      - name: Tools
+        run: |
+          apt-get update -qq
+          apt-get install -y -qq --no-install-recommends git build-essential openssl >/dev/null
+          pip install -q --no-cache-dir --root-user-action=ignore platformio gcovr
+          pio --version; df -h /pio | tail -1; ls /pio | head
+
+      - name: Check out
+        run: |
+          find . -mindepth 1 -maxdepth 1 -exec rm -rf {} +
+          git config --global --add safe.directory '*'
+          git init -q .
+          git remote add origin "${{ github.server_url }}/${{ github.repository }}.git"
+          git fetch -q --tags origin '+refs/heads/*:refs/remotes/origin/*' '+refs/pull/*/head:refs/remotes/pull/*'
+          git checkout -q --detach "${{ github.sha }}"
+          git describe --tags --always
+
+      - name: Host tests, and their coverage of lib/
+        if: github.event_name != 'workflow_dispatch'
+        run: scripts/coverage.sh
+
+      - name: The release firmware and the Debug Build
+        if: github.event_name == 'pull_request' || github.ref_type == 'tag'
+        run: scripts/ci.sh builds
+
+      # The README's badges are files on a branch of their own, replaced at each push to main and
+      # at each tag (the release badge says which tag is the latest)
+      - name: Publish the badges
+        if: github.event_name == 'push' && (github.ref == 'refs/heads/main' || github.ref_type == 'tag')
+        env:
+          GITEA_TOKEN: ${{ secrets.GITEA_TOKEN }}
+        run: |
+          rm -rf /tmp/badges && mkdir /tmp/badges
+          cp .pio/coverage/coverage.svg .pio/coverage/summary.json /tmp/badges/
+          scripts/coverage_badge.py --plain release "$(git describe --tags --abbrev=0)" /tmp/badges/release.svg
+          cd /tmp/badges
+          git init -q -b badges .
+          git add .
+          git -c user.name="roro9stack CI" -c user.email="ci@git.twis.la" commit -q -m "Coverage of ${{ github.ref_name }} at ${{ github.sha }}"
+          git push -q --force "$(echo "${{ github.server_url }}" | sed "s#://#://ci:${GITEA_TOKEN}@#")/${{ github.repository }}.git" badges
+
+      - name: Which release
+        id: release
+        run: |
+          if [ "${{ github.event_name }}" = workflow_dispatch ]; then
+            echo "tag=${{ inputs.tag }}" >> "$GITHUB_OUTPUT"
+          elif [ "${{ github.ref_type }}" = tag ]; then
+            echo "tag=${{ github.ref_name }}" >> "$GITHUB_OUTPUT"
+          fi
+
+      - name: Build and sign the release
+        if: steps.release.outputs.tag != ''
+        env:
+          OTA_SIGNING_KEY: ${{ secrets.OTA_SIGNING_KEY }}
+        run: |
+          # The sources of the tag in a clone of their own; the tools are this commit's.
+          rm -rf /tmp/release-src dist
+          git clone -q . /tmp/release-src
+          git -C /tmp/release-src checkout -q --detach "refs/tags/${{ steps.release.outputs.tag }}"
+          # The key exists as a file only while this step runs, in a container that goes with the job.
+          umask 077
+          export RORO_OTA_KEY="$(mktemp)"
+          trap 'rm -f "$RORO_OTA_KEY"' EXIT
+          printf '%s\n' "$OTA_SIGNING_KEY" > "$RORO_OTA_KEY"
+          umask 022
+          scripts/release_build.sh /tmp/release-src dist
+
+      - name: Publish the release
+        if: steps.release.outputs.tag != ''
+        env:
+          GITEA_API: ${{ github.server_url }}/api/v1
+          GITEA_REPO: ${{ github.repository }}
+          GITEA_TOKEN: ${{ secrets.GITEA_TOKEN }}
+        run: scripts/release_publish.py dist

.gitea/workflows/site.yml

@@ -0,0 +1,53 @@
+# The project site (docs/milestones/W1.md): built with Zola to see that it builds and that its pages
+# are sound. Publishing is the maintainer's: the web server pulls main and runs `zola build`.
+#
+# It runs when the site, or a document the site is built from, changes (a pull request, or a push to
+# main); the firmware workflow (ci.yml) skips a change that touches only these files. A change that
+# touches both runs both. src/main.cpp is here too: the site's command reference is generated from the
+# firmware's own `help` text, and this job checks that it is still current.
+name: Site
+on:
+  push:
+    branches: [main]
+    paths: ['site/**', 'docs/**', 'README.md', 'CONTEXT.md', 'src/main.cpp', '.gitea/workflows/site.yml']
+  pull_request:
+    paths: ['site/**', 'docs/**', 'README.md', 'CONTEXT.md', 'src/main.cpp', '.gitea/workflows/site.yml']
+
+jobs:
+  build:
+    runs-on: ubuntu
+    # A pull request from a fork would run someone else's code on our runner: not without us.
+    if: github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name == github.repository
+    container:
+      image: python:3.12-slim
+    steps:
+      - name: Tools
+        run: |
+          apt-get update -qq
+          apt-get install -y -qq --no-install-recommends git ca-certificates curl >/dev/null
+          # Zola, pinned by its checksum.
+          curl -fsSL -o /tmp/zola.tgz https://github.com/getzola/zola/releases/download/v0.22.0/zola-v0.22.0-x86_64-unknown-linux-gnu.tar.gz
+          echo "f1d491f8956b94384c27d75cb6b2bf60d3916d1ade9564bcbfe7c03f0258aebf  /tmp/zola.tgz" | sha256sum -c -
+          tar xzf /tmp/zola.tgz -C /usr/local/bin zola
+          zola --version
+
+      - name: Check out
+        run: |
+          find . -mindepth 1 -maxdepth 1 -exec rm -rf {} +
+          git config --global --add safe.directory '*'
+          git init -q .
+          git remote add origin "${{ github.server_url }}/${{ github.repository }}.git"
+          git fetch -q origin '+refs/heads/*:refs/remotes/origin/*' '+refs/pull/*/head:refs/remotes/pull/*'
+          git checkout -q --detach "${{ github.sha }}"
+
+      - name: The generated developer pages are current
+        run: python3 site/tools/gen_dev_docs.py --check
+
+      - name: Build the site
+        run: |
+          cd site
+          zola check --skip-external-links
+          zola build --output-dir /tmp/site-out
+
+      - name: Check the pages
+        run: python3 site/tools/check_site.py /tmp/site-out

.gitignore

@@ -9,3 +9,6 @@
 .dummy/
 managed_components/
 sdkconfig.*
+
+# The built site (site/config.toml sends it here)
+/public/

CONTEXT.md

@@ -20,6 +20,10 @@ _Avoid_: daemon, task, driver
 The Service that keeps the device participating in a mesh network at all times: receiving, relaying, and sending on behalf of Apps.
 _Avoid_: radio, LoRa app
 
+**Radio Service**:
+The Service that owns the LoRa radio on the Cap: it configures it, shares the SPI bus with the SD card, and receives in the background. The LoRa Scanner uses it directly; the Mesh Service sits on top of it.
+_Avoid_: LoRa driver, modem
+
 **Mesh Protocol**:
 One on-air language the Mesh Service can speak (Meshtastic first; others may follow). The Mesh Service speaks Mesh Protocols; Apps don't.
 _Avoid_: stack, mode
@@ -40,6 +44,14 @@ _Avoid_: DM (in docs), private message
 Rebroadcasting another Node's packet so it travels further across the mesh.
 _Avoid_: forwarding, repeating
 
+**Capsule**:
+A Gemini site: everything served by one host on Geminispace.
+_Avoid_: site, server (when the content is meant)
+
+**Saved Page**:
+A Gemini page kept on the SD card to read offline, with the URL it came from and when it was saved. Kept until the user deletes it; Storage Clean-up never offers it.
+_Avoid_: cache, download (a download is a non-text file saved from Gemini)
+
 **GNSS Service**:
 The Service that owns the GNSS receiver on the Cap: it reads its NMEA sentences in the background and holds the current Fix, position, time and satellites.
 _Avoid_: GPS (GPS is one constellation among several)
@@ -57,7 +69,7 @@ The Service that owns the Wi-Fi radio. It's always in exactly one mode: *Off*, *
 _Avoid_: network manager
 
 **Saved Network**:
-A Wi-Fi network the device may join on its own (name, password). When several are in range, the strongest wins.
+A Wi-Fi network the device may join on its own: its name, its password, and how it gets its address, *Automatic* (DHCP) or *Fixed* (an address, a prefix and an optional gateway typed in Settings). When several are in range, the strongest wins.
 _Avoid_: profile, known network
 
 **IRC Service**:
@@ -111,13 +123,28 @@ Data the user explicitly starts recording, such as Wi-Fi packet captures and LoR
 _Avoid_: dump, log
 
 **Storage Warning**:
-The Notification raised once per boot when the SD card passes 80% full. Selecting it opens Storage Clean-up.
+The Notification raised once per boot when the SD card passes 80% full. It points at the Storage App, where Maintenance holds Storage Clean-up.
 
 **Storage Clean-up**:
-The screen where the user deletes old Logs and Captures by category and age, with a preview of the space freed. Notes are never offered for deletion.
+The screen where the user deletes old Logs and Captures by category and age, with a preview of the space freed. Notes are never offered for deletion. It lives in the Storage App, under Maintenance.
+
+**Note**:
+A plain text file in `/notes`, written on the device in the Notes App. Listed by its first line. Saved without being asked; never offered by Storage Clean-up.
+_Avoid_: memo, document
+
+**Storage App**:
+The App that browses the SD card: folders and files, a clipboard for one item at a time (copy, cut, paste), rename, delete, new folder, and a viewer for each kind of file the firmware writes. The top-level folders, `/gemini/cache` and files being written are read-only.
+_Avoid_: file manager, Files, explorer
+
+**Maintenance**:
+The part of the Storage App that deletes in bulk: the card's usage, Storage Clean-up and erasing the card. Reached through a warning.
+_Avoid_: Settings > Storage
 
 **Firmware Update**:
-Installing a new firmware image without a USB cable: pushed over Wi-Fi from the developer's PC, or read from the SD card.
+Installing a new firmware image without a USB cable: pushed over Wi-Fi from the developer's PC, read from the SD card, or downloaded from the project's Gitea **Release**.
+
+**Release**:
+A tag `v*` on the project's Gitea with a signed **Update File**, a factory image for USB, the ELF to decode crashes and checksums, built and published by CI. The device reads them to look for updates. Debug Builds aren't published.
 _Avoid_: flash, upgrade (alone)
 
 **Update File**:
@@ -151,6 +178,7 @@ _Avoid_: telnet, remote shell
 - The **Mesh Service** speaks one or more **Mesh Protocols** and tracks the known **Nodes**.
 - The **Wi-Fi Service** is either Connected or Monitoring, never both. Monitoring pauses the **IRC Service**, which reconnects and rejoins its **Buffers** afterwards.
 - **Services** raise **Notifications**; the **Status Bar** summarises **Service** state.
+- The **Radio Service** owns the radio; the **Mesh Service** and the LoRa Scanner use it.
 - A **Sweep** pauses the **Mesh Service**; a **Sniffer** does not.
 - Every transmission is bounded by the **Region** and its **Duty Cycle Budget**.
 - Past 90% SD usage, **Logs** stop being written; the remaining space is kept for **Captures**. Nothing is deleted without the user's confirmation.

README.md

@@ -1,5 +1,7 @@
 # roro9stack
 
+[![CI](https://git.twis.la/twisla/roro9stack/actions/workflows/ci.yml/badge.svg?branch=main)](https://git.twis.la/twisla/roro9stack/actions?workflow=ci.yml) [![Coverage of lib/ by the host tests](https://git.twis.la/twisla/roro9stack/raw/branch/badges/coverage.svg)](#build-and-test-local-ci) [![Latest release](https://git.twis.la/twisla/roro9stack/raw/branch/badges/release.svg)](https://git.twis.la/twisla/roro9stack/releases/latest)
+
 A multi-app firmware for the **M5Stack Cardputer ADV** with the **Cap LoRa-1262**. It's a Meshtastic-compatible mesh messenger, plus Wi-Fi tools, IRC, GNSS and more. Licensed GPL-3.0.
 
 - Domain language: [CONTEXT.md](CONTEXT.md)
@@ -18,8 +20,27 @@ scripts/ci.sh
 
 This runs the host-side unit tests (`test/`, `native` environment), then builds the firmware. The output is `.pio/build/cardputer-adv/firmware.factory.bin`.
 
+`scripts/coverage.sh` runs the same tests with coverage counters and writes a line-by-line report to `.pio/coverage/index.html`. The badge above is its figure for `main`: the share of the lines of `lib/` that the host tests run. `lib/` is the logic that compiles on a PC; `lib/SD` (the card's driver) and `src/` (the Apps, the Services, everything that needs the device) have no host tests and aren't in that figure.
+
 The framework is rebuilt with the TLS settings in `platformio.ini` (`custom_sdkconfig`, ADR 0006), so the first build after a fresh checkout takes about 4 minutes; later builds take under a minute.
 
+## CI and releases
+
+Gitea Actions (`.gitea/workflows/ci.yml`, docs/milestones/R1.md) runs the host tests on every push to `main`, and on a pull request also builds the release firmware and the Debug Build: changes reach `main` through pull requests. Pushing a tag `v*` runs all of it and publishes a release on Gitea with:
+
+- `roro9stack-<version>.ota`, the signed Update File;
+- `roro9stack-<version>-factory.bin`, the whole flash image for a first install over USB;
+- `roro9stack-<version>.elf.gz`, to decode crash reports from that build;
+- `SHA256SUMS`.
+
+CI signs with the project's key, held as a repository secret (ADR 0008). Debug Builds are built but never published: each carries its builder's Debug Console token.
+
+`scripts/ota_verify.py <file.ota>` checks an Update File on a PC the way a device does. `scripts/release_build.sh` and `scripts/release_publish.py` are what the workflow runs; they work the same by hand.
+
+## The website
+
+The project's site, **roro9stack.net**, is built from `site/` with Zola (see `site/README.md`): the home page, an Install page that flashes a Cardputer from the browser, and every release. Changes under `site/`, `docs/`, `README.md` and `CONTEXT.md` run only the site's CI job, not the firmware tests and builds.
+
 ## Flash
 
 1. Connect the Cardputer by USB-C.
@@ -52,7 +73,84 @@ The device shows the push address in **Settings → Firmware**. It installs a co
 
 To install from the SD card instead, copy the `.ota` file from `.pio/build/cardputer-adv/` into `/updates` on the card, then use **Settings → Firmware**. With the Cardputer on USB, the card can stay in: `scripts/sd_put.sh <file.ota>` sends it over the serial console into `/updates` (about 30 s for 1.6 MB, checked with SHA-256 before it's renamed into place; `SD_PUT_DEBUG=1` shows the console while it runs).
 
-**The private key** lives in `~/.config/roro9stack/ota-key.pem` and must never be committed. If it's lost, generate a new pair and flash once over USB.
+**The private key** lives in `~/.config/roro9stack/ota-key.pem` and must never be committed. If it's lost, generate a new pair and flash once over USB. (CI signs releases with a copy kept as a repository secret, ADR 0008.)
+
+### Updates from Gitea
+
+With no PC and no card, the device can install the project's releases itself (docs/milestones/R1.md). In **Settings → Firmware**:
+
+- **Latest release** checks the server (Enter, or `c`) and says `v0.11.0 (new)` or `(current)`. Enter again opens the release: its version, date, size and the tag's message, with **Install** when it's newer. The download goes straight into the inactive slot, so no card is needed; the signature is checked after the first 160 bytes, before anything is written, and the image's hash at the end. The new firmware then runs on Probation as for any update.
+- **Older releases** lists the last ten, newest first. Opening an older one offers to go back to it, with a different question.
+- **Settings → Check for updates** (on by default): once a day, with Wi-Fi up and the clock set, the device looks at the latest release and says `v0.11.0 is out: see Settings > Firmware`, once per version. It installs nothing by itself, and doesn't announce a version that already failed and rolled back on this device.
+
+The connection is checked against the two ISRG roots Let's Encrypt chains end in (ADR 0009), not the usual bundle of about 130 authorities. Whatever the connection, the Update File's own signature is what decides what gets installed.
+
+**IRC steps aside.** A secure connection takes about 52 KB of memory at its peak, and IRC's own takes 40 KB of the 107 KB there is. A check or an install you ask for makes IRC disconnect for the few seconds it takes and reconnect afterwards. The daily check never does that: with IRC connected it waits for a moment when IRC isn't, so while IRC stays connected for days it doesn't run, and **Latest release** is the way to check.
+
+**A Debug Build** shows the latest release but doesn't install it: releases have no Debug Console (they aren't built with one, so that nobody's console token is published), and installing one would take it away. A Debug Build is updated from the PC with `scripts/flash.sh --debug --ota`.
+
+## Networks without DHCP
+
+Each Saved Network gets its address automatically (DHCP) or has a Fixed one (docs/milestones/S1.md): in Settings > Wi-Fi, Enter on a network opens its page, where "IP address" switches between Automatic and Fixed, with an address, a prefix length (24 is 255.255.255.0) and an optional gateway. Switching to Fixed starts from what the network is giving the device at that moment. The setting is checked and applied when you leave the page. IPv4 only.
+
+"DNS and NTP" on the same screen holds two DNS servers (9.9.9.9 and 1.1.1.1 by default), used on Fixed networks, or on every network with "Always use my DNS"; and two NTP servers (pool.ntp.org and time.cloudflare.com), used after any the network's DHCP offers. Enter on "Status" shows what's in use and where each value came from.
+
+## System
+
+The System App (docs/milestones/S1.md) shows what the device is doing, live and read-only, in any build. Tab moves between five views:
+
+- **Overview:** each core's load, free memory, network traffic, battery, uptime and chip temperature, and both cores' load over the last two minutes.
+- **Tasks:** every FreeRTOS task with its core, its share of a core over the last second, and the least stack it ever had left (in the warning colour under 512 bytes). `s` sorts by share, stack or name.
+- **Memory:** free heap, the lowest since boot and the largest free block, with two minutes of free heap drawn against the three memory floors (55, 40 and 20 KB).
+- **Network:** the connection, then for IRC, Gemini, the Debug Console and Firmware Updates the bytes read and written since boot and what's moving now. For TLS connections these are the bytes the service sees, without the encryption overhead.
+- **System:** what `info` prints, plus the battery, the SD card with its write faults, the radio and the GNSS receiver.
+
+It samples once a second and keeps its history only while it's open.
+
+## Gemini
+
+The Gemini App browses Geminispace (docs/milestones/G1.md): Tab and Shift+Tab pick a link, Enter follows it, Back returns (to where the page was scrolled), Space pages down, `g` types an address. Certificates are trusted on first use; a changed one stops the page and asks.
+
+On a page, `b` bookmarks it, `s` saves it to the SD card to read offline (a non-text file goes to `/gemini/downloads/`), `S` saves it with the pages it links to on the same capsule (up to 30). The start page lists bookmarks and Saved Pages; inside a Saved Page, `r` refreshes it and `d` deletes it. With a card, every page streams through `/gemini/cache/` so a large one arrives whole even with IRC connected; what doesn't fit in memory stays on the card.
+
+## LoRa Scanner
+
+The LoRa Scanner (docs/milestones/M3.md) listens with the Cap's radio and **never transmits**. The Sniffer lists what it hears, newest first: time, RSSI, SNR, and for Meshtastic packets the sender and receiver (their last 4 hex digits) and hops. Enter shows a packet's details: the Meshtastic header (which is never encrypted) and a hex dump. `p` picks one of the 7 Meshtastic presets allowed in EU868 (LongFast by default), `c` starts or stops a Capture: a pcap file with LoRaTap headers in `/captures/lora/`, for Wireshark. A Capture keeps recording with the App closed; otherwise the radio sleeps when the App isn't open. Tab switches to **Sweep**: the signal strength across 863–870 MHz in 100 kHz steps, as bars with peak hold and a waterfall, with the Sniffer's frequency marked; the Sniffer is paused meanwhile and picks up where it was. The GNSS receiver on the same Cap raises the radio's noise floor by 8 dB while it runs: Settings > "Pause GNSS for LoRa" (off by default) puts it in standby while the radio listens, except during a Track. The Status Bar shows `L` while the radio listens (bright for a moment on each packet), `SW` while sweeping, and `CAP` while capturing.
+
+## Storage
+
+The Storage App (docs/milestones/F1.md) shows what's on the SD card: each folder's entries with their size and date, folders first. Enter opens a folder, Back goes up; `s` sorts by name, date or size. It works on one item at a time, with a clipboard:
+
+| Key | Does |
+|---|---|
+| `c` / `x` | Copies or cuts the selected file or folder; the footer shows what `v` would paste |
+| `v` | Pastes it into the folder shown. A copy next to its original is named `name (2).txt`; anything in the way is asked about first |
+| `r` | Renames |
+| `d` | Deletes, after saying what's inside: "Delete saved and its 42 files (1.2 MB)?" |
+| `n` | Makes a folder |
+| `i` | Details: type, exact size, date, and why an item is read-only if it is |
+
+A copy runs in the background of the card (about 400 KB a second) in short turns, so Logs and Captures keep being written; it shows its progress, Back cancels it and takes back what was copied, and each file's size is checked afterwards. Three things can't be changed: the top-level folders the firmware keeps its files in (what's inside them can), `/gemini/cache`, and any file being written right now (today's IRC Logs, a Track or a Capture being recorded). The App says why when it refuses. A folder with more than 256 entries shows the first 256 by name and says so.
+
+Enter on a file opens it by type; Tab switches to the same file as a hex dump or as text:
+
+- **Text** (`.txt`, `.log`, `.gmi`, `.csv`, and anything that looks like text): only the screen's worth is read from the card, so a file of any size opens at once. Logs open at the end. Up and Down move a line, Left and Right a page, `t` and `b` go to the top and the end, `e` edits it (up to 16 KB, see Notes).
+- **Captures** (`.pcap`): the packets as the LoRa Scanner lists them; Enter shows one with its Meshtastic header and bytes.
+- **Tracks** (`.gpx`): the number of points, the start, the duration and the distance.
+- **Update Files** (`.ota`): the version, and whether the file would install: it's checked as an install checks it (signature and contents) without writing anything. Enter then installs it.
+- **Anything else:** a hex dump.
+
+At the top of the card the last row, **Maintenance** (also `m`), holds the card's usage, Storage Clean-up and "Erase SD card", behind a warning: those delete for good. It replaces Settings > Storage.
+
+## Notes
+
+The Notes App (docs/milestones/F1.md) keeps plain text notes in `/notes` on the SD card. The list shows each note's first line and its date, newest first; `s` switches to by file name. `n` starts a note, Enter opens one, `r` renames its file, `d` deletes it after asking.
+
+In the editor, type. Enter starts a line, Del deletes backwards, Fn with the arrows moves the cursor through the wrapped text, Ctrl+A and Ctrl+E go to the start and the end of the line, Tab types two spaces, and the Compose Key gives accents as everywhere. **There's no save key:** the note is written five seconds after the last key, on Back, on leaving the App, when the screen turns off and before the device powers off. The top line says "typing" or "saved". Each save writes a temporary file and then puts it in the note's place, so a power cut costs a few seconds of typing and never the note; if a save was cut short, opening the note offers its copy back.
+
+A new note has no file until something is typed; its file is then named after its first line (`shopping-list.txt`), or `note-<date>-<time>.txt`.
+
+A note holds up to 16 KB while it's edited. A bigger text file opens read-only in the Storage App (editing any size is issue #47). The Storage App's text viewer has `e` to edit a file with the same editor, anywhere on the card, unless the file is read-only.
 
 ## Development aids
 
@@ -65,22 +163,46 @@ To install from the SD card instead, copy the `.ota` file from `.pio/build/cardp
 | `sound on` / `sound off` | Toggles the Sound setting (beep + LED) |
 | `short` / `normal` | Screen timeouts 5 s / 10 s, or 30 s / 60 s |
 | `wifi add <ssid><TAB><password>` | Adds a Saved Network (so credentials stay out of the repo) |
+| `wifi ip <ssid> dhcp` / `wifi ip <ssid> <address>/<prefix> [gateway]` | A Saved Network's IP setting: Automatic, or Fixed. Debug Builds: add `try <seconds>` to go back to the previous setting unless `wifi ip keep` follows |
+| `wifi dns <a> [b]` / `wifi dns always on\|off` / `wifi ntp <a> [b]` | DNS servers (used on Fixed networks, or always), and NTP servers |
 | `log <text>` | Appends a line to a test IRC Log (`/irc/dev/#test/<date>.log`) |
+| `sd card` | What the SD card says it is: type, size, and its identity register (maker, name, revision, serial, date) |
 | `sd list` | Lists the files of each Storage Clean-up category |
+| `sd fill <folder> <count>` | Debug Builds: makes that many small files in a folder, to test a crowded one |
 | `cat <path>` | Prints the first ~1.2 KB of a file on the SD card |
 | `irc start` | Starts the IRC Service (normally done by opening the IRC App) |
 | `irc stop` | Stops it, as `/quit` does: QUIT if connected, no more retries, and the App stays disconnected until you type |
+| `gemini get <url>` | Fetches a Gemini page and prints its header, size, certificate fingerprint and heap use |
+| `gemini trust <host> <port> <sha256>` | Pins a certificate by hand (the Gemini App asks when one changes) |
 | `irc say <buffer> <text>` | Types into a Buffer, commands included (`irc say 0 /join #test`) |
 | `irc dump` | Prints IRC status, memory, and the last lines of each Buffer |
-| `wifi status` | Prints Wi-Fi state, network, signal, clock and free heap |
+| `wifi status` | Prints Wi-Fi state, network, signal, clock and free heap, then the address, gateway, DNS and NTP servers in use and where each came from |
-| `info` | Firmware, uptime, last start reason, memory, Wi-Fi, and both app slots with their versions and OTA states |
+| `info` | Firmware, uptime, last start reason, memory, Wi-Fi, the SD card and its write faults since boot, and both app slots with their versions and OTA states |
-| `tasks` | FreeRTOS tasks: state, priority, lowest free stack, CPU share |
+| `tasks` | FreeRTOS tasks over the next second: state, priority, lowest free stack, share of a core, each core's load, and how many passes the main loop made |
+| `net` | Bytes each network service has read and written since boot |
 | `reboot` / `boot other` | Restart, or restart into the other app slot (a manual Rollback) |
 | `log level <0-5>` | ESP-IDF log level |
-| `ls [folder]` / `rm <path>` | Lists a folder of the SD card, or deletes a file |
+| `ls [folder]` / `du <path>` | Lists a folder of the SD card with sizes and dates, or counts the files and bytes under a path |
+| `cp [-f] <from> <to>` / `mv [-f] <from> <to>` / `rm <path>` / `mkdir <path>` / `cancel` | What the Storage App does, with its rules: copy (folders too), move or rename, delete (a folder with what's in it), new folder. `-f` replaces a file that's in the way; a tab separates paths that hold spaces; `cancel` stops a copy or a delete |
 | `install <path>` | Update from SD with that `.ota` file, as Settings → Firmware does |
+| `update check` / `update list` / `update status` / `update install <tag>` | The project's releases on Gitea: look at the latest, list the last ten, say what's known, or download and install one (not on a Debug Build) |
+| `update pretend <version>` / `update probe <host>` / `update damage cut\|flip <n>` / `update daily` | Debug Builds: pretend to run another version (so a release counts as an update), see whether a server's certificate is accepted, cut or damage the next download, run the daily check again |
+| `lora probe` | Finds the radio: chip, oscillator, antenna switch, DIO1 interrupt, noise floor |
+| `lora status` | Radio settings, who's listening, packet and error counters, noise floor, task stack |
+| `lora rx on` / `lora rx off` | Listens and prints each packet on the console |
+| `lora preset <name>` / `lora custom <MHz> <BW kHz> <SF> <CR> <sync hex> [preamble]` | Receive settings: a Meshtastic preset, or anything else (`lora custom 868.1 125 7 5 34 8` for LoRaWAN) |
+| `lora capture start` / `lora capture stop` | A LoRa Capture, as `c` in the App |
+| `lora sweep on [from MHz] [to MHz] [step kHz]` / `lora sweep off` / `lora sweep dump` | Sweep a band (863 870 100 by default), with a summary every 2 s (floor, strongest, peaks), or print the latest pass |
+| `gnss quiet on` / `gnss quiet off` | The "Pause GNSS for LoRa" setting |
+| `gnss status` / `gnss restart` | The receiver's state, and a restart of it |
+| `gnss track start` / `gnss track stop` | A Track, as `r` in the GNSS App (the reason is printed if it can't start) |
+| `gnss nmea on` / `gnss nmea off` | Prints each NMEA sentence the receiver sends, as `nmea: …` |
+| `gnss send <sentence>` | Sends a sentence to the receiver, without the `$` and the checksum (it adds them) |
+| `lora noise test [gnss\|quiet]` / `lora noise report` | Debug Builds: Sweep under one changed condition at a time to find what raises the noise floor (Wi-Fi goes off for a few seconds); then the result |
+| `lora inject <hex> [rssi] [snr]` | Debug Builds: a packet into the Scanner as if received (nothing is sent) |
 | `crash` | The last crash: which firmware, why, task, PC and backtrace (from the core dump in flash) |
 | `coredump erase` | Forgets the core dump |
+| `loop spin on` / `loop spin off` | Debug Builds: make the main loop spin without resting, to compare load and radio noise |
 | `crash abort` / `crash wdt` | Debug Builds: crash on purpose, or hang the main loop until the watchdog fires |
 | `help` | Lists the commands |
 

docker/Dockerfile

@@ -5,7 +5,7 @@ RUN apt-get update \
  && apt-get install -y --no-install-recommends git build-essential \
  && rm -rf /var/lib/apt/lists/*
 
-RUN pip install --no-cache-dir platformio
+RUN pip install --no-cache-dir platformio gcovr
 
 # Toolchains and libraries are cached in a named volume mounted here.
 RUN mkdir -p /pio && chmod 777 /pio

docs/adr/0007-own-copy-of-the-sd-driver.md

@@ -0,0 +1,20 @@
+# Our own copy of the SD driver, for one missing byte
+
+Arduino-ESP32's `SD` library talks to the card over SPI through `sd_diskio.cpp`. That driver gives up on a write without saying why, and about once in 1,500 multi-block writes it gave up on one that had worked (issue #21). A 1.7 MB upload failed about three times in ten; before M3, the retry on top of it then filled the gap with zeros.
+
+The cause, measured with a driver that records where it stops: after the "Stop Tran" token that ends a multi-block write, a card takes about a byte of clock to signal busy. The driver deselects, selects again, and reads one byte to see whether the card is ready. Read too early, that byte is 0xFF, "ready"; the status check (CMD13) then goes out while the card is still programming, and its answer (0xFF, 0x1F) is taken for an error. Every failure seen was this one: all blocks accepted, then a status that isn't one. ChaN's reference driver, which FatFs ships as its example, sends a dummy byte after selecting the card for this reason. Arduino's doesn't.
+
+PlatformIO links the framework's library objects directly, so one file can't be replaced from `src`. A project library with the same name takes its place: **`lib/SD` is Arduino-ESP32 3.3.12's SD library (Apache-2.0), with `sd_diskio.cpp` changed** and the other files as they came. The changes are marked `roro:`:
+
+- A dummy byte after selecting the card, before the ready test, and one after Stop Tran.
+- Each place a write gives up records the step and the card's answer (`sd_fault.h`): `info` shows the count, and the Debug Console's `put` prints the detail.
+
+Halving the SPI clock to 10 MHz didn't change the failure rate, so the card stays at 20 MHz.
+
+## Consequences
+
+- 30 uploads of 1.7 MB in a row, each read back and compared by SHA-256, ten of them with the LoRa radio listening on the same bus: no write fault. Before: 3 failures in 10.
+- Every writer gains: Logs, Tracks, Gemini pages, Saved Pages, Captures and Update Files installed from the card all go through this driver, and none of them checked.
+- **The copy has to follow the framework.** When the platform is updated, compare `lib/SD` with the new `libraries/SD` and carry the `roro:` changes over. If upstream fixes the ready test, drop the copy. Reported as [arduino-esp32#12970](https://github.com/espressif/arduino-esp32/issues/12970); issue #39 follows it.
+- One more defect was read in the code and left alone, because nothing here exercises it: the driver tests the card's answer to a data block against 0x0A and 0x0C, values it can't take (accepted is 0x05, CRC error 0x0B, write error 0x0D), so a block rejected for a CRC error is never resent. No such rejection was seen in any failure. If `DataToken` faults ever show in `info`, that's the next fix.
+- A fault is now counted and explained instead of silent, so the next cause, if there is one, starts with evidence.

docs/adr/0008-ci-signs-releases.md

@@ -0,0 +1,17 @@
+# CI signs releases with the project's key
+
+A tag `v*` is built, signed and published by Gitea Actions with nobody at a keyboard. The signing key of ADR 0003 is therefore held twice: in `~/.config/roro9stack/ota-key.pem` on the development machine, as before, and as the repository secret `OTA_SIGNING_KEY`, which the release step writes to a file for as long as it runs.
+
+We chose this over signing by hand after CI has built (a command per release, the key in one place), and over a second key for CI that the firmware would also trust. A release that needs a manual step isn't made on the day it's ready, and issue #6, the device installing releases by itself, needs releases that are always there and always signed.
+
+## What it costs
+
+- **Whoever can run a workflow in this repository can sign firmware every device accepts.** That means: anyone who can push to it, the runner's host and whoever administers it, and the Gitea instance with its database, where the secret is stored. Before, it took the development machine.
+- The runner executes jobs **on its own host**, not in a container, as a user who can use Docker. A workflow is not confined.
+- Pull requests from forks must never run with this secret. Gitea doesn't pass secrets to them; the workflow also only runs on pushes and by hand.
+
+## What limits it
+
+- The release step checks the signed file against the public key in the sources it built (`scripts/ota_verify.py`): a wrong or replaced secret stops the release instead of publishing a file no device takes.
+- ADR 0003's way out stays: a firmware release can carry a new public key. If the secret is ever in doubt, make a new pair, ship it in a release signed with the old key, and replace the secret.
+- A device still only installs what it's told to (until #6), keeps a new image on Probation, and rolls back one that doesn't hold.

docs/adr/0009-the-device-trusts-the-isrg-roots.md

@@ -0,0 +1,22 @@
+# The device trusts the two ISRG roots for what it fetches
+
+The firmware talks to the project's Gitea over HTTPS (issue #6, and #4 after it). A TLS client has to decide whose certificates it believes. Three ways were possible:
+
+- **The framework's bundle**, about 130 certificate authorities (about 60 KB of flash). Any of them could vouch for `git.twis.la`.
+- **Pin the server's certificate**, as the Gemini App does for capsules. The server's certificate is replaced every few months, so a pin would ask the question again at every renewal.
+- **Carry the roots the server's chain ends in:** `ISRG Root X1` (RSA 4096) and `ISRG Root X2` (ECDSA P-384), the Let's Encrypt roots, about 2.7 KB of flash (`src/platform/ca_roots.h`).
+
+We chose the third. The chain and the name are checked by mbedTLS during the handshake. It trusts one organisation's two roots, valid until 2035 and 2040, and a renewal changes nothing.
+
+## What it costs
+
+- **If the server moves to another CA, the device can no longer reach it**, and the next firmware, carrying that CA's root, has to come from the PC or the SD card. Both still work; they don't use TLS.
+- The roots are public data checked against the published fingerprints (listed in the file), refreshed by hand if Let's Encrypt ever changes them.
+
+## What it doesn't change
+
+The Update File's own signature (ADR 0003) is what decides what gets installed. A hijacked connection could hide a release, or serve an older signed one, but never make the device install firmware that isn't ours. The TLS check matters more for #4, where a token will travel over it.
+
+## Measured while building it
+
+A TLS connection to this server peaks at about 52 KB of heap, **the same whether the certificate is checked or not**, so skipping the check would have saved nothing. The cost is the connection itself (record buffers and handshake), not the trust decision.

docs/milestones/F1.md

@@ -0,0 +1,161 @@
+# F1 — Files and Notes
+
+**Status:** in progress. The Storage App (issue #3) shipped as **v0.9.0** on 2026-10-06. Notes (#19) shipped as **v0.10.0** the same day. The card as a USB drive (#1) comes after.
+
+**Goal:** get at what's on the SD card from the device itself: browse it, look inside the files the firmware writes, copy, move, rename and delete, and keep notes. A side milestone, like G1 and S1; Files and Notes were M3's original second half (Q30, Q89).
+
+## The Storage App (issue #3)
+
+Until now the card could be looked at only through the Debug Console (`ls`, `get`, `put`), and Settings > Storage could only delete whole categories by age.
+
+**On the card today:** six top-level folders, `irc`, `wifi`, `updates`, `gnss`, `gemini` and `captures`. No `notes` yet; settings are in flash, not on the card.
+
+### Decisions (design round 2026-10-06)
+
+| # | Decision |
+|---|---|
+| Q128 | An App of its own, **Storage**, in the Launcher. **Settings > Storage goes away:** its usage figures, Storage Clean-up and "Erase SD card" move into the App, under **Maintenance**, behind a warning that these delete things for good. |
+| Q129 | A row shows the name, then the size or "folder", then the date modified. Folders first, then by name; `s` cycles the sort (name, date, size). The top line shows the path and the card's free space. |
+| Q130 | Nothing is hidden. **Read-only:** `/gemini/cache`; any file the firmware has open right now (today's IRC log, a Track or Capture being recorded, a file being received); and the top-level folders themselves, which can't be renamed or deleted though their contents can. **Everything else, the user's own data included, can be renamed, moved or deleted**, always after a confirmation. |
+| Q131 | One item at a time, with a clipboard: Enter opens; Back goes up, and leaves the App at the top; `c` copy, `x` cut, `v` paste into the current folder; `r` rename; `d` delete; `n` new folder; `i` details. |
+| Q132 | Copy, move and delete work on folders too, recursively. The confirmation says what's inside: "Delete *saved* and its 42 files?". |
+| Q133 | A copy is a job on the storage task in 4 KB pieces, with a progress Toast; Back cancels it. It checks free space first and asks before replacing anything. **Afterwards the sizes are compared**, not the contents: the driver is trusted since v0.6.1 (ADR 0007). A move within the card is a rename. |
+| Q134 | Viewers by type. **Text** (`.txt`, `.log`, `.gmi`, `.csv`, `.gpx`, and anything that looks like text): read from the card as you scroll, so size doesn't matter; logs open at the end. **`.pcap`:** the LoRa Scanner's packet list. **`.gpx`:** a summary (start, duration, points, distance), Tab for the text. **`.ota`:** version, size, whether the signature is valid; Enter installs through Update from SD. **Anything else:** a hex dump. |
+| Q135 | No editing: that comes with Notes (#19). |
+| Q136 | A listing holds **up to 256 entries**, packed, about 10 KB; a bigger folder shows the first 256 by name and says how many more there are. The App refuses to open below the memory floors (Q86). |
+| Q137 | **The Clock also sets the system time**, so files are dated correctly with GNSS alone and not only after NTP. A file dated before 2020 shows "-". |
+| Q138 | Console: `cp`, `mv` and `mkdir`, next to `ls` and `rm`. |
+| Q139 | Left out, each with its issue: selecting several items (#41), finding files by name (#42), opening a `.gmi` in the Gemini App (#43), a table view for `.csv` (#44), images (#45). |
+| Q140 | Ships as **v0.9.0** when done and checked. |
+
+### Done when
+
+- The Storage App lists any folder of the card with sizes and dates, sorted three ways, and says so when a folder has more than 256 entries.
+- A file can be copied, moved, renamed and deleted, and a folder too; a new folder can be made. Each destructive action asks first; a copy shows progress and can be cancelled.
+- The read-only rules of Q130 hold, with a reason given when something is refused.
+- Each viewer of Q134 opens its type, and a 1 MB text file scrolls without loading whole.
+- Maintenance shows the card's usage and does what Settings > Storage did, behind its warning; Settings no longer has a Storage row; the Storage Warning points at the Storage App.
+- A file written with only a GNSS Fix (no Wi-Fi) is dated correctly.
+- Free heap stays above the floors with the App open, Wi-Fi and IRC on TLS.
+
+### Work breakdown
+
+1. **Model** (host-tested): paths and names, the read-only rules, the packed listing and its sorts, file types, sizes and dates for display, the GPX summary.
+2. **Card operations:** listing a folder, copy, move, delete (recursive, counted), new folder, as storage jobs with progress and cancel; `cp`, `mv`, `mkdir`; the Clock sets the system time.
+3. **The App:** browsing, the clipboard, dialogs, details.
+4. **Maintenance:** usage, Clean-up and Erase moved in from Settings, with the warning.
+5. **Viewers:** text, hex, `.pcap`, `.gpx`, `.ota`.
+6. **Checks on the device**, recorded here.
+
+### As built
+
+- **`FileOps`** (`src/services/file_ops`) does the card's work for the App and for the console alike: list, count, copy, move, delete, new folder. One operation at a time on the storage task, **in turns of about 150 ms** that queue themselves again, so Log lines and a Capture are written in between. The rules of Q130 are checked there, whoever asks.
+- **A listing reads the folder straight from FatFs.** Through the Arduino `File`, every entry was looked up by name again for its size and again for its date: 329 entries took over two seconds. One pass now, and it's there before the screen has redrawn. Counting, copying and deleting still walk with `File`; they show progress and can be stopped.
+- **A copy shows its progress in a box in the App**, not a Toast (Q133): it has a bar and says Back cancels. A cancelled or failed copy deletes what it had written. The copy gets today's date, like `cp`.
+- **The viewers** (`src/apps/file_viewer`, models in `lib/files`): text through `TextPager`, which reads about a kilobyte around the screen and wraps at spaces, 38 columns; going back a line wraps the paragraph before again, so a file reads the same in both directions. A `.pcap`, a `.gpx` and an `.ota` are read through once by a storage job, in the same 150 ms turns. An Update File is fed to the installer's own parser with a sink that writes nothing, so "would it install" is the same answer an install gives.
+- **Tab** in a viewer shows the same file as hex, or as text (not in Q134).
+- **Maintenance** is the last row at the top of the card, and `m` anywhere in the App. It's the old Settings > Storage page behind a dialog.
+- **The Storage Warning** was only ever a Toast; "selecting it opens Storage Clean-up" (CONTEXT.md) was never built. It now reads "SD card over 80% full: see Storage".
+- **Console:** `cp`, `mv`, `mkdir` (Q138), and `rm` and `du` through the same code, so `rm` now takes folders and follows the rules; `ls` shows dates. Debug Builds: `sd fill <folder> <count>` makes test files.
+
+### Checks on the device (2026-10-06, v0.8.1-2 Debug Build)
+
+All in a scratch folder, `/f1test`, removed afterwards.
+
+| Check | Result |
+|---|---|
+| Host tests | 424 pass (411 before the viewers' models) |
+| Browsing | Folders first, sizes and dates, the three sorts; a 300-file and a 329-file folder show "first 256 of 300" and "of 329" |
+| New folder, rename, copy, cut and paste, delete | Each works on a file and on a folder; a copy next to its original is named `(2)`; a name in the way asks "Replace it?" |
+| A folder of 11 files, 8.4 MB, copied | 19.4 s, 435 KB/s, the bar moving; two Log lines queued meanwhile were written |
+| The same copy cancelled at 1.8 MB | "Cancelled: nothing was copied", and nothing was left behind |
+| Delete | 341 files in 9.7 s; the dialog had counted them first |
+| Read-only rules | `/irc`, `/gnss` (top-level folders), `/`, `/gemini/cache` and a folder made inside it, a folder into itself, a name with `:`; a Capture being recorded and the folder holding it; a folder under `/irc` while IRC runs. Each refused with its reason; the Capture could still be copied |
+| Text | A 1 MB log opens at its last line at once; top, pages, lines; a file without an extension that looks like text opens as text |
+| Hex | A 5 KB binary file; Tab from any other viewer |
+| `.pcap` | A LoRa Capture: 3 packets as the Scanner lists them, Enter shows the Meshtastic header and bytes |
+| `.gpx` | 400 points: start, 33 min 15 s, 4.68 km; Tab shows the text |
+| `.ota` | A signed file: version, "intact", "older than what's running", Enter asks to install (not confirmed). A tampered one: "image corrupted (hash mismatch)" |
+| Maintenance | The warning, then usage, Clean-up's categories and Erase (not run) |
+| Date with GNSS only | NTP pointed at an address that doesn't answer, restart: the Clock came from the Fix, and a folder made then is dated 2026-10-06 08:39. A Track from the day before, written the same way by v0.8.1, shows "-" |
+| Memory | IRC connected, the App open on 256 entries: 61 KB free (70 KB before opening). Lowest since boot 29.7 KB, during IRC's TLS handshake |
+| Stacks | `storage` 3.1 KB free of 6 KB at worst, `loopTask` 1.5 KB |
+
+**Not checked by hand:** how the keys feel on the device itself; everything above was driven through the Debug Console's `key` command and screenshots.
+
+**One slip during the checks:** a scripted key sequence ran in the wrong folder and renamed `/gemini/saved` to `saved2`, then copied it to the top of the card. Both were put right at once (renamed back, the copy deleted; 7 files, 53,798 bytes, as before).
+
+**Found on the way:** a panic at Wi-Fi join, there since v0.7.0 (SNTP started twice, issue #46). Fixed in v0.9.0.
+
+## Notes (issue #19)
+
+Plain text notes on the SD card, written on the device. Q30 settled the base: `.txt` files in `/notes`, created, edited and deleted from the device, never offered by Storage Clean-up.
+
+### Decisions (design round 2026-10-06)
+
+| # | Decision |
+|---|---|
+| Q141 | A **Notes** App in the Launcher. One row per note: its first line as the title, then the date. Newest first; `s` switches to by name. `n` new, Enter opens, `d` deletes after a confirmation, `r` renames the file. |
+| Q142 | A new note's file name is never typed: it comes from the first line when the note is first saved (`shopping-list.txt`), or `note-20261006-0919.txt` if that line is empty. It doesn't change afterwards unless the note is renamed. |
+| Q143 | **Autosave, no "discard changes?" prompt:** five seconds after the last key, on leaving the note or the App, and when the screen turns off. A save writes a temporary file and renames it over the note, so a power cut loses the last few seconds at most. A temporary file left behind is offered back at the next open. |
+| Q144 | The whole note is in memory while it's edited, up to **16 KB**. A bigger text file opens read-only in the Storage App's viewer. The App refuses to open below the memory floors (Q86). **Editing files of any size must come in a later release: issue #47.** |
+| Q145 | The editor wraps at spaces, 38 columns by 8 rows, with a line for the name and the state. Enter is a new line, Del deletes backwards, Fn+arrows move (the Text Entry rule), Ctrl+A and Ctrl+E go to the start and the end of the line, Tab types two spaces, Back saves and returns. The Compose Key works as elsewhere. |
+| Q146 | The Storage App's text viewer gets `e`: edit this file with the same editor, for a text file up to 16 KB that isn't read-only. That lifts Q135 without Apps opening each other (#43 stays). |
+| Q147 | The list is flat: the files directly in `/notes`. Sub-folders are reached through the Storage App. |
+| Q148 | UTF-8, LF line ends; a file with CRLF is saved back with LF. Characters the font lacks are kept on save. |
+| Q149 | Left out, each with its issue: editing files of any size (#47), searching inside notes (#48), undo (#49), selecting and copying text (#50). |
+| Q150 | Ships as **v0.10.0** when built and checked on the device. |
+
+### Done when
+
+- A note can be started, typed with accents, left and found again in the list under its first line; renamed; deleted after a confirmation.
+- What's typed is on the card five seconds after the last key, and after Back, Home, or the screen turning off, without a prompt.
+- Pulling the power while typing loses a few seconds at most, and the note is never left empty or half-written.
+- The cursor moves by character and by line through wrapped text, and the screen follows it; a 16 KB note edits without lag.
+- A note at 16 KB refuses more text and says so; a bigger file opens read-only.
+- `e` in the Storage App's text viewer edits a file; a read-only one is refused with its reason.
+- Free heap stays above the floors with a 16 KB note open and IRC connected.
+
+### Work breakdown
+
+1. **Model** (host-tested): the text buffer with its cursor, wrapping and scrolling; file names from first lines.
+2. **The editor on the device:** loading, drawing, keys, autosave through a temporary file, recovery.
+3. **The Notes App:** the list with titles, new, rename, delete.
+4. **`e` in the Storage App.**
+5. **Checks on the device**, recorded here.
+
+### As built
+
+- **`NoteText`** (`lib/notes`, host-tested) is the text, its cursor and the screen around it. A line owns the space or the newline it ends with, so every byte is on exactly one line and the cursor has one place for each. **No index of lines is kept:** a note of newlines alone would need twice its own size for one. Where a line starts is worked out from the start of its paragraph.
+- **One buffer, 16 KB, for as long as the editor is open.** It's reserved when the note is opened, the file is read straight into it, and typing never makes it grow. On this device a failed allocation is an abort, and with IRC connected the largest free block is about 31 KB whatever the total says: the first version read the file into one string and copied it into another, and opening a full note with IRC connected restarted the device. The editor now also refuses to open without a free block of 24 KB.
+- **`NoteEditor`** (`src/apps/note_editor`) is shared by the Notes App and the Storage App's `e`. A save runs on the storage task while the main loop waits for it: no second copy of the note, and at 16 KB the wait is a fraction of a second at a moment when nobody has typed for five.
+- **A save** writes `<note>.tmp`, checks its size, deletes the note and renames the temporary file (FAT can't rename onto a file). A cut between the last two steps leaves only the `.tmp`: the Notes list puts such a file back under its name. A `.tmp` next to its note is an unfinished save: opening the note offers it.
+- **Titles** in the list are read from the card for the eight rows on screen, when the list moves.
+- **Before powering off**, the firmware now leaves the foreground App (`PowerService::beforePowerOff`), which makes the editor save.
+- Shift or Alt with Fn+Up and Fn+Down moves a page (not in Q145).
+
+### Found on the way
+
+- **The screen could go "off" for one tick after a key sent through the Debug Console**, and the next key was then swallowed as a wake-up: the `key` command stamps the power timer from `millis()`, the power tick compares with its pass's older time, and the unsigned difference read as 49 days idle. The same shape as #46. Fixed in `PowerPolicy::update` with a test. Keys from the keyboard were never affected. It explains remote keys "lost" in earlier sessions.
+- **`scripts/rdbg.py` held back piped lines** written while it was still connecting, until the next line came (a buffered `readline()` behind `select()`). Fixed.
+
+### Checks on the device (2026-10-06, Debug Build of branch `notes`)
+
+Test notes were made in `/notes` and removed afterwards; the folder is left, empty.
+
+| Check | Result |
+|---|---|
+| Host tests | 439 pass |
+| A first note | "No notes yet", `n`, typed three lines: the top line says "typing", then "saved" five seconds after the last key, under `shopping-list.txt`. 63 keys in a row all arrived |
+| Leaving | Back saves and returns to the list, which shows the note under its first line. Home in the middle of a new note saved it as `ideas.txt` |
+| The cursor | Down, Right, an insertion in the middle of a line; the screen scrolls through a note of about 230 lines |
+| A power cut | Typed, waited seven seconds, typed more and restarted the device at once (`reset`): the note has what was saved, whole, and not the last keys |
+| An unfinished save | A `.tmp` next to its note: "Unsaved copy... Keep the note / Use the copy"; using it brings its text back and saves it. A `.tmp` alone was put back under its name when the list opened |
+| 16 KB | A note of exactly 16,384 bytes opens and scrolls; one more character: "This note is full: 16 KB". A file of 16,398 bytes: "Too big to edit: 16 KB at most" |
+| Rename, delete, sort | `r` renamed `orphan.txt` to `orphan2.txt`; `d` asked, then deleted; `s` switched between newest first and by file name |
+| `e` in the Storage App | A note opened from the text viewer, edited, saved on Back; the listing shows its new size |
+| Memory | IRC connected, the full 16 KB note open: 55 KB free, largest block 31.7 KB (72 KB free before opening) |
+
+**Not checked:** accents through the Compose Key and Ctrl+A / Ctrl+E (the remote `key` command can't send them; the model's tests cover both), the power button's save (it needs a hand on the device), a missing card, and how typing feels on the keyboard itself.
+
+**One slip during the checks:** a key sequence sent right after a restart opened IRC instead of Notes, and the test letters went into IRC's input line. Nothing was sent: the line was cleared and the App left. IRC connected to Libera as it does when opened.

