+++
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`.