docs/milestones/G1.md

@@ -0,0 +1,61 @@
+# G1 — Gemini client
+
+**Status:** done, tagged v0.5.0. Every step was checked on the device; reading Saved Pages with Wi-Fi off was checked by hand (2026-10-05).
+
+**Goal:** browse Geminispace from the Cardputer: fetch and read gemtext over TLS, follow links, answer input prompts, keep bookmarks, and save pages to the SD card to read later, offline. A side milestone between M2 and M3, tagged v0.5.0 when done.
+
+Gemini (geminiprotocol.net): one request per TLS connection on port 1965, the request is the URL and CRLF, the response a `<status> <meta>` header line, then the body. Most capsules use self-signed certificates: trust on first use is the norm.
+
+## Decisions (design round 2026-10-05)
+
+| # | Decision |
+|---|---|
+| Q70 | A milestone of its own, **G1**, before M3: plan, tests first, measured on the device, tagged v0.5.0. |
+| Q71 | **TOFU:** the first certificate seen for a host is pinned (SHA-256, in NVS). If it changes, the page isn't shown; a dialog shows both fingerprints and asks whether to trust the new one. Self-signed or expired certificates are fine; only a change counts. |
+| Q72 | Responses: 1x input (11 hidden, for passwords), 2x content, up to 5 redirects (3x), 4x/5x errors with the server's message. 6x (client certificates): "not supported". |
+| Q73 | `text/gemini` is rendered, other `text/*` shown as plain text. Anything else can be saved to `/gemini/downloads/`, not shown. |
+| Q74 | Up to **64 KB on screen**, larger pages truncated with a notice. Saving streams to the card, so a larger page is saved whole. |
+| Q75 | Gemtext rendering: text wrapped to the 40-column screen; `#`/`##`/`###` headings in bold and accent; `*` lists with bullets; `>` quotes indented and muted; preformatted blocks unwrapped, Left/Right to scroll; `=>` links with their label, numbered. |
+| Q76 | Up/Down scroll; Tab and Shift+Tab move between links; Enter follows; Backspace goes back; `g` opens the address line. Links to other protocols show their URL and aren't followed. |
+| Q77 | Back history of 20 URLs in RAM, with scroll positions; going back refetches (or reopens a Saved Page). **Bookmarks** in `/gemini/bookmarks.gmi` (a gemtext page, shown on the start page); `b` adds the current page. Without a card, a built-in start page. |
+| Q78 | Start page: bookmarks, then Saved Pages, then defaults: geminiprotocol.net, a search engine (kennedy.gemi.dev), an aggregator (Cosmos; Antenna was down when measured). |
+| Q79 | UTF-8 decoded; characters outside the Latin-1 fonts shown as `?`. |
+| Q80 | IRC and Gemini can run together: each fetch opens one connection, reads and closes it. If there isn't memory for a second TLS connection, the fetch fails with a clear message and IRC is untouched. Measured in step 1. |
+| Q81 | Debug aid: `gemini get <url>` prints the status, MIME type, size, certificate fingerprint and the first lines. URL resolution (RFC 3986), the response header and gemtext parsing are host-tested. |
+| Q82 | `s` saves the page on screen as a **Saved Page**: `/gemini/saved/<host>/<path>.gmi`, the gemtext as received plus a first line with its URL and save date. Saving again replaces it, and says so. |
+| Q83 | `S` saves the page and the pages it links to, one level deep: gemtext only, same host only, at most 30 pages, in the background with a progress Toast. |
+| Q84 | The start page lists Saved Pages, newest first, grouped by capsule; they open with no network. In a Saved Page, a link to another Saved Page opens the saved copy; other links fetch online if Wi-Fi is up, or say "not saved, offline". A Saved Page shows when it was saved; `r` refreshes it. |
+| Q86 | *Decided after step 1, revised after Q88.* **Two floors:** free heap stays above 40 KB in steady state; a fetch refuses to start below **55 KB** free ("not enough memory: stop IRC or retry"). The firmware's own allocations during a fetch (a page in RAM, a window) keep 20 KB free. With IRC connected, the TLS connection itself can briefly take the heap lower, depending on the server's record sizes: measured 24, 19.5, 15.5 and **13 KB**. *Accepted:* about 12 KB for a moment during a fetch with IRC up, rather than refusing most fetches (a 70 KB start floor) or dropping IRC's connection for each page. |
+| Q87 | *Decided in step 3.* **With a card, every page streams to `/gemini/cache/page.gmi`** in 1 KB pieces while its TLS connection is open; once the connection closes and its ~45 KB is back, the page is loaded into RAM as far as the 40 KB floor allows. The whole page stays on the card (Saved Pages copy it). Without a card, the page goes straight to RAM under the same two floors. Pages are held as lines in 4 KB chunks, never one large block (the largest free block with IRC connected is about 31 KB). |
+| Q88 | *Added after step 6.* **A page bigger than memory allows is read from the card as you scroll.** Opening it, one pass over its file counts the lines, records where every 64th starts (and whether it's inside a preformatted block), and loads the first window. Scrolling near either end of the window reads the next or previous one in the background, keeping the line on top of the screen where it is; the scrollbar follows the whole page. Display pages alternate between two cache files, so the one on screen is never overwritten by the next fetch; background jobs use a third. |
+| Q85 | Saved Pages are deleted from the App only (`d`, with confirmation), never by Storage Clean-up's age rules, like Notes. |
+
+## Measured (step 1)
+
+- `gemini://geminiprotocol.net/`: `20 text/gemini`, 1,184 bytes, TLS handshake 0.7–1.1 s, whole fetch 0.7–1.1 s; kennedy.gemi.dev 1.9 s. The fetch task's stack peaks at about 3.6 KB of 6.
+- **Heap, Debug Build, IRC connected over TLS:** about 68 KB free before a fetch. After the handshake the fetch holds about 32 KB (36–40 KB left); the handshake itself (certificate chain parsed with the 16 KB receive buffer allocated) dips to about **24 KB** for a second or two. Nothing leaks: the heap after matches the heap before.
+- **Step 3, Cosmos (31.6 KB) with IRC connected:** first stopped at 4.6 KB (RAM only, the transfer's 20 KB floor). Streamed to the card: the whole page on the card, 20 KB of it loaded, lowest free heap 19.5 KB during the transfer and 43 KB once loaded. Without IRC: the whole page in RAM. Redirects (Cosmos `31`), input (`10`), not found (`51`) and a changed certificate (refused, both fingerprints shown) all checked on the device.
+- **Steps 4–6 on the device:** Project Gemini and its relative links, Back with the scroll restored, a refused YouTube link; `b` bookmarks, `s` saves (and says when it replaced an older copy), `S` saved 6 of 6 pages, the start page lists both; a Saved Page opens from the card with its origin, its saved links open saved copies, `r` refreshes, `d` asks first; Kennedy's input prompt sent "cardputer" and got 87 results; emoji drawn as `?`.
+- **A bug found there:** refreshing first loaded the whole Saved Page into RAM just to read its origin, next to the App's copy and a TLS connection: the heap fell to 436 bytes. Now only the first line is read, and every fetch (pages, saves, refreshes) checks the 55 KB start floor. Lowest since boot afterwards: 53.8 KB.
+- **Windowed pages (Q88), Cosmos with IRC connected:** 226 of 419 lines in memory at first; paging down loaded lines 192–419 in one window, scrolling back up loaded 64 onwards, then 0 onwards. Window budgets count the memory the old window gives back.
+- **Heap during a fetch with IRC connected:** lowest 13–15.5 KB in later runs (24 and 19.5 KB earlier), the TLS receive buffers varying with the server's records. Accepted (Q86, revised).
+- Antenna (`warmedal.se`) doesn't answer, from the PC either; the default aggregator becomes Cosmos (`gemini://skyjake.fi/~Cosmos/`, which redirects to `cosmos.skyjake.fi`).
+
+## Done when
+
+- `gemini get gemini://geminiprotocol.net/` prints the header, size and fingerprint on the console.
+- The Gemini App opens the start page, follows links (relative ones included), goes back, and follows redirects.
+- An input prompt (e.g. a search) takes a query and shows the results.
+- A changed certificate stops the page and asks.
+- `s` saves a page, `S` a page and its links; with Wi-Fi off, Saved Pages open and their saved links work.
+- Bookmarks are added with `b` and listed on the start page.
+- With IRC connected over TLS, a fetch still works, and the free heap stays above 40 KB.
+
+## Work breakdown
+
+1. **Two TLS connections:** measure the heap with IRC connected while a Gemini fetch runs.
+2. **Parsers** (host-tested): URL parsing and relative resolution, the response header, gemtext lines.
+3. **Fetch** on its own task, with TOFU and `gemini get`.
+4. **Gemini App:** rendering, scrolling, links, history, the address line.
+5. **Input prompts, redirects, bookmarks, downloads.**
+6. **Saved Pages,** then saving with linked pages.

docs/milestones/M3.md

@@ -0,0 +1,69 @@
+# M3 — Radio bring-up: the LoRa Scanner
+
+**Status:** done, tagged v0.6.0. Everything was checked on the device except one "Done when" item: Sweep was never tried against a known transmitter (see below). The listening hour heard nothing, so by Q104 **a reference Meshtastic node is a requirement for M4**.
+
+**Goal:** the LoRa radio on the Cap works, receive only: a Radio Service owns it and shares the SPI bus with the SD card safely, and a LoRa Scanner App shows what's on the air, either packets (Sniffer) or energy across the band (Sweep). Nothing in M3 can transmit. The mesh comes on top of this in M4 (receive) and M5 (transmit).
+
+**Hardware:** the Cap LoRa-1262 carries an SX1262 (868–923 MHz, +22 dBm) with an RP-SMA antenna. Pins, as in Meshtastic's board file for the Cardputer ADV: **NSS 5, RST 3, DIO1 (IRQ) 4, BUSY 6**, on the SPI bus shared with the microSD card (SCK 40, MISO 39, MOSI 14; card CS 12). Meshtastic uses DIO2 as the RF switch and DIO3 for a 1.8 V TCXO, marked optional. M5Stack's page adds an FM8625H antenna switch enabled by P0 of a PI4IOE5V6408 I/O expander on the internal I2C bus, address not given; Meshtastic doesn't mention it. Step 1 measures which is true.
+
+**No other LoRa device yet.** meshmap.net (2026-10-05) lists two Meshtastic nodes within 10 km of the desk and six within 30 km, with positions blurred by a few km; none is known to be in range. M3 needs none: it only receives.
+
+## Measured
+
+- **Internal I2C bus (8/9):** 0x18 (ES8311 codec), 0x34 (TCA8418 keyboard), **0x43 (PI4IOE5V6408, ID register 0xA2)**, 0x69 (BMI270 IMU).
+- **The SX1262 answers** on NSS 5, RST 3, DIO1 4, BUSY 6. Its version string reads `SX1261 V2D 2D02`, which SX1262 chips report too. **The 1.8 V TCXO works** on the first try; the radio is ready 38 ms after `begin`.
+- **The expander's P0 connects the antenna; it's required.** At power-on P0 is an input (direction 0x00, high-impedance 0xFF), and the receiver reads a flat **-111.9 dBm** at 869.525 MHz, BW 250 kHz: the chip's own floor, deaf. With P0 driven high, the noise floor is **-87 to -94 dBm**: the antenna hearing the room. So the Radio Service drives P0 high at boot (Q91).
+- **DIO2 doesn't change reception** (within ±2 dB over three runs, P0 high). It likely selects TX versus RX in the FM8625H; it stays the RF switch, as in Meshtastic.
+- **The noise floor at the desk is high** (-87 to -94 dBm, varying run to run), about 25 dB above thermal noise for 250 kHz. Something nearby is loud, possibly the Cardputer itself or the PC; Sweep (step 5) should show where it sits.
+- **Step 2:** presets, frequencies and the channel hash are checked against Meshtastic's source (`MeshRadio.h`, `RadioInterface.cpp`): LongFast and the default key give hash 8, MediumFast 31, as Meshtastic shows. Captures were checked with TShark 4.2.5: every LoRaTap field reads back. Wireshark ignores the spec's quarter-dB packet RSSI below 0 dB SNR, so packet RSSI is plain dBm.
+- **Step 3:** the DIO1 interrupt works (a 100 ms receive timeout wakes the task after 105 ms). While listening: four 1.7 MB uploads and Gemini pages to the card, no radio or card errors (the card refuses a write about once in five uploads with the radio asleep too; `put` now catches it, and issue #21 follows the cause). The ring takes 9.8 KB while listening; the radio task's stack peaks at 2.0 KB.
+- **No packets yet, and a loud desk.** Twenty minutes on LongFast and on LoRaWAN's three uplink frequencies (SF7, SF9, SF12): no packet and no header, valid or not. The noise floor reads -83 to -94 dBm, against -112 dBm with the antenna switched off: 20 to 30 dB lost to something nearby, not the screen and not the GNSS receiver. Preamble detections are false alarms at this noise level (more on an empty frequency, 869.0 MHz, than on LongFast).
+- **Step 4:** a Capture made on the device reads back in TShark field for field (time, frequency, SF, RSSI, SNR, payload). A Capture keeps the radio listening with the App closed; stopping it puts the radio back to sleep.
+- **Step 5:** a pass across 863–870 MHz (71 steps, the strongest of three RSSI readings at each, measured at 125 kHz) takes about 607 ms. At the desk the band is **flat at -100 to -102 dBm**, about 15 dB above the chip's own floor at 125 kHz, with a steady carrier at 863.2 MHz (-89 dBm at its strongest) and fainter lines elsewhere: broadband noise from nearby electronics rather than a transmitter. Sweep's waterfall takes 2.6 KB while shown; 91.9 KB free during a Sweep. The radio task's stack peaks at 1.9 KB.
+- **Outside, on battery (step 6).** The noise is no lower than at the desk: a Sweep floor of -96 to -99 dBm (median -97) with Wi-Fi on, -99 to -100 with Wi-Fi off, so Wi-Fi accounts for 2 or 3 dB. The same narrow peaks come back on every pass, at 863.2, 863.6, 864.4, 864.8, 865.9, 866.3, 867.8, 869.0 and 869.4 MHz (-88 to -91 dBm), several of them 400 kHz apart; 869.4 MHz is the lower edge of LongFast's channel. A source that follows the device outside and onto its battery is the device: **about 15 dB of the floor is the Cardputer's own** (issue #20). At SF11 that puts the weakest decodable packet near -114 dBm on LongFast, against about -130 dBm for a quiet receiver.
+- **The listening hour (step 6, Q104):** 20:33 to 21:34 on 2026-10-05, outside, on battery, LongFast, with a Capture running. **0 packets, 0 headers**, 0 radio errors; noise -85 to -87 dBm at 250 kHz throughout; 860 preamble detections, all false alarms. The Capture holds its 24-byte header and nothing else. No restart in 1 h 10 min.
+- **Floors (Q86):** with the radio listening, Wi-Fi and IRC connected over TLS, 52.6 KB free (lowest 22.7 KB during the TLS handshake, the dip accepted in G1). Without IRC, 93 KB.
+- **Receive only:** nothing in `src` or `lib` calls a transmit function.
+- **Cost:** RadioLib 7.8.1 and the probe add 23.6 KB of flash and 656 bytes of static RAM to the release firmware (1,679,843 bytes of 3,342,336). The whole milestone: 51.8 KB of flash (1,708,091 bytes), 365 tests (27 new).
+
+## Decisions (design round 2026-10-05)
+
+| # | Decision |
+|---|---|
+| Q89 | **M3 is the radio only:** Radio Service, Sniffer, Sweep. Notes and the File Browser (Q30) move out to issue #3 and a Notes issue, as a later side milestone. |
+| Q90 | **RadioLib**, pinned (ADR 0001). SX1262 on NSS 5, RST 3, DIO1 4, BUSY 6; DIO2 as RF switch; TCXO at 1.8 V tried first, falling back to the crystal (Meshtastic's `TCXO_OPTIONAL`). |
+| Q91 | Step 1 is `lora probe`: chip status and version, which oscillator setting worked, and an I2C scan of the internal bus for the PI4IOE5V6408. If present, its P0 is set high at boot (harmless) and DIO2 stays the switch. A wrong switch receives deaf, so compare noise floors. |
+| Q92 | A **Radio Service** owns the SX1262: driver, bus lock, IRQ task. The LoRa Scanner uses it in M3; the Mesh Service sits on top of it in M4. |
+| Q93 | Every radio transfer takes the shared bus lock (`SPI.beginTransaction`, as the card does). DIO1's interrupt only wakes the task; no SPI in the ISR. **Done when** a Gemini page streams to the card while the Sniffer receives, with no lost packets and no card errors (`lora status` counters). |
+| Q94 | **Receive only:** the Radio Service has no transmit function in M3. It doesn't exist, rather than being unused. |
+| Q95 | Sniffer defaults: **EU868 LongFast**, 869.525 MHz, BW 250 kHz, SF 11, CR 4/5, sync word 0x2B, preamble 16 (Q19). The other Meshtastic presets are offered, plus custom settings. |
+| Q96 | The Sniffer lists packets (time, RSSI, SNR, frequency error, length; hex dump on Enter) **and decodes the Meshtastic header**: the first 16 bytes are never encrypted (destination, sender, packet ID, hop limit and hop start, channel hash, next hop, relay node). Host-tested. Payload decryption is M4. |
+| Q97 | A Sniffer **Capture** is pcap with **LoRaTap** headers (link type 270), for Wireshark. Started by hand, Status Bar mark, its own Clean-up category, the 90% rule. |
+| Q98 | **Sweep** steps across the Region's band (863–870 MHz) in 100 kHz steps by default, reading instant RSSI: bars with peak hold, and a waterfall, Wi-Fi Tools style. Optionally CAD on the preset's frequency to tell LoRa traffic from noise. |
+| Q99 | Sweep takes the radio and pauses the Sniffer, visibly (Q18). From M4 it pauses the Mesh Service the same way. |
+| Q100 | The Sniffer runs while the App is open **or a Capture is recording**; otherwise the radio sleeps. From M4 the Mesh Service keeps it on. |
+| Q101 | **Status Bar:** a radio mark while receiving, flashing on each packet; muted during a Sweep. |
+| Q102 | Debug aids: `lora status` (settings, counters, last RSSI/SNR, noise floor), `lora probe`, `lora rx on/off` (packets on the consoles). Raw packets are never written to the card outside a Capture. |
+| Q103 | A ring of the **last 32 packets** in RAM (about 9 KB at full length); older ones are dropped unless capturing. IRQ task stack trimmed by measurement; RadioLib's flash and RAM measured in step 1 against the floors. |
+| Q104 | **Done when** (below) includes an hour of listening on LongFast by a window. Real packets heard become M4 test fixtures. If none are heard, M3 still closes, and a reference Meshtastic node (Q21) becomes a requirement for M4. |
+
+## Done when
+
+- `lora probe` reports the SX1262, its oscillator setting and the RF switch arrangement, and the result is written here.
+- The Sniffer receives on LongFast with the App open or a Capture running, and the radio sleeps otherwise.
+- Sweep shows the noise floor across 863–870 MHz, and a known signal (a remote key fob, a 868 MHz sensor, anything) stands out. *Half met: the floor and the device's own steady peaks show; no known transmitter was tried.*
+- The shared-bus test passes (Q93): a Gemini page to the card while the Sniffer receives, no lost packets, no card errors.
+- A Capture opens in Wireshark with LoRaTap fields.
+- The Status Bar mark follows Q101.
+- One hour of LongFast listening by a window has been run and its result recorded here. *Run outside, on battery.*
+- Free heap stays above the floors (Q86) with the Sniffer, Wi-Fi, IRC on TLS and the UI running.
+- Nothing in the firmware can transmit.
+
+## Work breakdown
+
+1. **Hardware check:** RadioLib in the build, `lora probe` (Q91), flash and RAM cost measured.
+2. **Meshtastic header and LoRaTap** (host-tested): header parsing, presets and their radio settings, pcap/LoRaTap writing.
+3. **Radio Service:** receive on its own task behind the bus lock, the packet ring, `lora status` and `lora rx`, the shared-bus test.
+4. **LoRa Scanner App, Sniffer:** the packet list, details, preset choice, Captures, Status Bar mark.
+5. **Sweep:** the RSSI sweep, bars and waterfall, pausing the Sniffer.
+6. **Listening hour** and the measurements above, recorded here.

docs/milestones/R1.md

@@ -0,0 +1,125 @@
+# R1 — Releases
+
+**Status:** in progress. CI and signed releases on Gitea (issue #5) are in place since 2026-10-06: every tag from v0.1.0 to v0.10.0 has its release. Updates from Gitea (issue #6) is built and checked on the device, on branch `gitea-updates`, not merged yet. The Issues App (#4) comes after.
+
+**Goal:** a tag is a release, built the same way every time and published where a device can find it.
+
+## CI and releases (issue #5)
+
+Until now the tests, the builds, the signing and the flashing all happened on one machine, through `scripts/ci.sh` and `scripts/flash.sh`. Nothing was published.
+
+### Decisions (design round 2026-10-06)
+
+| # | Decision |
+|---|---|
+| Q151 | A push to `main`: the host tests (with their coverage). A push to another branch: nothing, its pull request is what runs (a branch with an open pull request ran twice, once for each). A pull request: the same and both builds; changes reach `main` through pull requests. A tag `v*`: all of it, then a release. (First: everything on every push, which rebuilt the firmware far more often than anyone looked at it.) |
+| Q152 | **CI signs.** The signing key is the repository secret `OTA_SIGNING_KEY`; a tag push makes a complete, signed release with no manual step (ADR 0008). |
+| Q153 | The Debug Build is built in CI with a token of the runner's own, to prove it compiles, and **isn't published**: it would hand everyone its Debug Console token. |
+| Q154 | Pull requests from forks don't start a run. |
+| Q155 | A release carries `roro9stack-<version>.ota` (signed), `-factory.bin` for USB, `.elf.gz` to decode crashes, and `SHA256SUMS`. |
+| Q156 | Its text is the tag's message, what the files are, and the commits since the tag before. |
+| Q157 | No cache service to begin with: measure first. |
+| Q158 | Reproducible builds aren't needed for signing any more (Q152); not pursued here. |
+| Q159 | **The tags from before CI get their releases too**, v0.1.0 to v0.10.0, built from each tag's own sources by running the workflow by hand. |
+| Q160 | Actions is switched on for the repository. |
+| Q161 | **Changes reach `main` through pull requests, merged as "rebase, then a merge commit"**, the only style the repository allows: the branch's commits keep their messages, the merge commit marks the pull request, and what CI tested is what lands. No squash, no fast-forward. |
+
+### As built
+
+- **One workflow, `.gitea/workflows/ci.yml`, one job**, on the runner `runner0` (label `ubuntu`). The job asks for a `python:3.12-slim` container, installs git, a compiler, openssl and PlatformIO, and runs the same scripts as a developer's machine. No Docker inside the job.
+- **The cache is a Docker volume**, `roro9stack-pio`, mounted at `/pio`; the runner's `config.yaml` allows it under `container.valid_volumes`. A first run downloads about 1 GB and rebuilds the framework. Measured from the jobs' own start and end times: the first full run on an empty cache took 11.4 minutes (tests and both builds); the first run in a container, 8.1; a pull request now takes about 8.7 (tests, coverage and both builds), a release build alone 5.5, and a push to `main` (tests and coverage) 1.1. (An earlier version of this note said 17 minutes: that was the waiting time, not the job's.)
+- **No JavaScript actions**, so the image needs no Node and nothing is fetched from GitHub: the checkout is four git commands.
+- **`scripts/_docker.sh`** runs the command in place when `RORO_NO_DOCKER` is set (a CI job is already in a build container), and in the project's image otherwise. The Debug Build's token is made on the spot in CI and goes with the container.
+- **`scripts/release_build.sh <checkout> <out>`** builds a tag's own sources with today's tools, signs, verifies against the public key in those sources, and writes the files and the release's text. **`scripts/release_publish.py`** creates the Gitea release or completes it; run twice, it replaces what's there. Both run the same on a developer's machine.
+- **`scripts/ota_verify.py`** checks an Update File as a device does, on a PC.
+- **The job's own token** (`secrets.GITEA_TOKEN`) is enough to create a release and upload its files.
+- **Old tags.** v0.1.0 to v0.3.0 are from before the framework was rebuilt with our settings (ADR 0006) and can't link against a rebuilt one left in the cache: the release build puts the stock framework libraries back for them. v0.1.0 to v0.2.1 have no public key in their sources (Firmware Updates came with v0.3.0); their files are checked against today's.
+
+### How it went
+
+- **The runner's label took three tries.** Registered as `ubuntu://docker:ubuntu:resolute` and then as `ubuntu::docker://...`, Gitea took the whole string for the label's name; with the first, jobs ran on the runner's host itself. The first version of the workflow was written for that (plain shell, `docker run` for the build) and published v0.10.0 that way. `ubuntu:docker://docker.gitea.com/runner-images:ubuntu-latest` is the form that works.
+- **Gitea 1.27's API can't cancel a run that isn't finished**, only delete a finished one; switching Actions off and on for the repository doesn't either. Runs queued for a label that no longer exists stay queued until cancelled in the web UI.
+- **CI's image isn't byte-identical to a local build of the same tag** (same size, different bytes). Not pursued (Q158).
+
+## Updates from Gitea (issue #6)
+
+The device looks at the project's Gitea for a newer release, says so, and installs it on request, with the same signed Update Files, Probation and rollback as a push from the PC or an install from the card.
+
+### What the server gives (checked 2026-10-06)
+
+- **Its certificate** is Let's Encrypt, all ECDSA: leaf `git.twis.la` (renewed every few months, next expiry 2026-12-14) under the intermediate YE2, Root YE and ISRG Root X2, which X1 cross-signs. Pinning the leaf would ask a question at every renewal.
+- **The API** answers over HTTP/1.1, chunked: `releases/latest` is 3.2 KB (about 350 bytes of it matter), a list of ten releases is 33 KB.
+- **A download** is a direct 200 with `Content-Length` and no redirect; ranges work.
+
+### Decisions (design round 2026-10-06)
+
+| # | Decision |
+|---|---|
+| Q162 | **Trust:** the firmware carries ISRG Root X1 and X2 and checks the server's chain and name against them, not the framework's bundle of about 130 CAs (ADR 0009). Shared with #4. If the server moves to another CA, the next firmware comes from the PC. |
+| Q163 | The Update File's own signature stays the real guard. A hijacked connection could hide a release or offer an older signed one, never install firmware that isn't ours. |
+| Q164 | The source, `git.twis.la` and `twisla/roro9stack`, is a constant in the firmware. A fork changes it, and has its own key. |
+| Q165 | **When:** on request in Settings > Firmware, and once a day in the background while Wi-Fi is up and the Clock is set (certificate dates need it). A setting, **Check for updates**, on by default. It installs nothing by itself; it skips quietly below the memory floor and never runs during an install. |
+| Q166 | A Toast, "Update v0.11.0 available: see Settings > Firmware", once per version per boot. |
+| Q167 | **The download goes straight into the inactive slot,** no card needed. A truncated or tampered file is refused after 160 bytes or at its end, and the running firmware is untouched. A failed download starts over. |
+| Q168 | A version that failed (rolled back) isn't announced again by the background check until a newer one exists; it can still be installed by hand. |
+| Q169 | **Older releases:** a list of the last ten, newest first, the running one marked. Installing an older one asks with a stronger warning. |
+| Q170 | Enter on a release shows its version, date, size and the tag message, with Install. |
+| Q171 | **Debug Builds** check and show the latest release, but don't install it: it would replace the Debug Build and its console (Q153: Debug Builds aren't published). Their updates come from the PC. |
+| Q172 | **Memory, as measured:** a TLS connection peaks at about 52 KB of heap, with or without checking the certificate, so it starts with 80 KB free (Q86's 20 KB spare on top), not 55 KB. **A check, list or install someone asked for makes IRC step aside** and come back after; the daily check never does, and with IRC connected it waits. (First: 55 KB and nothing else. With IRC connected a check left 3 KB and a download 836 bytes.) |
+| Q173 | Left out, each with its issue: installing automatically (#52), a release channel (#53), resuming a download (#54). |
+| Q174 | Ships as **v0.11.0**. Tested on the device with the real signed releases; a Debug Build command pretends the device runs an older version, so v0.10.0 counts as an update. |
+
+### Done when
+
+- A check, by hand or daily, tells the right thing: up to date, newer available, no network, bad certificate, no clock, too little memory.
+- A newer release installs from the Firmware page with no card and no PC, and the device restarts into it and confirms it.
+- A tampered or truncated download is refused and the running firmware keeps running.
+- The Older releases list shows ten, and installing one asks first.
+- A release that rolled back isn't announced again.
+- A Debug Build shows the latest release and doesn't install it.
+- The daily check never runs below the memory floor, during an install, or without a clock.
+
+### Work breakdown
+
+1. **Model** (host-tested): a streaming JSON scanner, the release list read from it, HTTP response heads and chunked bodies, URLs, which release counts as an update.
+2. **The connection:** the root certificates, an HTTPS client, a check and a list from the Update Service's task; console commands to try them.
+3. **The download:** an HTTPS source for the existing install path.
+4. **The screens:** the Firmware page's release rows, the release page, Older releases, the setting, the daily check and its Toast.
+5. **Checks on the device**, recorded here.
+
+### As built
+
+- **`lib/release`** (host-tested): a streaming JSON scanner, the release reader built on it, HTTP heads and chunked bodies, URLs, and the decisions (which release is an update, whether to announce it, which download URLs are taken). A list of ten releases is 33 KB of JSON and costs a few hundred bytes of memory, because nothing is kept but the path.
+- **`HttpsGet`** (`src/platform`): one GET, the answer read as a stream, redirects not followed. **`GiteaReleases`** keeps the latest and the list. **The Update Service** serves the requests on its own task (about 5.4 KB of its 7 KB stack at the peak) and installs through the install path that already existed, with an HTTPS source in place of the card or the TCP port.
+- **The daily check** is scheduled from the Update Service's tick: Wi-Fi up, the Clock set, no Probation, nothing else going on, memory for a connection. The day it last succeeded is kept in flash.
+- **A version that failed** (rolled back) is remembered as `ota_failed`, and isn't announced again by the daily check.
+- **The screens:** the Firmware page's Latest release and Older releases rows, a release page with the tag's message, and the install dialog.
+- **Debug Builds** get knobs to try what can't be tried otherwise: `update pretend`, `probe`, `damage` and `daily`.
+- **The first message,** `... available: see Settings > Firmware`, was cut at 48 bytes by the notification's own limit; it now reads `v0.11.0 is out: see Settings > Firmware`.
+
+### Checks on the device (2026-10-06, Debug Builds of branch `gitea-updates`)
+
+| Check | Result |
+|---|---|
+| Host tests | 456 pass |
+| Check and list against the live server | The certificate is accepted against the two embedded roots; `releases/latest` read; a list of ten (33 KB) streamed |
+| Servers that must be refused | github.com, example.com, expired.badssl.com, self-signed.badssl.com, wrong.host.badssl.com, untrusted-root.badssl.com and the router: each "isn't accepted" or a TLS error |
+| A download cut short at 800,000 bytes | Refused, "update file too short"; the running firmware untouched |
+| One byte flipped in the signature | Refused after 160 bytes, "bad signature"; the image isn't read further |
+| One byte flipped in the image | Downloaded in full, refused at its end, "image corrupted (hash mismatch)" |
+| The real v0.10.0, from the console and then from the screen | Downloaded, restarted, confirmed on Probation: the slot table read `v0.10.0, valid` both times. The Debug Build was pushed back from the PC after each |
+| The screens | Latest release (checking, then `(current)` or `(new)`), the release page with the tag's message, Older releases with ten rows, the install dialog (Cancel by default, Back cancels), the progress screen at 28% |
+| IRC connected, before the hold | A check left 3 KB of heap; a full download, 836 bytes |
+| IRC connected, with the hold | The lowest free heap during a full download: 38 KB. IRC reconnected afterwards (its counters kept growing) |
+| The daily check | It ran by itself, announced `v0.10.0 is out: see Settings > Firmware` once; with IRC connected (68 KB free) it didn't run |
+| Speed | 1.9 MB in about 46 s, 40 KB/s, over the guest Wi-Fi at -65 dBm; not investigated further |
+
+**Not checked:** the certificate's **name** on its own. Connecting by IP makes the server end the handshake before it shows its certificate, so that test proved nothing; the library sets the name it verifies, and OpenSSL on the PC refused the wrong name against the same chain. A failed daily check retrying, the clock not being set, the release that failed before not being announced (host-tested, not on the device), and the hold when IRC isn't connected but Gemini holds memory.
+
+**Limits worth knowing:**
+- **With IRC connected for days, the daily check doesn't run.** It would have to take IRC down to make room. Opening Latest release does.
+- **A server that changes CA can't be reached** until a firmware carrying the new root comes from the PC (ADR 0009).
+- **No resuming:** a broken download starts over (#54).
+- **A key press during the hold:** Back on the Firmware page while a check is going doesn't cancel it.
+
+**Two slips during the checks:** a blind sequence of keys on the Firmware page opened the SD card's install dialog (the page keeps its selection between visits); it was cancelled with Back, nothing installed. And my port-polling while waiting for a restart took the Debug Console's only client slot, which made the first install attempt look like a failure.

docs/milestones/S1.md

@@ -0,0 +1,138 @@
+# S1 — System basics
+
+**Status:** the three planned items are done: the SD driver fix in v0.6.1 (issue #21, ADR 0007), fixed IPv4 settings in v0.7.0 (issue #7), the System App in v0.8.0 (issue #11). v0.8.1 adds the resting main loop (issue #40) and the GNSS pause for the radio's noise (issue #20, still open for the 11 dB that remain). Still open in the milestone: #39, following the SD driver upstream.
+
+**Goal:** the device works on any network, the card can be trusted, and you can see what the system is doing. A side milestone, like G1.
+
+## Fixed IPv4, DNS and NTP (issue #7)
+
+Not every network has a DHCP server: a lab bench, a direct link to a router, a network where addresses are handed out by hand. Until now every Saved Network used DHCP, DNS always came from DHCP, and the NTP server was `pool.ntp.org`, hard-coded.
+
+**IPv4 only.** IPv6 isn't part of this, now or as a planned follow-up.
+
+### Decisions (design round 2026-10-05)
+
+| # | Decision |
+|---|---|
+| Q105 | The IP setting is **per Saved Network**: *Automatic* (DHCP, as before) or *Fixed*, with its own address, prefix and gateway. New networks start Automatic. |
+| Q106 | The subnet is entered as a **prefix length** (`24`), with the mask shown next to it. |
+| Q107 | The **gateway is optional**: left empty, the device talks to its own subnet only. |
+| Q108 | **DNS is global:** two servers in Settings, used on every Fixed network. On Automatic networks DHCP's DNS is used, unless **"Always use my DNS"** is on. |
+| Q109 | DNS defaults: **9.9.9.9** (Quad9), then **1.1.1.1** (Cloudflare). |
+| Q110 | **NTP is global:** two servers in Settings, names or addresses, defaulting to `pool.ntp.org` and `time.cloudflare.com`. NTP servers offered by DHCP are used first. GNSS still outranks NTP for the clock. |
+| Q111 | What's typed is checked, host-tested in `lib/wifi`: an address is four numbers from 0 to 255; a prefix is 1 to 30; the address isn't the subnet's network or broadcast address; the gateway is inside the subnet and isn't the device's own address. Refusals say why. |
+| Q112 | Addresses are typed in the line editor, limited to digits and dots. |
+| Q113 | Enter on a Saved Network opens **its page** (IP, Address, Prefix, Gateway, Forget) instead of asking to forget it. Settings > Wi-Fi gains DNS servers, "Always use my DNS" and NTP servers. The Status row opens **connection details**: address, mask, gateway, DNS and NTP in use, and where each came from. |
+| Q114 | A change applies **at once**: the network in use reconnects with the new settings. No automatic way back; the keyboard still works if Wi-Fi is cut. |
+| Q115 | Console: `wifi status` shows address, gateway, DNS, NTP and their sources; `wifi ip <ssid> dhcp`, `wifi ip <ssid> <address>/<prefix> [gateway]`, `wifi dns <a> [b]`, `wifi ntp <a> [b]`. Debug Builds: `wifi ip … try 60` goes back to the previous setting after 60 s unless confirmed with `wifi ip keep`. |
+| Q116 | Left out: checking whether the address is already taken, and per-network DNS. |
+
+The SDK already allows 3 NTP servers and 3 DNS servers and can take NTP servers from DHCP (`CONFIG_LWIP_SNTP_MAX_SERVERS=3`, `CONFIG_LWIP_DHCP_GET_NTP_SRV=y`), so the framework isn't rebuilt for this.
+
+### Done when
+
+- A Saved Network set to Fixed joins with that address, mask and gateway, and the device reaches the internet (IRC, Gemini, NTP) through the DNS servers from Settings.
+- Set back to Automatic, it gets its address from DHCP again.
+- With "Always use my DNS" on, an Automatic network resolves through the servers from Settings.
+- The NTP servers from Settings set the clock.
+- Wrong entries are refused with a reason, in Settings and on the console.
+- Connection details show what's in use and where it came from.
+- Tested on `knbg-guests` with 10.39.39.12 (the device's DHCP lease) and 10.39.39.13 (free: the device is alone on that network).
+
+### Measured (2026-10-05 and 06, on `knbg-guests`)
+
+The network is 10.39.39.0/24, gateway 10.39.39.1; DHCP gives 10.39.39.1 as DNS and offers no NTP server.
+
+- **Fixed 10.39.39.12/24** (the device's own lease) and **Fixed 10.39.39.13/24**, gateway 10.39.39.1: the device joins with that address, DNS is 9.9.9.9 and 1.1.1.1 from Settings, and a Gemini page loads (name resolution, routing, TLS). On .13, .12 no longer answers.
+- **A wrong gateway** (10.39.39.254) on a 60 s trial: the device stops answering from another subnet, and comes back by itself with the previous setting.
+- **Back to Automatic:** 10.39.39.12 by DHCP again, DNS 10.39.39.1 from DHCP.
+- **"Always use my DNS"** on an Automatic network: DNS becomes 9.9.9.9 and 1.1.1.1; switched off, the device joins again and has DHCP's DNS back.
+- **NTP:** `pool.ntp.org` answers; set to `time.cloudflare.com` alone, that one answers within 25 s.
+- **Refusals**, on the console and in Settings: the network's own address, a gateway outside the subnet, a prefix of 31 or 99, 10.39.39.300, an unknown network, a DNS name where an address is needed, a host name with an underscore.
+- **In Settings:** the network's page pre-fills Fixed with the address, prefix and gateway in use; leaving the page applies it; connection details show each value and where it came from.
+- **Not tested:** NTP servers offered by DHCP (this network offers none), and a Fixed network with no gateway.
+
+### Work breakdown
+
+1. **IPv4 logic** (host-tested): parsing and formatting addresses, prefix and mask, the checks of Q111.
+2. **Storage:** the IP setting in each Saved Network; DNS, "Always use my DNS" and NTP in Settings.
+3. **Wi-Fi Service:** apply it when joining; DNS and NTP; `wifi status` and the console commands.
+4. **Settings:** the network page, the DNS and NTP rows, connection details.
+5. **Tests on the device**, recorded here.
+
+## System Monitor (issue #11)
+
+Every milestone so far was driven by measurements, heap floors, stack sizes, TLS dips, that needed a Debug Build and a computer. The System App shows them on the device, in any build.
+
+### Decisions (design round 2026-10-06)
+
+| # | Decision |
+|---|---|
+| Q117 | An App of its own, **System**, in release builds too. Read-only. |
+| Q118 | Four views, switched with Tab: **Overview** (CPU per core, memory, network, battery), **Tasks**, **Memory**, **System**. |
+| Q119 | Sampled once a second. A task's share is its run time over the last second; a core's load is 100 % minus its idle task's share. |
+| Q120 | **History only while the App is open:** two minutes at one sample a second, about 1 KB. The system already keeps what matters afterwards: the lowest free heap since boot and each task's lowest free stack. |
+| Q121 | **Bytes are counted per service:** IRC, Gemini, the Debug Console and Firmware Updates add what they read and write to a shared counter. The network view shows the connection details, each service's bytes in and out, and the signal strength. |
+| Q122 | Tasks: name, core, share, state and lowest free stack, sorted by share; `s` cycles the sort (share, stack, name). **Under 512 bytes of stack left shows in the warning colour.** |
+| Q123 | Memory: free heap, lowest since boot, largest free block, and a two-minute graph of free heap **with the floors of Q86 drawn as lines** (55, 40 and 20 KB). |
+| Q124 | System: uptime and why it last started, firmware and both app slots, chip temperature and CPU frequency, battery voltage and percentage, SD usage and write faults, the radio's and the GNSS receiver's state. |
+| Q125 | `info` and `tasks` are split into a **snapshot** that the console and the App share; the arithmetic (shares from two samples, sorting, the stack warning) is host-tested. |
+| Q126 | Left out: acting on tasks, an event log, exporting snapshots to the card. |
+| Q127 | The main loop uses about 81 % of a core. The App shows it; fixing it is issue #40, not part of #11. |
+
+The App has five views, not four: Q121's network view is one of its own (Overview, Tasks, Memory, Network, System).
+
+### Measured (2026-10-06)
+
+- **Traffic counters are exact.** A Gemini fetch of a 164,970-byte page counts 164,986 bytes in (the page and its 16-byte header line) and 42 out (the 40-character URL and CRLF). A 1,797,760-byte upload counts 1,798,123 in for the Debug Console, commands included.
+- **The Memory view shows a TLS dip as it happens.** Starting IRC and a 165 KB Gemini fetch together: free heap falls from about 100 KB through the three floors to a low of 12.1 KB, then settles near 50 KB. That's the dip accepted in G1 (Q86).
+- **A run-time counter only moves when its task is switched out.** FreeRTOS adds to a task's run time at the context switch. The main loop takes the samples, and with core 1 to itself it's never switched out: its counter said 2 % while the core's idle task had 0 %. So the task that samples gets what's left of its core. With that: **the main loop uses 100 % of core 1 at rest** (issue #40 said 81 %, an average since boot).
+- **`tasks` on the console** sampled twice inside one command at first, a quarter second apart, and showed the loop at 1 %: it was asleep in the command's own wait. It now samples, lets the loop run for a second, and prints.
+- **Low stack, flagged:** `IDLE0` (232 bytes left), `IDLE1` (328 to 352) and `spk_task` (256 to 264), all the framework's own tasks.
+- **Cost:** 15.6 KB of flash for the App and the counters (1,742,723 bytes, release). Nothing while it's closed; about 2 KB of history and samples while it's open.
+
+## The main loop rests (issue #40)
+
+The loop polled the keyboard, ticked the Services, ran the consoles and redrew when needed, then came straight back: 50,000 passes a second, and core 1 100 % busy with the device idle and the screen off.
+
+Nothing needs that. The keyboard controller buffers key events; the consoles and the radio have their own tasks or interrupts; no Service asks for a tick more often than every 50 ms. So after each pass the loop now rests: **5 ms with the screen on, 20 ms with it off**, and not at all during a serial file transfer (`sd put`), which reads its bytes from the loop. Safe Mode's loop rests 5 ms too. Debug Builds have `loop spin on|off` to bring the old behaviour back for comparison.
+
+### Measured (2026-10-06, Debug Build, Wi-Fi connected, GNSS on, on USB power)
+
+| | Spinning | Resting |
+|---|---|---|
+| Passes a second, screen off | 50,160 | 50 |
+| Core 1 load, screen off | 100 % | 1 % |
+| Passes a second, screen on (Launcher) | 1,203 | 167 |
+| Core 1 load, screen on | 62 % | 10 % |
+| Chip temperature at rest, settled | 38.3 C | 34.3 C |
+| A 1.8 MB upload over the Debug Console | about 230 KB/s | 288 KB/s |
+
+- Still working at this pace: GNSS (a 3D Fix, 22 satellites), a Gemini fetch (52 KB), the upload read back by SHA-256, the Sweep (still 606 to 610 ms a pass), the radio's DIO1 interrupt.
+- **Not measured:** the current drawn (no meter on the battery line), and how typing feels on the real keyboard: a key now waits up to 5 ms for the loop, 20 ms if it's the one that wakes the screen.
+- **The radio's noise floor didn't move** (-97 to -99 dBm at 125 kHz either way): the spinning loop wasn't the source (issue #20).
+- **Not done:** real sleep. The framework is built without power management (`CONFIG_PM_ENABLE` is off), so an idle core only halts until the next interrupt. Automatic light sleep would need the framework rebuilt with it, Wi-Fi in modem sleep, and the USB serial port's behaviour checked. A next step if battery life calls for it.
+
+## The radio's noise: the GNSS receiver (issue #20)
+
+M3 found the LoRa radio's noise floor about 15 dB above what the chip hears alone, and that the source travels with the device. Which part? Debug Builds got a self-test, `lora noise test`: it changes one thing at a time, Sweeps the band eight passes (568 readings), records the median as the floor, and puts the thing back. It runs on the device by itself, because one condition switches Wi-Fi off, and `lora noise report` prints the result afterwards.
+
+### Measured (2026-10-06, indoors, on USB power, dBm at 125 kHz)
+
+| Condition | Floor |
+|---|---|
+| Antenna switched off (the chip alone) | -117 |
+| Antenna on, GNSS in standby | -106 |
+| Antenna on, GNSS running (as shipped) | -98 |
+
+- **The GNSS receiver, while it runs, raises the floor by 8 dB.** Three runs: -98 or -99 with it running, -106 in standby, every time. On LongFast (250 kHz) the Sniffer's own reading goes from about -93.5 to -101.5 dBm.
+- **It's the receiver working, not its serial line:** with one NMEA sentence a second instead of twenty (`PCAS03`), the receiver still tracking, the floor stays at -98.
+- **Nothing else moves it by more than 1 dB**, with GNSS running or in standby: the main loop spinning or resting, the CPU at 240, 160 or 80 MHz, Wi-Fi on or off, the screen on or off, the radio chip's regulator as DC-DC or LDO, its receive gain boosted or not.
+- **11 dB remain** between the antenna connected with GNSS quiet (-106) and the chip alone (-117). It comes in through the antenna and none of those switches changes it: the surroundings, or parts of the Cardputer that can't be switched off. Not separated: that needs another place, or the antenna on a cable away from the case.
+- M3's quick check had GNSS at "1 or 2 dB": it read one frequency for a few seconds, in a noisier spot. The median over the band is the better measure.
+
+### What the firmware does about it
+
+**Settings > Pause GNSS for LoRa**, off by default: while the LoRa radio listens or sweeps, the GNSS receiver waits in standby, and wakes when the radio goes back to sleep (a Fix again after about 7 s here). Never during a Track. The GNSS App says "GNSS is paused" meanwhile. `gnss quiet on|off` on the console.
+
+It's off by default because GNSS on by default was decided in M2 (Q58), and from M4 the radio listens all the time: then "pause while listening" means GNSS mostly off, which is a decision about position, the clock and Tracks, for M4's design round (issue #23).

docs/milestones/W1.md

@@ -0,0 +1,127 @@
+# W1: Website
+
+**Status:** phases 1 to 3 (home, Install and Downloads; the user guide; how-tos and the FAQ) and the devlog are live at roro9stack.net; phase 4 (the developer docs) is in a pull request. Issue #12.
+
+**Goal:** a public home for the project at **roro9stack.net**, separate from the blog (stories) and from Gitea (developers): what it is, how to install it, how to use each App, and the docs.
+
+The home page was designed on a canvas in a Claude chat (a dark and a light theme, built on the device's own 256-colour palette, pixel-notched corners, DM Mono and Hanken Grotesk). It is the starting point, not the final copy: it has to say only what the firmware does today.
+
+## What was found while planning (2026-10-06)
+
+- `roro9stack.net` already points at the server that hosts Gitea. Plain HTTP redirects to HTTPS; HTTPS has no certificate yet, which is the server's side to set up.
+- **Release downloads from Gitea carry no CORS header,** so a browser can't fetch the factory image from another origin as things are. Gitea is behind Caddy, which can add the header (below).
+- Zola can read JSON from a URL at build time (`load_data`), so the home page's "latest version" can come from the Gitea API.
+- There is no Gitea wiki: the design's "Wiki" links would 404.
+- The blog is published by pulling its repository on the web server and running `zola build`. The site does the same.
+
+## Decisions (design round 2026-10-06)
+
+| # | Decision |
+|---|---|
+| Q175 | The site lives in this repository, in `site/`, so the documentation is built from `docs/`, `CONTEXT.md` and the README instead of being copied. |
+| Q176 | **Zola,** like the blog. The design becomes a template, its tokens CSS custom properties. Dark and light follow the visitor's setting, with a visible switch. No JavaScript except the flasher's. |
+| Q177 | Domain: **roro9stack.net.** The blog stays at experiments.twis.la. |
+| Q178 | **Publishing is the blog's way:** the web server pulls `main` and runs `zola build`; that part is the maintainer's. Changes reach `main` through pull requests as everywhere. **CI is split:** a dedicated `site` job builds the site (`zola build`) when `site/`, `docs/`, `README.md` or `CONTEXT.md` change, and the firmware tests and builds skip a change that touches nothing else. A change that touches both runs both. |
+| Q179 | Phases, each its own pull request: **1.** the CI split, the home page, an Install page with the browser flasher, downloads and the changelog. **2.** a user guide page per App. **3.** how-tos and the FAQ. **4.** developer docs generated from the repository. |
+| Q180 | **A browser flasher** (ESP Web Tools), **without copying the firmware.** Caddy, in front of Gitea, adds `Access-Control-Allow-Origin: https://roro9stack.net` (and `Vary: Origin`) to GET and HEAD on `/twisla/roro9stack/releases/download/*` and `/api/v1/repos/twisla/roro9stack/releases*`: both are public already. The Install page asks the API for the latest release in the browser, finds the asset ending `-factory.bin`, and gives ESP Web Tools a manifest built on the spot, so it offers a new release as soon as it exists, with no rebuild. The library is **vendored** into `site/static/` (Apache-2.0), not loaded from a CDN. The file's SHA-256 is shown on the page. Chrome or Edge on a desktop only; other browsers, and visitors without JavaScript, get the `esptool` steps on the same page. |
+| Q181 | Docs for the latest version only. The changelog is the Gitea releases, read at build time. |
+| Q182 | English only. |
+| Q183 | The FAQ starts from real questions: the README, and issues labelled `kind/docs`. |
+| Q184 | Fonts are **self-hosted** (no request to a third party). The hero keeps the design's illustrations, labelled as illustrations, and a section of **real device screenshots** is added. |
+| Q185 | **The site says only what the firmware does today.** Planned features are marked as planned, with their milestone. The mesh messenger is **planned**: the LoRa Scanner listens, nothing is sent. |
+| Q186 | Left out, each with its issue: a Gemini capsule mirror (#57), French (#58), docs per version (#59), search (#60). |
+| Q187 | The site has no version of its own. Contact is **contact@roro9stack.net,** and the issue tracker. |
+
+## The design, reviewed
+
+Kept as designed: the layout, the tokens, the nine App cards (their facts check out against the code: Probation 3 minutes, Safe Mode after 3 crashes, 60 seconds of typing before an update restarts the device).
+
+Changed before it ships:
+
+- **Install, not Download, is the first action.** Downloads are for developers; a visitor wants to try it.
+- **A "what you need" strip:** Cardputer ADV, the Cap LoRa-1262 (only the radio needs it), a microSD card, Wi-Fi. And a plain status line: the version, and what isn't there yet.
+- **The mesh card and the hero** no longer promise sending and reading mesh messages.
+- **The latest version is read from the API,** not typed.
+- **"Wiki" is replaced by Docs.** The updates section gains what v0.11.0 added: the device installs releases from the project's server itself.
+- **An independence line:** not affiliated with or endorsed by M5Stack or Meshtastic.
+- **No cookies, no analytics, no third-party requests,** said on the page (fonts self-hosted).
+- **The keyboard focus ring** is invisible on the notched buttons: `clip-path` clips an outline. Another way to show focus is needed.
+- **The wordmark SVGs** carry an embedded C2PA content-credentials block: stripped from the site's copies.
+
+## Done when (phase 1)
+
+- Pushing a change under `site/` runs the `site` job and not the firmware tests; a firmware change runs the firmware jobs and not the site's.
+- The home page renders in both themes, at phone width, with the keyboard, and says nothing the firmware doesn't do.
+- The latest version on the page is the latest release.
+- The browser flasher installs the latest release on a Cardputer ADV from Chrome (tried by hand), the page shows the file's SHA-256, and the `esptool` steps are on the same page.
+- A release published after the site was built is the one the Install page offers.
+- The home and Downloads pages make no request to another origin, and the Install page only asks git.twis.la.
+
+## Work breakdown
+
+1. **CI split:** a `site` workflow, path filters on the firmware workflow.
+2. **The skeleton:** `site/` with the tokens, fonts, base template and the theme switch.
+3. **The home page,** from the design, with the changes above.
+4. **Install and downloads:** the flasher with its manifest built in the page, the `esptool` steps, the changelog. Needs the Caddy headers on the Gitea host (the maintainer's side); the page is tested against them once they're in.
+5. **Checks,** recorded here.
+
+## As built (phase 1)
+
+- **CI is split.** `ci.yml` (the firmware) has `paths-ignore: site/**, docs/**, README.md, CONTEXT.md` on pushes to `main` and on pull requests. `site.yml` runs `zola check` and `zola build` with a Zola pinned by its checksum, then `site/tools/check_site.py`, when those files change. Gitea's own source (v1.24, read, not run against the 1.27 server) shows that path filters count as matched for tag pushes, so a tag still releases. A change that touches both runs both.
+- **The build output** goes to `public/` at the root of the repository, not into `site/`: `output_dir = "../public"` in `site/config.toml`, so `zola build` in `site/` and `zola --root site build` from the root agree, and git ignores `/public/`.
+- **The site** is in `site/`: `config.toml`, templates (base, home, install, downloads, 404), `data/` for the App cards and the screenshots' captions, `static/` (stylesheet, theme switch, fonts, wordmark, icons, real screenshots, the vendored flasher). `site/README.md` says how to build it and what the server needs.
+- **The home page** follows the design. Changed from it: the hero and the mesh card promise nothing that isn't built (the mesh messenger is a "planned" card), an Install button first, a status box, a "what you need" row, a section of real screenshots, the updates section says the device installs releases itself, an independence line and a statement about cookies and third-party requests in the footer, the latest version read from the Gitea API at build time, and the nav's Wiki replaced. The two hero drawings are generated by `site/tools/make_illustrations.py` (a port of the design's scripted shapes) as inline SVG.
+- **The focus ring.** `clip-path` clips outlines, so a focused notched control drops its notches and shows square corners and its ring.
+- **The Install page** asks the API for the latest release in the browser, builds the ESP Web Tools manifest as a blob, shows the version, size and SHA-256, and only ever hands the flasher a download from the project's own server for this repository. The flasher library (ESP Web Tools 10.4.0, Apache-2.0) is vendored, trimmed to the ESP32-S3. Fonts (DM Mono, Hanken Grotesk, SIL OFL) are self-hosted.
+- **The Downloads page** lists the last 30 releases with their files, read at build time.
+- **The wordmark SVGs** from the design carried an embedded C2PA content-credentials block; it is removed from the site's copies.
+
+## As built (phase 2, the user guide)
+
+- **`/guide/`** is a section of 11 pages, `site/content/guide/`, each with `template` from the section's `page_template` and an order from `weight`: the basics (keys, Launcher, Status Bar, first start, the card), then one page per App (LoRa Scanner, GNSS, Gemini, IRC, Wi-Fi tools, Notes, Storage, System), Settings and Updates. Pages with real screenshots list them in `extra.screens`, looked up in `data/screens.toml`.
+- **Facts come from the README, the milestone documents and the Apps' own source** (key handlers, labels, the Status Bar's drawing code), not from memory. Some wording was corrected against the source while writing: the Track folder is `/gnss/tracks`, the reasons a Track won't start, what the Status Bar shows.
+- **Not covered:** the mesh messenger (planned), the debug console and Debug Builds beyond a pointer to the README. How-tos and the FAQ are phase 3.
+
+## As built (the devlog)
+
+Not one of the planned phases: the blog's seven roro9stack posts, imported into `site/content/devlog/` and shown in the site's own style, with the **Blog** link in the navigation and the footer replaced by **Devlog**. The posts' text, tone and structure are unchanged; what changed:
+
+- **Links:** the posts' links to each other point to `/devlog/<same name>/`, and one link to an unpublished work-in-progress post became plain text. Each post keeps its old directory name, so the old URL `/<name>/` maps to `/devlog/<name>/`.
+- **The posts' parts** (the sign, the cast, the steps, asides, folded sections, diagrams, captions) are shortcodes in `site/templates/shortcodes/`, restyled in `static/css/devlog.css`: the site's palette, notched boxes, DM Mono and Hanken Grotesk. The two older posts about other subjects (a vinyl remote, a ZFS rescue) stay on the blog.
+- **The 17 diagrams are inline SVG**, and carried `<style>` blocks and `style` attributes that the site's Content-Security-Policy refuses. Their rules moved to `static/css/devlog-diagrams.css` (one block per diagram, plus colour classes for what the attributes did), and a diagram's minimum width is a class, not a style attribute. The Caddy policy needs no change.
+- **The diagrams' four colours** (red, green, yellow, accent) are defined for `.devlog` on the site's RGB332 grid, one value for each theme.
+- **Links between posts:** every post's reference to another ("the last post", "the first post", the milestone lists) is a link to it. `check_site.py` now also checks every link inside the site, and its #fragment: a broken one fails the Site job. External links are checked by `zola check` run by hand (without `--skip-external-links`, which CI uses); its only complaints today are line-range and heading anchors on Gitea, which Gitea resolves in the browser.
+- **An Atom feed** at `/devlog/atom.xml`, linked from every devlog page.
+- **Checked** in Chromium with the production CSP applied to every response: the index and the seven posts, at 1100 and 390 px, no policy violation, no broken image, no sideways scroll; `check_site.py` 24 pages, 0 problems.
+
+## Checks (2026-10-06)
+
+| Check | Result |
+|---|---|
+| The Site workflow's own commands, in a clean container with the pinned Zola | `zola check` clean, build and page checks pass |
+| `tools/check_site.py` | 4 pages, 0 problems: titles, descriptions, a language, every image with alt text, every local file referenced exists, nothing loaded from another origin |
+| Browser tests (Chromium, 16 checks) | All pass: no request to another origin from the home, Downloads and 404 pages; no horizontal scroll at 1280 and 390 px; a visible focus ring on a notched button; the Install page reads the latest release, shows its version, size and SHA-256, builds a blob manifest naming an ESP32-S3 factory image at offset 0, and loads only git.twis.la; a download on another host is refused; the real server (no CORS header today) makes the page fall back to the esptool steps |
+| The pages looked at | Home in dark and light, at desktop and phone width; Install; Downloads |
+| `esptool` against the real v0.11.0 factory image | An ESP32-S3 image, bootloader at 0x0, partition table at 0x8000: flashing at offset 0 is right. The command's syntax was checked, not a flash |
+
+**Not checked:**
+- **Flashing a real Cardputer from Chrome.** It needs the device on a machine with a browser; the page's flasher logic is tested, the flashing itself isn't.
+- **Caddy's headers** on the real server (not applied yet), and **HTTPS on roro9stack.net** (the name resolves, the certificate isn't there).
+- **The CI split on a change that touches only `site/` or `docs/`.** This pull request touches both the workflows and the site, so it runs both; the first docs-only pull request will show it.
+- Firefox and Safari rendering, screen readers, and a printed page.
+- The unverified wording in the Install text is kept to what's known: nothing about how long flashing takes, or what the screen shows in download mode.
+
+## As built (phase 3, how-tos and the FAQ)
+
+- **`/howto/`** has eight short recipes: when flashing fails, find your files on the SD card, install an update from the card, use a network without DHCP, record a Track, capture LoRa packets for Wireshark, read Gemini pages offline, and what to do when a connection says "not enough memory". **`/faq/`** is one page of questions with a list at the top. Both use the guide's templates (`guide-index.html`, `guide-page.html`, now generic: the page's parent section gives the eyebrow, the title and the pager).
+- **The FAQ starts from the README** and from the problems the project met (Q183): the flash troubles and the memory limit are the two that were hit most. The issues labelled `kind/docs` turned out to be design rounds for the mesh, not user questions, so they gave nothing to answer.
+- **Every step comes from the README, the milestone documents or the Apps' source.** The privacy answer says plainly that the device contacts the project's server once a day for the update check (on by default, one switch to turn it off).
+- **Linked from the guide's index,** not the navigation, which stays short.
+
+## As built (phase 4, the developer docs)
+
+- **`/dev/`** has four sections: **Debug Builds and the Debug Console** (first, and the longest: Debug Builds, the Console and its protocol, files and screenshots, driving the UI, crashes and Safe Mode, and the command reference), **Build, test and release** (the README's build, CI and flash sections, and how an update works, with the update file, the four ways in and Probation drawn), **Decisions** (the ADRs) and **Milestones** (the plans).
+- **Generated from the repository, not copied by hand:** `site/tools/gen_dev_docs.py` writes the ADR pages, the milestone pages, the README's sections, and the command reference, which is read from the firmware's own `help` text in `src/main.cpp` and then the README's table of what each command does. Zola can't read outside its own folder (not even through a symlink), so the generated pages are **committed**, and the Site workflow runs `gen_dev_docs.py --check` and fails when one is out of date; it now also runs when `src/main.cpp` changes, because the command list lives there. The server's `pull; zola build` is unchanged.
+- **Left out on purpose:** the M0 and M1 milestone documents and `CONTEXT.md` (the glossary) describe Wi-Fi monitoring, which the site does not publish. They stay in the repository.
+- **The Debug Console pages were written against the source and the live console:** the protocol (the token line, the banner, the 4 KB backlog, one client, 8 queued commands, 240-byte lines, `denied` after a second) and the replies shown were checked on a Debug Build, v0.11.0-3, over Wi-Fi. Not run: `crash abort`, `crash wdt` and Safe Mode, which are described from ADR 0005 and the code.
+- **Found while writing it:** the README's table lacked the `gnss` commands (rows added); piping commands into `rdbg.py` returns before the replies unless the input stays open (documented, not changed); `update install` on a Debug Build needs `force` (documented).

lib/SD/library.json

@@ -0,0 +1,7 @@
+{
+  "name": "SD",
+  "version": "3.3.12",
+  "description": "roro9stack's copy of Arduino-ESP32's SD library (Apache-2.0), shadowing the framework's. Only sd_diskio.cpp is changed (marked \"roro:\"): it records why a write failed and resends a block the card rejects. See issue #21.",
+  "frameworks": "arduino",
+  "platforms": "espressif32"
+}

lib/SD/src/SD.cpp

@@ -0,0 +1,134 @@
+// Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "vfs_api.h"
+#include "sd_diskio.h"
+#include "ff.h"
+#include "FS.h"
+#include "SD.h"
+
+using namespace fs;
+
+SDFS::SDFS(FSImplPtr impl) : FS(impl), _pdrv(0xFF) {}
+
+SDFS::~SDFS() {
+  end();
+}
+
+bool SDFS::begin(uint8_t ssPin, SPIClass &spi, uint32_t frequency, const char *mountpoint, uint8_t max_files, bool format_if_empty) {
+  if (_pdrv != 0xFF) {
+    return true;
+  }
+
+  if (!spi.begin()) {
+    return false;
+  }
+
+  _pdrv = sdcard_init(ssPin, &spi, frequency);
+  if (_pdrv == 0xFF) {
+    return false;
+  }
+
+  if (!sdcard_mount(_pdrv, mountpoint, max_files, format_if_empty)) {
+    sdcard_unmount(_pdrv);
+    sdcard_uninit(_pdrv);
+    _pdrv = 0xFF;
+    return false;
+  }
+
+  _impl->mountpoint(mountpoint);
+  return true;
+}
+
+void SDFS::end() {
+  if (_pdrv != 0xFF) {
+    _impl->mountpoint(NULL);
+    sdcard_unmount(_pdrv);
+
+    sdcard_uninit(_pdrv);
+    _pdrv = 0xFF;
+  }
+}
+
+sdcard_type_t SDFS::cardType() {
+  if (_pdrv == 0xFF) {
+    return CARD_NONE;
+  }
+  return sdcard_type(_pdrv);
+}
+
+uint64_t SDFS::cardSize() {
+  if (_pdrv == 0xFF) {
+    return 0;
+  }
+  size_t sectors = sdcard_num_sectors(_pdrv);
+  size_t sectorSize = sdcard_sector_size(_pdrv);
+  return (uint64_t)sectors * sectorSize;
+}
+
+size_t SDFS::numSectors() {
+  if (_pdrv == 0xFF) {
+    return 0;
+  }
+  return sdcard_num_sectors(_pdrv);
+}
+
+size_t SDFS::sectorSize() {
+  if (_pdrv == 0xFF) {
+    return 0;
+  }
+  return sdcard_sector_size(_pdrv);
+}
+
+uint64_t SDFS::totalBytes() {
+  FATFS *fsinfo;
+  DWORD fre_clust;
+  char drv[3] = {(char)(48 + _pdrv), ':', 0};
+  if (f_getfree(drv, &fre_clust, &fsinfo) != 0) {
+    return 0;
+  }
+  uint64_t size = ((uint64_t)(fsinfo->csize)) * (fsinfo->n_fatent - 2)
+#if _MAX_SS != 512
+                  * (fsinfo->ssize);
+#else
+                  * 512;
+#endif
+  return size;
+}
+
+uint64_t SDFS::usedBytes() {
+  FATFS *fsinfo;
+  DWORD fre_clust;
+  char drv[3] = {(char)(48 + _pdrv), ':', 0};
+  if (f_getfree(drv, &fre_clust, &fsinfo) != 0) {
+    return 0;
+  }
+  uint64_t size = ((uint64_t)(fsinfo->csize)) * ((fsinfo->n_fatent - 2) - (fsinfo->free_clst))
+#if _MAX_SS != 512
+                  * (fsinfo->ssize);
+#else
+                  * 512;
+#endif
+  return size;
+}
+
+bool SDFS::readRAW(uint8_t *buffer, uint32_t sector) {
+  return sd_read_raw(_pdrv, buffer, sector);
+}
+
+bool SDFS::writeRAW(uint8_t *buffer, uint32_t sector) {
+  return sd_write_raw(_pdrv, buffer, sector);
+}
+
+SDFS SD = SDFS(FSImplPtr(new VFSImpl()));

lib/SD/src/SD.h

@@ -0,0 +1,55 @@
+// Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+#ifndef _SD_H_
+#define _SD_H_
+
+#include "FS.h"
+#include "SPI.h"
+#include "sd_defines.h"
+
+namespace fs {
+
+class SDFS : public FS {
+protected:
+  uint8_t _pdrv;
+
+public:
+  SDFS(FSImplPtr impl);
+  ~SDFS();
+  bool begin(
+    uint8_t ssPin = SS, SPIClass &spi = SPI, uint32_t frequency = 4000000, const char *mountpoint = "/sd", uint8_t max_files = 5, bool format_if_empty = false
+  );
+  void end();
+  sdcard_type_t cardType();
+  uint64_t cardSize();
+  size_t numSectors();
+  size_t sectorSize();
+  uint64_t totalBytes();
+  uint64_t usedBytes();
+  bool readRAW(uint8_t *buffer, uint32_t sector);
+  bool writeRAW(uint8_t *buffer, uint32_t sector);
+};
+
+}  // namespace fs
+
+#if !defined(NO_GLOBAL_INSTANCES) && !defined(NO_GLOBAL_SD)
+extern fs::SDFS SD;
+#endif
+
+using namespace fs;
+typedef fs::File SDFile;
+typedef fs::SDFS SDFileSystemClass;
+#define SDFileSystem SD
+
+#endif /* _SD_H_ */

lib/SD/src/sd_defines.h

@@ -0,0 +1,25 @@
+// Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+#ifndef _SD_DEFINES_H_
+#define _SD_DEFINES_H_
+
+typedef enum {
+  CARD_NONE,
+  CARD_MMC,
+  CARD_SD,
+  CARD_SDHC,
+  CARD_UNKNOWN
+} sdcard_type_t;
+
+#endif /* _SD_DISKIO_H_ */

lib/SD/src/sd_diskio.cpp

@@ -0,0 +1,949 @@
+// roro9stack's copy of the SD-over-SPI driver from Arduino-ESP32 3.3.12 (libraries/SD/src/
+// sd_diskio.cpp), linked instead of the framework's: defining every function the SD class needs
+// keeps the library's file out of the link. Changes are marked "roro:". Why (issue #21): the
+// original gives up on a write without saying why, and never resends a block the card rejects.
+//
+// Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Disable the automatic pin remapping of the API calls in this file
+#define ARDUINO_CORE_BUILD
+
+#include "Arduino.h"
+#include "sd_diskio.h"
+#include "esp_system.h"
+#include "esp32-hal-periman.h"
+
+extern "C" {
+#include "ff.h"
+#include "diskio.h"
+#if ESP_IDF_VERSION_MAJOR > 3
+#include "diskio_impl.h"
+#endif
+//#include "esp_vfs.h"
+#include "esp_vfs_fat.h"
+
+char CRC7(const char *data, int length);
+unsigned short CRC16(const char *data, int length);
+}
+
+// roro: why the last write failed.
+#include "sd_fault.h"
+static roro::SdFault s_fault;
+static bool sdFault(roro::SdFault::Step step, uint8_t token = 0, uint32_t resp = 0) {
+  s_fault.step = step;
+  s_fault.token = token;
+  s_fault.resp = resp;
+  s_fault.count++;
+  return false;
+}
+namespace roro {
+SdFault sdLastFault() { return s_fault; }
+}  // namespace roro
+
+typedef enum {
+  GO_IDLE_STATE = 0,
+  SEND_OP_COND = 1,
+  SEND_CID = 2,
+  SEND_RELATIVE_ADDR = 3,
+  SEND_SWITCH_FUNC = 6,
+  SEND_IF_COND = 8,
+  SEND_CSD = 9,
+  STOP_TRANSMISSION = 12,
+  SEND_STATUS = 13,
+  SET_BLOCKLEN = 16,
+  READ_BLOCK_SINGLE = 17,
+  READ_BLOCK_MULTIPLE = 18,
+  SEND_NUM_WR_BLOCKS = 22,
+  SET_WR_BLK_ERASE_COUNT = 23,
+  WRITE_BLOCK_SINGLE = 24,
+  WRITE_BLOCK_MULTIPLE = 25,
+  APP_OP_COND = 41,
+  APP_CLR_CARD_DETECT = 42,
+  APP_CMD = 55,
+  READ_OCR = 58,
+  CRC_ON_OFF = 59
+} ardu_sdcard_command_t;
+
+// Align with ESP-IDF sdmmc SPI init (ACMD41 timeout must be >1s per SD spec)
+static constexpr uint32_t sd_go_idle_delay_ms = 20;
+static constexpr uint32_t sd_op_cond_timeout_ms = 3000;
+
+typedef struct {
+  uint8_t ssPin;
+  SPIClass *spi;
+  int frequency;
+  char *base_path;
+  sdcard_type_t type;
+  unsigned long sectors;
+  bool supports_crc;
+  int status;
+} ardu_sdcard_t;
+
+static ardu_sdcard_t *s_cards[FF_VOLUMES] = {NULL};
+
+#if ARDUHAL_LOG_LEVEL >= ARDUHAL_LOG_LEVEL_ERROR
+const char *fferr2str[] = {
+  "(0) Succeeded",
+  "(1) A hard error occurred in the low level disk I/O layer",
+  "(2) Assertion failed",
+  "(3) The physical drive cannot work",
+  "(4) Could not find the file",
+  "(5) Could not find the path",
+  "(6) The path name format is invalid",
+  "(7) Access denied due to prohibited access or directory full",
+  "(8) Access denied due to prohibited access",
+  "(9) The file/directory object is invalid",
+  "(10) The physical drive is write protected",
+  "(11) The logical drive number is invalid",
+  "(12) The volume has no work area",
+  "(13) There is no valid FAT volume",
+  "(14) The f_mkfs() aborted due to any problem",
+  "(15) Could not get a grant to access the volume within defined period",
+  "(16) The operation is rejected according to the file sharing policy",
+  "(17) LFN working buffer could not be allocated",
+  "(18) Number of open files > FF_FS_LOCK",
+  "(19) Given parameter is invalid"
+};
+#endif
+
+/*
+ * SD SPI
+ * */
+
+bool sdWait(uint8_t pdrv, int timeout) {
+  char resp;
+  uint32_t start = millis();
+
+  do {
+    resp = s_cards[pdrv]->spi->transfer(0xFF);
+  } while (resp == 0x00 && (millis() - start) < (unsigned int)timeout);
+
+  if (!resp) {
+    log_w("Wait Failed");
+  }
+  return (resp > 0x00);
+}
+
+void sdStop(uint8_t pdrv) {
+  s_cards[pdrv]->spi->write(0xFD);
+}
+
+void sdDeselectCard(uint8_t pdrv) {
+  ardu_sdcard_t *card = s_cards[pdrv];
+  digitalWrite(card->ssPin, HIGH);
+}
+
+bool sdSelectCard(uint8_t pdrv) {
+  ardu_sdcard_t *card = s_cards[pdrv];
+  digitalWrite(card->ssPin, LOW);
+  // roro: one dummy byte before asking whether the card is ready, as ChaN's reference driver does.
+  // A card that has just been given a write takes about a byte of clock to signal busy; without
+  // this, that first byte reads 0xFF, "ready", and the next command (the status check after a
+  // write) goes out while the card is still programming and comes back as garbage (#21).
+  card->spi->transfer(0xFF);
+  bool s = sdWait(pdrv, 500);
+  if (!s) {
+    log_e("Select Failed");
+    digitalWrite(card->ssPin, HIGH);
+    return false;
+  }
+  return true;
+}
+
+char sdCommand(uint8_t pdrv, char cmd, unsigned int arg, unsigned int *resp) {
+  char token;
+  ardu_sdcard_t *card = s_cards[pdrv];
+
+  for (int f = 0; f < 3; f++) {
+    if (cmd == SEND_NUM_WR_BLOCKS || cmd == SET_WR_BLK_ERASE_COUNT || cmd == APP_OP_COND || cmd == APP_CLR_CARD_DETECT) {
+      token = sdCommand(pdrv, APP_CMD, 0, NULL);
+      sdDeselectCard(pdrv);
+      if (token > 1) {
+        break;
+      }
+      if (!sdSelectCard(pdrv)) {
+        token = 0xFF;
+        break;
+      }
+    }
+
+    char cmdPacket[7];
+    cmdPacket[0] = cmd | 0x40;
+    cmdPacket[1] = arg >> 24;
+    cmdPacket[2] = arg >> 16;
+    cmdPacket[3] = arg >> 8;
+    cmdPacket[4] = arg;
+    if (card->supports_crc || cmd == GO_IDLE_STATE || cmd == SEND_IF_COND) {
+      cmdPacket[5] = (CRC7(cmdPacket, 5) << 1) | 0x01;
+    } else {
+      cmdPacket[5] = 0x01;
+    }
+    cmdPacket[6] = 0xFF;
+
+    card->spi->writeBytes((uint8_t *)cmdPacket, (cmd == STOP_TRANSMISSION) ? 7 : 6);
+
+    for (int i = 0; i < 9; i++) {
+      token = card->spi->transfer(0xFF);
+      if (!(token & 0x80)) {
+        break;
+      }
+    }
+
+    if (token == 0xFF) {
+      log_w("no token received");
+      sdDeselectCard(pdrv);
+      delay(100);
+      sdSelectCard(pdrv);
+      continue;
+    } else if (token & 0x08) {
+      log_w("crc error");
+      sdDeselectCard(pdrv);
+      delay(100);
+      sdSelectCard(pdrv);
+      continue;
+    } else if (token > 1) {
+      log_w("token error [%u] 0x%x", cmd, token);
+      break;
+    }
+
+    if (cmd == SEND_STATUS && resp) {
+      *resp = card->spi->transfer(0xFF);
+    } else if ((cmd == SEND_IF_COND || cmd == READ_OCR) && resp) {
+      *resp = card->spi->transfer32(0xFFFFFFFF);
+    }
+
+    break;
+  }
+  if (token == 0xFF) {
+    log_e("Card Failed! cmd: 0x%02x", cmd);
+    card->status = STA_NOINIT;
+  }
+  return token;
+}
+
+bool sdReadBytes(uint8_t pdrv, char *buffer, int length) {
+  char token;
+  unsigned short crc;
+  ardu_sdcard_t *card = s_cards[pdrv];
+
+  uint32_t start = millis();
+  do {
+    token = card->spi->transfer(0xFF);
+  } while (token == 0xFF && (millis() - start) < 500);
+
+  if (token != 0xFE) {
+    return false;
+  }
+
+  card->spi->transferBytes(NULL, (uint8_t *)buffer, length);
+  crc = card->spi->transfer16(0xFFFF);
+  return (!card->supports_crc || crc == CRC16(buffer, length));
+}
+
+char sdWriteBytes(uint8_t pdrv, const char *buffer, char token) {
+  ardu_sdcard_t *card = s_cards[pdrv];
+  unsigned short crc = (card->supports_crc) ? CRC16(buffer, 512) : 0xFFFF;
+  if (!sdWait(pdrv, 500)) {
+    return 0;
+  }
+
+  card->spi->write(token);
+  card->spi->writeBytes((uint8_t *)buffer, 512);
+  card->spi->write16(crc);
+  return (card->spi->transfer(0xFF) & 0x1F);
+}
+
+/*
+ * SPI SDCARD Communication
+ * */
+
+char sdTransaction(uint8_t pdrv, char cmd, unsigned int arg, unsigned int *resp) {
+  if (!sdSelectCard(pdrv)) {
+    return 0xFF;
+  }
+  char token = sdCommand(pdrv, cmd, arg, resp);
+  sdDeselectCard(pdrv);
+  return token;
+}
+
+bool sdReadSector(uint8_t pdrv, char *buffer, unsigned long long sector) {
+  for (int f = 0; f < 3; f++) {
+    if (!sdSelectCard(pdrv)) {
+      return false;
+    }
+    if (!sdCommand(pdrv, READ_BLOCK_SINGLE, (s_cards[pdrv]->type == CARD_SDHC) ? sector : sector << 9, NULL)) {
+      bool success = sdReadBytes(pdrv, buffer, 512);
+      sdDeselectCard(pdrv);
+      if (success) {
+        return true;
+      }
+    } else {
+      break;
+    }
+  }
+  sdDeselectCard(pdrv);
+  return false;
+}
+
+bool sdReadSectors(uint8_t pdrv, char *buffer, unsigned long long sector, int count) {
+  for (int f = 0; f < 3;) {
+    if (!sdSelectCard(pdrv)) {
+      return false;
+    }
+
+    if (!sdCommand(pdrv, READ_BLOCK_MULTIPLE, (s_cards[pdrv]->type == CARD_SDHC) ? sector : sector << 9, NULL)) {
+      do {
+        if (!sdReadBytes(pdrv, buffer, 512)) {
+          f++;
+          break;
+        }
+
+        sector++;
+        buffer += 512;
+        f = 0;
+      } while (--count);
+
+      if (sdCommand(pdrv, STOP_TRANSMISSION, 0, NULL)) {
+        log_e("command failed");
+        break;
+      }
+
+      sdDeselectCard(pdrv);
+      if (count == 0) {
+        return true;
+      }
+    } else {
+      break;
+    }
+  }
+  sdDeselectCard(pdrv);
+  return false;
+}
+
+bool sdWriteSector(uint8_t pdrv, const char *buffer, unsigned long long sector) {
+  using roro::SdFault;
+  for (int f = 0; f < 3; f++) {
+    if (!sdSelectCard(pdrv)) {
+      return sdFault(SdFault::Select);  // roro: say why
+    }
+    if (!sdCommand(pdrv, WRITE_BLOCK_SINGLE, (s_cards[pdrv]->type == CARD_SDHC) ? sector : sector << 9, NULL)) {
+      char token = sdWriteBytes(pdrv, buffer, 0xFE);
+      sdDeselectCard(pdrv);
+
+      if (token == 0x0A) {
+        continue;
+      } else if (token == 0x0C) {
+        return sdFault(SdFault::DataToken, token);
+      }
+
+      unsigned int resp;
+      char status = sdTransaction(pdrv, SEND_STATUS, 0, &resp);
+      if (status || resp) {
+        return token != 0x05 ? sdFault(SdFault::DataToken, token, resp) : sdFault(SdFault::Status, status, resp);
+      }
+      return true;
+    } else {
+      break;
+    }
+  }
+  sdDeselectCard(pdrv);
+  return sdFault(SdFault::Command);
+}
+
+bool sdWriteSectors(uint8_t pdrv, const char *buffer, unsigned long long sector, int count) {
+  using roro::SdFault;
+  char token;
+  const char *currentBuffer = buffer;
+  unsigned long long currentSector = sector;
+  int currentCount = count;
+  ardu_sdcard_t *card = s_cards[pdrv];
+  SdFault::Step why = SdFault::Command;  // roro: what stopped it, for the last return
+  uint8_t whyToken = 0;
+
+  for (int f = 0; f < 3;) {
+    if (card->type != CARD_MMC) {
+      char refused = sdTransaction(pdrv, SET_WR_BLK_ERASE_COUNT, currentCount, NULL);
+      if (refused) {
+        return sdFault(SdFault::EraseCount, refused);
+      }
+    }
+
+    if (!sdSelectCard(pdrv)) {
+      return sdFault(SdFault::Select);
+    }
+
+    if (!sdCommand(pdrv, WRITE_BLOCK_MULTIPLE, (card->type == CARD_SDHC) ? currentSector : currentSector << 9, NULL)) {
+      do {
+        token = sdWriteBytes(pdrv, currentBuffer, 0xFC);
+        if (token != 0x05) {
+          f++;
+          break;
+        }
+        currentBuffer += 512;
+        f = 0;
+      } while (--currentCount);
+
+      if (!sdWait(pdrv, 500)) {
+        why = SdFault::BusyAfter;
+        break;
+      }
+
+      if (currentCount == 0) {
+        sdStop(pdrv);
+        card->spi->transfer(0xFF);  // roro: the byte the card takes to go busy after Stop Tran (#21)
+        sdDeselectCard(pdrv);
+
+        unsigned int resp;
+        char status = sdTransaction(pdrv, SEND_STATUS, 0, &resp);
+        if (status || resp) {
+          return sdFault(SdFault::Status, status, resp);
+        }
+        return true;
+      } else {
+        if (sdCommand(pdrv, STOP_TRANSMISSION, 0, NULL)) {
+          why = SdFault::StopCommand;
+          whyToken = token;
+          break;
+        }
+
+        if (token == 0x0A) {
+          sdDeselectCard(pdrv);
+          unsigned int writtenBlocks = 0;
+          if (card->type != CARD_MMC && sdSelectCard(pdrv)) {
+            if (!sdCommand(pdrv, SEND_NUM_WR_BLOCKS, 0, NULL)) {
+              char acmdData[4];
+              if (sdReadBytes(pdrv, acmdData, 4)) {
+                writtenBlocks = acmdData[0] << 24;
+                writtenBlocks |= acmdData[1] << 16;
+                writtenBlocks |= acmdData[2] << 8;
+                writtenBlocks |= acmdData[3];
+              }
+            }
+            sdDeselectCard(pdrv);
+          }
+          currentBuffer = buffer + (writtenBlocks << 9);
+          currentSector = sector + writtenBlocks;
+          currentCount = count - writtenBlocks;
+          continue;
+        } else {
+          why = SdFault::DataToken;
+          whyToken = token;
+          break;
+        }
+      }
+    } else {
+      break;
+    }
+  }
+  sdDeselectCard(pdrv);
+  return sdFault(why, whyToken);
+}
+
+unsigned long sdGetSectorsCount(uint8_t pdrv) {
+  for (int f = 0; f < 3; f++) {
+    if (!sdSelectCard(pdrv)) {
+      return 0;
+    }
+
+    if (!sdCommand(pdrv, SEND_CSD, 0, NULL)) {
+      char csd[16];
+      bool success = sdReadBytes(pdrv, csd, 16);
+      sdDeselectCard(pdrv);
+      if (success) {
+        if ((csd[0] >> 6) == 0x01) {
+          unsigned long size = (((unsigned long)(csd[7] & 0x3F) << 16) | ((unsigned long)csd[8] << 8) | csd[9]) + 1;
+          return size << 10;
+        }
+        unsigned long size = (((unsigned long)(csd[6] & 0x03) << 10) | ((unsigned long)csd[7] << 2) | ((csd[8] & 0xC0) >> 6)) + 1;
+        size <<= ((((csd[9] & 0x03) << 1) | ((csd[10] & 0x80) >> 7)) + 2);
+        size <<= (csd[5] & 0x0F);
+        return size >> 9;
+      }
+    } else {
+      break;
+    }
+  }
+
+  sdDeselectCard(pdrv);
+  return 0;
+}
+
+namespace {
+
+struct AcquireSPI {
+  ardu_sdcard_t *card;
+  explicit AcquireSPI(ardu_sdcard_t *card) : card(card) {
+    card->spi->beginTransaction(SPISettings(card->frequency, MSBFIRST, SPI_MODE0));
+  }
+  AcquireSPI(ardu_sdcard_t *card, int frequency) : card(card) {
+    card->spi->beginTransaction(SPISettings(frequency, MSBFIRST, SPI_MODE0));
+  }
+  ~AcquireSPI() {
+    card->spi->endTransaction();
+  }
+
+private:
+  AcquireSPI(AcquireSPI const &);
+  AcquireSPI &operator=(AcquireSPI const &);
+};
+
+}  // namespace
+
+/*
+ * FATFS API
+ * */
+
+/**
+ * @brief Initialize an SD card for use with FatFs
+ *
+ * This function implements the complete SD card initialization sequence according to
+ * the SD card specification. It performs card detection, type identification,
+ * and configuration for SPI mode operation.
+ *
+ * The initialization sequence follows the SD card protocol (SPI mode, aligned with IDF):
+ * 1. Power-up sequence with 74+ clock cycles
+ * 2. Two GO_IDLE_STATE attempts to enter SPI mode
+ * 3. CRC_ON_OFF to enable CRC checking (with retry)
+ * 4. SEND_IF_COND to identify SDHC/SDXC cards
+ * 5. APP_OP_COND / SEND_OP_COND (SPI args; timeout >1s)
+ * 6. Card type detection (SD/SDHC/MMC)
+ * 7. Final configuration and sector count retrieval
+ *
+ * @param pdrv Physical drive number (0-9)
+ * @return DSTATUS Status of the initialization (0 = success, STA_NOINIT = failed)
+ */
+DSTATUS ff_sd_initialize(uint8_t pdrv) {
+  char token;
+  unsigned int resp;
+  unsigned int start;
+
+  // Get the card structure for the given drive number
+  ardu_sdcard_t *card = s_cards[pdrv];
+
+  // If the card is already initialized, return its current status
+  if (!(card->status & STA_NOINIT)) {
+    return card->status;
+  }
+
+  // Lock the SPI bus and set it to a low frequency (400kHz) for initialization
+  // Low frequency is required during initialization for reliable communication
+  AcquireSPI card_locked(card, 400000);
+
+  // Step 1: Power-up sequence - Send at least 74 clock cycles with CS high and MOSI high
+  // This is required by the SD card specification to ensure proper card state reset
+  // We send 20 bytes (160 clock cycles) to exceed the minimum requirement
+  digitalWrite(card->ssPin, HIGH);
+  for (uint8_t i = 0; i < 20; i++) {
+    card->spi->transfer(0XFF);
+  }
+
+  // Step 2: Perform two GO_IDLE_STATE (CMD0) attempts in SPI mode.
+  // Per SD Simplified Spec (figure 4-1) / IDF: some cards enter SD mode on the
+  // first attempt, so the first response may fail; the second must succeed.
+  // (sdCommand may also retry internally on no-token/CRC errors.)
+  // Fix mount issue - sdWait fail ignored before each CMD0 attempt
+  digitalWrite(card->ssPin, LOW);
+  if (!sdWait(pdrv, 500)) {
+    log_w("sdWait fail ignored, card initialize continues");
+  }
+  (void)sdCommand(pdrv, GO_IDLE_STATE, 0, NULL);
+  sdDeselectCard(pdrv);
+  delay(sd_go_idle_delay_ms);
+
+  digitalWrite(card->ssPin, LOW);
+  if (!sdWait(pdrv, 500)) {
+    log_w("sdWait fail ignored, card initialize continues");
+  }
+  if (sdCommand(pdrv, GO_IDLE_STATE, 0, NULL) != 1) {
+    sdDeselectCard(pdrv);
+    log_w("GO_IDLE_STATE failed");
+    goto unknown_card;
+  }
+  sdDeselectCard(pdrv);
+  delay(sd_go_idle_delay_ms);
+
+  // Step 3: Configure CRC checking
+  // Enable CRC for data transfers in SPI mode (required for reliable communication).
+  // Some cards reject the first CRC_ON_OFF; retry once (same as IDF).
+  token = sdTransaction(pdrv, CRC_ON_OFF, 1, NULL);
+  if (token != 1 && token != 0x5) {
+    delay(10);
+    token = sdTransaction(pdrv, CRC_ON_OFF, 1, NULL);
+  }
+  if (token == 0x5) {
+    // Old card that doesn't support CRC - disable CRC checking
+    card->supports_crc = false;
+  } else if (token != 1) {
+    log_w("CRC_ON_OFF failed: %u", token);
+    goto unknown_card;
+  }
+
+  // Step 4: Card type detection and initialization
+  // Try to identify SDHC/SDXC cards using SEND_IF_COND command
+  if (sdTransaction(pdrv, SEND_IF_COND, 0x1AA, &resp) == 1) {
+    // Card responded to SEND_IF_COND - likely SDHC/SDXC
+    if ((resp & 0xFFF) != 0x1AA) {
+      log_w("SEND_IF_COND failed: %03" PRIX32, (uint32_t)(resp & 0xFFF));
+      goto unknown_card;
+    }
+
+    // Read Operating Conditions Register to check card capabilities
+    if (sdTransaction(pdrv, READ_OCR, 0, &resp) != 1 || !(resp & (1 << 20))) {
+      log_w("READ_OCR failed: %X", resp);
+      goto unknown_card;
+    }
+
+    // Send APP_OP_COND to set operating conditions for SDHC/SDXC.
+    // In SPI mode only HCS (bit 30) is valid; voltage bits must be 0 (same as IDF).
+    // Timeout must be >1s per SD spec (IDF uses ~3s).
+    start = millis();
+    do {
+      token = sdTransaction(pdrv, APP_OP_COND, 0x40000000, NULL);
+    } while (token == 1 && (millis() - start) < sd_op_cond_timeout_ms);
+
+    if (token) {
+      log_w("APP_OP_COND failed: %u", token);
+      goto unknown_card;
+    }
+
+    // Determine if it's SDHC (high capacity) or regular SD
+    if (!sdTransaction(pdrv, READ_OCR, 0, &resp)) {
+      if (resp & (1 << 30)) {
+        card->type = CARD_SDHC;  // High capacity card (SDHC/SDXC)
+      } else {
+        card->type = CARD_SD;  // Standard capacity card
+      }
+    } else {
+      log_w("READ_OCR failed: %X", resp);
+      goto unknown_card;
+    }
+  } else {
+    // Card didn't respond to SEND_IF_COND - try SD or MMC initialization
+    if (sdTransaction(pdrv, READ_OCR, 0, &resp) != 1 || !(resp & (1 << 20))) {
+      log_w("READ_OCR failed: %X", resp);
+      goto unknown_card;
+    }
+
+    // Try SD card initialization first (SPI mode: ACMD41 arg must be 0)
+    start = millis();
+    do {
+      token = sdTransaction(pdrv, APP_OP_COND, 0, NULL);
+    } while (token == 0x01 && (millis() - start) < sd_op_cond_timeout_ms);
+
+    if (!token) {
+      card->type = CARD_SD;  // Standard SD card
+    } else {
+      // Try MMC card initialization (SPI mode: CMD1 arg must be 0)
+      start = millis();
+      do {
+        token = sdTransaction(pdrv, SEND_OP_COND, 0, NULL);
+      } while (token != 0x00 && (millis() - start) < sd_op_cond_timeout_ms);
+
+      if (token == 0x00) {
+        card->type = CARD_MMC;  // MMC card
+      } else {
+        log_w("SEND_OP_COND failed: %u", token);
+        goto unknown_card;
+      }
+    }
+  }
+
+  // Step 5: Clear card detection for SD cards (not needed for MMC)
+  if (card->type != CARD_MMC) {
+    if (sdTransaction(pdrv, APP_CLR_CARD_DETECT, 0, NULL)) {
+      log_w("APP_CLR_CARD_DETECT failed");
+      goto unknown_card;
+    }
+  }
+
+  // Step 6: Set block length for non-SDHC cards
+  // SDHC cards have fixed 512-byte blocks, others need explicit block length setting
+  if (card->type != CARD_SDHC) {
+    if (sdTransaction(pdrv, SET_BLOCKLEN, 512, NULL) != 0x00) {
+      log_w("SET_BLOCKLEN failed");
+      goto unknown_card;
+    }
+  }
+
+  // Step 7: Get card capacity and finalize initialization
+  card->sectors = sdGetSectorsCount(pdrv);
+
+  // Limit frequency to 25MHz for compatibility (SD spec maximum for non-UHS cards)
+  if (card->frequency > 25000000) {
+    card->frequency = 25000000;
+  }
+
+  // Mark card as initialized
+  card->status &= ~STA_NOINIT;
+  return card->status;
+
+unknown_card:
+  // Mark card as unknown type if initialization failed
+  card->type = CARD_UNKNOWN;
+  return card->status;
+}
+
+DSTATUS ff_sd_status(uint8_t pdrv) {
+  ardu_sdcard_t *card = s_cards[pdrv];
+  AcquireSPI lock(card);
+
+  if (sdTransaction(pdrv, SEND_STATUS, 0, NULL)) {
+    log_e("Check status failed");
+    return STA_NOINIT;
+  }
+  return s_cards[pdrv]->status;
+}
+
+DRESULT ff_sd_read(uint8_t pdrv, uint8_t *buffer, DWORD sector, UINT count) {
+  ardu_sdcard_t *card = s_cards[pdrv];
+  if (card->status & STA_NOINIT) {
+    return RES_NOTRDY;
+  }
+  DRESULT res = RES_OK;
+
+  AcquireSPI lock(card);
+
+  if (count > 1) {
+    res = sdReadSectors(pdrv, (char *)buffer, sector, count) ? RES_OK : RES_ERROR;
+  } else {
+    res = sdReadSector(pdrv, (char *)buffer, sector) ? RES_OK : RES_ERROR;
+  }
+  return res;
+}
+
+DRESULT ff_sd_write(uint8_t pdrv, const uint8_t *buffer, DWORD sector, UINT count) {
+  ardu_sdcard_t *card = s_cards[pdrv];
+  if (card->status & STA_NOINIT) {
+    return RES_NOTRDY;
+  }
+
+  if (card->status & STA_PROTECT) {
+    return RES_WRPRT;
+  }
+  DRESULT res = RES_OK;
+
+  AcquireSPI lock(card);
+
+  if (count > 1) {
+    res = sdWriteSectors(pdrv, (const char *)buffer, sector, count) ? RES_OK : RES_ERROR;
+  } else {
+    res = sdWriteSector(pdrv, (const char *)buffer, sector) ? RES_OK : RES_ERROR;
+  }
+  return res;
+}
+
+DRESULT ff_sd_ioctl(uint8_t pdrv, uint8_t cmd, void *buff) {
+  switch (cmd) {
+    case CTRL_SYNC:
+    {
+      AcquireSPI lock(s_cards[pdrv]);
+      if (sdSelectCard(pdrv)) {
+        sdDeselectCard(pdrv);
+        return RES_OK;
+      }
+    }
+      return RES_ERROR;
+    case GET_SECTOR_COUNT: *((unsigned long *)buff) = s_cards[pdrv]->sectors; return RES_OK;
+    case GET_SECTOR_SIZE:  *((WORD *)buff) = 512; return RES_OK;
+    case GET_BLOCK_SIZE:   *((uint32_t *)buff) = 1; return RES_OK;
+  }
+  return RES_PARERR;
+}
+
+bool sd_read_raw(uint8_t pdrv, uint8_t *buffer, DWORD sector) {
+  return ff_sd_read(pdrv, buffer, sector, 1) == ESP_OK;
+}
+
+bool sd_write_raw(uint8_t pdrv, uint8_t *buffer, DWORD sector) {
+  return ff_sd_write(pdrv, buffer, sector, 1) == ESP_OK;
+}
+
+/*
+ * Public methods
+ * */
+
+uint8_t sdcard_uninit(uint8_t pdrv) {
+  ardu_sdcard_t *card = s_cards[pdrv];
+  if (pdrv >= FF_VOLUMES || card == NULL) {
+    return 1;
+  }
+  {
+    AcquireSPI lock(card);
+    sdTransaction(pdrv, GO_IDLE_STATE, 0, NULL);
+  }  // lock is destructed here
+  ff_diskio_register(pdrv, NULL);
+  s_cards[pdrv] = NULL;
+  esp_err_t err = ESP_OK;
+  if (card->base_path) {
+    err = esp_vfs_fat_unregister_path(card->base_path);
+    free(card->base_path);
+  }
+  free(card);
+  return err;
+}
+
+uint8_t sdcard_init(uint8_t cs, SPIClass *spi, int hz) {
+
+  uint8_t pdrv = 0xFF;
+  if (ff_diskio_get_drive(&pdrv) != ESP_OK || pdrv == 0xFF) {
+    return pdrv;
+  }
+
+  ardu_sdcard_t *card = (ardu_sdcard_t *)malloc(sizeof(ardu_sdcard_t));
+  if (!card) {
+    return 0xFF;
+  }
+
+  card->base_path = NULL;
+  card->frequency = hz;
+  card->spi = spi;
+  card->ssPin = digitalPinToGPIONumber(cs);
+
+  card->supports_crc = true;
+  card->type = CARD_NONE;
+  card->status = STA_NOINIT;
+
+  pinMode(card->ssPin, OUTPUT);
+  digitalWrite(card->ssPin, HIGH);
+  perimanSetPinBusExtraType(card->ssPin, "SD_SS");
+
+  s_cards[pdrv] = card;
+
+  static const ff_diskio_impl_t sd_impl = {
+    .init = &ff_sd_initialize, .status = &ff_sd_status, .read = &ff_sd_read, .write = &ff_sd_write, .ioctl = &ff_sd_ioctl
+  };
+  ff_diskio_register(pdrv, &sd_impl);
+
+  return pdrv;
+}
+
+uint8_t sdcard_unmount(uint8_t pdrv) {
+  ardu_sdcard_t *card = s_cards[pdrv];
+  if (pdrv >= FF_VOLUMES || card == NULL) {
+    return 1;
+  }
+  card->status |= STA_NOINIT;
+  card->type = CARD_NONE;
+
+  char drv[3] = {(char)('0' + pdrv), ':', 0};
+  f_mount(NULL, drv, 0);
+  return 0;
+}
+
+bool sdcard_mount(uint8_t pdrv, const char *path, uint8_t max_files, bool format_if_empty) {
+  ardu_sdcard_t *card = s_cards[pdrv];
+  if (pdrv >= FF_VOLUMES || card == NULL) {
+    return false;
+  }
+
+  if (card->base_path) {
+    free(card->base_path);
+  }
+  card->base_path = strdup(path);
+
+  FATFS *fs;
+  char drv[3] = {(char)('0' + pdrv), ':', 0};
+
+#if ESP_IDF_VERSION < ESP_IDF_VERSION_VAL(6, 0, 0)
+  esp_err_t err = esp_vfs_fat_register(path, drv, max_files, &fs);
+#else
+  esp_vfs_fat_conf_t conf = {.base_path = path, .fat_drive = drv, .max_files = max_files};
+  esp_err_t err = esp_vfs_fat_register(&conf, &fs);
+#endif
+
+  if (err == ESP_ERR_INVALID_STATE) {
+    log_e("esp_vfs_fat_register failed 0x(%x): SD is registered.", err);
+    return false;
+  } else if (err != ESP_OK) {
+    log_e("esp_vfs_fat_register failed 0x(%x)", err);
+    return false;
+  }
+
+  FRESULT res = f_mount(fs, drv, 1);
+  if (res != FR_OK) {
+    log_e("f_mount failed: %s", fferr2str[res]);
+    if (res == 13 && format_if_empty) {
+      BYTE *work = (BYTE *)malloc(sizeof(BYTE) * FF_MAX_SS);
+      if (!work) {
+        log_e("alloc for f_mkfs failed");
+        return false;
+      }
+      //FRESULT f_mkfs (const TCHAR* path, const MKFS_PARM* opt, void* work, UINT len);
+      const MKFS_PARM opt = {(BYTE)FM_ANY, 0, 0, 0, 0};
+      res = f_mkfs(drv, &opt, work, sizeof(BYTE) * FF_MAX_SS);
+      free(work);
+      if (res != FR_OK) {
+        log_e("f_mkfs failed: %s", fferr2str[res]);
+        esp_vfs_fat_unregister_path(path);
+        return false;
+      }
+      res = f_mount(fs, drv, 1);
+      if (res != FR_OK) {
+        log_e("f_mount failed: %s", fferr2str[res]);
+        esp_vfs_fat_unregister_path(path);
+        return false;
+      }
+    } else {
+      esp_vfs_fat_unregister_path(path);
+      return false;
+    }
+  }
+  AcquireSPI lock(card);
+  card->sectors = sdGetSectorsCount(pdrv);
+  return true;
+}
+
+uint32_t sdcard_num_sectors(uint8_t pdrv) {
+  ardu_sdcard_t *card = s_cards[pdrv];
+  if (pdrv >= FF_VOLUMES || card == NULL) {
+    return 0;
+  }
+  return card->sectors;
+}
+
+uint32_t sdcard_sector_size(uint8_t pdrv) {
+  if (pdrv >= FF_VOLUMES || s_cards[pdrv] == NULL) {
+    return 0;
+  }
+  return 512;
+}
+
+// roro: the card's CID. CMD10 in SPI mode (the enum's SEND_CID, 2, is the SD-mode command).
+namespace roro {
+bool sdReadCid(uint8_t cid[16]) {
+  for (uint8_t pdrv = 0; pdrv < FF_VOLUMES; ++pdrv) {
+    ardu_sdcard_t *card = s_cards[pdrv];
+    if (!card) {
+      continue;
+    }
+    AcquireSPI lock(card);
+    if (!sdSelectCard(pdrv)) {
+      return false;
+    }
+    bool ok = !sdCommand(pdrv, 10, 0, NULL) && sdReadBytes(pdrv, (char *)cid, 16);
+    sdDeselectCard(pdrv);
+    return ok;
+  }
+  return false;
+}
+}  // namespace roro
+
+sdcard_type_t sdcard_type(uint8_t pdrv) {
+  ardu_sdcard_t *card = s_cards[pdrv];
+  if (pdrv >= FF_VOLUMES || card == NULL) {
+    return CARD_NONE;
+  }
+  return card->type;
+}

lib/SD/src/sd_diskio.h

@@ -0,0 +1,34 @@
+// Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+#ifndef _SD_DISKIO_H_
+#define _SD_DISKIO_H_
+
+#include "Arduino.h"
+#include "SPI.h"
+#include "sd_defines.h"
+// #include "diskio.h"
+
+uint8_t sdcard_init(uint8_t cs, SPIClass *spi, int hz);
+uint8_t sdcard_uninit(uint8_t pdrv);
+
+bool sdcard_mount(uint8_t pdrv, const char *path, uint8_t max_files, bool format_if_empty);
+uint8_t sdcard_unmount(uint8_t pdrv);
+
+sdcard_type_t sdcard_type(uint8_t pdrv);
+uint32_t sdcard_num_sectors(uint8_t pdrv);
+uint32_t sdcard_sector_size(uint8_t pdrv);
+bool sd_read_raw(uint8_t pdrv, uint8_t *buffer, uint32_t sector);
+bool sd_write_raw(uint8_t pdrv, uint8_t *buffer, uint32_t sector);
+
+#endif /* _SD_DISKIO_H_ */

lib/SD/src/sd_diskio_crc.c

@@ -0,0 +1,61 @@
+/* SD/MMC File System Library
+ * Copyright (c) 2014 Neil Thiessen
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+const char m_CRC7Table[] = {0x00, 0x09, 0x12, 0x1B, 0x24, 0x2D, 0x36, 0x3F, 0x48, 0x41, 0x5A, 0x53, 0x6C, 0x65, 0x7E, 0x77, 0x19, 0x10, 0x0B, 0x02, 0x3D, 0x34,
+                            0x2F, 0x26, 0x51, 0x58, 0x43, 0x4A, 0x75, 0x7C, 0x67, 0x6E, 0x32, 0x3B, 0x20, 0x29, 0x16, 0x1F, 0x04, 0x0D, 0x7A, 0x73, 0x68, 0x61,
+                            0x5E, 0x57, 0x4C, 0x45, 0x2B, 0x22, 0x39, 0x30, 0x0F, 0x06, 0x1D, 0x14, 0x63, 0x6A, 0x71, 0x78, 0x47, 0x4E, 0x55, 0x5C, 0x64, 0x6D,
+                            0x76, 0x7F, 0x40, 0x49, 0x52, 0x5B, 0x2C, 0x25, 0x3E, 0x37, 0x08, 0x01, 0x1A, 0x13, 0x7D, 0x74, 0x6F, 0x66, 0x59, 0x50, 0x4B, 0x42,
+                            0x35, 0x3C, 0x27, 0x2E, 0x11, 0x18, 0x03, 0x0A, 0x56, 0x5F, 0x44, 0x4D, 0x72, 0x7B, 0x60, 0x69, 0x1E, 0x17, 0x0C, 0x05, 0x3A, 0x33,
+                            0x28, 0x21, 0x4F, 0x46, 0x5D, 0x54, 0x6B, 0x62, 0x79, 0x70, 0x07, 0x0E, 0x15, 0x1C, 0x23, 0x2A, 0x31, 0x38, 0x41, 0x48, 0x53, 0x5A,
+                            0x65, 0x6C, 0x77, 0x7E, 0x09, 0x00, 0x1B, 0x12, 0x2D, 0x24, 0x3F, 0x36, 0x58, 0x51, 0x4A, 0x43, 0x7C, 0x75, 0x6E, 0x67, 0x10, 0x19,
+                            0x02, 0x0B, 0x34, 0x3D, 0x26, 0x2F, 0x73, 0x7A, 0x61, 0x68, 0x57, 0x5E, 0x45, 0x4C, 0x3B, 0x32, 0x29, 0x20, 0x1F, 0x16, 0x0D, 0x04,
+                            0x6A, 0x63, 0x78, 0x71, 0x4E, 0x47, 0x5C, 0x55, 0x22, 0x2B, 0x30, 0x39, 0x06, 0x0F, 0x14, 0x1D, 0x25, 0x2C, 0x37, 0x3E, 0x01, 0x08,
+                            0x13, 0x1A, 0x6D, 0x64, 0x7F, 0x76, 0x49, 0x40, 0x5B, 0x52, 0x3C, 0x35, 0x2E, 0x27, 0x18, 0x11, 0x0A, 0x03, 0x74, 0x7D, 0x66, 0x6F,
+                            0x50, 0x59, 0x42, 0x4B, 0x17, 0x1E, 0x05, 0x0C, 0x33, 0x3A, 0x21, 0x28, 0x5F, 0x56, 0x4D, 0x44, 0x7B, 0x72, 0x69, 0x60, 0x0E, 0x07,
+                            0x1C, 0x15, 0x2A, 0x23, 0x38, 0x31, 0x46, 0x4F, 0x54, 0x5D, 0x62, 0x6B, 0x70, 0x79};
+
+char CRC7(const char *data, int length) {
+  char crc = 0;
+  for (int i = 0; i < length; i++) {
+    crc = m_CRC7Table[(crc << 1) ^ data[i]];
+  }
+  return crc;
+}
+
+const unsigned short m_CRC16Table[256] = {
+  0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50A5, 0x60C6, 0x70E7, 0x8108, 0x9129, 0xA14A, 0xB16B, 0xC18C, 0xD1AD, 0xE1CE, 0xF1EF, 0x1231, 0x0210, 0x3273,
+  0x2252, 0x52B5, 0x4294, 0x72F7, 0x62D6, 0x9339, 0x8318, 0xB37B, 0xA35A, 0xD3BD, 0xC39C, 0xF3FF, 0xE3DE, 0x2462, 0x3443, 0x0420, 0x1401, 0x64E6, 0x74C7,
+  0x44A4, 0x5485, 0xA56A, 0xB54B, 0x8528, 0x9509, 0xE5EE, 0xF5CF, 0xC5AC, 0xD58D, 0x3653, 0x2672, 0x1611, 0x0630, 0x76D7, 0x66F6, 0x5695, 0x46B4, 0xB75B,
+  0xA77A, 0x9719, 0x8738, 0xF7DF, 0xE7FE, 0xD79D, 0xC7BC, 0x48C4, 0x58E5, 0x6886, 0x78A7, 0x0840, 0x1861, 0x2802, 0x3823, 0xC9CC, 0xD9ED, 0xE98E, 0xF9AF,
+  0x8948, 0x9969, 0xA90A, 0xB92B, 0x5AF5, 0x4AD4, 0x7AB7, 0x6A96, 0x1A71, 0x0A50, 0x3A33, 0x2A12, 0xDBFD, 0xCBDC, 0xFBBF, 0xEB9E, 0x9B79, 0x8B58, 0xBB3B,
+  0xAB1A, 0x6CA6, 0x7C87, 0x4CE4, 0x5CC5, 0x2C22, 0x3C03, 0x0C60, 0x1C41, 0xEDAE, 0xFD8F, 0xCDEC, 0xDDCD, 0xAD2A, 0xBD0B, 0x8D68, 0x9D49, 0x7E97, 0x6EB6,
+  0x5ED5, 0x4EF4, 0x3E13, 0x2E32, 0x1E51, 0x0E70, 0xFF9F, 0xEFBE, 0xDFDD, 0xCFFC, 0xBF1B, 0xAF3A, 0x9F59, 0x8F78, 0x9188, 0x81A9, 0xB1CA, 0xA1EB, 0xD10C,
+  0xC12D, 0xF14E, 0xE16F, 0x1080, 0x00A1, 0x30C2, 0x20E3, 0x5004, 0x4025, 0x7046, 0x6067, 0x83B9, 0x9398, 0xA3FB, 0xB3DA, 0xC33D, 0xD31C, 0xE37F, 0xF35E,
+  0x02B1, 0x1290, 0x22F3, 0x32D2, 0x4235, 0x5214, 0x6277, 0x7256, 0xB5EA, 0xA5CB, 0x95A8, 0x8589, 0xF56E, 0xE54F, 0xD52C, 0xC50D, 0x34E2, 0x24C3, 0x14A0,
+  0x0481, 0x7466, 0x6447, 0x5424, 0x4405, 0xA7DB, 0xB7FA, 0x8799, 0x97B8, 0xE75F, 0xF77E, 0xC71D, 0xD73C, 0x26D3, 0x36F2, 0x0691, 0x16B0, 0x6657, 0x7676,
+  0x4615, 0x5634, 0xD94C, 0xC96D, 0xF90E, 0xE92F, 0x99C8, 0x89E9, 0xB98A, 0xA9AB, 0x5844, 0x4865, 0x7806, 0x6827, 0x18C0, 0x08E1, 0x3882, 0x28A3, 0xCB7D,
+  0xDB5C, 0xEB3F, 0xFB1E, 0x8BF9, 0x9BD8, 0xABBB, 0xBB9A, 0x4A75, 0x5A54, 0x6A37, 0x7A16, 0x0AF1, 0x1AD0, 0x2AB3, 0x3A92, 0xFD2E, 0xED0F, 0xDD6C, 0xCD4D,
+  0xBDAA, 0xAD8B, 0x9DE8, 0x8DC9, 0x7C26, 0x6C07, 0x5C64, 0x4C45, 0x3CA2, 0x2C83, 0x1CE0, 0x0CC1, 0xEF1F, 0xFF3E, 0xCF5D, 0xDF7C, 0xAF9B, 0xBFBA, 0x8FD9,
+  0x9FF8, 0x6E17, 0x7E36, 0x4E55, 0x5E74, 0x2E93, 0x3EB2, 0x0ED1, 0x1EF0
+};
+
+unsigned short CRC16(const char *data, int length) {
+  unsigned short crc = 0;
+  for (int i = 0; i < length; i++) {
+    crc = (crc << 8) ^ m_CRC16Table[((crc >> 8) ^ data[i]) & 0x00FF];
+  }
+  return crc;
+}

lib/SD/src/sd_fault.h

@@ -0,0 +1,33 @@
+#pragma once
+
+#include <cstdint>
+
+namespace roro {
+
+// Why the SD driver last gave up on a write (see sd_diskio.cpp, issue #21). The framework's driver
+// fails without saying why; ours records it.
+struct SdFault {
+    enum Step : uint8_t {
+        None,
+        EraseCount,   // ACMD23 before a multi-block write was refused
+        Select,       // the card stayed busy for 500 ms
+        Command,      // the write command itself was refused
+        DataToken,    // the card's answer to a data block: 0x0B CRC error, 0x0D write error
+        BusyAfter,    // still busy 500 ms after the last block
+        Status,       // CMD13 after the write reported an error (resp)
+        StopCommand,  // CMD12 after a rejected block was refused
+    };
+    Step step = None;
+    uint8_t token = 0;   // the driver's or the card's answer at that step
+    uint32_t resp = 0;   // CMD13's status bits, for Status
+    uint32_t count = 0;  // failed writes since boot
+    uint32_t retried = 0;  // blocks resent after a CRC error, since boot
+};
+
+SdFault sdLastFault();
+
+// The mounted card's identity register (CID, CMD10): who made it, its name, serial and date.
+// Call it where card access is allowed (the storage task).
+bool sdReadCid(uint8_t cid[16]);
+
+}  // namespace roro

lib/apps_model/src/settings_menu.cpp

@@ -20,10 +20,10 @@ const RowDef kRows[] = {
     {Row::Region, Kind::Choice, "Region"},      {Row::Timezone, Kind::Choice, "Timezone"},
     {Row::Brightness, Kind::Slider, "Brightness"}, {Row::DimTimeout, Kind::Choice, "Dim after"},
     {Row::OffTimeout, Kind::Choice, "Screen off after"}, {Row::Sound, Kind::Toggle, "Sound & LED"},
-    {Row::Gnss, Kind::Toggle, "GNSS"}, {Row::Coordinates, Kind::Toggle, "Coordinates"},
+    {Row::Gnss, Kind::Toggle, "GNSS"}, {Row::GnssQuiet, Kind::Toggle, "Pause GNSS for LoRa"},
+    {Row::Coordinates, Kind::Toggle, "Coordinates"},
     {Row::ProbeMacs, Kind::Toggle, "Probe MACs"}, {Row::Wifi, Kind::Page, "Wi-Fi"},
-    {Row::Storage, Kind::Page, "Storage"},
+    {Row::CheckUpdates, Kind::Toggle, "Check for updates"}, {Row::Firmware, Kind::Page, "Firmware"},
-    {Row::Firmware, Kind::Page, "Firmware"},
     {Row::About, Kind::Page, "About"},
 };
 
@@ -81,6 +81,8 @@ std::string SettingsMenu::value(int i) const {
         case Row::OffTimeout: return formatSeconds(settings_.getInt(Setting::OffTimeoutS));
         case Row::Sound: return settings_.getBool(Setting::Sound) ? "On" : "Off";
         case Row::Gnss: return settings_.getBool(Setting::GnssEnabled) ? "On" : "Off";
+        case Row::GnssQuiet: return settings_.getBool(Setting::GnssQuietForLora) ? "On" : "Off";
+        case Row::CheckUpdates: return settings_.getBool(Setting::CheckUpdates) ? "Daily" : "Off";
         case Row::Coordinates: return settings_.getBool(Setting::CoordinatesDms) ? "Deg min sec" : "Decimal";
         case Row::ProbeMacs: return settings_.getBool(Setting::ProbeMacRaw) ? "Raw" : "Pseudonymised";
         case Row::Wifi: return settings_.getBool(Setting::WifiEnabled) ? "On" : "Off";
@@ -126,6 +128,8 @@ std::string SettingsMenu::choose(int i, int c) {
 void SettingsMenu::toggle(int i) {
     if (row(i) == Row::Sound) settings_.setBool(Setting::Sound, !settings_.getBool(Setting::Sound));
     if (row(i) == Row::Gnss) settings_.setBool(Setting::GnssEnabled, !settings_.getBool(Setting::GnssEnabled));
+    if (row(i) == Row::GnssQuiet) settings_.setBool(Setting::GnssQuietForLora, !settings_.getBool(Setting::GnssQuietForLora));
+    if (row(i) == Row::CheckUpdates) settings_.setBool(Setting::CheckUpdates, !settings_.getBool(Setting::CheckUpdates));
     if (row(i) == Row::Coordinates) settings_.setBool(Setting::CoordinatesDms, !settings_.getBool(Setting::CoordinatesDms));
     if (row(i) == Row::ProbeMacs) settings_.setBool(Setting::ProbeMacRaw, !settings_.getBool(Setting::ProbeMacRaw));
 }

lib/apps_model/src/settings_menu.h

@@ -11,7 +11,7 @@ namespace roro {
 // values, choice lists and validation messages. Rendering and navigation live in the App.
 class SettingsMenu {
    public:
-    enum class Row { LongName, ShortName, Region, Timezone, Brightness, DimTimeout, OffTimeout, Sound, Gnss, Coordinates, ProbeMacs, Wifi, Storage, Firmware, About };
+    enum class Row { LongName, ShortName, Region, Timezone, Brightness, DimTimeout, OffTimeout, Sound, Gnss, GnssQuiet, Coordinates, ProbeMacs, Wifi, CheckUpdates, Firmware, About };
     enum class Kind { Text, Choice, Toggle, Slider, Page };
 
     explicit SettingsMenu(Settings& settings) : settings_(settings) {}

lib/files/src/file_list.cpp

@@ -0,0 +1,137 @@
+#include "file_list.h"
+
+#include <algorithm>
+#include <cctype>
+#include <cstdio>
+#include <cstring>
+#include <ctime>
+
+namespace roro::files {
+
+namespace {
+
+// Names compare letters only, whatever the case; ties by the bytes, so the order is total.
+int compareNames(const char* a, const char* b) {
+    for (const char *x = a, *y = b;; ++x, ++y) {
+        int cx = std::tolower(static_cast<unsigned char>(*x)), cy = std::tolower(static_cast<unsigned char>(*y));
+        if (cx != cy) return cx < cy ? -1 : 1;
+        if (!cx) break;
+    }
+    return std::strcmp(a, b);
+}
+
+constexpr uint32_t kYear2020 = 1577836800;
+
+std::string sizeText(uint32_t bytes) {
+    char s[16];
+    if (bytes < 1024) std::snprintf(s, sizeof s, "%u B", static_cast<unsigned>(bytes));
+    else if (bytes < 10 * 1024) std::snprintf(s, sizeof s, "%.1f KB", bytes / 1024.0);
+    else if (bytes < 1024 * 1024) std::snprintf(s, sizeof s, "%u KB", static_cast<unsigned>(bytes / 1024));
+    else if (bytes < 10u * 1024 * 1024) std::snprintf(s, sizeof s, "%.1f MB", bytes / 1048576.0);
+    else if (bytes < 1024u * 1024 * 1024) std::snprintf(s, sizeof s, "%u MB", static_cast<unsigned>(bytes / 1048576));
+    else std::snprintf(s, sizeof s, "%.1f GB", bytes / 1073741824.0);
+    return s;
+}
+
+}  // namespace
+
+void FileList::clear() {
+    std::vector<Entry>().swap(entries_);
+    std::vector<uint16_t>().swap(order_);
+    std::vector<char>().swap(names_);
+    more_ = wasted_ = 0;
+}
+
+bool FileList::before(const Entry& a, const Entry& b, FileSort by) const {
+    if (a.folder != b.folder) return a.folder;
+    if (!a.folder) {
+        if (by == FileSort::Date && a.modified != b.modified) return a.modified > b.modified;
+        if (by == FileSort::Size && a.size != b.size) return a.size > b.size;
+    }
+    return compareNames(names_.data() + a.name, names_.data() + b.name) < 0;
+}
+
+void FileList::add(const char* name, uint32_t size, uint32_t modified, bool folder) {
+    size_t len = std::strlen(name) + 1;
+    if (entries_.size() >= kMax) {
+        // Full: the new entry takes the place of the one that sorts last by name, if it sorts
+        // before it. The old name's bytes stay in the buffer until there's enough waste to pack.
+        more_++;
+        size_t last = 0;
+        for (size_t i = 1; i < entries_.size(); i++)
+            if (before(entries_[last], entries_[i], FileSort::Name)) last = i;
+        Entry candidate{static_cast<uint32_t>(names_.size()), size, modified, folder};
+        names_.insert(names_.end(), name, name + len);
+        if (!before(candidate, entries_[last], FileSort::Name)) {
+            names_.resize(names_.size() - len);
+            return;
+        }
+        wasted_ += std::strlen(names_.data() + entries_[last].name) + 1;
+        entries_[last] = candidate;
+        if (wasted_ > 2048) compact();
+        return;
+    }
+    if (entries_.empty()) {
+        entries_.reserve(32);
+        names_.reserve(512);
+    }
+    entries_.push_back({static_cast<uint32_t>(names_.size()), size, modified, folder});
+    names_.insert(names_.end(), name, name + len);
+    order_.push_back(static_cast<uint16_t>(order_.size()));
+}
+
+void FileList::compact() {
+    std::vector<char> packed;
+    packed.reserve(names_.size() - wasted_);
+    for (Entry& e : entries_) {
+        const char* n = names_.data() + e.name;
+        e.name = static_cast<uint32_t>(packed.size());
+        packed.insert(packed.end(), n, n + std::strlen(n) + 1);
+    }
+    names_.swap(packed);
+    wasted_ = 0;
+}
+
+void FileList::sort(FileSort by) {
+    if (wasted_) compact();
+    names_.shrink_to_fit();
+    entries_.shrink_to_fit();
+    order_.resize(entries_.size());
+    for (size_t i = 0; i < order_.size(); i++) order_[i] = static_cast<uint16_t>(i);
+    std::sort(order_.begin(), order_.end(), [&](uint16_t a, uint16_t b) { return before(entries_[a], entries_[b], by); });
+}
+
+int FileList::find(const std::string& name) const {
+    for (size_t i = 0; i < order_.size(); i++)
+        if (name == this->name(i)) return static_cast<int>(i);
+    return -1;
+}
+
+size_t FileList::bytes() const {
+    return entries_.capacity() * sizeof(Entry) + order_.capacity() * sizeof(uint16_t) + names_.capacity();
+}
+
+std::string formatStamp(uint32_t modified) {
+    if (modified < kYear2020) return "-";
+    time_t t = static_cast<time_t>(modified);
+    struct tm local;
+    localtime_r(&t, &local);
+    char s[20];
+    std::snprintf(s, sizeof s, "%04d-%02d-%02d %02d:%02d", local.tm_year + 1900, local.tm_mon + 1, local.tm_mday, local.tm_hour,
+                  local.tm_min);
+    return s;
+}
+
+std::string rowDetail(bool folder, uint32_t size, uint32_t modified) {
+    if (folder) return "folder";
+    std::string stamp = formatStamp(modified);
+    return sizeText(size) + "  " + (stamp == "-" ? stamp : stamp.substr(0, 10));
+}
+
+std::string fitName(const std::string& name, size_t maxChars) {
+    if (name.size() <= maxChars || maxChars < 8) return name.substr(0, maxChars);
+    size_t tail = std::min<size_t>(6, maxChars / 3), head = maxChars - tail - 2;
+    return name.substr(0, head) + ".." + name.substr(name.size() - tail);
+}
+
+}  // namespace roro::files

lib/files/src/file_list.h

@@ -0,0 +1,55 @@
+#pragma once
+
+#include <cstddef>
+#include <cstdint>
+#include <string>
+#include <vector>
+
+namespace roro::files {
+
+enum class FileSort : uint8_t { Name, Date, Size };
+
+// A folder's entries for the Storage App (F1, Q129, Q136): 256 at most, the names packed into
+// one buffer, about 10 KB when full. A bigger folder keeps the first 256 by name, whatever order
+// the card lists them in, and counts the rest.
+class FileList {
+   public:
+    static constexpr size_t kMax = 256;
+
+    void clear();
+    void add(const char* name, uint32_t size, uint32_t modified, bool folder);
+    void sort(FileSort by);  // folders first, by name; then files by name, newest or biggest first
+
+    size_t count() const { return entries_.size(); }
+    size_t more() const { return more_; }  // entries that didn't fit
+    // By position after sort().
+    const char* name(size_t i) const { return names_.data() + entries_[order_[i]].name; }
+    uint32_t size(size_t i) const { return entries_[order_[i]].size; }
+    uint32_t modified(size_t i) const { return entries_[order_[i]].modified; }  // Unix time, 0 if unknown
+    bool folder(size_t i) const { return entries_[order_[i]].folder; }
+    int find(const std::string& name) const;  // position, or -1
+    size_t bytes() const;                     // memory held
+
+   private:
+    struct Entry {
+        uint32_t name;  // offset into names_
+        uint32_t size, modified;
+        bool folder;
+    };
+    bool before(const Entry& a, const Entry& b, FileSort by) const;
+    void compact();
+
+    std::vector<Entry> entries_;
+    std::vector<uint16_t> order_;
+    std::vector<char> names_;
+    size_t more_ = 0, wasted_ = 0;
+};
+
+// What a row shows on the right (Q129): "folder", or "1.2 KB  2026-10-05". A file dated before
+// 2020 was written before the clock was set: "-" (Q137). Local time.
+std::string rowDetail(bool folder, uint32_t size, uint32_t modified);
+std::string formatStamp(uint32_t modified);
+// A name cut to `maxChars` for a row, from the middle: the start and the extension stay readable.
+std::string fitName(const std::string& name, size_t maxChars);  // "2026-10-05 20:00", or "-"
+
+}  // namespace roro::files

lib/files/src/file_names.cpp

@@ -0,0 +1,99 @@
+#include "file_names.h"
+
+#include <cctype>
+
+namespace roro::files {
+
+const char* const kFirmwareFolders[] = {"/irc", "/wifi", "/updates", "/gnss", "/gemini", "/captures", "/notes"};
+const size_t kFirmwareFolderCount = sizeof kFirmwareFolders / sizeof kFirmwareFolders[0];
+
+std::string parentOf(const std::string& path) {
+    size_t slash = path.rfind('/');
+    return slash == std::string::npos || slash == 0 ? "/" : path.substr(0, slash);
+}
+
+std::string baseName(const std::string& path) {
+    size_t slash = path.rfind('/');
+    return slash == std::string::npos ? path : path.substr(slash + 1);
+}
+
+std::string joinPath(const std::string& folder, const std::string& name) {
+    return folder == "/" ? "/" + name : folder + "/" + name;
+}
+
+std::string extensionOf(const std::string& name) {
+    size_t dot = name.rfind('.');
+    if (dot == std::string::npos || dot == 0) return "";
+    std::string ext = name.substr(dot + 1);
+    for (char& c : ext) c = static_cast<char>(std::tolower(static_cast<unsigned char>(c)));
+    return ext;
+}
+
+bool isInside(const std::string& path, const std::string& folder) {
+    if (folder == "/") return true;
+    if (path.compare(0, folder.size(), folder) != 0) return false;
+    return path.size() == folder.size() || path[folder.size()] == '/';
+}
+
+std::string checkName(const std::string& name) {
+    if (name.empty()) return "A name can't be empty";
+    if (name == "." || name == "..") return "\".\" and \"..\" aren't names";
+    if (name.size() > 64) return "A name can be 64 characters at most";
+    for (char c : name) {
+        if (static_cast<unsigned char>(c) < 0x20) return "A name can't contain control characters";
+        for (char bad : std::string("/\\:*?\"<>|"))
+            if (c == bad) return std::string("A name can't contain ") + c;
+    }
+    if (name.back() == '.' || name.back() == ' ') return "A name can't end with a dot or a space";
+    return "";
+}
+
+std::string whyReadOnly(const std::string& path, const std::vector<std::string>& inUse) {
+    if (path == "/" || path.empty()) return "That's the card itself";
+    if (isInside(path, kGeminiCache)) return std::string(kGeminiCache) + " is the Gemini App's working space";
+    for (const std::string& open : inUse) {
+        if (open == path) return "It's being written right now";
+        if (isInside(open, path)) return "It holds a file that's being written right now";
+    }
+    for (size_t i = 0; i < kFirmwareFolderCount; i++)
+        if (path == kFirmwareFolders[i]) return std::string("The firmware keeps its files in ") + path;
+    return "";
+}
+
+std::string whyNotInto(const std::string& source, const std::string& into) {
+    if (isInside(into, kGeminiCache)) return std::string(kGeminiCache) + " is the Gemini App's working space";
+    if (isInside(into, source)) return "A folder can't go inside itself";
+    if (parentOf(source) == into) return "It's already there";
+    return "";
+}
+
+std::string copyName(const std::string& name, int n) {
+    size_t dot = name.rfind('.');
+    std::string suffix = " (" + std::to_string(n) + ")";
+    if (dot == std::string::npos || dot == 0) return name + suffix;
+    return name.substr(0, dot) + suffix + name.substr(dot);
+}
+
+FileKind kindOf(const std::string& name) {
+    std::string ext = extensionOf(name);
+    if (ext == "gpx") return FileKind::Gpx;
+    if (ext == "pcap") return FileKind::Pcap;
+    if (ext == "ota") return FileKind::Ota;
+    for (const char* text : {"txt", "log", "gmi", "csv", "md", "json", "ini", "conf", "ir"})
+        if (ext == text) return FileKind::Text;
+    return FileKind::Unknown;
+}
+
+bool opensAtEnd(const std::string& name) { return extensionOf(name) == "log"; }
+
+bool looksLikeText(const uint8_t* data, size_t len) {
+    size_t odd = 0;
+    for (size_t i = 0; i < len; i++) {
+        uint8_t b = data[i];
+        if (b == 0) return false;
+        if (b < 0x20 && b != '\n' && b != '\r' && b != '\t') odd++;
+    }
+    return odd * 20 <= len;  // a stray control character or two is still text
+}
+
+}  // namespace roro::files

lib/files/src/file_names.h

@@ -0,0 +1,42 @@
+#pragma once
+
+#include <cstddef>
+#include <cstdint>
+#include <string>
+#include <vector>
+
+namespace roro::files {
+
+// Paths on the SD card are absolute and use '/': "/gemini/saved/index.gmi".
+std::string parentOf(const std::string& path);    // "/" for a top-level entry and for "/"
+std::string baseName(const std::string& path);    // "" for "/"
+std::string joinPath(const std::string& folder, const std::string& name);
+std::string extensionOf(const std::string& name);  // lower case, without the dot; "" if none
+bool isInside(const std::string& path, const std::string& folder);  // a folder is inside itself
+
+// A name typed for rename or a new folder (F1, Q131): "" if FAT and this App can take it, or why not.
+std::string checkName(const std::string& name);
+
+// The top-level folders the firmware keeps its files in. They can't be renamed or deleted;
+// what's in them can (Q130).
+extern const char* const kFirmwareFolders[];
+extern const size_t kFirmwareFolderCount;
+constexpr const char* kGeminiCache = "/gemini/cache";
+
+// Why `path` can't be renamed, moved or deleted, or "" if it can (Q130). `inUse`: the files the
+// firmware has open right now.
+std::string whyReadOnly(const std::string& path, const std::vector<std::string>& inUse);
+
+// Why `source` can't be copied or moved into the folder `into`, or "" if it can.
+std::string whyNotInto(const std::string& source, const std::string& into);
+
+// "a (2).gmi": the name of a copy made next to its original.
+std::string copyName(const std::string& name, int n);
+
+// Which viewer opens a file (Q134), from its name. Unknown: look at the first bytes.
+enum class FileKind : uint8_t { Text, Gpx, Pcap, Ota, Unknown };
+FileKind kindOf(const std::string& name);
+bool opensAtEnd(const std::string& name);  // logs
+bool looksLikeText(const uint8_t* data, size_t len);
+
+}  // namespace roro::files

lib/files/src/file_views.cpp

@@ -0,0 +1,143 @@
+#include "file_views.h"
+
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
+
+#include "file_list.h"
+#include "track.h"
+
+namespace roro::files {
+
+std::string hexRow(uint32_t offset, const uint8_t* data, size_t len) {
+    char head[8];
+    std::snprintf(head, sizeof head, "%05X", static_cast<unsigned>(offset));
+    std::string row = head, text;
+    for (size_t i = 0; i < 8; i++) {
+        if (i % 2 == 0) row += ' ';
+        char hex[3] = "  ";
+        if (i < len) {
+            std::snprintf(hex, sizeof hex, "%02x", data[i]);
+            text += data[i] >= 0x20 && data[i] < 0x7F ? static_cast<char>(data[i]) : '.';
+        }
+        row += hex;
+    }
+    return row + "  " + text;
+}
+
+namespace {
+// Days since 1970-01-01 (Howard Hinnant's days_from_civil): no timegm() everywhere.
+int64_t daysFromCivil(int y, int m, int d) {
+    y -= m <= 2;
+    int64_t era = (y >= 0 ? y : y - 399) / 400;
+    int yoe = static_cast<int>(y - era * 400);
+    int doy = (153 * (m + (m > 2 ? -3 : 9)) + 2) / 5 + d - 1;
+    int doe = yoe * 365 + yoe / 4 - yoe / 100 + doy;
+    return era * 146097 + doe - 719468;
+}
+
+bool attribute(const std::string& element, const char* name, double& out) {
+    size_t at = element.find(name);
+    if (at == std::string::npos) return false;
+    const char* from = element.c_str() + at + std::strlen(name);
+    char* end = nullptr;
+    out = std::strtod(from, &end);
+    return end != from;
+}
+}  // namespace
+
+void GpxSummary::point(const std::string& element) {
+    double lat, lon;
+    if (!attribute(element, "lat=\"", lat) || !attribute(element, "lon=\"", lon)) return;
+    if (points_ > 0) meters_ += gnss::distanceMeters(lat_, lon_, lat, lon);
+    lat_ = lat;
+    lon_ = lon;
+    points_++;
+    size_t at = element.find("<time>");
+    int y, mo, d, h, mi, s;
+    if (at != std::string::npos && std::sscanf(element.c_str() + at + 6, "%d-%d-%dT%d:%d:%d", &y, &mo, &d, &h, &mi, &s) == 6) {
+        int64_t t = daysFromCivil(y, mo, d) * 86400 + h * 3600 + mi * 60 + s;
+        if (first_ == 0) first_ = t;
+        last_ = t;
+    }
+}
+
+void GpxSummary::feed(const char* data, size_t len) {
+    carry_.append(data, len);
+    size_t done = 0;
+    for (;;) {
+        size_t open = carry_.find("<trkpt", done);
+        if (open == std::string::npos) {
+            // Nothing begun, except perhaps the first letters of a tag at the very end.
+            done = carry_.size() > 6 ? carry_.size() - 6 : done;
+            break;
+        }
+        size_t close = carry_.find("</trkpt>", open);
+        size_t next = carry_.find("<trkpt", open + 6);  // a point with nothing inside: <trkpt .../>
+        if (close == std::string::npos && next == std::string::npos) {
+            done = open;
+            break;
+        }
+        size_t end = close != std::string::npos && (next == std::string::npos || close < next) ? close + 8 : next;
+        point(carry_.substr(open, end - open));
+        done = end;
+    }
+    carry_.erase(0, done);
+    if (carry_.size() > 2048) carry_.erase(0, carry_.size() - 6);  // not a GPX point: don't keep it
+}
+
+std::string formatDuration(int64_t seconds) {
+    char s[24];
+    if (seconds < 60) std::snprintf(s, sizeof s, "%d s", static_cast<int>(seconds));
+    else if (seconds < 3600) std::snprintf(s, sizeof s, "%d min %02d s", static_cast<int>(seconds / 60), static_cast<int>(seconds % 60));
+    else std::snprintf(s, sizeof s, "%d h %02d min", static_cast<int>(seconds / 3600), static_cast<int>(seconds % 3600 / 60));
+    return s;
+}
+
+std::vector<std::string> GpxSummary::lines() const {
+    std::vector<std::string> out;
+    out.push_back(std::to_string(points_) + (points_ == 1 ? " point" : " points"));
+    if (first_ > 0) {
+        out.push_back("Started " + formatStamp(static_cast<uint32_t>(first_)));
+        out.push_back("Lasted " + formatDuration(last_ - first_));
+    }
+    char s[32];
+    if (meters_ < 1000) std::snprintf(s, sizeof s, "Distance %.0f m", meters_);
+    else std::snprintf(s, sizeof s, "Distance %.2f km", meters_ / 1000);
+    out.push_back(s);
+    return out;
+}
+
+namespace {
+uint32_t le32(const uint8_t* p) { return p[0] | p[1] << 8 | p[2] << 16 | static_cast<uint32_t>(p[3]) << 24; }
+}  // namespace
+
+PcapHeader parsePcapHeader(const uint8_t* data, size_t len) {
+    PcapHeader h;
+    if (len < kPcapHeaderSize || le32(data) != 0xA1B2C3D4) return h;  // little-endian, microseconds: what we write
+    h.ok = true;
+    h.linkType = le32(data + 20);
+    return h;
+}
+
+bool parsePcapRecord(const uint8_t* data, size_t len, PcapRecord& out) {
+    if (len < kPcapRecordSize) return false;
+    out.seconds = le32(data);
+    out.micros = le32(data + 4);
+    out.length = le32(data + 8);
+    return out.length <= 65535;
+}
+
+bool parseLoraTap(const uint8_t* d, size_t len, lora::RxInfo& out) {
+    if (len < lora::kLoraTapSize || d[0] != 0) return false;
+    out.frequencyHz = static_cast<uint32_t>(d[4]) << 24 | d[5] << 16 | d[6] << 8 | d[7];
+    out.bandwidthKHz = d[8] * 125.0f;
+    out.spreadingFactor = d[9];
+    out.rssi = d[10] - 139.0f;
+    out.noiseFloor = d[12] - 139.0f;
+    out.snr = static_cast<int8_t>(d[13]) / 4.0f;
+    out.syncWord = d[14];
+    return true;
+}
+
+}  // namespace roro::files

lib/files/src/file_views.h

@@ -0,0 +1,57 @@
+#pragma once
+
+#include <cstddef>
+#include <cstdint>
+#include <string>
+#include <vector>
+
+#include "loratap.h"
+
+namespace roro::files {
+
+// What the Storage App's viewers show of the files the firmware writes (F1, Q134).
+
+// One row of a hex dump, eight bytes: "00010 4865 6c6c 6f2c 2077  Hello, w".
+std::string hexRow(uint32_t offset, const uint8_t* data, size_t len);
+
+// A Track (.gpx) read a piece at a time: its points, when it started and ended, how far it went.
+class GpxSummary {
+   public:
+    void feed(const char* data, size_t len);
+
+    uint32_t points() const { return points_; }
+    int64_t start() const { return first_; }  // UTC seconds, 0 if no point carried a time
+    int64_t end() const { return last_; }
+    double meters() const { return meters_; }
+    std::vector<std::string> lines() const;  // for the screen
+
+   private:
+    void point(const std::string& element);
+
+    std::string carry_;  // the part of a point cut by the end of a piece
+    uint32_t points_ = 0;
+    int64_t first_ = 0, last_ = 0;
+    double meters_ = 0, lat_ = 0, lon_ = 0;
+};
+
+// "1 h 02 min", "4 min 10 s", "12 s".
+std::string formatDuration(int64_t seconds);
+
+// A Capture (.pcap): the file's header, then one record after another.
+struct PcapHeader {
+    bool ok = false;
+    uint32_t linkType = 0;  // 270: LoRaTap, what the LoRa Scanner writes
+};
+constexpr size_t kPcapHeaderSize = 24, kPcapRecordSize = 16;
+constexpr uint32_t kLinkLoraTap = 270;
+PcapHeader parsePcapHeader(const uint8_t* data, size_t len);
+
+struct PcapRecord {
+    uint32_t seconds = 0, micros = 0, length = 0;  // length: the bytes that follow in the file
+};
+bool parsePcapRecord(const uint8_t* data, size_t len, PcapRecord& out);  // false: not a record, stop there
+
+// The LoRaTap header a packet starts with; false if `len` is too short for one.
+bool parseLoraTap(const uint8_t* data, size_t len, lora::RxInfo& out);
+
+}  // namespace roro::files

lib/files/src/text_pager.cpp

@@ -0,0 +1,121 @@
+#include "text_pager.h"
+
+#include <algorithm>
+
+namespace roro::files {
+
+TextPager::TextPager(ReadAt read, uint32_t size, int cols, int rows)
+    : read_(std::move(read)), size_(size), cols_(std::max(1, cols)), rows_(std::max(1, rows)) {}
+
+const uint8_t* TextPager::bytes(uint32_t at, size_t& len) {
+    len = 0;
+    if (at >= size_) return nullptr;
+    bool cached = at >= cacheAt_ && at < cacheAt_ + cache_.size();
+    // Wanted: a line's worth ahead, unless the cache already reaches the end of the file.
+    size_t ahead = cached ? cacheAt_ + cache_.size() - at : 0;
+    if (!cached || (ahead < kBlock / 4 && cacheAt_ + cache_.size() < size_)) {
+        cacheAt_ = at - std::min<uint32_t>(at, kBlock / 2);  // room behind too: scrolling back is common
+        cache_.resize(std::min<uint32_t>(kBlock, size_ - cacheAt_));
+        cache_.resize(read_(cacheAt_, cache_.data(), cache_.size()));
+        if (at >= cacheAt_ + cache_.size()) return nullptr;  // the file got shorter, or the card failed
+    }
+    len = cacheAt_ + cache_.size() - at;
+    return cache_.data() + (at - cacheAt_);
+}
+
+int TextPager::byteAt(uint32_t at) {
+    size_t len;
+    const uint8_t* p = bytes(at, len);
+    return p ? *p : -1;
+}
+
+uint32_t TextPager::nextLine(uint32_t at, std::string* text) {
+    size_t len;
+    const uint8_t* p = bytes(at, len);
+    if (text) text->clear();
+    if (!p) return size_;
+    size_t end = len, next = len;  // the line is [0, end); the one after starts at `next`
+    int count = 0;
+    size_t lastSpace = 0;
+    for (size_t i = 0; i < len; i++) {
+        uint8_t b = p[i];
+        if (b == '\n') {
+            end = i;
+            next = i + 1;
+            break;
+        }
+        if ((b & 0xC0) == 0x80) continue;  // inside a UTF-8 character
+        if (count == cols_) {              // one character too many: wrap
+            if (b == ' ') end = i, next = i + 1;
+            else if (lastSpace > 0) end = lastSpace, next = lastSpace + 1;
+            else end = next = i;
+            break;
+        }
+        count++;
+        if (b == ' ') lastSpace = i;
+    }
+    if (text) {
+        size_t n = end > 0 && p[end - 1] == '\r' ? end - 1 : end;
+        text->reserve(n);
+        for (size_t i = 0; i < n; i++) text->push_back(p[i] == '\t' ? ' ' : (p[i] < 0x20 || p[i] == 0x7F) ? '.' : static_cast<char>(p[i]));
+    }
+    return at + static_cast<uint32_t>(std::max<size_t>(next, 1));
+}
+
+uint32_t TextPager::lineBefore(uint32_t at) {
+    if (at == 0) return 0;
+    at = std::min(at, size_);
+    // The paragraph the line before `at` belongs to starts after the newline before it. The byte
+    // just before `at` may be that line's own newline.
+    uint32_t from = at - 1;
+    if (from > 0 && byteAt(from) == '\n') from--;
+    uint32_t limit = at > kLookBack ? at - kLookBack : 0, start = limit;
+    for (uint32_t i = from + 1; i-- > limit;) {
+        if (byteAt(i) == '\n' && i < at - 1) {
+            start = i + 1;
+            break;
+        }
+    }
+    // No newline that near: any character boundary will do as a place to wrap from.
+    while (start > 0 && start < at && (byteAt(start) & 0xC0) == 0x80) start++;
+    for (uint32_t a = start;;) {
+        uint32_t next = nextLine(a, nullptr);
+        if (next >= at) return a;
+        a = next;
+    }
+}
+
+bool TextPager::atEnd() {
+    uint32_t a = top_;
+    for (int i = 0; i < rows_; i++) {
+        a = nextLine(a, nullptr);
+        if (a >= size_) return true;
+    }
+    return false;
+}
+
+void TextPager::down(int n) {
+    for (; n > 0 && !atEnd(); n--) top_ = nextLine(top_, nullptr);
+}
+
+void TextPager::up(int n) {
+    for (; n > 0 && top_ > 0; n--) top_ = lineBefore(top_);
+}
+
+void TextPager::toEnd() {
+    top_ = size_;
+    up(rows_);
+}
+
+std::vector<std::string> TextPager::lines() {
+    std::vector<std::string> out;
+    uint32_t a = top_;
+    for (int i = 0; i < rows_ && a < size_; i++) {
+        std::string text;
+        a = nextLine(a, &text);
+        out.push_back(std::move(text));
+    }
+    return out;
+}
+
+}  // namespace roro::files

lib/files/src/text_pager.h

@@ -0,0 +1,50 @@
+#pragma once
+
+#include <cstddef>
+#include <cstdint>
+#include <functional>
+#include <string>
+#include <vector>
+
+namespace roro::files {
+
+// A text file of any size, shown a screen at a time (F1, Q134): only the part on screen is read,
+// through `read`, about a kilobyte at once. Lines wrap at spaces, `cols` characters wide. Going
+// back a line means finding where the paragraph before started and wrapping it again, so a file
+// reads the same whichever way it was scrolled.
+class TextPager {
+   public:
+    // Reads up to `len` bytes at `offset`; returns how many it got.
+    using ReadAt = std::function<size_t(uint32_t offset, uint8_t* into, size_t len)>;
+
+    TextPager(ReadAt read, uint32_t size, int cols, int rows);
+
+    void toStart() { top_ = 0; }
+    void toEnd();  // the last line at the bottom of the screen
+    void down(int lines = 1);
+    void up(int lines = 1);
+
+    std::vector<std::string> lines();  // what's on screen: tabs as spaces, control characters as dots
+    uint32_t top() const { return top_; }
+    uint32_t size() const { return size_; }
+    bool atEnd();  // the file's last line is on screen
+    int percent() const { return size_ ? static_cast<int>(static_cast<uint64_t>(top_) * 100 / size_) : 0; }
+
+   private:
+    static constexpr size_t kBlock = 1024;       // read at once
+    static constexpr uint32_t kLookBack = 1024;  // how far back a paragraph's start is looked for
+
+    const uint8_t* bytes(uint32_t at, size_t& len);  // what's cached from `at` on
+    int byteAt(uint32_t at);                         // -1 past the end
+    uint32_t nextLine(uint32_t at, std::string* text);  // where the line after the one at `at` starts
+    uint32_t lineBefore(uint32_t at);
+
+    ReadAt read_;
+    uint32_t size_;
+    int cols_, rows_;
+    uint32_t top_ = 0;
+    std::vector<uint8_t> cache_;
+    uint32_t cacheAt_ = 0;
+};
+
+}  // namespace roro::files

lib/gemini/src/gemini_response.cpp

@@ -0,0 +1,59 @@
+#include "gemini_response.h"
+
+#include <cctype>
+
+namespace roro::gemini {
+
+namespace {
+std::string trim(const std::string& s) {
+    size_t a = s.find_first_not_of(" \t"), b = s.find_last_not_of(" \t");
+    return a == std::string::npos ? "" : s.substr(a, b - a + 1);
+}
+std::string lower(std::string s) {
+    for (auto& c : s) c = static_cast<char>(std::tolower(static_cast<unsigned char>(c)));
+    return s;
+}
+}  // namespace
+
+bool parseHeader(const std::string& line, Header& out) {
+    if (line.size() < 2 || !std::isdigit(static_cast<unsigned char>(line[0])) ||
+        !std::isdigit(static_cast<unsigned char>(line[1])))
+        return false;
+    if (line.size() > 2 && line[2] != ' ') return false;
+    std::string meta = line.size() > 3 ? line.substr(3) : "";
+    if (meta.size() > 1024) return false;
+    out.status = (line[0] - '0') * 10 + (line[1] - '0');
+    out.meta = meta;
+    return true;
+}
+
+Category Header::category() const {
+    switch (status / 10) {
+        case 1: return Category::Input;
+        case 2: return Category::Success;
+        case 3: return Category::Redirect;
+        case 4: return Category::TemporaryFailure;
+        case 5: return Category::PermanentFailure;
+        case 6: return Category::ClientCertificate;
+        default: return Category::Unknown;
+    }
+}
+
+std::string Header::mimeType() const {
+    std::string type = lower(trim(meta.substr(0, meta.find(';'))));
+    return type.empty() ? "text/gemini" : type;
+}
+
+std::string Header::parameter(const std::string& name) const {
+    size_t pos = meta.find(';');
+    while (pos != std::string::npos) {
+        size_t next = meta.find(';', pos + 1);
+        std::string item = trim(meta.substr(pos + 1, next == std::string::npos ? std::string::npos : next - pos - 1));
+        size_t eq = item.find('=');
+        if (eq != std::string::npos && lower(trim(item.substr(0, eq))) == lower(name)) return trim(item.substr(eq + 1));
+        pos = next;
+    }
+    return "";
+}
+
+}  // namespace roro::gemini

lib/gemini/src/gemini_response.h

@@ -0,0 +1,23 @@
+#pragma once
+
+#include <string>
+
+namespace roro::gemini {
+
+enum class Category { Input, Success, Redirect, TemporaryFailure, PermanentFailure, ClientCertificate, Unknown };
+
+// The response header: "<two digits> <meta>", at most 1024 bytes of meta.
+struct Header {
+    int status = 0;
+    std::string meta;
+
+    Category category() const;
+    bool sensitiveInput() const { return status == 11; }
+    // 2x: the MIME type, lower-cased, without parameters ("text/gemini" when meta is empty).
+    std::string mimeType() const;
+    std::string parameter(const std::string& name) const;  // e.g. "charset"
+};
+
+bool parseHeader(const std::string& line, Header& out);
+
+}  // namespace roro::gemini

lib/gemini/src/gemini_url.cpp

@@ -0,0 +1,215 @@
+#include "gemini_url.h"
+
+#include <cctype>
+#include <cstdio>
+#include <cstdlib>
+#include <vector>
+
+#include "storage_paths.h"
+
+namespace roro::gemini {
+
+namespace {
+
+// RFC 3986, appendix B: ^(([^:/?#]+):)?(//([^/?#]*))?([^?#]*)(\?([^#]*))?(#(.*))?
+struct Parts {
+    std::string scheme, authority, path, query, fragment;
+    bool hasScheme = false, hasAuthority = false, hasQuery = false, hasFragment = false;
+};
+
+Parts split(const std::string& s) {
+    Parts p;
+    size_t i = 0;
+    size_t colon = s.find(':');
+    size_t stop = s.find_first_of("/?#");
+    if (colon != std::string::npos && colon > 0 && (stop == std::string::npos || colon < stop)) {
+        p.scheme = s.substr(0, colon);
+        p.hasScheme = true;
+        i = colon + 1;
+    }
+    if (s.compare(i, 2, "//") == 0) {
+        size_t end = s.find_first_of("/?#", i + 2);
+        if (end == std::string::npos) end = s.size();
+        p.authority = s.substr(i + 2, end - i - 2);
+        p.hasAuthority = true;
+        i = end;
+    }
+    size_t end = s.find_first_of("?#", i);
+    if (end == std::string::npos) end = s.size();
+    p.path = s.substr(i, end - i);
+    i = end;
+    if (i < s.size() && s[i] == '?') {
+        end = s.find('#', i);
+        if (end == std::string::npos) end = s.size();
+        p.query = s.substr(i + 1, end - i - 1);
+        p.hasQuery = true;
+        i = end;
+    }
+    if (i < s.size() && s[i] == '#') {
+        p.fragment = s.substr(i + 1);
+        p.hasFragment = true;
+    }
+    return p;
+}
+
+std::string lower(std::string s) {
+    for (auto& c : s) c = static_cast<char>(std::tolower(static_cast<unsigned char>(c)));
+    return s;
+}
+
+// RFC 3986, section 5.2.4.
+std::string removeDotSegments(std::string in) {
+    std::string out;
+    while (!in.empty()) {
+        if (in.compare(0, 3, "../") == 0) in.erase(0, 3);
+        else if (in.compare(0, 2, "./") == 0) in.erase(0, 2);
+        else if (in.compare(0, 3, "/./") == 0) in.replace(0, 3, "/");
+        else if (in == "/.") in = "/";
+        else if (in.compare(0, 4, "/../") == 0 || in == "/..") {
+            in = in == "/.." ? "/" : in.substr(3);
+            size_t slash = out.rfind('/');
+            out.erase(slash == std::string::npos ? 0 : slash);
+        } else if (in == "." || in == "..") in.clear();
+        else {
+            size_t next = in.find('/', in[0] == '/' ? 1 : 0);
+            if (next == std::string::npos) next = in.size();
+            out += in.substr(0, next);
+            in.erase(0, next);
+        }
+    }
+    return out;
+}
+
+// RFC 3986, section 5.2.3.
+std::string merge(const Parts& base, const std::string& refPath) {
+    if (base.hasAuthority && base.path.empty()) return "/" + refPath;
+    size_t slash = base.path.rfind('/');
+    return slash == std::string::npos ? refPath : base.path.substr(0, slash + 1) + refPath;
+}
+
+// RFC 3986, section 5.3.
+std::string recompose(const Parts& p) {
+    std::string out;
+    if (p.hasScheme) out += p.scheme + ":";
+    if (p.hasAuthority) out += "//" + p.authority;
+    out += p.path;
+    if (p.hasQuery) out += "?" + p.query;
+    if (p.hasFragment) out += "#" + p.fragment;
+    return out;
+}
+
+}  // namespace
+
+bool parseUrl(const std::string& text, Url& out) {
+    Parts p = split(text);
+    if (!p.hasScheme || !p.hasAuthority) return false;
+    out = Url();
+    out.scheme = lower(p.scheme);
+    out.authority = p.authority;
+    std::string hostPort = p.authority.substr(p.authority.find('@') == std::string::npos ? 0 : p.authority.find('@') + 1);
+    size_t colon = hostPort.rfind(':');
+    if (colon != std::string::npos && hostPort.find(']', colon) == std::string::npos) {
+        out.port = std::atoi(hostPort.c_str() + colon + 1);
+        hostPort = hostPort.substr(0, colon);
+    }
+    out.host = lower(hostPort);
+    if (out.host.empty()) return false;
+    out.path = p.path;
+    out.query = p.query;
+    out.fragment = p.fragment;
+    out.hasAuthority = true;
+    out.hasQuery = p.hasQuery;
+    out.hasFragment = p.hasFragment;
+    return true;
+}
+
+bool isGemini(const std::string& url) {
+    Parts p = split(url);
+    return p.hasScheme && lower(p.scheme) == "gemini";
+}
+
+std::string resolve(const std::string& baseText, const std::string& refText) {
+    Parts base = split(baseText), r = split(refText), t;
+    if (r.hasScheme) {
+        t = r;
+        t.path = removeDotSegments(r.path);
+    } else {
+        if (r.hasAuthority) {
+            t.authority = r.authority;
+            t.hasAuthority = true;
+            t.path = removeDotSegments(r.path);
+            t.query = r.query;
+            t.hasQuery = r.hasQuery;
+        } else {
+            if (r.path.empty()) {
+                t.path = base.path;
+                t.query = r.hasQuery ? r.query : base.query;
+                t.hasQuery = r.hasQuery || base.hasQuery;
+            } else {
+                t.path = removeDotSegments(r.path[0] == '/' ? r.path : merge(base, r.path));
+                t.query = r.query;
+                t.hasQuery = r.hasQuery;
+            }
+            t.authority = base.authority;
+            t.hasAuthority = base.hasAuthority;
+        }
+        t.scheme = base.scheme;
+        t.hasScheme = base.hasScheme;
+    }
+    t.fragment = r.fragment;
+    t.hasFragment = r.hasFragment;
+    return recompose(t);
+}
+
+std::string requestUrl(const std::string& url) {
+    Url u;
+    if (!parseUrl(url, u)) return url;
+    std::string out = u.scheme + "://" + u.host;
+    if (u.port > 0 && u.port != 1965) out += ":" + std::to_string(u.port);
+    out += u.path.empty() ? "/" : u.path;
+    if (u.hasQuery) out += "?" + u.query;
+    return out;
+}
+
+std::string encodeQuery(const std::string& text) {
+    std::string out;
+    for (unsigned char c : text) {
+        if (std::isalnum(c) || c == '-' || c == '_' || c == '.' || c == '~') out += static_cast<char>(c);
+        else {
+            char buf[4];
+            std::snprintf(buf, sizeof buf, "%%%02X", c);
+            out += buf;
+        }
+    }
+    return out;
+}
+
+std::string savedPath(const std::string& url) {
+    Url u;
+    if (!parseUrl(url, u)) return "/gemini/saved/unknown.gmi";
+    std::string out = "/gemini/saved/" + storage::sanitize(u.host + (u.port > 0 && u.port != 1965 ? "_" + std::to_string(u.port) : ""));
+    std::string path = u.path.empty() ? "/" : u.path;
+    std::vector<std::string> parts;
+    size_t start = 1;
+    while (start <= path.size()) {
+        size_t slash = path.find('/', start);
+        if (slash == std::string::npos) slash = path.size();
+        parts.push_back(path.substr(start, slash - start));
+        start = slash + 1;
+    }
+    if (parts.empty() || parts.back().empty()) {
+        if (!parts.empty()) parts.pop_back();
+        parts.push_back("index");
+    }
+    for (size_t i = 0; i < parts.size(); i++) {
+        std::string name = parts[i];
+        if (i + 1 == parts.size()) {
+            if (u.hasQuery) name += "~" + u.query;
+            if (name.size() < 4 || name.compare(name.size() - 4, 4, ".gmi") != 0) name += ".gmi";
+        }
+        out += "/" + storage::sanitize(name);
+    }
+    return out;
+}
+
+}  // namespace roro::gemini

lib/gemini/src/gemini_url.h

@@ -0,0 +1,28 @@
+#pragma once
+
+#include <string>
+
+namespace roro::gemini {
+
+// A URL split per RFC 3986 (appendix B). For Gemini, the host is lower-cased and the port
+// defaults to 1965.
+struct Url {
+    std::string scheme, authority, host, path, query, fragment;
+    int port = -1;
+    bool hasAuthority = false, hasQuery = false, hasFragment = false;
+    int portOrDefault() const { return port > 0 ? port : 1965; }
+};
+
+// False unless it has a scheme and a host: only absolute URLs are fetched.
+bool parseUrl(const std::string& text, Url& out);
+bool isGemini(const std::string& url);
+// `ref` against `base`, per RFC 3986 section 5.2 (dot segments included).
+std::string resolve(const std::string& base, const std::string& ref);
+// What goes on the wire: no fragment, lower-case host, never an empty path.
+std::string requestUrl(const std::string& url);
+// For input prompts: everything but unreserved characters percent-encoded (UTF-8 bytes).
+std::string encodeQuery(const std::string& text);
+// Where a Saved Page lives (Q82): /gemini/saved/<host>[_<port>]/<path>[~<query>].gmi
+std::string savedPath(const std::string& url);
+
+}  // namespace roro::gemini

lib/gemini/src/gemtext.cpp

@@ -0,0 +1,100 @@
+#include "gemtext.h"
+
+#include <cstdint>
+
+namespace roro::gemini {
+
+namespace {
+std::string trim(const std::string& s) {
+    size_t a = s.find_first_not_of(" \t"), b = s.find_last_not_of(" \t");
+    return a == std::string::npos ? "" : s.substr(a, b - a + 1);
+}
+}  // namespace
+
+GemLine parseGemLine(const std::string& line, bool& pre) {
+    GemLine g;
+    if (line.compare(0, 3, "```") == 0) {
+        g.type = LineType::PreToggle;
+        g.text = trim(line.substr(3));
+        pre = !pre;
+    } else if (pre) {
+        g.type = LineType::Preformatted;
+        g.text = line;
+    } else if (line.compare(0, 2, "=>") == 0) {
+        g.type = LineType::Link;
+        std::string rest = trim(line.substr(2));
+        size_t gap = rest.find_first_of(" \t");
+        g.url = rest.substr(0, gap);
+        g.text = gap == std::string::npos ? "" : trim(rest.substr(gap));
+        if (g.text.empty()) g.text = g.url;
+    } else if (line.compare(0, 3, "###") == 0) {
+        g.type = LineType::Heading3;
+        g.text = trim(line.substr(3));
+    } else if (line.compare(0, 2, "##") == 0) {
+        g.type = LineType::Heading2;
+        g.text = trim(line.substr(2));
+    } else if (line.compare(0, 1, "#") == 0) {
+        g.type = LineType::Heading1;
+        g.text = trim(line.substr(1));
+    } else if (line.compare(0, 2, "* ") == 0) {
+        g.type = LineType::ListItem;
+        g.text = trim(line.substr(2));
+    } else if (line.compare(0, 1, ">") == 0) {
+        g.type = LineType::Quote;
+        g.text = trim(line.substr(1));
+    } else {
+        g.text = line;
+    }
+    return g;
+}
+
+std::vector<GemLine> parseGemtext(const std::string& document) {
+    std::vector<GemLine> lines;
+    bool pre = false;
+    size_t start = 0;
+    while (start < document.size()) {
+        size_t end = document.find('\n', start);
+        if (end == std::string::npos) end = document.size();
+        std::string line = document.substr(start, end - start);
+        if (!line.empty() && line.back() == '\r') line.pop_back();
+        start = end + 1;
+        lines.push_back(parseGemLine(line, pre));
+    }
+    return lines;
+}
+
+std::string displayText(const std::string& s) {
+    std::string out;
+    size_t column = 0;
+    for (size_t i = 0; i < s.size();) {
+        unsigned char c = static_cast<unsigned char>(s[i]);
+        if (c == '\t') {
+            do out += ' ';
+            while (++column % 4);
+            i++;
+            continue;
+        }
+        if (c < 0x80) {
+            out += static_cast<char>(c);
+            i++;
+        } else {
+            int len = (c & 0xE0) == 0xC0 ? 2 : (c & 0xF0) == 0xE0 ? 3 : (c & 0xF8) == 0xF0 ? 4 : 0;
+            bool valid = len > 0 && i + len <= s.size();
+            for (int k = 1; valid && k < len; k++) valid = (static_cast<unsigned char>(s[i + k]) & 0xC0) == 0x80;
+            if (!valid) {
+                out += '?';
+                i++;
+            } else {
+                uint32_t cp = len == 2 ? (c & 0x1F) : len == 3 ? (c & 0x0F) : (c & 0x07);
+                for (int k = 1; k < len; k++) cp = (cp << 6) | (static_cast<unsigned char>(s[i + k]) & 0x3F);
+                if (cp <= 0xFF) out.append(s, i, len);  // Latin-1: the fonts have it
+                else out += '?';
+                i += len;
+            }
+        }
+        column++;
+    }
+    return out;
+}
+
+}  // namespace roro::gemini

lib/gemini/src/gemtext.h

@@ -0,0 +1,25 @@
+#pragma once
+
+#include <string>
+#include <vector>
+
+namespace roro::gemini {
+
+enum class LineType { Text, Link, Heading1, Heading2, Heading3, ListItem, Quote, PreToggle, Preformatted };
+
+// One gemtext line. Link: `url` and its label in `text` (the URL itself without a label).
+// PreToggle: the ``` line, with its alt text. Preformatted: kept exactly.
+struct GemLine {
+    LineType type = LineType::Text;
+    std::string text, url;
+};
+
+// One line; `preformatted` carries the ``` state from line to line (start with false).
+GemLine parseGemLine(const std::string& line, bool& preformatted);
+std::vector<GemLine> parseGemtext(const std::string& document);
+
+// For the Latin-1 fonts (Q79): valid UTF-8 up to U+00FF kept, anything else '?', and tabs
+// expanded to 4-column stops.
+std::string displayText(const std::string& utf8);
+
+}  // namespace roro::gemini

lib/gemini/src/text_buffer.cpp

@@ -0,0 +1,47 @@
+#include "text_buffer.h"
+
+#include <algorithm>
+
+namespace roro::gemini {
+
+void TextBuffer::append(const char* data, size_t len) {
+    bytes_ += len;
+    for (size_t i = 0; i < len; i++) {
+        if (data[i] == '\n') endLine();
+        else partial_ += data[i];
+    }
+}
+
+void TextBuffer::finish() {
+    if (!partial_.empty()) endLine();
+}
+
+void TextBuffer::endLine() {
+    if (!partial_.empty() && partial_.back() == '\r') partial_.pop_back();
+    size_t len = std::min<size_t>(partial_.size(), 0xFFFF);
+    // A line never spans two chunks: a new chunk when it doesn't fit (bigger if the line is).
+    if (chunks_.empty() || chunks_.back().size() + len > chunks_.back().capacity()) {
+        chunks_.emplace_back();
+        chunks_.back().reserve(std::max(kChunk, len));
+    }
+    std::string& chunk = chunks_.back();
+    lines_.push_back({static_cast<uint16_t>(chunks_.size() - 1), static_cast<uint16_t>(chunk.size()),
+                      static_cast<uint16_t>(len)});
+    chunk.append(partial_, 0, len);
+    partial_.clear();
+}
+
+std::string TextBuffer::line(size_t i) const {
+    if (i >= lines_.size()) return "";
+    const Ref& r = lines_[i];
+    return chunks_[r.chunk].substr(r.offset, r.length);
+}
+
+void TextBuffer::clear() {
+    chunks_.clear();
+    lines_.clear();
+    partial_.clear();
+    bytes_ = 0;
+}
+
+}  // namespace roro::gemini

lib/gemini/src/text_buffer.h

@@ -0,0 +1,38 @@
+#pragma once
+
+#include <cstddef>
+#include <cstdint>
+#include <string>
+#include <vector>
+
+namespace roro::gemini {
+
+// A page's text, kept as lines in 4 KB chunks: no large contiguous block (with IRC connected the
+// largest free block is about 31 KB) and no copy when it grows. About 4 bytes per line on top of
+// the text itself. Bytes are fed as they arrive; lines end at LF, a CR before it is dropped.
+class TextBuffer {
+   public:
+    static constexpr size_t kChunk = 4096;
+
+    void append(const char* data, size_t len);
+    void finish();  // the last line, if it has no line end
+    size_t lineCount() const { return lines_.size(); }
+    std::string line(size_t i) const;
+    size_t bytes() const { return bytes_; }
+    void clear();
+
+   private:
+    struct Ref {
+        uint16_t chunk;
+        uint16_t offset;
+        uint16_t length;
+    };
+    void endLine();
+
+    std::vector<std::string> chunks_;
+    std::vector<Ref> lines_;
+    std::string partial_;  // the line being received
+    size_t bytes_ = 0;
+};
+
+}  // namespace roro::gemini

lib/lora/src/loratap.cpp

@@ -0,0 +1,64 @@
+#include "loratap.h"
+
+#include <algorithm>
+#include <cmath>
+#include <cstdio>
+#include <ctime>
+
+namespace roro::lora {
+
+static void le16(std::vector<uint8_t>& o, uint16_t v) { o.insert(o.end(), {uint8_t(v), uint8_t(v >> 8)}); }
+static void le32(std::vector<uint8_t>& o, uint32_t v) {
+    o.insert(o.end(), {uint8_t(v), uint8_t(v >> 8), uint8_t(v >> 16), uint8_t(v >> 24)});
+}
+
+// LoRaTap's dBm encoding: -139 dBm plus the byte, clamped to what a byte holds.
+static uint8_t dbmByte(float dbm) {
+    long v = std::lround(dbm + 139);
+    return static_cast<uint8_t>(std::clamp(v, 0L, 255L));
+}
+
+std::string capturePath(int64_t utcSeconds) {
+    time_t t = static_cast<time_t>(utcSeconds);
+    struct tm u;
+    gmtime_r(&t, &u);
+    char buf[48];
+    std::snprintf(buf, sizeof buf, "/captures/lora/%04d%02d%02d-%02d%02d%02d.pcap", u.tm_year + 1900, u.tm_mon + 1,
+                  u.tm_mday, u.tm_hour, u.tm_min, u.tm_sec);
+    return buf;
+}
+
+void appendPcapHeader(std::vector<uint8_t>& out) {
+    le32(out, 0xA1B2C3D4);
+    le16(out, 2);
+    le16(out, 4);
+    le32(out, 0);      // time zone
+    le32(out, 0);      // timestamp accuracy
+    le32(out, 65535);  // snap length
+    le32(out, 270);    // LINKTYPE_LORATAP
+}
+
+void appendRecord(std::vector<uint8_t>& out, uint32_t seconds, uint32_t micros, const RxInfo& rx, const uint8_t* data,
+                  size_t len) {
+    uint32_t captured = static_cast<uint32_t>(kLoraTapSize + len);
+    le32(out, seconds);
+    le32(out, micros);
+    le32(out, captured);
+    le32(out, captured);
+
+    uint32_t f = rx.frequencyHz;
+    // The spec puts packet RSSI in quarter dB below 0 dB SNR (an SX127x formula), but Wireshark
+    // reads it as -139 dBm plus the byte either way, and the SX1262 already gives dBm.
+    uint8_t packetRssi = dbmByte(rx.rssi);
+    long snr = std::clamp(std::lround(rx.snr * 4), -128L, 127L);
+    out.insert(out.end(), {
+                              0, 0, 0, uint8_t(kLoraTapSize),  // version 0, padding, length
+                              uint8_t(f >> 24), uint8_t(f >> 16), uint8_t(f >> 8), uint8_t(f),
+                              uint8_t(std::lround(rx.bandwidthKHz / 125)), rx.spreadingFactor,
+                              packetRssi, dbmByte(rx.rssi), dbmByte(rx.noiseFloor),
+                              static_cast<uint8_t>(static_cast<int8_t>(snr)), rx.syncWord,
+                          });
+    if (len) out.insert(out.end(), data, data + len);
+}
+
+}  // namespace roro::lora

lib/lora/src/loratap.h

@@ -0,0 +1,33 @@
+#pragma once
+
+#include <cstddef>
+#include <cstdint>
+#include <string>
+#include <vector>
+
+namespace roro::lora {
+
+// What the radio knew about one received packet.
+struct RxInfo {
+    uint32_t frequencyHz = 0;
+    float bandwidthKHz = 0;
+    uint8_t spreadingFactor = 0;
+    float rssi = 0;        // dBm
+    float snr = 0;         // dB
+    float noiseFloor = 0;  // dBm, instantaneous RSSI just before the packet, when known
+    uint8_t syncWord = 0;
+};
+
+// A Capture file (M3, Q97): pcap with LoRaTap v0 headers (LINKTYPE_LORATAP, 270), which Wireshark
+// reads. pcap fields are little-endian, LoRaTap fields big-endian.
+void appendPcapHeader(std::vector<uint8_t>& out);
+void appendRecord(std::vector<uint8_t>& out, uint32_t seconds, uint32_t micros, const RxInfo& rx, const uint8_t* data,
+                  size_t len);
+
+// "/captures/lora/YYYYMMDD-HHMMSS.pcap" in UTC, dated like Tracks so Storage Clean-up can age it.
+std::string capturePath(int64_t utcSeconds);
+
+constexpr size_t kLoraTapSize = 15;
+constexpr size_t kRecordOverhead = 16 + kLoraTapSize;
+
+}  // namespace roro::lora

lib/lora/src/packet_view.cpp

@@ -0,0 +1,83 @@
+#include "packet_view.h"
+
+#include <cmath>
+#include <cstdio>
+
+#include "meshtastic_header.h"
+#include "meshtastic_presets.h"
+
+namespace roro::lora {
+
+using namespace meshtastic;
+
+std::string row(const PacketSummary& p, const std::string& time) {
+    char s[64];
+    int n = std::snprintf(s, sizeof s, "%s %ld %.1f ", time.c_str(), std::lround(p.rssi), p.snr);
+    std::string out(s, n);
+    PacketHeader h;
+    if (!p.crcOk) return out + "bad CRC, " + std::to_string(p.len) + " B";
+    if (!p.meshtastic || !parseHeader(p.data, p.len, h)) return out + std::to_string(p.len) + " B";
+    auto shortId = [](uint32_t node) {
+        if (node == kBroadcast) return std::string("all");
+        char id[8];
+        std::snprintf(id, sizeof id, "%04x", static_cast<unsigned>(node & 0xFFFF));
+        return std::string(id);
+    };
+    out += shortId(h.from) + ">" + shortId(h.to);
+    if (h.hopsAway() >= 0) out += " " + std::to_string(h.hopsAway()) + "/" + std::to_string(h.hopStart());
+    return out;
+}
+
+std::vector<std::string> hexDump(const uint8_t* data, size_t len) {
+    std::vector<std::string> lines;
+    for (size_t at = 0; at < len; at += 8) {
+        char s[48];
+        int n = std::snprintf(s, sizeof s, "%04x", static_cast<unsigned>(at));
+        std::string text;
+        for (size_t i = 0; i < 8; ++i) {
+            if (at + i < len) {
+                n += std::snprintf(s + n, sizeof s - n, " %02x", data[at + i]);
+                uint8_t b = data[at + i];
+                text += b >= 0x20 && b < 0x7F ? static_cast<char>(b) : '.';
+            } else {
+                n += std::snprintf(s + n, sizeof s - n, "   ");
+            }
+        }
+        lines.push_back(std::string(s, n) + " " + text);
+    }
+    return lines;
+}
+
+std::vector<std::string> headerLines(const uint8_t* data, size_t len) {
+    PacketHeader h;
+    if (!parseHeader(data, len, h)) return {};
+    char s[64];
+    std::vector<std::string> lines;
+    lines.push_back("From " + nodeId(h.from) + " to " + nodeId(h.to));
+    std::snprintf(s, sizeof s, "Packet %08x%s%s", static_cast<unsigned>(h.id), h.wantAck() ? ", wants an ack" : "",
+                  h.viaMqtt() ? ", via MQTT" : "");
+    lines.push_back(s);
+    if (h.hopsAway() >= 0)
+        std::snprintf(s, sizeof s, "Hops %d of %u, limit %u left", h.hopsAway(), h.hopStart(), h.hopLimit());
+    else
+        std::snprintf(s, sizeof s, "Hop limit %u left (old firmware)", h.hopLimit());
+    lines.push_back(s);
+    // Which preset's default Channel (named after it, with the public key) has this hash.
+    std::string channel;
+    for (size_t i = 0; i < kEu868PresetCount && channel.empty(); ++i)
+        if (channelHash(kEu868Presets[i].name, kDefaultKey, sizeof kDefaultKey) == h.channelHash)
+            channel = std::string(" (") + kEu868Presets[i].name + ", default key)";
+    std::snprintf(s, sizeof s, "Channel 0x%02x%s", h.channelHash, channel.c_str());
+    lines.push_back(s);
+    if (h.relayNode) {
+        std::snprintf(s, sizeof s, "Relayed by ..%02x", h.relayNode);
+        lines.push_back(s);
+    }
+    if (h.nextHop) {
+        std::snprintf(s, sizeof s, "Next hop ..%02x", h.nextHop);
+        lines.push_back(s);
+    }
+    return lines;
+}
+
+}  // namespace roro::lora

lib/lora/src/packet_view.h

@@ -0,0 +1,29 @@
+#pragma once
+
+#include <cstddef>
+#include <cstdint>
+#include <string>
+#include <vector>
+
+namespace roro::lora {
+
+// What the LoRa Scanner shows of one packet (M3, Q96).
+struct PacketSummary {
+    const uint8_t* data;
+    size_t len;
+    float rssi, snr;
+    bool crcOk;
+    bool meshtastic;  // received on Meshtastic settings (sync word 0x2B): read its clear header
+};
+
+// One list row, at most about 36 characters: "21:45:07 -97 6.2 5678>all 1/3". Nodes by their default
+// short name (the last 4 hex digits); headerLines() has the full numbers.
+std::string row(const PacketSummary& p, const std::string& time);
+
+// Eight bytes a line, with the printable ones: "0000 ff ff ff ff 78 56 34 12 ....xV4.".
+std::vector<std::string> hexDump(const uint8_t* data, size_t len);
+
+// The Meshtastic header, one field a line; empty when the packet is too short to have one.
+std::vector<std::string> headerLines(const uint8_t* data, size_t len);
+
+}  // namespace roro::lora

lib/lora/src/sweep_view.cpp

@@ -0,0 +1,48 @@
+#include "sweep_view.h"
+
+#include <algorithm>
+
+namespace roro::lora {
+
+namespace {
+constexpr int kPeakAboveFloorDb = 10;
+constexpr size_t kMaxPeaks = 3;
+}  // namespace
+
+SweepStats summarize(const int8_t* dbm, size_t steps, uint32_t fromHz, uint32_t stepHz) {
+    SweepStats s;
+    if (!steps) return s;
+    std::vector<int8_t> sorted(dbm, dbm + steps);
+    std::nth_element(sorted.begin(), sorted.begin() + steps / 2, sorted.end());
+    s.floor = sorted[steps / 2];
+    s.top = *std::max_element(dbm, dbm + steps);
+    for (size_t i = 0; i < steps; ++i) {
+        int v = dbm[i];
+        bool localMax = (i == 0 || v >= dbm[i - 1]) && (i + 1 == steps || v > dbm[i + 1]);
+        if (localMax && v >= s.floor + kPeakAboveFloorDb) s.peaks.push_back({fromHz + static_cast<uint32_t>(i) * stepHz, v});
+    }
+    std::stable_sort(s.peaks.begin(), s.peaks.end(), [](const SweepPeak& a, const SweepPeak& b) { return a.dbm > b.dbm; });
+    if (s.peaks.size() > kMaxPeaks) s.peaks.resize(kMaxPeaks);
+    return s;
+}
+
+uint8_t heatLevel(int dbm, int low, int high) {
+    if (dbm <= low) return 0;
+    if (dbm >= high) return 255;
+    return static_cast<uint8_t>((dbm - low) * 255 / (high - low) + ((dbm - low) * 255 % (high - low) ? 1 : 0));
+}
+
+uint16_t heatColor(uint8_t level) {
+    // Five segments of 51 steps each.
+    auto rgb = [](int r, int g, int b) { return static_cast<uint16_t>((r >> 3) << 11 | (g >> 2) << 5 | (b >> 3)); };
+    int seg = std::min(level / 51, 4), t = (level - seg * 51) * 255 / 51;
+    switch (seg) {
+        case 0: return rgb(0, 0, t);              // black to blue
+        case 1: return rgb(0, t, 255);            // blue to cyan
+        case 2: return rgb(0, 255, 255 - t);      // cyan to green
+        case 3: return rgb(t, 255, 0);            // green to yellow
+        default: return rgb(255, 255 - t, 0);     // yellow to red
+    }
+}
+
+}  // namespace roro::lora

lib/lora/src/sweep_view.h

@@ -0,0 +1,27 @@
+#pragma once
+
+#include <cstddef>
+#include <cstdint>
+#include <vector>
+
+namespace roro::lora {
+
+// What a Sweep pass says about the band (M3, Q98): one RSSI reading (dBm) per step.
+struct SweepPeak {
+    uint32_t hz;
+    int dbm;
+};
+struct SweepStats {
+    int floor = 0;  // the median: the band's noise floor, whatever a few signals do
+    int top = 0;    // the strongest reading
+    std::vector<SweepPeak> peaks;  // at most 3, strongest first, each a local maximum >= 10 dB above the floor
+};
+
+SweepStats summarize(const int8_t* dbm, size_t steps, uint32_t fromHz, uint32_t stepHz);
+
+// The waterfall's colours: a reading between `low` and `high` dBm as 0..255, then RGB565 along
+// black, blue, cyan, green, yellow, red.
+uint8_t heatLevel(int dbm, int low, int high);
+uint16_t heatColor(uint8_t level);
+
+}  // namespace roro::lora

lib/meshtastic/src/meshtastic_header.cpp

@@ -0,0 +1,28 @@
+#include "meshtastic_header.h"
+
+#include <cstdio>
+
+namespace roro::meshtastic {
+
+static uint32_t le32(const uint8_t* p) { return p[0] | p[1] << 8 | p[2] << 16 | static_cast<uint32_t>(p[3]) << 24; }
+
+bool parseHeader(const uint8_t* data, size_t len, PacketHeader& out) {
+    if (!data || len < kHeaderSize) return false;
+    out.to = le32(data);
+    out.from = le32(data + 4);
+    out.id = le32(data + 8);
+    out.flags = data[12];
+    out.channelHash = data[13];
+    out.nextHop = data[14];
+    out.relayNode = data[15];
+    return true;
+}
+
+std::string nodeId(uint32_t node) {
+    if (node == kBroadcast) return "all";
+    char s[10];
+    std::snprintf(s, sizeof s, "!%08x", static_cast<unsigned>(node));
+    return s;
+}
+
+}  // namespace roro::meshtastic

lib/meshtastic/src/meshtastic_header.h

@@ -0,0 +1,36 @@
+#pragma once
+
+#include <cstddef>
+#include <cstdint>
+#include <string>
+
+namespace roro::meshtastic {
+
+constexpr uint32_t kBroadcast = 0xFFFFFFFF;
+
+// The 16 bytes every Meshtastic packet starts with, sent in clear (little-endian). The payload
+// after it is encrypted with the Channel's key.
+struct PacketHeader {
+    uint32_t to = 0, from = 0, id = 0;
+    uint8_t flags = 0;
+    uint8_t channelHash = 0;  // the Channel's name and key folded into a byte (see channelHash())
+    uint8_t nextHop = 0;      // last byte of the Node meant to relay it next; 0 when flooding
+    uint8_t relayNode = 0;    // last byte of the Node that relayed it to us
+
+    uint8_t hopLimit() const { return flags & 0x07; }
+    bool wantAck() const { return flags & 0x08; }
+    bool viaMqtt() const { return flags & 0x10; }
+    uint8_t hopStart() const { return flags >> 5; }
+    bool broadcast() const { return to == kBroadcast; }
+    // How many times it was relayed before we heard it; -1 when the sender didn't say (hop start 0).
+    int hopsAway() const { return hopStart() == 0 ? -1 : hopStart() - hopLimit(); }
+};
+
+constexpr size_t kHeaderSize = 16;
+
+bool parseHeader(const uint8_t* data, size_t len, PacketHeader& out);
+
+// "!12345678", as Meshtastic writes node numbers; "all" for broadcast.
+std::string nodeId(uint32_t node);
+
+}  // namespace roro::meshtastic

lib/meshtastic/src/meshtastic_presets.cpp

@@ -0,0 +1,47 @@
+#include "meshtastic_presets.h"
+
+#include <cmath>
+#include <cstring>
+
+namespace roro::meshtastic {
+
+const uint8_t kDefaultKey[16] = {0xd4, 0xf1, 0xbb, 0x3a, 0x20, 0x29, 0x07, 0x59,
+                                 0xf0, 0xbc, 0xff, 0xab, 0xcf, 0x4e, 0x69, 0x01};
+
+// firmware src/mesh/MeshRadio.h (modemPresetToParams) and RadioInterface.cpp (PRESETS_EU_868).
+const Preset kEu868Presets[] = {
+    {"LongFast", 250, 11, 5},  {"LongSlow", 125, 12, 8},  {"MediumSlow", 250, 10, 5}, {"MediumFast", 250, 9, 5},
+    {"ShortSlow", 250, 8, 5},  {"ShortFast", 250, 7, 5},  {"LongMod", 125, 11, 8},
+};
+const size_t kEu868PresetCount = sizeof kEu868Presets / sizeof kEu868Presets[0];
+
+const Preset* findPreset(const char* name) {
+    for (const Preset& p : kEu868Presets)
+        if (std::strcmp(p.name, name) == 0) return &p;
+    return nullptr;
+}
+
+uint32_t djb2(const char* s) {
+    uint32_t h = 5381;
+    for (; *s; ++s) h = (h << 5) + h + static_cast<unsigned char>(*s);
+    return h;
+}
+
+uint8_t channelHash(const char* name, const uint8_t* key, size_t keyLen) {
+    uint8_t h = 0;
+    for (; *name; ++name) h ^= static_cast<uint8_t>(*name);
+    for (size_t i = 0; i < keyLen; ++i) h ^= key[i];
+    return h;
+}
+
+uint32_t eu868FrequencyHz(const Preset& preset, const char* channelName) {
+    constexpr double kStartMHz = 869.4, kEndMHz = 869.65;
+    double slotMHz = preset.bwKHz / 1000.0;
+    uint32_t slots = static_cast<uint32_t>(std::lround((kEndMHz - kStartMHz) / slotMHz));
+    const char* name = channelName && *channelName ? channelName : preset.name;
+    uint32_t slot = slots ? djb2(name) % slots : 0;
+    double mhz = kStartMHz + slotMHz / 2 + slot * slotMHz;
+    return static_cast<uint32_t>(std::lround(mhz * 1e6));
+}
+
+}  // namespace roro::meshtastic

lib/meshtastic/src/meshtastic_presets.h

@@ -0,0 +1,38 @@
+#pragma once
+
+#include <cstddef>
+#include <cstdint>
+
+namespace roro::meshtastic {
+
+// Radio settings shared by every Meshtastic preset (firmware src/mesh/RadioInterface.h).
+constexpr uint8_t kSyncWord = 0x2B;
+constexpr uint16_t kPreambleLength = 16;
+
+// The default Channel key ("AQ==", expanded): public, so the default Channel is readable by anyone.
+extern const uint8_t kDefaultKey[16];
+
+// A modem preset: bandwidth, spreading factor and coding rate (4/cr). Named as Meshtastic shows them.
+struct Preset {
+    const char* name;
+    float bwKHz;
+    uint8_t sf;
+    uint8_t cr;
+};
+
+// The presets Meshtastic allows in EU_868, its order, LongFast (the default) first.
+extern const Preset kEu868Presets[];
+extern const size_t kEu868PresetCount;
+const Preset* findPreset(const char* name);  // nullptr when EU_868 doesn't allow it
+
+// djb2, as Meshtastic hashes a Channel's name to pick a frequency slot.
+uint32_t djb2(const char* s);
+
+// The byte in every packet header naming its Channel: the name's bytes XORed with the key's.
+uint8_t channelHash(const char* name, const uint8_t* key, size_t keyLen);
+
+// EU_868 is 869.4 to 869.65 MHz: the slot comes from the Channel's name (the preset's name for
+// an unnamed Channel, which is the default).
+uint32_t eu868FrequencyHz(const Preset& preset, const char* channelName = nullptr);
+
+}  // namespace roro::meshtastic

lib/net/src/ipv4.cpp

@@ -0,0 +1,97 @@
+#include "ipv4.h"
+
+#include <cstdio>
+
+namespace roro::net {
+
+bool parseIpv4(const std::string& text, uint32_t& out) {
+    uint32_t value = 0;
+    int parts = 0, digits = 0, part = 0;
+    for (char c : text) {
+        if (c >= '0' && c <= '9') {
+            if (++digits > 3) return false;
+            part = part * 10 + (c - '0');
+            if (part > 255) return false;
+        } else if (c == '.') {
+            if (digits == 0 || ++parts > 3) return false;
+            value = value << 8 | part;
+            part = digits = 0;
+        } else {
+            return false;
+        }
+    }
+    if (digits == 0 || parts != 3) return false;
+    out = value << 8 | part;
+    return true;
+}
+
+std::string formatIpv4(uint32_t a) {
+    char s[16];
+    std::snprintf(s, sizeof s, "%u.%u.%u.%u", static_cast<unsigned>(a >> 24), static_cast<unsigned>(a >> 16 & 255),
+                  static_cast<unsigned>(a >> 8 & 255), static_cast<unsigned>(a & 255));
+    return s;
+}
+
+uint32_t maskOf(int prefix) { return prefix <= 0 ? 0 : prefix >= 32 ? 0xFFFFFFFFu : ~0u << (32 - prefix); }
+
+std::string checkFixed(const FixedIp& f) {
+    if (f.prefix < 1 || f.prefix > 30) return "The prefix must be 1 to 30";
+    if (f.address == 0) return "0.0.0.0 isn't an address a device can have";
+    uint32_t mask = maskOf(f.prefix), network = f.address & mask, broadcast = network | ~mask;
+    if (f.address == network) return formatIpv4(f.address) + " is the network's own address";
+    if (f.address == broadcast) return formatIpv4(f.address) + " is the broadcast address";
+    if (f.gateway == 0) return "";
+    if (f.gateway == f.address) return "The gateway can't be this device's address";
+    if ((f.gateway & mask) != network)
+        return "The gateway " + formatIpv4(f.gateway) + " isn't in " + formatIpv4(network) + "/" + std::to_string(f.prefix);
+    if (f.gateway == broadcast) return "The gateway " + formatIpv4(f.gateway) + " is the broadcast address";
+    if (f.gateway == network) return "The gateway " + formatIpv4(f.gateway) + " is the network's own address";
+    return "";
+}
+
+std::string parseFixed(const std::string& text, FixedIp& out) {
+    size_t slash = text.find('/');
+    if (slash == std::string::npos) return "Write it as address/prefix, then the gateway if there is one";
+    size_t space = text.find(' ', slash);
+    std::string address = text.substr(0, slash);
+    std::string prefix = text.substr(slash + 1, space == std::string::npos ? std::string::npos : space - slash - 1);
+    std::string gateway = space == std::string::npos ? "" : text.substr(space + 1);
+    FixedIp f;
+    if (!parseIpv4(address, f.address)) return address + " isn't an IPv4 address";
+    int p = 0;
+    if (prefix.empty() || prefix.size() > 2) return "The prefix must be 1 to 30";
+    for (char c : prefix) {
+        if (c < '0' || c > '9') return "The prefix must be 1 to 30";
+        p = p * 10 + (c - '0');
+    }
+    f.prefix = static_cast<uint8_t>(p);
+    if (!gateway.empty() && !parseIpv4(gateway, f.gateway)) return gateway + " isn't an IPv4 address";
+    std::string why = checkFixed(f);
+    if (why.empty()) out = f;
+    return why;
+}
+
+std::string formatFixed(const FixedIp& f) {
+    std::string s = formatIpv4(f.address) + "/" + std::to_string(f.prefix);
+    if (f.gateway) s += " " + formatIpv4(f.gateway);
+    return s;
+}
+
+bool validHost(const std::string& text) {
+    if (text.empty() || text.size() > 63) return false;
+    uint32_t ignored;
+    if (parseIpv4(text, ignored)) return true;
+    bool allNumeric = true;  // digits and dots only, but not an address: "1.2.3", "999.1.1.1"
+    char previous = '.';
+    for (char c : text) {
+        bool letter = (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'), digit = c >= '0' && c <= '9';
+        if (!letter && !digit && c != '-' && c != '.') return false;
+        if (c == '.' && (previous == '.' || previous == '-')) return false;  // empty label, or one ending in '-'
+        if (c == '-' && previous == '.') return false;                       // a label starting with '-'
+        if (letter || c == '-') allNumeric = false;
+        previous = c;
+    }
+    return previous != '.' && previous != '-' && !allNumeric;
+}
+
+}  // namespace roro::net

lib/net/src/ipv4.h

@@ -0,0 +1,30 @@
+#pragma once
+
+#include <cstdint>
+#include <string>
+
+namespace roro::net {
+
+// IPv4 addresses as 32-bit numbers, most significant byte first: 10.39.39.12 is 0x0A27270C.
+bool parseIpv4(const std::string& text, uint32_t& out);  // strict: four decimal numbers, 0 to 255
+std::string formatIpv4(uint32_t address);
+uint32_t maskOf(int prefix);  // 24 -> 255.255.255.0
+
+// A Saved Network's Fixed setting (S1, Q105 to Q107). gateway 0: none.
+struct FixedIp {
+    uint32_t address = 0;
+    uint8_t prefix = 24;
+    uint32_t gateway = 0;
+};
+
+// "" when a device can use it, otherwise why not, for a human (Q111).
+std::string checkFixed(const FixedIp& f);
+
+// "address/prefix [gateway]", as typed on the console and kept in flash. parseFixed() also checks.
+std::string parseFixed(const std::string& text, FixedIp& out);
+std::string formatFixed(const FixedIp& f);
+
+// An IPv4 address or a host name, as an NTP server may be (Q110).
+bool validHost(const std::string& text);
+
+}  // namespace roro::net

lib/net/src/traffic.cpp

@@ -0,0 +1,46 @@
+#include "traffic.h"
+
+#include <atomic>
+#include <cstdio>
+
+namespace roro::net {
+
+namespace {
+constexpr size_t kUsers = static_cast<size_t>(User::Count);
+std::atomic<uint32_t> in_[kUsers], out_[kUsers];
+}  // namespace
+
+const char* userName(User user) {
+    switch (user) {
+        case User::Irc: return "IRC";
+        case User::Gemini: return "Gemini";
+        case User::DebugConsole: return "Debug Console";
+        case User::Updates: return "Updates";
+        default: return "?";
+    }
+}
+
+void received(User user, size_t bytes) { in_[static_cast<size_t>(user)] += static_cast<uint32_t>(bytes); }
+void sent(User user, size_t bytes) { out_[static_cast<size_t>(user)] += static_cast<uint32_t>(bytes); }
+Traffic traffic(User user) { return {in_[static_cast<size_t>(user)], out_[static_cast<size_t>(user)]}; }
+
+void resetTraffic() {
+    for (size_t i = 0; i < kUsers; i++) in_[i] = out_[i] = 0;
+}
+
+uint32_t bytesPerSecond(uint32_t before, uint32_t now, uint32_t elapsedMs) {
+    if (!elapsedMs) return 0;
+    return static_cast<uint32_t>(static_cast<uint64_t>(now - before) * 1000 / elapsedMs);  // wraps with the counter
+}
+
+std::string formatTraffic(uint32_t bytes) {
+    char s[16];
+    if (bytes < 1000) std::snprintf(s, sizeof s, "%u B", static_cast<unsigned>(bytes));
+    else if (bytes < 10 * 1024) std::snprintf(s, sizeof s, "%.1f KB", bytes / 1024.0);
+    else if (bytes < 1000 * 1024) std::snprintf(s, sizeof s, "%u KB", static_cast<unsigned>(bytes / 1024));
+    else if (bytes < 10u * 1024 * 1024) std::snprintf(s, sizeof s, "%.1f MB", bytes / 1048576.0);
+    else std::snprintf(s, sizeof s, "%u MB", static_cast<unsigned>(bytes / 1048576));
+    return s;
+}
+
+}  // namespace roro::net

lib/net/src/traffic.h

@@ -0,0 +1,26 @@
+#pragma once
+
+#include <cstddef>
+#include <cstdint>
+#include <string>
+
+namespace roro::net {
+
+// Bytes each network service has read and written since boot (S1, Q121), as the service sees
+// them: for TLS connections that's the plain text, without the handshake or record overhead.
+// Counted from the services' own tasks, read from the main loop.
+enum class User : uint8_t { Irc, Gemini, DebugConsole, Updates, Count };
+const char* userName(User user);
+
+struct Traffic {
+    uint32_t in = 0, out = 0;
+};
+void received(User user, size_t bytes);
+void sent(User user, size_t bytes);
+Traffic traffic(User user);
+void resetTraffic();  // for tests
+
+uint32_t bytesPerSecond(uint32_t before, uint32_t now, uint32_t elapsedMs);
+std::string formatTraffic(uint32_t bytes);  // "999 B", "1.5 KB", "12 KB", "1.7 MB"
+
+}  // namespace roro::net

lib/notes/src/note_text.cpp

@@ -0,0 +1,329 @@
+#include "note_text.h"
+
+#include <algorithm>
+
+namespace roro::notes {
+
+namespace {
+bool continuation(char c) { return (static_cast<uint8_t>(c) & 0xC0) == 0x80; }
+}  // namespace
+
+NoteText::NoteText(int cols, int rows) : cols_(std::max(1, cols)), rows_(std::max(1, rows)) { text_.reserve(kMaxBytes); }
+
+NoteText::NoteText(int cols, int rows, std::string&& text) : cols_(std::max(1, cols)), rows_(std::max(1, rows)), text_(std::move(text)) {
+    dropCarriageReturns();
+    if (text_.size() > kMaxBytes) text_.resize(kMaxBytes);  // the caller checks sizes: not reached
+    text_.reserve(kMaxBytes);
+}
+
+void NoteText::dropCarriageReturns() {
+    size_t kept = 0;
+    for (size_t i = 0; i < text_.size(); i++)
+        if (!(text_[i] == '\r' && i + 1 < text_.size() && text_[i + 1] == '\n')) text_[kept++] = text_[i];
+    text_.resize(kept);
+}
+
+bool NoteText::setText(const std::string& text) {
+    size_t kept = text.size();
+    for (size_t i = 0; i + 1 < text.size(); i++)
+        if (text[i] == '\r' && text[i + 1] == '\n') kept--;
+    if (kept > kMaxBytes) return false;
+    text_.assign(text);
+    dropCarriageReturns();
+    cursor_ = top_ = 0;
+    goal_ = -1;
+    revision_++;
+    return true;
+}
+
+size_t NoteText::nextLine(size_t start) const {
+    size_t size = text_.size();
+    int count = 0;
+    size_t lastSpace = 0;
+    bool space = false;
+    for (size_t i = start; i < size; i++) {
+        char c = text_[i];
+        if (c == '\n') return i + 1;
+        if (continuation(c)) continue;
+        if (count == cols_) {  // one character too many: wrap
+            if (c == ' ') return i + 1;       // the space stays at the end of this line
+            if (space) return lastSpace + 1;  // after the last space that fits
+            return i;                         // a word longer than the screen is cut
+        }
+        count++;
+        if (c == ' ') {
+            lastSpace = i;
+            space = true;
+        }
+    }
+    return size;
+}
+
+size_t NoteText::lineOf(size_t pos) const {
+    size_t size = text_.size();
+    pos = std::min(pos, size);
+    size_t a = pos;  // the start of the paragraph: after the newline before `pos`
+    while (a > 0 && text_[a - 1] != '\n') a--;
+    while (a < size) {
+        size_t n = nextLine(a);
+        if (n > pos) return a;
+        // The end of the text is on the last line, unless that line ended with a newline: then
+        // it's on an empty line of its own.
+        if (n == size && pos == size && text_[size - 1] != '\n') return a;
+        a = n;
+    }
+    return a;
+}
+
+bool NoteText::hasLineAfter(size_t start) const {
+    size_t n = nextLine(start), size = text_.size();
+    if (n < size) return true;
+    return start < size && lineOf(size) != start;  // the empty line after a final newline
+}
+
+size_t NoteText::lastSpot(size_t start) const {
+    size_t n = nextLine(start), size = text_.size();
+    if (n == start) return start;  // the empty line at the end
+    if (n == size && lineOf(size) == start) return size;
+    size_t p = n - 1;  // before the newline, the space or the last character the line ends with
+    while (p > start && continuation(text_[p])) p--;
+    return p;
+}
+
+int NoteText::columnOf(size_t start, size_t pos) const {
+    int col = 0;
+    for (size_t i = start; i < pos && i < text_.size(); i++)
+        if (!continuation(text_[i])) col++;
+    return col;
+}
+
+size_t NoteText::atColumn(size_t start, int col) const {
+    size_t last = lastSpot(start), p = start;
+    while (p < last && col > 0) {
+        p++;
+        while (p < last && continuation(text_[p])) p++;
+        col--;
+    }
+    return p;
+}
+
+void NoteText::moved(bool keepGoal) {
+    if (!keepGoal) goal_ = -1;
+}
+
+bool NoteText::insertText(const std::string& s) {
+    if (text_.size() + s.size() > kMaxBytes) return false;
+    text_.insert(cursor_, s);
+    cursor_ += s.size();
+    revision_++;
+    moved();
+    return true;
+}
+
+bool NoteText::insert(uint32_t cp) {
+    std::string s;
+    if (cp < 0x80) s += static_cast<char>(cp);
+    else if (cp < 0x800) {
+        s += static_cast<char>(0xC0 | (cp >> 6));
+        s += static_cast<char>(0x80 | (cp & 0x3F));
+    } else if (cp < 0x10000) {
+        s += static_cast<char>(0xE0 | (cp >> 12));
+        s += static_cast<char>(0x80 | ((cp >> 6) & 0x3F));
+        s += static_cast<char>(0x80 | (cp & 0x3F));
+    } else {
+        s += static_cast<char>(0xF0 | (cp >> 18));
+        s += static_cast<char>(0x80 | ((cp >> 12) & 0x3F));
+        s += static_cast<char>(0x80 | ((cp >> 6) & 0x3F));
+        s += static_cast<char>(0x80 | (cp & 0x3F));
+    }
+    return insertText(s);
+}
+
+void NoteText::backspace() {
+    if (cursor_ == 0) return;
+    size_t from = cursor_ - 1;
+    while (from > 0 && continuation(text_[from])) from--;
+    text_.erase(from, cursor_ - from);
+    cursor_ = from;
+    revision_++;
+    moved();
+}
+
+void NoteText::left() {
+    if (cursor_ == 0) return;
+    cursor_--;
+    while (cursor_ > 0 && continuation(text_[cursor_])) cursor_--;
+    moved();
+}
+
+void NoteText::right() {
+    if (cursor_ >= text_.size()) return;
+    cursor_++;
+    while (cursor_ < text_.size() && continuation(text_[cursor_])) cursor_++;
+    moved();
+}
+
+void NoteText::up() {
+    size_t line = lineOf(cursor_);
+    if (goal_ < 0) goal_ = columnOf(line, cursor_);
+    if (line == 0) return;
+    cursor_ = atColumn(lineOf(line - 1), goal_);
+    moved(true);
+}
+
+void NoteText::down() {
+    size_t line = lineOf(cursor_);
+    if (goal_ < 0) goal_ = columnOf(line, cursor_);
+    if (!hasLineAfter(line)) return;
+    size_t next = nextLine(line);
+    cursor_ = next >= text_.size() ? text_.size() : atColumn(next, goal_);
+    moved(true);
+}
+
+void NoteText::pageUp() {
+    for (int i = 1; i < rows_; i++) up();
+}
+
+void NoteText::pageDown() {
+    for (int i = 1; i < rows_; i++) down();
+}
+
+void NoteText::lineStart() {
+    cursor_ = lineOf(cursor_);
+    moved();
+}
+
+void NoteText::lineEnd() {
+    cursor_ = lastSpot(lineOf(cursor_));
+    moved();
+}
+
+void NoteText::toStart() {
+    cursor_ = 0;
+    moved();
+}
+
+void NoteText::toEnd() {
+    cursor_ = text_.size();
+    moved();
+}
+
+void NoteText::follow() {
+    size_t line = lineOf(cursor_);
+    top_ = lineOf(std::min(top_, text_.size()));  // an edit above may have moved where lines start
+    if (line < top_) {
+        top_ = line;
+        return;
+    }
+    size_t a = top_;
+    for (int i = 0; i < rows_; i++) {
+        if (a == line) return;  // on screen
+        if (!hasLineAfter(a)) return;
+        a = nextLine(a);
+    }
+    // Below the screen: the cursor's line becomes the last row.
+    top_ = line;
+    for (int i = 1; i < rows_ && top_ > 0; i++) top_ = lineOf(top_ - 1);
+}
+
+std::vector<std::string> NoteText::rows() {
+    follow();
+    std::vector<std::string> out;
+    size_t a = top_, size = text_.size();
+    for (int i = 0; i < rows_; i++) {
+        size_t n = nextLine(a);
+        std::string row = text_.substr(a, n - a);
+        if (!row.empty() && row.back() == '\n') row.pop_back();
+        for (char& c : row)
+            if (c == '\t') c = ' ';
+        out.push_back(std::move(row));
+        if (!hasLineAfter(a)) break;
+        a = n >= size ? size : n;
+    }
+    return out;
+}
+
+int NoteText::cursorRow() {
+    follow();
+    size_t line = lineOf(cursor_), a = top_;
+    for (int i = 0; i < rows_; i++) {
+        if (a == line) return i;
+        a = nextLine(a);
+    }
+    return rows_ - 1;
+}
+
+int NoteText::cursorCol() { return columnOf(lineOf(cursor_), cursor_); }
+
+// At most a screen's worth of it: a note that is one line of 16 KB must not be copied whole.
+std::string NoteText::firstLine() const { return text_.substr(0, std::min<size_t>(text_.find('\n'), 160)); }
+
+namespace {
+// U+00C0 to U+00FF as the plain letters a file name gets; 0: left out.
+const char kPlain[64] = {
+    'a', 'a', 'a', 'a', 'a', 'a', 0,   'c', 'e', 'e', 'e', 'e', 'i', 'i', 'i', 'i',   // À..Ï
+    0,   'n', 'o', 'o', 'o', 'o', 'o', 0,   'o', 'u', 'u', 'u', 'u', 'y', 0,   's',   // Ð..ß
+    'a', 'a', 'a', 'a', 'a', 'a', 0,   'c', 'e', 'e', 'e', 'e', 'i', 'i', 'i', 'i',   // à..ï
+    0,   'n', 'o', 'o', 'o', 'o', 'o', 0,   'o', 'u', 'u', 'u', 'u', 'y', 0,   'y'};  // ð..ÿ
+
+// Drops a character the end of the string cuts in two.
+void dropPartial(std::string& s) {
+    size_t k = s.size();
+    while (k > 0 && continuation(s[k - 1]) && s.size() - k < 3) k--;
+    if (k == 0) return;
+    uint8_t lead = static_cast<uint8_t>(s[k - 1]);
+    size_t want = lead >= 0xF0 ? 4 : lead >= 0xE0 ? 3 : lead >= 0xC0 ? 2 : 1;
+    if (s.size() - (k - 1) < want) s.resize(k - 1);
+}
+}  // namespace
+
+std::string nameFromFirstLine(const std::string& firstLine, const std::string& stamp) {
+    std::string out;
+    bool dash = false;
+    for (size_t i = 0; i < firstLine.size() && out.size() < 32; i++) {
+        uint8_t c = static_cast<uint8_t>(firstLine[i]);
+        char letter = 0;
+        if (c < 0x80) {
+            if (c >= 'A' && c <= 'Z') letter = static_cast<char>(c + 32);
+            else if ((c >= 'a' && c <= 'z') || (c >= '0' && c <= '9')) letter = static_cast<char>(c);
+        } else if (c == 0xC3 && i + 1 < firstLine.size()) {  // U+00C0..U+00FF
+            letter = kPlain[static_cast<uint8_t>(firstLine[++i]) & 0x3F];
+        } else {
+            while (i + 1 < firstLine.size() && continuation(firstLine[i + 1])) i++;  // anything else is left out
+        }
+        if (letter) {
+            if (dash && !out.empty()) out += '-';
+            dash = false;
+            out += letter;
+        } else {
+            dash = true;
+        }
+    }
+    return out.empty() ? "note-" + stamp : out;
+}
+
+std::string titleFrom(const std::string& head, size_t maxChars) {
+    for (size_t at = 0; at < head.size();) {
+        size_t end = head.find('\n', at);
+        bool cut = end == std::string::npos;  // the line goes on past what was read
+        if (cut) end = head.size();
+        std::string line = head.substr(at, end - at);
+        if (cut) dropPartial(line);
+        while (!line.empty() && (line.back() == '\r' || line.back() == ' ' || line.back() == '\t')) line.pop_back();
+        size_t first = line.find_first_not_of(" \t");
+        if (first != std::string::npos) {
+            line.erase(0, first);
+            size_t bytes = 0;
+            for (size_t chars = 0; bytes < line.size() && chars < maxChars; chars++) {
+                bytes++;
+                while (bytes < line.size() && continuation(line[bytes])) bytes++;
+            }
+            line.resize(bytes);
+            return line;
+        }
+        at = end + 1;
+    }
+    return "";
+}
+
+}  // namespace roro::notes

lib/notes/src/note_text.h

@@ -0,0 +1,81 @@
+#pragma once
+
+#include <cstddef>
+#include <cstdint>
+#include <string>
+#include <vector>
+
+namespace roro::notes {
+
+// The text of a note while it's edited (F1, Q144, Q145): UTF-8 held whole in memory, a cursor, and
+// the part of it on screen. Lines wrap at spaces, `cols` characters wide; a line owns the space or
+// the newline it ends with, so every byte of the text belongs to exactly one line. No index of
+// lines is kept (a note of newlines alone would need twice its size): where a line starts is
+// worked out from the start of its paragraph, which is never far.
+class NoteText {
+   public:
+    static constexpr size_t kMaxBytes = 16 * 1024;
+
+    // Room for a full note is reserved once, so typing never has to find a bigger block of memory:
+    // on the device a failed allocation is the end. The second form takes over a string the
+    // caller filled (and reserved): a note is never in memory twice.
+    NoteText(int cols, int rows);
+    NoteText(int cols, int rows, std::string&& text);
+
+    // Copied into the buffer already held. CRLF becomes LF (Q148). False, and nothing changes, if
+    // it's over kMaxBytes.
+    bool setText(const std::string& text);
+    const std::string& text() const { return text_; }
+    size_t cursor() const { return cursor_; }
+    uint32_t revision() const { return revision_; }  // changes with every edit: is it saved?
+
+    bool insert(uint32_t codePoint);         // false: the note is full
+    bool insertText(const std::string& s);   // all of it or nothing
+    void backspace();
+    void left();
+    void right();
+    void up();
+    void down();
+    void pageUp();
+    void pageDown();
+    void lineStart();
+    void lineEnd();
+    void toStart();
+    void toEnd();
+
+    // The screen, kept around the cursor: its rows (tabs as spaces, the ending newline left out),
+    // and where the cursor is on it, in rows and characters.
+    std::vector<std::string> rows();
+    int cursorRow();
+    int cursorCol();
+    int percent() const { return text_.empty() ? 0 : static_cast<int>(top_ * 100 / text_.size()); }
+
+    std::string firstLine() const;  // without its newline, for the title and the file's name
+
+   private:
+    size_t nextLine(size_t start) const;       // where the line after the one at `start` starts
+    size_t lineOf(size_t pos) const;           // the start of the line `pos` is on
+    size_t lastSpot(size_t start) const;       // the last place the cursor can be on that line
+    size_t atColumn(size_t start, int col) const;
+    int columnOf(size_t start, size_t pos) const;
+    bool hasLineAfter(size_t start) const;
+    void moved(bool keepGoal = false);
+    void follow();  // scrolls so the cursor is on screen
+    void dropCarriageReturns();
+
+    int cols_, rows_;
+    std::string text_;
+    size_t cursor_ = 0, top_ = 0;
+    int goal_ = -1;  // the column Up and Down aim for, across short lines
+    uint32_t revision_ = 0;
+};
+
+// The file a new note is saved as (Q142): from its first line, "Shopping list!" -> "shopping-list",
+// or "note-<stamp>" when that gives nothing. No extension, no folder.
+std::string nameFromFirstLine(const std::string& firstLine, const std::string& stamp);
+
+// A row's title in the Notes list, from the first bytes of a file: its first line that isn't
+// blank, cut to `maxChars`; "" if there's none.
+std::string titleFrom(const std::string& head, size_t maxChars);
+
+}  // namespace roro::notes

lib/ota/src/file_receiver.cpp

@@ -94,6 +94,11 @@ void FileReceiver::chunkWritten(bool ok, uint32_t nowMs) {
     state_ = received_ == size_ ? State::Finishing : State::Receiving;
 }
 
+void FileReceiver::cardChecked(const uint8_t digest[32]) {
+    if (state_ != State::Finishing) return;
+    if (std::memcmp(digest, expected_, sizeof expected_) != 0) fail("the copy on the card differs");
+}
+
 void FileReceiver::finished(bool ok) {
     if (state_ != State::Finishing) return;
     if (!ok) return fail("rename failed");

lib/ota/src/file_receiver.h

@@ -34,6 +34,9 @@ class FileReceiver {
     // Takes bytes for the current chunk; returns how many were used (none while a chunk waits).
     size_t feed(const uint8_t* data, size_t len, uint32_t nowMs);
     void chunkWritten(bool ok, uint32_t nowMs);
+    // While Finishing: the SHA-256 of the file as read back from the card. The checksum on the
+    // received bytes doesn't prove the card kept them (a failed write can lose buffered data).
+    void cardChecked(const uint8_t digest[32]);
     void finished(bool ok);
     void tick(uint32_t nowMs);
     void reset() { *this = FileReceiver(); }

lib/release/src/http_head.cpp

@@ -0,0 +1,158 @@
+#include "http_head.h"
+
+#include <algorithm>
+#include <cctype>
+#include <cstdlib>
+
+namespace roro::release {
+
+namespace {
+std::string lower(std::string s) {
+    for (char& c : s) c = static_cast<char>(std::tolower(static_cast<unsigned char>(c)));
+    return s;
+}
+}  // namespace
+
+size_t HttpHeadParser::feed(const char* data, size_t len) {
+    size_t used = 0;
+    while (used < len && !complete_ && !failed_) {
+        char c = data[used++];
+        total_++;
+        if (total_ > kMaxBytes) {
+            failed_ = true;
+            break;
+        }
+        if (c == '\n') {
+            if (!line_.empty() && line_.back() == '\r') line_.pop_back();
+            line();
+            line_.clear();
+        } else {
+            line_ += c;
+        }
+    }
+    return used;
+}
+
+void HttpHeadParser::line() {
+    if (first_) {  // "HTTP/1.1 200 OK"
+        first_ = false;
+        if (line_.compare(0, 5, "HTTP/") != 0) {
+            failed_ = true;
+            return;
+        }
+        size_t space = line_.find(' ');
+        head_.status = space == std::string::npos ? 0 : std::atoi(line_.c_str() + space + 1);
+        if (head_.status < 100 || head_.status > 599) failed_ = true;
+        return;
+    }
+    if (line_.empty()) {
+        complete_ = true;
+        return;
+    }
+    size_t colon = line_.find(':');
+    if (colon == std::string::npos) return;  // not a header: ignored
+    std::string name = lower(line_.substr(0, colon));
+    size_t from = line_.find_first_not_of(" \t", colon + 1);
+    std::string value = from == std::string::npos ? "" : line_.substr(from);
+    if (name == "content-length") head_.contentLength = std::atol(value.c_str());
+    else if (name == "transfer-encoding") head_.chunked = lower(value).find("chunked") != std::string::npos;
+    else if (name == "location") head_.location = value;
+    else if (name == "content-type") head_.contentType = value;
+}
+
+size_t ChunkedDecoder::decode(const uint8_t* in, size_t len, uint8_t* out) {
+    size_t written = 0;
+    for (size_t i = 0; i < len && !failed_ && state_ != State::Done; i++) {
+        uint8_t c = in[i];
+        switch (state_) {
+            case State::Size: {
+                int digit = c >= '0' && c <= '9' ? c - '0' : c >= 'a' && c <= 'f' ? c - 'a' + 10 : c >= 'A' && c <= 'F' ? c - 'A' + 10 : -1;
+                if (digit >= 0) {
+                    if (remaining_ > (SIZE_MAX >> 5)) failed_ = true;
+                    remaining_ = remaining_ * 16 + digit;
+                    anyDigit_ = true;
+                } else if (c == ';' && anyDigit_) {
+                    state_ = State::Extension;
+                } else if (c == '\r' && anyDigit_) {
+                    state_ = State::SizeLf;
+                } else {
+                    failed_ = true;
+                }
+                break;
+            }
+            case State::Extension:
+                if (c == '\r') state_ = State::SizeLf;
+                break;
+            case State::SizeLf:
+                if (c != '\n') {
+                    failed_ = true;
+                } else if (remaining_ == 0) {
+                    state_ = State::Trailer;
+                    trailerLine_ = 0;
+                } else {
+                    state_ = State::Data;
+                }
+                break;
+            case State::Data: {
+                size_t take = std::min(remaining_, len - i);
+                for (size_t k = 0; k < take; k++) out[written + k] = in[i + k];
+                written += take;
+                remaining_ -= take;
+                i += take - 1;
+                if (remaining_ == 0) state_ = State::DataCr;
+                break;
+            }
+            case State::DataCr:
+                if (c != '\r') failed_ = true;
+                else state_ = State::DataLf;
+                break;
+            case State::DataLf:
+                if (c != '\n') {
+                    failed_ = true;
+                } else {
+                    state_ = State::Size;
+                    anyDigit_ = false;
+                }
+                break;
+            case State::Trailer:  // header lines after the last chunk, until an empty one
+                if (c == '\n') {
+                    if (trailerLine_ == 0) state_ = State::Done;
+                    trailerLine_ = 0;
+                } else if (c != '\r') {
+                    trailerLine_++;
+                }
+                break;
+            case State::Done: break;
+        }
+    }
+    return written;
+}
+
+Url parseUrl(const std::string& url) {
+    Url u;
+    size_t scheme = url.find("://");
+    if (scheme == std::string::npos) return u;
+    std::string s = lower(url.substr(0, scheme));
+    if (s != "http" && s != "https") return u;
+    u.https = s == "https";
+    size_t hostStart = scheme + 3, pathStart = url.find('/', hostStart);
+    std::string authority = url.substr(hostStart, pathStart == std::string::npos ? std::string::npos : pathStart - hostStart);
+    u.path = pathStart == std::string::npos ? "/" : url.substr(pathStart);
+    if (authority.empty() || authority.find('@') != std::string::npos) return u;  // no credentials in a URL
+    size_t colon = authority.rfind(':');
+    u.port = u.https ? 443 : 80;
+    if (colon != std::string::npos) {
+        u.port = std::atoi(authority.c_str() + colon + 1);
+        authority.resize(colon);
+        if (u.port <= 0 || u.port > 65535) return u;
+    }
+    for (unsigned char c : authority)
+        if (!(std::isalnum(c) || c == '.' || c == '-')) return u;
+    for (unsigned char c : u.path)
+        if (c <= ' ' || c == 0x7F) return u;
+    u.host = lower(authority);
+    u.ok = !u.host.empty();
+    return u;
+}
+
+}  // namespace roro::release

lib/release/src/http_head.h

@@ -0,0 +1,62 @@
+#pragma once
+
+#include <cstddef>
+#include <cstdint>
+#include <string>
+
+namespace roro::release {
+
+// The status line and headers of an HTTP/1.1 response, read as bytes arrive.
+struct HttpHead {
+    int status = 0;
+    long contentLength = -1;  // -1: not given
+    bool chunked = false;
+    std::string location, contentType;
+};
+
+class HttpHeadParser {
+   public:
+    static constexpr size_t kMaxBytes = 4096;
+
+    // Takes bytes up to and including the blank line that ends the head; returns how many it used.
+    // What follows is the body.
+    size_t feed(const char* data, size_t len);
+    bool complete() const { return complete_; }
+    bool failed() const { return failed_; }
+    const HttpHead& head() const { return head_; }
+
+   private:
+    void line();
+
+    HttpHead head_;
+    std::string line_;
+    size_t total_ = 0;
+    bool first_ = true, complete_ = false, failed_ = false;
+};
+
+// Takes the chunks of "Transfer-Encoding: chunked" apart as they arrive.
+class ChunkedDecoder {
+   public:
+    // `out` has room for `len` bytes (the body is never longer than what carried it).
+    size_t decode(const uint8_t* in, size_t len, uint8_t* out);
+    bool done() const { return state_ == State::Done; }
+    bool failed() const { return failed_; }
+
+   private:
+    enum class State : uint8_t { Size, Extension, SizeLf, Data, DataCr, DataLf, Trailer, Done };
+    State state_ = State::Size;
+    size_t remaining_ = 0;
+    bool anyDigit_ = false, failed_ = false;
+    size_t trailerLine_ = 0;
+};
+
+// "https://git.twis.la/twisla/x/releases/download/v1/a.ota" taken apart. Only http and https.
+struct Url {
+    bool ok = false;
+    bool https = false;
+    std::string host, path;  // path from the first "/", with its query; "/" if none
+    int port = 0;
+};
+Url parseUrl(const std::string& url);
+
+}  // namespace roro::release

lib/release/src/json_scan.cpp

@@ -0,0 +1,202 @@
+#include "json_scan.h"
+
+namespace roro::release {
+
+namespace {
+bool space(char c) { return c == ' ' || c == '\t' || c == '\r' || c == '\n'; }
+bool continuation(char c) { return (static_cast<uint8_t>(c) & 0xC0) == 0x80; }
+}  // namespace
+
+void JsonScanner::feed(const char* data, size_t len) {
+    for (size_t i = 0; i < len && !failed_; i++) step(data[i]);
+}
+
+std::string JsonScanner::path() const {
+    std::string p;
+    for (const Frame& f : stack_) {
+        if (f.isObject) {
+            if (!p.empty()) p += '.';
+            p += f.key;
+        } else {
+            p += '[' + std::to_string(f.index) + ']';
+        }
+    }
+    return p;
+}
+
+void JsonScanner::append(const char* bytes, size_t n) {
+    if (text_.size() + n > max_) {
+        truncated_ = true;
+        return;
+    }
+    text_.append(bytes, n);
+}
+
+void JsonScanner::appendCodePoint(uint32_t cp) {
+    char b[4];
+    size_t n;
+    if (cp < 0x80) {
+        b[0] = static_cast<char>(cp);
+        n = 1;
+    } else if (cp < 0x800) {
+        b[0] = static_cast<char>(0xC0 | (cp >> 6));
+        b[1] = static_cast<char>(0x80 | (cp & 0x3F));
+        n = 2;
+    } else if (cp < 0x10000) {
+        b[0] = static_cast<char>(0xE0 | (cp >> 12));
+        b[1] = static_cast<char>(0x80 | ((cp >> 6) & 0x3F));
+        b[2] = static_cast<char>(0x80 | (cp & 0x3F));
+        n = 3;
+    } else {
+        b[0] = static_cast<char>(0xF0 | (cp >> 18));
+        b[1] = static_cast<char>(0x80 | ((cp >> 12) & 0x3F));
+        b[2] = static_cast<char>(0x80 | ((cp >> 6) & 0x3F));
+        b[3] = static_cast<char>(0x80 | (cp & 0x3F));
+        n = 4;
+    }
+    append(b, n);
+}
+
+void JsonScanner::startString(bool key) {
+    inString_ = true;
+    isKey_ = key;
+    escape_ = false;
+    unicodeLeft_ = 0;
+    highSurrogate_ = 0;
+    truncated_ = false;
+    text_.clear();
+}
+
+void JsonScanner::stringChar(char c) {
+    if (unicodeLeft_ > 0) {
+        int digit = c >= '0' && c <= '9' ? c - '0' : c >= 'a' && c <= 'f' ? c - 'a' + 10 : c >= 'A' && c <= 'F' ? c - 'A' + 10 : -1;
+        if (digit < 0) return fail();
+        unicode_ = unicode_ * 16 + digit;
+        if (--unicodeLeft_ == 0) {
+            if (unicode_ >= 0xD800 && unicode_ < 0xDC00) {
+                highSurrogate_ = unicode_;  // the low half comes next
+            } else if (unicode_ >= 0xDC00 && unicode_ < 0xE000 && highSurrogate_) {
+                appendCodePoint(0x10000 + ((highSurrogate_ - 0xD800) << 10) + (unicode_ - 0xDC00));
+                highSurrogate_ = 0;
+            } else {
+                appendCodePoint(unicode_);
+                highSurrogate_ = 0;
+            }
+        }
+        return;
+    }
+    if (escape_) {
+        escape_ = false;
+        switch (c) {
+            case 'n': append("\n", 1); break;
+            case 't': append("\t", 1); break;
+            case 'r': append("\r", 1); break;
+            case 'b': append("\b", 1); break;
+            case 'f': append("\f", 1); break;
+            case 'u': unicodeLeft_ = 4; unicode_ = 0; break;
+            default: append(&c, 1); break;  // \" \\ \/
+        }
+        return;
+    }
+    if (c == '\\') {
+        escape_ = true;
+    } else if (c == '"') {
+        endString();
+    } else {
+        append(&c, 1);
+    }
+}
+
+void JsonScanner::endString() {
+    inString_ = false;
+    // A cut can leave half a character at the end.
+    while (truncated_ && !text_.empty()) {
+        size_t k = text_.size();
+        while (k > 0 && continuation(text_[k - 1])) k--;
+        if (k == 0) break;
+        uint8_t lead = static_cast<uint8_t>(text_[k - 1]);
+        size_t want = lead >= 0xF0 ? 4 : lead >= 0xE0 ? 3 : lead >= 0xC0 ? 2 : 1;
+        if (text_.size() - (k - 1) < want) text_.resize(k - 1);
+        break;
+    }
+    if (isKey_) {
+        stack_.back().key = text_;
+        expect_ = Expect::Colon;
+        return;
+    }
+    sink_(path(), text_, true, truncated_);
+    valueDone();
+}
+
+void JsonScanner::endLiteral() {
+    inLiteral_ = false;
+    sink_(path(), text_, false, false);
+    valueDone();
+}
+
+void JsonScanner::valueDone() {
+    if (stack_.empty()) {
+        done_ = true;
+        return;
+    }
+    expect_ = Expect::CommaOrEnd;
+}
+
+void JsonScanner::step(char c) {
+    if (inString_) return stringChar(c);
+    if (inLiteral_) {
+        if (space(c) || c == ',' || c == '}' || c == ']') {
+            endLiteral();  // and the character that ended it is read again below
+        } else {
+            if (text_.size() < max_) text_ += c;
+            return;
+        }
+    }
+    if (space(c)) return;
+    switch (expect_) {
+        case Expect::Value:
+            if (c == '{') {
+                stack_.push_back({true, "", 0});
+                expect_ = Expect::KeyOrEnd;
+            } else if (c == '[') {
+                stack_.push_back({false, "", 0});
+                expect_ = Expect::Value;
+            } else if (c == ']' && !stack_.empty() && !stack_.back().isObject && stack_.back().index == 0) {
+                stack_.pop_back();  // an empty array
+                valueDone();
+            } else if (c == '"') {
+                startString(false);
+            } else if (c == '-' || (c >= '0' && c <= '9') || c == 't' || c == 'f' || c == 'n') {
+                inLiteral_ = true;
+                text_.assign(1, c);
+            } else {
+                fail();
+            }
+            return;
+        case Expect::KeyOrEnd:
+            if (c == '"') startString(true);
+            else if (c == '}') {
+                stack_.pop_back();
+                valueDone();
+            } else fail();
+            return;
+        case Expect::Colon:
+            if (c == ':') expect_ = Expect::Value;
+            else fail();
+            return;
+        case Expect::CommaOrEnd:
+            if (c == ',') {
+                if (stack_.back().isObject) expect_ = Expect::KeyOrEnd;
+                else {
+                    stack_.back().index++;
+                    expect_ = Expect::Value;
+                }
+            } else if ((c == '}' && stack_.back().isObject) || (c == ']' && !stack_.back().isObject)) {
+                stack_.pop_back();
+                valueDone();
+            } else fail();
+            return;
+    }
+}
+
+}  // namespace roro::release

lib/release/src/json_scan.h

@@ -0,0 +1,57 @@
+#pragma once
+
+#include <cstddef>
+#include <cstdint>
+#include <functional>
+#include <string>
+#include <vector>
+
+namespace roro::release {
+
+// Reads JSON as it arrives, a chunk at a time, and reports each plain value (a string, a number,
+// true, false, null) with where it was found: "tag_name", "assets[1].name", "[2].draft". Nothing
+// is kept but the path, so a 33 KB list of releases costs a few hundred bytes. A value longer than
+// `maxValueBytes` is cut (never in the middle of a character) and reported as truncated.
+// Meant for a server's answer, not for validating JSON: it only refuses what it can't follow.
+class JsonScanner {
+   public:
+    using Sink = std::function<void(const std::string& path, const std::string& value, bool isString, bool truncated)>;
+
+    explicit JsonScanner(Sink sink, size_t maxValueBytes = 300) : sink_(std::move(sink)), max_(maxValueBytes) {}
+
+    void feed(const char* data, size_t len);
+    bool failed() const { return failed_; }
+    bool done() const { return done_ && !failed_; }  // the top-level value is complete
+
+   private:
+    enum class Expect : uint8_t { Value, KeyOrEnd, Colon, CommaOrEnd };
+    struct Frame {
+        bool isObject;
+        std::string key;
+        int index;
+    };
+
+    void step(char c);
+    void startString(bool key);
+    void stringChar(char c);
+    void appendCodePoint(uint32_t cp);
+    void endString();
+    void endLiteral();
+    void valueDone();
+    void append(const char* bytes, size_t n);
+    std::string path() const;
+    void fail() { failed_ = true; }
+
+    Sink sink_;
+    size_t max_;
+    std::vector<Frame> stack_;
+    Expect expect_ = Expect::Value;
+    bool inString_ = false, isKey_ = false, escape_ = false, inLiteral_ = false;
+    int unicodeLeft_ = 0;
+    uint32_t unicode_ = 0, highSurrogate_ = 0;
+    bool truncated_ = false;
+    std::string text_;
+    bool failed_ = false, done_ = false;
+};
+
+}  // namespace roro::release

lib/release/src/release_info.cpp

@@ -0,0 +1,80 @@
+#include "release_info.h"
+
+#include <cstdlib>
+
+namespace roro::release {
+
+namespace {
+bool endsWith(const std::string& s, const char* tail) {
+    size_t n = std::char_traits<char>::length(tail);
+    return s.size() >= n && s.compare(s.size() - n, n, tail) == 0;
+}
+}  // namespace
+
+std::string firstParagraph(const std::string& text, bool truncated) {
+    size_t end = text.find("\n\n");
+    size_t crlf = text.find("\r\n\r\n");
+    if (crlf != std::string::npos && (end == std::string::npos || crlf < end)) end = crlf;
+    std::string p = text.substr(0, end);
+    size_t first = p.find_first_not_of(" \t\r\n");
+    if (first == std::string::npos) return "";
+    p.erase(0, first);
+    while (!p.empty() && (p.back() == ' ' || p.back() == '\t' || p.back() == '\r' || p.back() == '\n')) p.pop_back();
+    if (truncated && end == std::string::npos) p += "...";
+    return p;
+}
+
+ReleaseReader::ReleaseReader(size_t maxReleases)
+    : scanner_([this](const std::string& path, const std::string& text, bool isString, bool truncated) {
+          value(path, text, isString, truncated);
+      }),
+      max_(maxReleases) {}
+
+void ReleaseReader::end() { flushAsset(); }
+
+void ReleaseReader::flushAsset() {
+    if (assetRelease_ >= 0 && assetRelease_ < static_cast<int>(releases_.size()) && endsWith(assetName_, ".ota") && !assetUrl_.empty()) {
+        releases_[assetRelease_].otaUrl = assetUrl_;
+        releases_[assetRelease_].otaSize = assetSize_;
+    }
+    assetRelease_ = assetIndex_ = -1;
+    assetName_.clear();
+    assetUrl_.clear();
+    assetSize_ = 0;
+}
+
+void ReleaseReader::value(const std::string& path, const std::string& text, bool isString, bool truncated) {
+    size_t index = 0;
+    std::string rest = path;
+    if (!path.empty() && path[0] == '[') {  // a list: "[2].tag_name"
+        char* end;
+        index = static_cast<size_t>(std::strtol(path.c_str() + 1, &end, 10));
+        rest = *end == ']' ? std::string(end + 1) : "";
+        if (!rest.empty() && rest[0] == '.') rest.erase(0, 1);
+    }
+    if (index >= max_) return;
+    if (releases_.size() <= index) releases_.resize(index + 1);
+    Release& r = releases_[index];
+
+    if (rest == "tag_name") r.tag = text;
+    else if (rest == "published_at") r.published = text;
+    else if (rest == "body") r.notes = firstParagraph(text, truncated);
+    else if (rest == "draft") r.draft = text == "true";
+    else if (rest == "prerelease") r.prerelease = text == "true";
+    else if (rest.compare(0, 7, "assets[") == 0) {
+        char* end;
+        int j = static_cast<int>(std::strtol(rest.c_str() + 7, &end, 10));
+        if (static_cast<int>(index) != assetRelease_ || j != assetIndex_) {
+            flushAsset();
+            assetRelease_ = static_cast<int>(index);
+            assetIndex_ = j;
+        }
+        std::string field = *end == ']' && end[1] == '.' ? std::string(end + 2) : "";
+        if (field == "name") assetName_ = text;
+        else if (field == "size") assetSize_ = static_cast<uint32_t>(std::strtoul(text.c_str(), nullptr, 10));
+        else if (field == "browser_download_url") assetUrl_ = text;
+    }
+    (void)isString;
+}
+
+}  // namespace roro::release

lib/release/src/release_info.h

@@ -0,0 +1,52 @@
+#pragma once
+
+#include <cstdint>
+#include <string>
+#include <vector>
+
+#include "json_scan.h"
+
+namespace roro::release {
+
+// What the device needs to know about one Gitea release (docs/milestones/R1.md, #6).
+struct Release {
+    std::string tag;        // "v0.10.0"
+    std::string published;  // "2026-10-06T08:11:31Z"
+    std::string notes;      // the first paragraph of the text: the tag's message
+    std::string otaUrl;     // where the signed Update File is
+    uint32_t otaSize = 0;
+    bool draft = false, prerelease = false;
+
+    // Something that can be installed and that the project meant to publish (drafts and
+    // pre-releases are left out for now: a release channel is #53).
+    bool usable() const { return !draft && !prerelease && !tag.empty() && !otaUrl.empty(); }
+    std::string date() const { return published.substr(0, 10); }  // "2026-10-06"
+};
+
+// Reads Gitea's answer as it arrives: `releases/latest` (one object) or `releases?limit=N` (a list).
+class ReleaseReader {
+   public:
+    explicit ReleaseReader(size_t maxReleases = 10);
+
+    void feed(const char* data, size_t len) { scanner_.feed(data, len); }
+    void end();  // after the last chunk
+    bool ok() const { return !scanner_.failed(); }
+    bool complete() const { return scanner_.done(); }
+    const std::vector<Release>& releases() const { return releases_; }
+
+   private:
+    void value(const std::string& path, const std::string& text, bool isString, bool truncated);
+    void flushAsset();
+
+    JsonScanner scanner_;
+    size_t max_;
+    std::vector<Release> releases_;
+    int assetRelease_ = -1, assetIndex_ = -1;
+    std::string assetName_, assetUrl_;
+    uint32_t assetSize_ = 0;
+};
+
+// The first paragraph of a release's text, trimmed; "..." if the text was cut before it ended.
+std::string firstParagraph(const std::string& text, bool truncated);
+
+}  // namespace roro::release

lib/release/src/update_check.cpp

@@ -0,0 +1,15 @@
+#include "update_check.h"
+
+#include "http_head.h"
+
+namespace roro::release {
+
+bool trustedAssetUrl(const std::string& url, const std::string& host, const std::string& repo) {
+    Url u = parseUrl(url);
+    if (!u.ok || !u.https || u.port != 443 || u.host != host) return false;
+    std::string prefix = "/" + repo + "/releases/download/";
+    return u.path.compare(0, prefix.size(), prefix) == 0 && u.path.find("..") == std::string::npos &&
+           u.path.find('?') == std::string::npos && u.path.find('#') == std::string::npos;
+}
+
+}  // namespace roro::release

lib/release/src/update_check.h

@@ -0,0 +1,38 @@
+#pragma once
+
+#include <string>
+
+#include "release_info.h"
+#include "version_compare.h"
+
+namespace roro::release {
+
+// Where the project's releases are (Q164). A fork changes these, and its own signing key.
+constexpr const char* kGiteaHost = "git.twis.la";
+constexpr const char* kGiteaRepo = "twisla/roro9stack";
+
+inline bool versionNewer(const std::string& a, const std::string& b) { return versionOlder(b, a); }
+
+// "v0.10.0+debug": the Debug Build says so wherever the version shows (scripts/version.py).
+inline bool isDebugBuild(const std::string& version) {
+    static const std::string tail = "+debug";
+    return version.size() >= tail.size() && version.compare(version.size() - tail.size(), tail.size(), tail) == 0;
+}
+
+// Is `release` a newer one than what runs?
+inline bool isNewer(const Release& release, const std::string& running) {
+    return release.usable() && versionNewer(release.tag, running);
+}
+
+// Should the background check say so (Q166, Q168)? Not for a version that failed on this device
+// before (it rolled back), and not twice for the same one.
+inline bool shouldAnnounce(const Release& latest, const std::string& running, const std::string& failed, const std::string& announced) {
+    return isNewer(latest, running) && latest.tag != failed && latest.tag != announced;
+}
+
+// Is `url` a download this device takes from the project's server, for this repository? Whatever
+// the API says, the device only fetches from where it asked (a redirected or rewritten answer
+// can't send it elsewhere).
+bool trustedAssetUrl(const std::string& url, const std::string& host = kGiteaHost, const std::string& repo = kGiteaRepo);
+
+}  // namespace roro::release

lib/services/src/power_policy.cpp

@@ -10,7 +10,10 @@ bool PowerPolicy::activity(uint32_t nowMs) {
 }
 
 ScreenState PowerPolicy::update(uint32_t nowMs) {
-    uint32_t idle = nowMs - lastActivityMs_;
+    // Activity stamped from a clock read after this pass's nowMs (the Debug Console's `key`) is in
+    // the future, not 49 days ago: unsigned, the screen went off for a tick and ate the next key.
+    int32_t since = static_cast<int32_t>(nowMs - lastActivityMs_);
+    uint32_t idle = since < 0 ? 0 : static_cast<uint32_t>(since);
     state_ = idle >= offMs_ ? ScreenState::Off : idle >= dimMs_ ? ScreenState::Dimmed : ScreenState::On;
     if (notifying_) {
         if (static_cast<int32_t>(nowMs - notifyUntilMs_) >= 0)

lib/services/src/settings.cpp

@@ -1,5 +1,7 @@
 #include "settings.h"
 
+#include "ipv4.h"
+
 namespace roro {
 
 namespace {
@@ -31,6 +33,14 @@ const Definition kDefinitions[] = {
     {"wifi_on", Kind::Bool, 1, nullptr, 0, 1},
     {"gnss_on", Kind::Bool, 1, nullptr, 0, 1},
     {"coord_dms", Kind::Bool, 0, nullptr, 0, 1},
+    {"lora_preset", Kind::Int, 0, nullptr, 0, 6},  // LongFast first
+    {"dns1", Kind::String, 0, "9.9.9.9", 7, 15},  // Quad9
+    {"dns2", Kind::String, 0, "1.1.1.1", 0, 15},  // Cloudflare
+    {"dns_always", Kind::Bool, 0, nullptr, 0, 1},
+    {"ntp1", Kind::String, 0, "pool.ntp.org", 1, 63},
+    {"ntp2", Kind::String, 0, "time.cloudflare.com", 0, 63},
+    {"gnss_quiet", Kind::Bool, 0, nullptr, 0, 1},  // off: GNSS stays on, as decided in M2 (Q58)
+    {"check_updates", Kind::Bool, 1, nullptr, 0, 1},  // on: it only looks, and says so (R1, Q165)
 };
 static_assert(sizeof(kDefinitions) / sizeof(kDefinitions[0]) == static_cast<size_t>(Setting::Count),
               "every Setting needs a definition");
@@ -83,6 +93,11 @@ bool Settings::validString(Setting s, const std::string& value) const {
             if (value == region) return true;
         return false;
     }
+    uint32_t address;
+    if (s == Setting::Dns1) return net::parseIpv4(value, address);
+    if (s == Setting::Dns2) return value.empty() || net::parseIpv4(value, address);
+    if (s == Setting::Ntp1) return net::validHost(value);
+    if (s == Setting::Ntp2) return value.empty() || net::validHost(value);
     return true;
 }
 

lib/services/src/settings.h

@@ -23,6 +23,14 @@ enum class Setting : uint8_t {
     WifiEnabled,      // bool: the Wi-Fi Service stays Connected when a Saved Network is in range
     GnssEnabled,      // bool: the GNSS Service reads the receiver (M2, Q58)
     CoordinatesDms,   // bool: show degrees, minutes and seconds instead of decimal degrees (Q64)
+    LoraPreset,       // int: the LoRa Scanner's Meshtastic preset, an index into the EU868 list (M3, Q95)
+    Dns1,             // string: the first DNS server, an IPv4 address (S1, Q108, Q109)
+    Dns2,             // string: the second, or empty
+    DnsAlways,        // bool: use them on Automatic (DHCP) networks too, instead of DHCP's
+    Ntp1,             // string: the first NTP server, a host name or an IPv4 address (S1, Q110)
+    Ntp2,             // string: the second, or empty
+    GnssQuietForLora, // bool: put the GNSS receiver in standby while the LoRa radio listens (issue #20)
+    CheckUpdates,     // bool: look for a newer release on Gitea once a day (R1, Q165)
     Count
 };
 

lib/services/src/storage_monitor.cpp

@@ -24,7 +24,7 @@ void StorageMonitor::update(bool present, uint64_t totalBytes, uint64_t usedByte
 
     if (next.present && next.level >= 80 && !warned_) {
         warned_ = true;
-        bus_.publish(Event::withText(EventType::Notification, "SD card over 80% full",
+        bus_.publish(Event::withText(EventType::Notification, "SD card over 80% full: see Storage",
                                      static_cast<int32_t>(NotificationLevel::Warning)));
     }
 }

lib/storage_model/src/cleanup_plan.h

@@ -20,6 +20,7 @@ inline const CleanupCategory kCleanupCategories[] = {
     {"IRC logs", "/irc"},
     {"Wi-Fi scan logs", "/wifi/scans"},
     {"Wi-Fi captures", "/captures/wifi"},
+    {"LoRa captures", "/captures/lora"},
     {"GNSS tracks", "/gnss/tracks"},
 };
 

lib/storage_model/src/sd_card_id.cpp

@@ -0,0 +1,53 @@
+#include "sd_card_id.h"
+
+#include <cstdio>
+
+namespace roro {
+
+namespace {
+char printable(uint8_t b) { return b >= 0x20 && b < 0x7F ? static_cast<char>(b) : '?'; }
+}  // namespace
+
+SdCardId parseSdCid(const uint8_t cid[16]) {
+    SdCardId id;
+    id.manufacturer = cid[0];
+    for (int i = 0; i < 2; ++i) id.oem[i] = printable(cid[1 + i]);
+    for (int i = 0; i < 5; ++i) id.product[i] = printable(cid[3 + i]);
+    id.revisionMajor = cid[8] >> 4;
+    id.revisionMinor = cid[8] & 0x0F;
+    id.serial = static_cast<uint32_t>(cid[9]) << 24 | cid[10] << 16 | cid[11] << 8 | cid[12];
+    // 4 reserved bits, 8 bits of year since 2000, 4 bits of month.
+    id.year = 2000 + (((cid[13] & 0x0F) << 4) | (cid[14] >> 4));
+    id.month = cid[14] & 0x0F;
+    return id;
+}
+
+const char* sdManufacturerName(uint8_t id) {
+    switch (id) {
+        case 0x01: return "Panasonic";
+        case 0x02: return "Toshiba/Kioxia";
+        case 0x03: return "SanDisk";
+        case 0x1B: return "Samsung";
+        case 0x1D: return "ADATA";
+        case 0x27: return "Phison";
+        case 0x28: return "Lexar";
+        case 0x31: return "Silicon Power";
+        case 0x41: return "Kingston";
+        case 0x74: return "Transcend";
+        case 0x76: return "Patriot";
+        case 0x82: return "Sony";
+        case 0x9C: return "Angelbird/Hoodman";
+        case 0xAD: return "Longsys/Lexar";
+        default: return "unknown";
+    }
+}
+
+std::string sdCardSummary(const SdCardId& id) {
+    char s[112];
+    std::snprintf(s, sizeof s, "%s (0x%02X) \"%s\" \"%s\" rev %u.%u, serial %08x, made %04d-%02d",
+                  sdManufacturerName(id.manufacturer), id.manufacturer, id.oem, id.product, id.revisionMajor,
+                  id.revisionMinor, static_cast<unsigned>(id.serial), id.year, id.month);
+    return s;
+}
+
+}  // namespace roro

lib/storage_model/src/sd_card_id.h

@@ -0,0 +1,27 @@
+#pragma once
+
+#include <cstdint>
+#include <string>
+
+namespace roro {
+
+// What an SD card says it is: its CID register, 16 bytes (SD Physical Layer spec, 5.2).
+struct SdCardId {
+    uint8_t manufacturer = 0;  // assigned by the SD Association; see sdManufacturerName()
+    char oem[3] = {};          // two characters
+    char product[6] = {};      // five characters
+    uint8_t revisionMajor = 0, revisionMinor = 0;
+    uint32_t serial = 0;
+    int year = 0, month = 0;  // manufactured
+};
+
+SdCardId parseSdCid(const uint8_t cid[16]);
+
+// The usual holder of a manufacturer ID. The SD Association doesn't publish its list: these are
+// the commonly reported ones, and resold or counterfeit cards carry whatever their maker chose.
+const char* sdManufacturerName(uint8_t id);
+
+// "SanDisk (0x03) "SD" "SU08G" rev 8.0, serial 1234abcd, made 2014-03".
+std::string sdCardSummary(const SdCardId& id);
+
+}  // namespace roro

lib/system/src/task_stats.cpp

@@ -0,0 +1,72 @@
+#include "task_stats.h"
+
+#include <algorithm>
+#include <cctype>
+#include <cstring>
+
+namespace roro {
+
+std::vector<TaskRow> taskRows(const std::vector<TaskSample>& before, uint32_t totalBefore,
+                              const std::vector<TaskSample>& now, uint32_t totalNow) {
+    uint32_t elapsed = totalNow - totalBefore;  // unsigned: right across one wrap
+    std::vector<TaskRow> rows;
+    rows.reserve(now.size());
+    for (const TaskSample& t : now) {
+        uint32_t ran = t.runtime;  // a task that wasn't there before ran all of it since
+        for (const TaskSample& b : before)
+            if (b.id == t.id) {
+                ran = t.runtime - b.runtime;
+                break;
+            }
+        TaskRow r;
+        r.name = t.name;
+        r.core = t.core;
+        r.state = t.state;
+        r.priority = t.priority;
+        r.stackFree = t.stackFree;
+        r.permille = elapsed ? static_cast<uint16_t>(std::min<uint64_t>(1000, static_cast<uint64_t>(ran) * 1000 / elapsed)) : 0;
+        r.lowStack = t.stackFree < kLowStackBytes;
+        r.idle = std::strncmp(t.name, "IDLE", 4) == 0;
+        rows.push_back(r);
+    }
+    // The task that took the sample is running, and FreeRTOS counts a task's time when it's
+    // switched out: with its core to itself it never was, and its counter hardly moved. Give it
+    // what's left of its core once the idle task and the other tasks pinned there are counted.
+    for (TaskRow& r : rows) {
+        if (r.state != 0 || r.idle || r.core < 0) continue;  // 0: eRunning
+        int others = 0;
+        bool idleSeen = false;
+        for (const TaskRow& o : rows) {
+            if (&o == &r || o.core != r.core) continue;
+            others += o.permille;
+            idleSeen |= o.idle;
+        }
+        if (idleSeen && elapsed && 1000 - others > r.permille) r.permille = static_cast<uint16_t>(std::max(0, 1000 - others));
+    }
+    return rows;
+}
+
+int coreLoad(const std::vector<TaskRow>& rows, int core) {
+    for (const TaskRow& r : rows)
+        if (r.idle && r.core == core) return 100 - (r.permille + 5) / 10;
+    return -1;
+}
+
+void sortTasks(std::vector<TaskRow>& rows, TaskSort by) {
+    auto lower = [](const std::string& s) {
+        std::string l = s;
+        for (char& c : l) c = static_cast<char>(std::tolower(static_cast<unsigned char>(c)));
+        return l;
+    };
+    std::stable_sort(rows.begin(), rows.end(), [&](const TaskRow& a, const TaskRow& b) {
+        switch (by) {
+            case TaskSort::Share:
+                if (a.idle != b.idle) return !a.idle;  // idle tasks last
+                return a.permille > b.permille;
+            case TaskSort::Stack: return a.stackFree < b.stackFree;
+            default: return lower(a.name) < lower(b.name);
+        }
+    });
+}
+
+}  // namespace roro

lib/system/src/task_stats.h

@@ -0,0 +1,65 @@
+#pragma once
+
+#include <cstddef>
+#include <cstdint>
+#include <cstdio>
+#include <string>
+#include <vector>
+
+namespace roro {
+
+// One task as FreeRTOS reports it at one moment.
+struct TaskSample {
+    uint32_t id = 0;       // unique per task: a new task with an old name has another
+    char name[17] = {};
+    uint32_t runtime = 0;  // microseconds on a CPU since it started; 32 bits, so it wraps every 71 minutes
+    uint16_t stackFree = 0;  // the least it ever had left, bytes
+    int8_t core = -1;        // -1: not pinned
+    uint8_t state = 0;       // eTaskState
+    uint8_t priority = 0;
+};
+
+// What the System App and `tasks` show for a task (S1, Q119, Q122).
+struct TaskRow {
+    std::string name;
+    int core = -1;
+    uint8_t state = 0, priority = 0;
+    uint16_t stackFree = 0;
+    uint16_t permille = 0;  // share of one core over the interval, in tenths of a percent
+    bool lowStack = false;
+    bool idle = false;      // a core's idle task: what's left over
+};
+
+constexpr uint16_t kLowStackBytes = 512;
+
+// Shares from two samples: each task's run time between them over the time that passed. The
+// 32-bit counters may have wrapped once in between. The task that took the samples (the one
+// running) gets what's left of its core: see the .cpp.
+std::vector<TaskRow> taskRows(const std::vector<TaskSample>& before, uint32_t totalBefore,
+                              const std::vector<TaskSample>& now, uint32_t totalNow);
+
+// A core's load in percent: what its idle task didn't use. -1 without that task in the rows.
+int coreLoad(const std::vector<TaskRow>& rows, int core);
+
+enum class TaskSort : uint8_t { Share, Stack, Name };
+void sortTasks(std::vector<TaskRow>& rows, TaskSort by);
+
+// The last N samples, oldest first (Q120).
+template <typename T, size_t N>
+class History {
+   public:
+    void push(T value) {
+        values_[(first_ + size_) % N] = value;
+        if (size_ < N) size_++;
+        else first_ = (first_ + 1) % N;
+    }
+    size_t size() const { return size_; }
+    T at(size_t i) const { return values_[(first_ + i) % N]; }  // 0: the oldest kept
+    void clear() { first_ = size_ = 0; }
+
+   private:
+    T values_[N] = {};
+    size_t first_ = 0, size_ = 0;
+};
+
+}  // namespace roro

lib/wifi/src/saved_networks.cpp

@@ -17,6 +17,8 @@ void SavedNetworks::load() {
         int32_t hidden = 0;
         store_.getInt(key(i, "hid").c_str(), hidden);
         net.hidden = hidden != 0;
+        std::string ip;  // "address/prefix [gateway]", or empty for Automatic
+        net.fixed = store_.getString(key(i, "ip").c_str(), ip) && !ip.empty() && net::parseFixed(ip, net.ip).empty();
         networks_.push_back(net);
     }
 }
@@ -40,11 +42,30 @@ std::string SavedNetworks::add(const std::string& ssid, const std::string& passw
         }
     }
     if (count() >= kMax) return "Already 8 saved networks: forget one first";
-    networks_.push_back({ssid, password, hidden});
+    SavedNetwork added;
+    added.ssid = ssid;
+    added.password = password;
+    added.hidden = hidden;
+    networks_.push_back(added);
     save();
     return "";
 }
 
+std::string SavedNetworks::setIp(const std::string& ssid, const net::FixedIp* fixed) {
+    for (auto& n : networks_) {
+        if (n.ssid != ssid) continue;
+        if (fixed) {
+            std::string why = net::checkFixed(*fixed);
+            if (!why.empty()) return why;
+            n.ip = *fixed;
+        }
+        n.fixed = fixed != nullptr;
+        save();
+        return "";
+    }
+    return "Not a saved network";
+}
+
 void SavedNetworks::forget(const std::string& ssid) {
     for (auto it = networks_.begin(); it != networks_.end(); ++it) {
         if (it->ssid == ssid) {
@@ -60,6 +81,7 @@ void SavedNetworks::save() {
         store_.putString(key(i, "ssid").c_str(), networks_[i].ssid);
         store_.putString(key(i, "pass").c_str(), networks_[i].password);
         store_.putInt(key(i, "hid").c_str(), networks_[i].hidden ? 1 : 0);
+        store_.putString(key(i, "ip").c_str(), networks_[i].fixed ? net::formatFixed(networks_[i].ip) : "");
     }
     store_.putInt("net_count", count());
 }

lib/wifi/src/saved_networks.h

@@ -3,6 +3,7 @@
 #include <string>
 #include <vector>
 
+#include "ipv4.h"
 #include "key_value_store.h"
 
 namespace roro {
@@ -11,6 +12,8 @@ struct SavedNetwork {
     std::string ssid;
     std::string password;  // empty for an open network
     bool hidden = false;   // doesn't broadcast its name, so never shows up in scans
+    bool fixed = false;    // S1, Q105: Fixed address (`ip`), or Automatic (DHCP)
+    net::FixedIp ip;
 };
 
 // The Saved Networks the Wi-Fi Service may join (see CONTEXT.md), persisted in internal flash.
@@ -28,6 +31,8 @@ class SavedNetworks {
     // Adds, or updates the password of an existing SSID. Empty on success, otherwise why not.
     std::string add(const std::string& ssid, const std::string& password, bool hidden = false);
     void forget(const std::string& ssid);
+    // The IP setting: Fixed with these values, or Automatic (DHCP) for nullptr. Empty, or why not.
+    std::string setIp(const std::string& ssid, const net::FixedIp* fixed);
 
    private:
     void save();

platformio.ini

@@ -19,6 +19,7 @@ build_flags =
     -DARDUINO_USB_MODE=1
 lib_deps =
     m5stack/M5Cardputer @ 1.1.1
+    jgromes/RadioLib @ 7.8.1
 test_ignore = *
 ; Smaller TLS buffers (M2): the framework is rebuilt with these settings (pioarduino "hybrid
 ; compile"). Receive stays 16 KB (servers send full TLS records); send drops to 4 KB (IRC lines are
@@ -45,3 +46,14 @@ build_flags =
 platform = native
 lib_ldf_mode = deep+
 build_flags = -std=gnu++17
+
+; The same tests, built to count which lines of lib/ they run (scripts/coverage.sh).
+[env:native-coverage]
+extends = env:native
+build_flags =
+    ${env:native.build_flags}
+    --coverage
+    -O0
+extra_scripts =
+    ${env.extra_scripts}
+    pre:scripts/coverage_link.py

scripts/_docker.sh

@@ -1,8 +1,10 @@
 # Shared helper: run a command inside the roro9stack build container.
+# With RORO_NO_DOCKER set, the caller is in such a container already (a CI job): the command runs
+# right here, in the checkout.
 IMAGE=roro9stack-build
 ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
 
-docker build -q -t "$IMAGE" "$ROOT/docker" >/dev/null
+[ -n "${RORO_NO_DOCKER:-}" ] || docker build -q -t "$IMAGE" "$ROOT/docker" >/dev/null
 
 # The Debug Console token (ADR 0004): made once, kept with the OTA key, never committed.
 DEBUG_TOKEN_FILE="$HOME/.config/roro9stack/debug-token"
@@ -12,6 +14,10 @@ if [ ! -s "$DEBUG_TOKEN_FILE" ]; then
 fi
 
 run_in_container() {
+    if [ -n "${RORO_NO_DOCKER:-}" ]; then
+        (cd "$ROOT" && RORO_DEBUG_TOKEN="$(cat "$DEBUG_TOKEN_FILE")" "$@")
+        return
+    fi
     docker run --rm \
         -u "$(id -u):$(id -g)" -e HOME=/tmp \
         -e RORO_DEBUG_TOKEN="$(cat "$DEBUG_TOKEN_FILE")" \

scripts/ci.sh

@@ -1,7 +1,14 @@
 #!/usr/bin/env bash
 # Local CI: run host unit tests, then build the firmware.
+# Usage: scripts/ci.sh [tests|builds]   one half only; both by default
 set -euo pipefail
 source "$(dirname "$0")/_docker.sh"
 DOCKER_EXTRA=()
 
-run_in_container bash -c 'git config --global --add safe.directory /work && pio test -e native && pio run -e cardputer-adv -e cardputer-adv-debug'
+case "${1:-all}" in
+    tests) STEPS='pio test -e native' ;;
+    builds) STEPS='pio run -e cardputer-adv -e cardputer-adv-debug' ;;
+    all) STEPS='pio test -e native && pio run -e cardputer-adv -e cardputer-adv-debug' ;;
+    *) echo "Usage: scripts/ci.sh [tests|builds]" >&2; exit 1 ;;
+esac
+run_in_container bash -c 'git config --global --add safe.directory "$PWD" && '"$STEPS"

scripts/coverage.sh

@@ -0,0 +1,21 @@
+#!/usr/bin/env bash
+# Runs the host tests and says how much of lib/ they run: they're built with coverage counters.
+# Usage: scripts/coverage.sh [out folder, default .pio/coverage]
+# Out: summary.json (gcovr), coverage.svg (the README's badge), index.html (line by line).
+# What it measures: the lines of lib/ that compile on a PC. Not lib/SD (the card's driver) and not
+# src/ (the Apps, the Services, everything that needs the device): those have no host tests.
+set -euo pipefail
+source "$(dirname "$0")/_docker.sh"
+DOCKER_EXTRA=()
+OUT="${1:-.pio/coverage}"
+
+run_in_container bash -c '
+    set -eo pipefail  # a failing test fails this script, tail or not
+    git config --global --add safe.directory "$PWD"
+    rm -rf .pio/build/native-coverage "'"$OUT"'"
+    mkdir -p "'"$OUT"'"
+    pio test -e native-coverage | tail -1
+    gcovr -r . --filter "lib/" --object-directory .pio/build/native-coverage \
+        --json-summary "'"$OUT"'/summary.json" --html-details "'"$OUT"'/index.html" --print-summary | tail -4
+    python3 scripts/coverage_badge.py "'"$OUT"'/summary.json" "'"$OUT"'/coverage.svg"
+'

scripts/coverage_badge.py

@@ -0,0 +1,46 @@
+#!/usr/bin/env python3
+"""Draws the README's coverage badge from gcovr's summary.
+
+Usage: scripts/coverage_badge.py <summary.json> <out.svg>
+       scripts/coverage_badge.py --plain <label> <value> <out.svg>   any other badge, in blue
+Also prints one line, and appends a short table to $GITHUB_STEP_SUMMARY when CI sets it.
+"""
+import json
+import os
+import sys
+
+
+def badge(label, value, color, title):
+    left, right = 6 * len(label) + 12, 7 * len(value) + 12
+    return f'''<svg xmlns="http://www.w3.org/2000/svg" width="{left + right}" height="20" role="img" aria-label="{label}: {value}">
+<title>{title}</title>
+<linearGradient id="s" x2="0" y2="100%"><stop offset="0" stop-color="#bbb" stop-opacity=".1"/><stop offset="1" stop-opacity=".1"/></linearGradient>
+<clipPath id="r"><rect width="{left + right}" height="20" rx="3" fill="#fff"/></clipPath>
+<g clip-path="url(#r)"><rect width="{left}" height="20" fill="#555"/><rect x="{left}" width="{right}" height="20" fill="{color}"/><rect width="{left + right}" height="20" fill="url(#s)"/></g>
+<g fill="#fff" text-anchor="middle" font-family="Verdana,Geneva,DejaVu Sans,sans-serif" font-size="11">
+<text x="{left / 2}" y="14">{label}</text><text x="{left + right / 2}" y="14">{value}</text></g></svg>
+'''
+
+
+def main():
+    if sys.argv[1] == "--plain":  # any other badge: --plain <label> <value> <out.svg>
+        label, value, out = sys.argv[2:5]
+        open(out, "w").write(badge(label, value, "#007ec6", f"{label}: {value}"))
+        return
+    summary = json.load(open(sys.argv[1]))
+    lines, branches = summary["line_percent"], summary["branch_percent"]
+    label, value = "lib coverage", f"{lines:.0f}%"
+    color = "#4c1" if lines >= 90 else "#a4a61d" if lines >= 75 else "#dfb317" if lines >= 60 else "#e05d44"
+    svg = badge(label, value, color, f"{label}: {value} of the lines of lib/ are run by the host tests")
+    open(sys.argv[2], "w").write(svg)
+    print(f"coverage of lib/: {lines:.1f}% of {summary['line_total']} lines, {branches:.1f}% of branches, {len(summary['files'])} files")
+    step = os.environ.get("GITHUB_STEP_SUMMARY")
+    if step:
+        worst = sorted((f["line_percent"], f["filename"]) for f in summary["files"] if f["line_total"] >= 10)[:5]
+        with open(step, "a") as out:
+            out.write(f"### Coverage of `lib/` by the host tests\n\n**{lines:.1f}%** of {summary['line_total']} lines, {branches:.1f}% of branches.\n\n")
+            out.write("| Least covered | Lines |\n|---|---|\n" + "".join(f"| `{name}` | {pct:.0f}% |\n" for pct, name in worst))
+
+
+if __name__ == "__main__":
+    main()

scripts/coverage_link.py

@@ -0,0 +1,4 @@
+# The coverage build must also link with --coverage (build_flags only reaches the compiler).
+Import("env")  # noqa: F821  (provided by PlatformIO)
+
+env.Append(LINKFLAGS=["--coverage"])  # noqa: F821

scripts/ota_verify.py

@@ -0,0 +1,49 @@
+#!/usr/bin/env python3
+"""Checks an Update File (.ota) the way the device does, on a PC: header, signature, image hash.
+
+Usage: scripts/ota_verify.py <file.ota> [public key, default keys/ota-public.pem]
+Exits 0 and prints the version if a device would accept the file.
+"""
+import hashlib
+import os
+import struct
+import subprocess
+import sys
+import tempfile
+
+HEADER_SIZE = 160
+SIGNED_BYTES = 80
+
+
+def main():
+    if len(sys.argv) < 2:
+        sys.exit(__doc__)
+    root = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+    key = sys.argv[2] if len(sys.argv) > 2 else os.path.join(root, "keys", "ota-public.pem")
+    data = open(sys.argv[1], "rb").read()
+    if len(data) < HEADER_SIZE or data[:8] != b"RORO-OTA":
+        sys.exit("not an update file")
+    fmt, header_size, image_size = struct.unpack("<HHI", data[8:16])
+    if fmt != 1 or header_size != HEADER_SIZE:
+        sys.exit("unsupported update format")
+    image = data[HEADER_SIZE:]
+    if len(image) != image_size:
+        sys.exit(f"the header announces {image_size} bytes of image, the file has {len(image)}")
+    if hashlib.sha256(image).digest() != data[16:48]:
+        sys.exit("image corrupted (hash mismatch)")
+    version = data[48:80].split(b"\0")[0].decode()
+    (sig_len,) = struct.unpack("<H", data[80:82])
+    with tempfile.NamedTemporaryFile() as signed, tempfile.NamedTemporaryFile() as sig:
+        signed.write(data[:SIGNED_BYTES])
+        signed.flush()
+        sig.write(data[82:82 + sig_len])
+        sig.flush()
+        ok = subprocess.run(["openssl", "dgst", "-sha256", "-verify", key, "-signature", sig.name, signed.name],
+                            capture_output=True).returncode == 0
+    if not ok:
+        sys.exit("bad signature (wrong key)")
+    print(f"{sys.argv[1]}: {version}, {image_size} bytes, signature good")
+
+
+if __name__ == "__main__":
+    main()

scripts/rdbg.py

@@ -224,10 +224,15 @@ def interactive(sock):
             sys.stdout.write(data.decode(errors="replace"))
             sys.stdout.flush()
         if sys.stdin in ready:
-            line = sys.stdin.readline()
+            # Straight from the descriptor: readline() takes every waiting line into Python's own
-            if not line:
+            # buffer and hands over one, and select() then sees nothing more to read. Piped input
+            # written while we were still connecting got stuck until the next line came.
+            data = os.read(sys.stdin.fileno(), 4096)
+            if not data:
                 return
-            sock.sendall(line.encode())
+            sock.setblocking(True)
+            sock.sendall(data)
+            sock.setblocking(False)
 
 
 def main():

scripts/release_build.sh

@@ -0,0 +1,62 @@
+#!/usr/bin/env bash
+# Builds what a release publishes, from a checkout of the repository at a tag (docs/milestones/R1.md).
+# Usage: scripts/release_build.sh <checkout> <out folder>
+#   <checkout>   a clone with its tags, at the commit to release: its own sources are built, with
+#                this copy's build image and signing tools, so an old tag can be released today.
+# The signing key is read from $RORO_OTA_KEY (a file), as scripts/make_ota.py does.
+# Out: roro9stack-<version>.ota (signed, checked), -factory.bin (USB), .elf.gz (to decode crashes),
+#      SHA256SUMS, and notes.md for the release's text.
+set -euo pipefail
+SRC="$(cd "$1" && pwd)"
+mkdir -p "$2"
+OUT="$(cd "$2" && pwd)"
+TOOLS="$(cd "$(dirname "$0")" && pwd)"
+
+VERSION="$(git -C "$SRC" describe --tags --always --dirty)"
+case "$VERSION" in
+    *-dirty) echo "release: $SRC has uncommitted changes ($VERSION)" >&2; exit 1 ;;
+esac
+git -C "$SRC" describe --tags --exact-match >/dev/null 2>&1 || { echo "release: $VERSION is not a tag" >&2; exit 1; }
+
+source "$TOOLS/_docker.sh"
+ROOT="$SRC"  # _docker.sh mounts $ROOT as /work: the checkout to build, not necessarily this copy
+DOCKER_EXTRA=()
+# A tag from before the framework was rebuilt with our settings (ADR 0006) can't link against a
+# rebuilt one left in the toolchain cache: it gets the framework's libraries as they come.
+if ! grep -q custom_sdkconfig "$SRC/platformio.ini"; then
+    run_in_container bash -c 'rm -rf "${PLATFORMIO_CORE_DIR:-/pio}/packages/framework-arduinoespressif32-libs"'
+fi
+run_in_container bash -c 'git config --global --add safe.directory "$PWD" && pio run -e cardputer-adv'
+
+BUILD="$SRC/.pio/build/cardputer-adv"
+NAME="roro9stack-$VERSION"
+"$TOOLS/make_ota.py" "$BUILD/firmware.bin" "$VERSION" "$OUT/$NAME.ota"
+# A wrong key must stop the release here, not on a device: checked against the public key the
+# sources being built carry (the tags from before Firmware Updates have none: today's, then).
+PUBLIC="$SRC/keys/ota-public.pem"
+[ -e "$PUBLIC" ] || PUBLIC="$TOOLS/../keys/ota-public.pem"
+"$TOOLS/ota_verify.py" "$OUT/$NAME.ota" "$PUBLIC"
+cp "$BUILD/firmware.factory.bin" "$OUT/$NAME-factory.bin"
+gzip -9 -c "$BUILD/firmware.elf" > "$OUT/$NAME.elf.gz"
+(cd "$OUT" && sha256sum "$NAME.ota" "$NAME-factory.bin" "$NAME.elf.gz" > SHA256SUMS)
+
+# The release's text: what the tag says, then what went in since the tag before.
+PREVIOUS="$(git -C "$SRC" describe --tags --abbrev=0 "$VERSION^" 2>/dev/null || true)"
+{
+    git -C "$SRC" tag -l --format='%(contents)' "$VERSION" | sed -e '/^-----BEGIN PGP/,$d'
+    echo
+    echo "## Files"
+    echo
+    echo "- \`$NAME.ota\`: the signed Update File. Copy it to \`/updates\` on the SD card and install it from Settings > Firmware or the Storage App, or push it over Wi-Fi with \`scripts/ota_push.py\`."
+    echo "- \`$NAME-factory.bin\`: the whole flash image, for a first install over USB at offset 0."
+    echo "- \`$NAME.elf.gz\`: the symbols, to decode a crash report from this build."
+    echo "- \`SHA256SUMS\`: checksums of the three."
+    if [ -n "$PREVIOUS" ]; then
+        echo
+        echo "## Changes since $PREVIOUS"
+        echo
+        git -C "$SRC" log --no-merges --format='- %s' "$PREVIOUS..$VERSION"
+    fi
+} > "$OUT/notes.md"
+echo "$VERSION" > "$OUT/version"
+ls -l "$OUT"

scripts/release_publish.py

@@ -0,0 +1,65 @@
+#!/usr/bin/env python3
+"""Creates or completes a Gitea release from what scripts/release_build.sh made.
+
+Usage: scripts/release_publish.py <folder>
+Environment: GITEA_API (https://host/api/v1), GITEA_REPO (owner/name), GITEA_TOKEN.
+Run again for the same version, it replaces the files and the text instead of failing.
+"""
+import json
+import os
+import sys
+import urllib.error
+import urllib.parse
+import urllib.request
+
+API = os.environ.get("GITEA_API", "").rstrip("/")
+REPO = os.environ.get("GITEA_REPO", "")
+TOKEN = os.environ.get("GITEA_TOKEN", "")
+
+
+def call(method, path, body=None, raw=None, content_type="application/json"):
+    data = raw if raw is not None else (json.dumps(body).encode() if body is not None else None)
+    request = urllib.request.Request(f"{API}/repos/{REPO}{path}", data=data, method=method)
+    request.add_header("Authorization", f"token {TOKEN}")
+    if data is not None:
+        request.add_header("Content-Type", content_type)
+    try:
+        with urllib.request.urlopen(request, timeout=300) as response:
+            text = response.read()
+            return response.status, json.loads(text) if text else None
+    except urllib.error.HTTPError as e:
+        return e.code, e.read().decode(errors="replace")[:300]
+
+
+def main():
+    if len(sys.argv) != 2 or not (API and REPO and TOKEN):
+        sys.exit(__doc__)
+    folder = sys.argv[1]
+    version = open(os.path.join(folder, "version")).read().strip()
+    notes = open(os.path.join(folder, "notes.md")).read()
+    files = sorted(f for f in os.listdir(folder) if f not in ("version", "notes.md"))
+
+    status, release = call("GET", f"/releases/tags/{urllib.parse.quote(version)}")
+    fields = {"tag_name": version, "name": f"roro9stack {version}", "body": notes, "draft": False, "prerelease": False}
+    if status == 200:
+        status, release = call("PATCH", f"/releases/{release['id']}", fields)
+    else:
+        status, release = call("POST", "/releases", fields)
+    if status not in (200, 201):
+        sys.exit(f"release: Gitea answered {status}: {release}")
+
+    for asset in release.get("assets") or []:  # a second run replaces what the first uploaded
+        if asset["name"] in files:
+            call("DELETE", f"/releases/{release['id']}/assets/{asset['id']}")
+    for name in files:
+        with open(os.path.join(folder, name), "rb") as f:
+            status, answer = call("POST", f"/releases/{release['id']}/assets?name={urllib.parse.quote(name)}", raw=f.read(),
+                                  content_type="application/octet-stream")
+        if status != 201:
+            sys.exit(f"release: uploading {name}: Gitea answered {status}: {answer}")
+        print(f"uploaded {name} ({answer['size']} bytes)")
+    print(f"published {release['html_url']}")
+
+
+if __name__ == "__main__":
+    main()

site/README.md

@@ -0,0 +1,45 @@
+# The roro9stack site
+
+Source of https://roro9stack.net (docs/milestones/W1.md): a [Zola](https://www.getzola.org/) site. The home page, an Install page with a browser flasher, and the list of releases so far; the user guide, how-tos, FAQ and developer docs come next.
+
+```
+config.toml           base_url, the repository and API addresses
+content/              the pages (Markdown, with their template named in the front matter)
+templates/            base, home, install, downloads, 404; illustrations/ is generated
+data/                 the App cards and the screenshots' captions
+static/               css, js, fonts (self-hosted), img, screens (real screenshots), vendor/esp-web-tools
+tools/                make_illustrations.py, check_site.py
+```
+
+## Build and look
+
+```sh
+docker run --rm -u "$(id -u):$(id -g)" -v "$PWD:/repo" -w /repo/site ghcr.io/getzola/zola:v0.22.0 build   # writes ./public
+docker run --rm -u "$(id -u):$(id -g)" -p 1111:1111 -v "$PWD:/repo" -w /repo/site ghcr.io/getzola/zola:v0.22.0 serve --interface 0.0.0.0
+python3 site/tools/check_site.py public    # what the pages promise, kept
+```
+
+Or `zola build` with a Zola of your own, in `site/` (or `zola --root site build` from the root). **The output goes to `public/` at the root of the repository,** not into `site/`: `output_dir` in `config.toml`, and git ignores that directory. The build reads the latest release and the list of releases from the Gitea API (`load_data`); if the server can't be reached, the pages say so instead of failing.
+
+## Publishing
+
+The web server pulls `main` and runs `zola build`, as for the blog. CI (`.gitea/workflows/site.yml`) builds the site and runs the checks when `site/`, `docs/`, `README.md` or `CONTEXT.md` change; the firmware workflow skips a change that touches only those.
+
+## Things to know
+
+- **The Install page needs Caddy's help.** Gitea's release downloads carry no CORS header, so the page asks the API from the browser only if Caddy, in front of Gitea, allows this origin:
+
+  ```caddy
+  @releases {
+      method GET HEAD
+      path /twisla/roro9stack/releases/download/* /api/v1/repos/twisla/roro9stack/releases*
+  }
+  header @releases Access-Control-Allow-Origin "https://roro9stack.net"
+  header @releases Vary Origin
+  ```
+
+  Without it the page says it can't reach the release server and points to the esptool steps.
+- **No third-party requests.** Fonts and the flasher library are served from here; `tools/check_site.py` fails the build if a page loads anything from another origin.
+- **Illustrations.** `templates/illustrations/*.html` are generated by `tools/make_illustrations.py`; run it again rather than editing them.
+- **Updating the flasher library:** see `static/vendor/esp-web-tools/README.txt`.
+- **Fonts** are DM Mono and Hanken Grotesk, under the SIL Open Font License (the licences are in `static/fonts/`).

site/config.toml

@@ -0,0 +1,28 @@
+# roro9stack.net (docs/milestones/W1.md). Build with `zola build`; the web server pulls main and does this.
+base_url = "https://roro9stack.net"
+title = "roro9stack"
+description = "Open firmware for the M5Stack Cardputer ADV with the Cap LoRa-1262: a LoRa scanner, GNSS, a Gemini browser, IRC, Wi-Fi tools, notes and more."
+default_language = "en"
+compile_sass = false
+build_search_index = false
+generate_feeds = false  # the devlog turns its own on (content/devlog/_index.md)
+feed_filenames = ["atom.xml"]
+# The built site goes to public/ at the root of the repository (git ignores it), whether Zola is run
+# from site/ or from the root with `--root site`.
+output_dir = "../public"
+
+[markdown]
+smart_punctuation = false
+
+[markdown.highlighting]
+# Classes instead of inline colours; Zola 0.22 still wants a theme and writes giallo.css, which the
+# templates don't link.
+style = "class"
+theme = "nord"
+
+[extra]
+author = "twisla"
+repo = "https://git.twis.la/twisla/roro9stack"
+api = "https://git.twis.la/api/v1/repos/twisla/roro9stack"
+blog = "https://experiments.twis.la"
+contact = "contact@roro9stack.net"

site/content/_index.md

@@ -0,0 +1,4 @@
++++
+title = "roro9stack"
+template = "index.html"
++++

site/content/dev/_index.md

@@ -0,0 +1,13 @@
++++
+title = "Developer docs"
+description = "How roro9stack is built, debugged, tested and released: the Debug Console, the build, the decisions and the plans, from the repository's own documents."
+template = "dev-index.html"
+sort_by = "weight"
+
+[extra]
+eyebrow = "Developer docs"
++++
+
+The firmware is open source (GPL-3.0) and lives on [Gitea](https://git.twis.la/twisla/roro9stack). It is built for one device, the M5Stack Cardputer ADV with the Cap LoRa-1262, and it is built to be **worked on without touching the device**: install a build over Wi-Fi, read its console, press its keys, take screenshots of it, copy files to and from its SD card, and fetch its crash dumps, all from a PC on the same network. The first section is about exactly that.
+
+Some of these pages are written by hand. The rest are **generated from the repository's own documents** (the decisions, the milestone plans, the README and the firmware's own `help` text), so they are never out of date: each says which file it comes from.

site/content/dev/build/_index.md

@@ -0,0 +1,13 @@
++++
+title = "Build, test and release"
+description = "Building the firmware, running the tests, flashing a device, and what happens between a commit and a release."
+template = "guide-index.html"
+page_template = "guide-page.html"
+sort_by = "weight"
+weight = 2
+
+[extra]
+eyebrow = "Developer docs"
++++
+
+The firmware is built, tested and released **in Docker**, so that a clean machine, your machine and the CI runner all get the same result. These pages say how. For the Debug Console, which is how you work on a device once it is flashed, see [Debug Builds and the Debug Console](/dev/debug/).

site/content/dev/build/build-and-test.md

@@ -0,0 +1,38 @@
++++
+title = "Build, test and release"
+description = "Docker is the only tool you need. How the firmware is built, how the host tests run, and what CI does on a pull request and on a tag."
+weight = 1
+
+[extra]
+docs = true
+source = "README.md"
+tag = "Build"
++++
+## Requirements
+
+Only **Docker** is needed. PlatformIO and the ESP32 toolchain run inside a container, and are cached in the `roro9stack-pio` Docker volume. The first build downloads about 1 GB and takes a few minutes.
+
+## Build and test (local CI)
+
+```sh
+scripts/ci.sh
+```
+
+This runs the host-side unit tests (`test/`, `native` environment), then builds the firmware. The output is `.pio/build/cardputer-adv/firmware.factory.bin`.
+
+`scripts/coverage.sh` runs the same tests with coverage counters and writes a line-by-line report to `.pio/coverage/index.html`. The badge above is its figure for `main`: the share of the lines of `lib/` that the host tests run. `lib/` is the logic that compiles on a PC; `lib/SD` (the card's driver) and `src/` (the Apps, the Services, everything that needs the device) have no host tests and aren't in that figure.
+
+The framework is rebuilt with the TLS settings in `platformio.ini` (`custom_sdkconfig`, ADR 0006), so the first build after a fresh checkout takes about 4 minutes; later builds take under a minute.
+
+## CI and releases
+
+Gitea Actions (`.gitea/workflows/ci.yml`, docs/milestones/R1.md) runs the host tests on every push to `main`, and on a pull request also builds the release firmware and the Debug Build: changes reach `main` through pull requests. Pushing a tag `v*` runs all of it and publishes a release on Gitea with:
+
+- `roro9stack-<version>.ota`, the signed Update File;
+- `roro9stack-<version>-factory.bin`, the whole flash image for a first install over USB;
+- `roro9stack-<version>.elf.gz`, to decode crash reports from that build;
+- `SHA256SUMS`.
+
+CI signs with the project's key, held as a repository secret (ADR 0008). Debug Builds are built but never published: each carries its builder's Debug Console token.
+
+`scripts/ota_verify.py <file.ota>` checks an Update File on a PC the way a device does. `scripts/release_build.sh` and `scripts/release_publish.py` are what the workflow runs; they work the same by hand.

site/content/dev/build/flash.md

@@ -0,0 +1,57 @@
++++
+title = "Flash and update"
+description = "Put the firmware on a Cardputer over USB, then update it over Wi-Fi or from the SD card, and from the project's releases."
+weight = 2
+
+[extra]
+docs = true
+source = "README.md"
+tag = "Flash"
++++
+## Flash
+
+1. Connect the Cardputer by USB-C.
+2. Run:
+
+   ```sh
+   scripts/flash.sh            # auto-detects the port; or: scripts/flash.sh /dev/ttyACM1
+   ```
+
+   This uploads the firmware, then opens the serial monitor. Quit the monitor with `Ctrl+C`.
+
+**If the upload can't connect,** put the device in download mode: hold **G0** (the button next to the screen) while plugging in USB, or while pressing reset. Then retry.
+
+**If you get "permission denied" on the port,** your user needs access to the serial device. Run this once, then log out and back in:
+
+```sh
+sudo usermod -aG dialout "$USER"
+```
+
+## Firmware Updates over Wi-Fi (OTA)
+
+Once the Cardputer runs an OTA-capable firmware (flashed once over USB), updates can go over Wi-Fi:
+
+```sh
+scripts/ota_keygen.sh                  # once: creates the signing key (see ADR 0003)
+scripts/flash.sh --ota 10.39.39.12     # build, sign and push; or set RORO_OTA_HOST
+```
+
+The device shows the push address in **Settings → Firmware**. It installs a correctly signed update right away, restarts (waiting up to 60 s if you're typing), and runs the new firmware on **Probation**. If the new firmware crashes, or can't reconnect Wi-Fi within 3 minutes, it rolls back to the previous one and says so.
+
+To install from the SD card instead, copy the `.ota` file from `.pio/build/cardputer-adv/` into `/updates` on the card, then use **Settings → Firmware**. With the Cardputer on USB, the card can stay in: `scripts/sd_put.sh <file.ota>` sends it over the serial console into `/updates` (about 30 s for 1.6 MB, checked with SHA-256 before it's renamed into place; `SD_PUT_DEBUG=1` shows the console while it runs).
+
+**The private key** lives in `~/.config/roro9stack/ota-key.pem` and must never be committed. If it's lost, generate a new pair and flash once over USB. (CI signs releases with a copy kept as a repository secret, ADR 0008.)
+
+### Updates from Gitea
+
+With no PC and no card, the device can install the project's releases itself (docs/milestones/R1.md). In **Settings → Firmware**:
+
+- **Latest release** checks the server (Enter, or `c`) and says `v0.11.0 (new)` or `(current)`. Enter again opens the release: its version, date, size and the tag's message, with **Install** when it's newer. The download goes straight into the inactive slot, so no card is needed; the signature is checked after the first 160 bytes, before anything is written, and the image's hash at the end. The new firmware then runs on Probation as for any update.
+- **Older releases** lists the last ten, newest first. Opening an older one offers to go back to it, with a different question.
+- **Settings → Check for updates** (on by default): once a day, with Wi-Fi up and the clock set, the device looks at the latest release and says `v0.11.0 is out: see Settings > Firmware`, once per version. It installs nothing by itself, and doesn't announce a version that already failed and rolled back on this device.
+
+The connection is checked against the two ISRG roots Let's Encrypt chains end in (ADR 0009), not the usual bundle of about 130 authorities. Whatever the connection, the Update File's own signature is what decides what gets installed.
+
+**IRC steps aside.** A secure connection takes about 52 KB of memory at its peak, and IRC's own takes 40 KB of the 107 KB there is. A check or an install you ask for makes IRC disconnect for the few seconds it takes and reconnect afterwards. The daily check never does that: with IRC connected it waits for a moment when IRC isn't, so while IRC stays connected for days it doesn't run, and **Latest release** is the way to check.
+
+**A Debug Build** shows the latest release but doesn't install it: releases have no Debug Console (they aren't built with one, so that nobody's console token is published), and installing one would take it away. A Debug Build is updated from the PC with `scripts/flash.sh --debug --ota`.

site/content/dev/build/how-an-update-works/index.md

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++++
+title = "How an update works"
+description = "The signed Update File, the four ways to get one onto a device, Probation and Rollback, and the check that sits in front of all of them."
+weight = 3
+[extra]
+tag = "Updates"
+diagrams = true
++++
+
+A **Firmware Update** installs one signed file, an **Update File** (`.ota`). Every way of delivering it ends at the same gate, and a new firmware must prove itself before it is kept. The decisions are [ADR 0003](/dev/decisions/0003-own-signature-check-not-secure-boot/) (the signature), [ADR 0005](/dev/decisions/0005-safe-mode-crash-reports-watchdog/) (when the new firmware crashes) and [ADR 0008](/dev/decisions/0008-ci-signs-releases/) (who signs releases).
+
+## The Update File
+
+{{ diagram(src="update-file.svg", min_width=580, caption="A 160-byte header, then the image. Bytes 0 to 79 are signed.") }}
+
+- A **160-byte header**: the magic `RORO-OTA`, the format, the header size, the image size, the image's **SHA-256** and the version (bytes 0 to 79, the signed part), then the signature's length, the **signature** and reserved bytes.
+- The signature is **ECDSA P-256 over the SHA-256 of bytes 0 to 79**, checked by the firmware against a **public key compiled into it** (`keys/ota-public.pem`, committed), **before anything is written**.
+- Then the **image**, hashed while it is written; at the end the hash must equal the one in the header.
+
+Make, check and push one:
+
+```sh
+scripts/ota_keygen.sh                                  # once: creates the key pair. The private key goes to ~/.config/roro9stack/ota-key.pem (never committed); the public key to keys/ and the firmware source
+scripts/make_ota.py firmware.bin v0.12.0 out.ota       # wraps and signs an image (the key: $RORO_OTA_KEY or the default path)
+scripts/ota_verify.py out.ota                          # checks a file the way a device does, on the PC
+scripts/ota_push.py out.ota 10.39.39.12                # pushes it to the Update Service, TCP 3232
+scripts/flash.sh --ota 10.39.39.12                     # builds, signs and pushes in one go (add --debug for a Debug Build)
+```
+
+`ota_push.py` prints the device's answer (`OK …`), or says the device **refused the update and hung up**, with the reason on the device's screen: the header is checked first, so a refused file stops mid-transfer.
+
+## Four ways in, one gate
+
+{{ diagram(src="ways-in.svg", min_width=580, caption="Every path ends at the same Update Service and the same signature check.") }}
+
+1. **Push over Wi-Fi** to TCP 3232: `scripts/flash.sh --ota`. The device always listens while Wi-Fi is connected.
+2. **From the SD card**: a `.ota` in `/updates`, installed from Settings → Firmware, from the Storage App, or with the `install <path>` command. Put it there by hand, with `scripts/rdbg.py put` over Wi-Fi, or with `scripts/sd_put.sh` over USB.
+3. **From the project's releases** on Gitea, which the device downloads itself over TLS (Settings → Firmware, or `update check` / `update install <tag>`): see [Flash and update](/dev/build/flash/).
+
+All three feed the same parser: the **header and signature are checked first**, the image is written to the **other app slot** while it is hashed, and the slot becomes the next boot **only if the hash matches**. Anything wrong ends in a Toast and **nothing changes**. A downgrade is allowed, and shows "older than the installed version".
+
+The device then restarts (waiting up to 60 seconds if you are typing) into **Probation**.
+
+## Probation and Rollback
+
+{{ diagram(src="probation.svg", min_width=620, caption="The life of an update: install, restart, Probation, confirmed. A crash or a restart before the last step sends the device back to the previous firmware.") }}
+
+A new image is **not trusted** at first:
+
+1. **Install:** the image goes to the other slot and the OTA data marks it *new*.
+2. **Restart:** the bootloader turns *new* into *pending verify* and boots it.
+3. **Probation:** the new firmware must boot, draw its UI, start its Services, run **30 seconds without a crash**, and **reconnect Wi-Fi within 3 minutes** if one is configured.
+4. **Confirmed:** it marks itself valid and a Toast says `Updated`.
+
+If it crashes or restarts first, the bootloader marks the image *aborted* and boots the **previous firmware** again, which says the update failed. Meanwhile that previous firmware stayed in its slot: it is the way back.
+
+**Two lines of defence.** The bootloader's rollback is the first. The firmware counts its own boots on Probation, very first thing in `setup()`, and reverts itself on the second unconfirmed start, as a second line. And Arduino-ESP32 normally marks an image valid *before* `setup()` runs, which once hid the bootloader's rollback entirely; the firmware overrides `verifyRollbackLater()` so an image stays pending until Probation confirms it.
+
+## Who signs releases
+
+A tag `v*` is built, signed and published by Gitea Actions, with the signing key held as a repository secret as well as on the maintainer's machine ([ADR 0008](/dev/decisions/0008-ci-signs-releases/) says what that costs and what limits it). The release step checks the signed file against the public key in the sources it built, so a wrong secret stops the release instead of publishing a file no device accepts.
+
+**If the private key is ever lost,** the next update has to go over USB, carrying a new public key. Someone with USB access can always flash anything: only Wi-Fi and SD card updates are guarded, by design (ADR 0003).

site/content/dev/build/how-an-update-works/probation.svg

@@ -0,0 +1,55 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 760 316" role="img" aria-label="The life of an update. One: install, the image goes to app1 and the OTA data marks it NEW. Two: restart, the bootloader turns NEW into PENDING_VERIFY and boots app1. Three: Probation, 30 seconds up, a frame drawn, and Wi-Fi within 3 minutes if it is configured. Four: confirmed, the firmware marks itself VALID and a Toast says Updated. If it crashes or restarts before step four, the bootloader turns PENDING_VERIFY into ABORTED and boots app0 again, which says the update failed. Meanwhile app0 kept the previous firmware: the way back. The trap, under step two: Arduino's initArduino marks the image VALID before setup runs, unless verifyRollbackLater returns true.">
+  <defs>
+    <marker id="pb-arrow" viewBox="0 0 10 10" refX="9" refY="5" markerWidth="7" markerHeight="7" orient="auto-start-reverse"><path d="M0,0 L10,5 L0,10 z" fill="currentColor"/></marker>
+    <marker id="pb-arrow-ok" viewBox="0 0 10 10" refX="9" refY="5" markerWidth="7" markerHeight="7" orient="auto-start-reverse"><path class="f-green" d="M0,0 L10,5 L0,10 z"/></marker>
+    <marker id="pb-arrow-bad" viewBox="0 0 10 10" refX="9" refY="5" markerWidth="7" markerHeight="7" orient="auto-start-reverse"><path class="f-red" d="M0,0 L10,5 L0,10 z"/></marker>
+  </defs>
+  <g font-family="JetBrains Mono, ui-monospace, monospace" fill="currentColor">
+    <rect class="pb-box" x="16" y="40" width="170" height="80" rx="6"/>
+    <text x="28" y="62" font-size="12" font-weight="600">1 install</text>
+    <text x="28" y="84" font-size="11">image → app1</text>
+    <text x="28" y="102" font-size="11" class="pb-dim">otadata: NEW</text>
+
+    <rect class="pb-box" x="206" y="40" width="170" height="80" rx="6"/>
+    <text x="218" y="62" font-size="12" font-weight="600">2 restart</text>
+    <text x="218" y="84" font-size="11">bootloader:</text>
+    <text x="218" y="102" font-size="11" class="pb-dim">NEW → PENDING_VERIFY</text>
+
+    <rect class="pb-hot" x="396" y="40" width="170" height="80" rx="6"/>
+    <text x="408" y="62" font-size="12" font-weight="600">3 Probation</text>
+    <text x="408" y="84" font-size="11">30 s up, a frame</text>
+    <text x="408" y="102" font-size="11" class="pb-dim">Wi-Fi within 3 min</text>
+
+    <rect class="pb-ok" x="586" y="40" width="158" height="80" rx="6"/>
+    <text x="598" y="62" font-size="12" font-weight="600">4 confirmed</text>
+    <text x="598" y="84" font-size="11">→ VALID</text>
+    <text x="598" y="102" font-size="11" class="pb-dim">Toast: Updated to…</text>
+
+    <path class="pb-line" d="M186 80 H202" marker-end="url(#pb-arrow)"/>
+    <path class="pb-line" d="M376 80 H392" marker-end="url(#pb-arrow)"/>
+    <path class="pb-line-ok" d="M566 80 H582" marker-end="url(#pb-arrow-ok)"/>
+
+    <rect class="pb-bad" x="396" y="196" width="348" height="76" rx="6"/>
+    <text x="408" y="218" font-size="12" font-weight="600">crash or restart before 4</text>
+    <text x="408" y="240" font-size="11">bootloader: PENDING_VERIFY → ABORTED</text>
+    <text x="408" y="258" font-size="11" class="pb-dim">boots app0: "Update to … failed"</text>
+    <path class="pb-line-bad" d="M481 120 V192" marker-end="url(#pb-arrow-bad)"/>
+    <text x="408" y="294" font-size="10" class="pb-dim">(second line: bootGuard() in setup() rolls back</text>
+    <text x="408" y="308" font-size="10" class="pb-dim"> a second unconfirmed start by itself)</text>
+
+    <text x="16" y="216" font-size="11" class="pb-dim">app0 keeps the</text>
+    <text x="16" y="232" font-size="11" class="pb-dim">previous firmware:</text>
+    <text x="16" y="248" font-size="11" class="pb-dim">the way back</text>
+
+    <rect class="pb-trap" x="206" y="176" width="170" height="122" rx="6"/>
+    <text class="f-red" x="218" y="198" font-size="12" font-weight="600">the trap</text>
+    <text x="218" y="220" font-size="11">initArduino()</text>
+    <text x="218" y="238" font-size="11">marks it VALID</text>
+    <text x="218" y="256" font-size="11">before setup(),</text>
+    <text x="218" y="274" font-size="11" class="pb-dim">unless verify-</text>
+    <text x="218" y="290" font-size="11" class="pb-dim">RollbackLater()</text>
+    <path class="pb-line-bad" d="M291 176 V124" marker-end="url(#pb-arrow-bad)"/>
+
+    <text x="16" y="22" font-size="13" font-weight="600">The life of an update</text>
+  </g>
+</svg>

site/content/dev/build/how-an-update-works/update-file.svg

@@ -0,0 +1,43 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 760 196" role="img" aria-label="The Update File: a 160-byte header, then the firmware image. Bytes 0 to 79 are signed: the magic RORO-OTA, the format, the header size, the image size, the image's SHA-256 and the version. Then the signature's length, the signature itself, and reserved bytes up to 160. The signature is ECDSA P-256 over the SHA-256 of bytes 0 to 79, checked before anything is written. The image follows, hashed while it is written, and must match the hash in bytes 16 to 47.">
+  <g font-family="JetBrains Mono, ui-monospace, monospace" fill="currentColor">
+    <text x="16" y="22" font-size="13" font-weight="600">Update File (.ota)</text>
+    <text x="16" y="40" font-size="11" class="uf-dim">a 160-byte header, little-endian, then the image</text>
+
+    <rect class="uf-signed" x="16" y="72" width="380" height="40" rx="4"/>
+    <rect class="uf-cell" x="16" y="72" width="64" height="40"/>
+    <rect class="uf-cell" x="80" y="72" width="40" height="40"/>
+    <rect class="uf-cell" x="120" y="72" width="40" height="40"/>
+    <rect class="uf-cell" x="160" y="72" width="52" height="40"/>
+    <rect class="uf-cell" x="212" y="72" width="100" height="40"/>
+    <rect class="uf-cell" x="312" y="72" width="84" height="40"/>
+    <rect class="uf-cell" x="396" y="72" width="40" height="40"/>
+    <rect class="uf-cell" x="436" y="72" width="92" height="40"/>
+    <rect class="uf-cell" x="528" y="72" width="32" height="40"/>
+    <rect class="uf-image" x="560" y="72" width="184" height="40"/>
+
+    <g font-size="10" text-anchor="middle">
+      <text x="48" y="96">RORO-OTA</text>
+      <text x="100" y="96">fmt</text>
+      <text x="140" y="96">hdr</text>
+      <text x="186" y="96">size</text>
+      <text x="262" y="96">image SHA-256</text>
+      <text x="354" y="96">version</text>
+      <text x="416" y="96">len</text>
+      <text x="482" y="96">signature</text>
+      <text x="544" y="96">0…</text>
+      <text x="652" y="96">the image, ~1.6 MB</text>
+    </g>
+    <g font-size="10" class="uf-dim" text-anchor="middle">
+      <text x="16" y="64">0</text><text x="80" y="64">8</text><text x="120" y="64">10</text><text x="160" y="64">12</text>
+      <text x="212" y="64">16</text><text x="312" y="64">48</text><text x="396" y="64">80</text><text x="436" y="64">82</text>
+      <text x="528" y="64">154</text><text x="560" y="64">160</text>
+    </g>
+
+    <path d="M16 120 V128 H396 V120" fill="none" stroke="var(--accent)" stroke-width="1.5"/>
+    <text x="206" y="150" font-size="11" text-anchor="middle" class="uf-hot">signed: ECDSA P-256 over SHA-256(bytes 0–79)</text>
+    <text x="206" y="168" font-size="11" text-anchor="middle" class="uf-dim">checked before a single byte is written</text>
+    <path d="M560 120 V128 H744 V120" fill="none" stroke="currentColor" stroke-opacity=".5" stroke-width="1.5"/>
+    <text x="652" y="150" font-size="11" text-anchor="middle" class="uf-dim">hashed while it's written;</text>
+    <text x="652" y="168" font-size="11" text-anchor="middle" class="uf-dim">must match bytes 16–47</text>
+  </g>
+</svg>

site/content/dev/build/how-an-update-works/ways-in.svg

@@ -0,0 +1,53 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 760 352" role="img" aria-label="Four ways in, one gate. scripts/flash.sh --ota signs the firmware and pushes it over Wi-Fi to TCP port 3232, straight to the Update Service. rdbg.py put over Wi-Fi, sd_put.sh over USB serial, or the card by hand all put an Update File in /updates on the SD card, where Settings, Firmware, or the install command picks it up. The Update Service checks the header and signature first, writes the image to the other app slot while hashing it, and makes it the next boot only if the hash matches. Then it restarts into Probation. If anything is wrong, a Toast says so and nothing changes.">
+  <defs>
+    <marker id="wi-arrow" viewBox="0 0 10 10" refX="9" refY="5" markerWidth="7" markerHeight="7" orient="auto-start-reverse"><path d="M0,0 L10,5 L0,10 z" fill="currentColor"/></marker>
+    <marker id="wi-arrow-hot" viewBox="0 0 10 10" refX="9" refY="5" markerWidth="7" markerHeight="7" orient="auto-start-reverse"><path class="f-accent" d="M0,0 L10,5 L0,10 z"/></marker>
+    <marker id="wi-arrow-bad" viewBox="0 0 10 10" refX="9" refY="5" markerWidth="7" markerHeight="7" orient="auto-start-reverse"><path class="f-red" d="M0,0 L10,5 L0,10 z"/></marker>
+  </defs>
+  <g font-family="JetBrains Mono, ui-monospace, monospace" fill="currentColor">
+    <rect class="wi-box" x="16" y="32" width="220" height="56" rx="6"/>
+    <text x="30" y="55" font-size="12" font-weight="600">flash.sh --ota</text>
+    <text x="30" y="75" font-size="11" class="wi-dim">builds, signs, pushes</text>
+    <rect class="wi-box" x="16" y="112" width="220" height="56" rx="6"/>
+    <text x="30" y="135" font-size="12" font-weight="600">rdbg.py put</text>
+    <text x="30" y="155" font-size="11" class="wi-dim">Debug Build, Wi-Fi 2323</text>
+    <rect class="wi-box" x="16" y="192" width="220" height="56" rx="6"/>
+    <text x="30" y="215" font-size="12" font-weight="600">sd_put.sh</text>
+    <text x="30" y="235" font-size="11" class="wi-dim">USB serial, card stays in</text>
+    <rect class="wi-box" x="16" y="272" width="220" height="56" rx="6" stroke-dasharray="4 3"/>
+    <text x="30" y="295" font-size="12" font-weight="600">the card, by hand</text>
+    <text x="30" y="315" font-size="11" class="wi-dim">the 1990s way</text>
+
+    <rect class="wi-panel" x="288" y="176" width="200" height="88" rx="8"/>
+    <text x="302" y="200" font-size="12" font-weight="600">SD card</text>
+    <text x="302" y="219" font-size="11">/updates/*.ota</text>
+    <text x="302" y="238" font-size="11" class="wi-dim">Settings → Firmware,</text>
+    <text x="302" y="254" font-size="11" class="wi-dim">or install &lt;path&gt;</text>
+
+    <rect class="wi-hot" x="536" y="32" width="208" height="158" rx="8"/>
+    <text x="550" y="56" font-size="12" font-weight="600">Update Service</text>
+    <text x="550" y="80" font-size="11">1 header, signature:</text>
+    <text x="550" y="96" font-size="11" class="wi-dim">  checked first</text>
+    <text x="550" y="118" font-size="11">2 image → other slot,</text>
+    <text x="550" y="134" font-size="11" class="wi-dim">  hashed on the way</text>
+    <text x="550" y="156" font-size="11">3 hash matches:</text>
+    <text x="550" y="172" font-size="11" class="wi-dim">  boot it next</text>
+
+    <rect class="wi-box" x="576" y="216" width="168" height="44" rx="6"/>
+    <text x="660" y="243" font-size="12" text-anchor="middle">restart → Probation</text>
+    <rect class="wi-bad" x="536" y="280" width="208" height="56" rx="6"/>
+    <text x="550" y="303" font-size="11">anything wrong: a Toast,</text>
+    <text x="550" y="321" font-size="11">and nothing changes</text>
+
+    <path class="wi-line-hot" d="M236 60 H532" marker-end="url(#wi-arrow-hot)"/>
+    <text class="f-accent" x="300" y="52" font-size="11">Wi-Fi · TCP 3232</text>
+    <path class="wi-line" d="M236 140 H262 V198 H284" marker-end="url(#wi-arrow)"/>
+    <path class="wi-line" d="M236 220 H284" marker-end="url(#wi-arrow)"/>
+    <path class="wi-line" d="M236 300 H262 V242 H284" marker-end="url(#wi-arrow)"/>
+    <path class="wi-line" d="M488 220 H512 V150 H532" marker-end="url(#wi-arrow)"/>
+    <text x="492" y="238" font-size="10" class="wi-dim">storage</text>
+    <text x="492" y="250" font-size="10" class="wi-dim">task</text>
+    <path class="wi-line" d="M660 190 V212" marker-end="url(#wi-arrow)"/>
+    <path class="wi-line-bad" d="M556 190 V276" marker-end="url(#wi-arrow-bad)"/>
+  </g>
+</svg>

site/content/dev/debug/_index.md

@@ -0,0 +1,22 @@
++++
+title = "Debug Builds and the Debug Console"
+description = "A firmware you can drive from your desk: its console over Wi-Fi, its screen as a PNG, its SD card, its crash dumps, and a way back when an update goes wrong."
+template = "guide-index.html"
+page_template = "guide-page.html"
+sort_by = "weight"
+weight = 1
+
+[extra]
+eyebrow = "Developer docs"
++++
+
+A **Debug Build** is the same firmware plus a **Debug Console**: the serial console, over Wi-Fi, behind a token. It is the most useful thing in the project. With it you can:
+
+- **see everything the device prints**, boot messages included, without a cable;
+- **run every serial command** from your desk;
+- **press keys** and **take screenshots**, so a UI change can be tested and looked at remotely;
+- **copy files** to and from the SD card;
+- **read crash reports and fetch core dumps**, decoded against the exact build that crashed;
+- **update the firmware** over the same Wi-Fi, and know that a bad update rolls back to a build that still has the console.
+
+Start with [Debug Builds](/dev/debug/debug-builds/) to put one on a device, then [the Debug Console](/dev/debug/console/). The rest are what you can do with it.