beacon-buildroot/AGENTS.md

Beacon CM4 — Quick Reference

Full docs: beacon-buildroot/README.md

Build

cd ~/repos/buildroot-beacon
make -C rpi-buildroot-fork O=$(pwd)/output BR2_EXTERNAL=$(pwd)/beacon-buildroot -j$(nproc)
# outputs: output/images/rootfs.raucb  update.raucb  sdcard.img.xz

Flash (initial, EMMC_DISABLE jumper bridged)

./beacon-buildroot/scripts/flash-cm4.sh          # auto-detect
./beacon-buildroot/scripts/flash-cm4.sh /dev/sda  # explicit device

SSH / find IP

CM4=$(ip neigh show dev enp0s31f6 | awk '/e4:5f:01:e9:13:96/{print $1}')
sshpass -p beacon ssh user@$CM4   # login: user / beacon

OTA Update

# transfer (scp broken on Dropbear — use tee pipe):
sshpass -p beacon ssh user@$CM4 'sudo tee /upload/rootfs.raucb >/dev/null' \
  < output/images/rootfs.raucb
# install + reboot:
sshpass -p beacon ssh user@$CM4 'rauc install /upload/rootfs.raucb && sudo reboot'
# after reboot — find new IP, then:
sshpass -p beacon ssh user@$CM4 'rauc status mark-good && rauc status'

UART

picocom -b 115200 /dev/ttyUSB1                          # interactive (GPIO14/15)
socat -u /dev/ttyUSB1,b115200,rawer,crnl OPEN:/tmp/uart.log,creat,trunc &  # headless capture

Rescue

Short GPIO4 (pin 7) → GND (pin 9) during power-on → boots /dev/mmcblk0p2.

Secure Boot (Milestone 2)

update-pieeprom.sh -k private.pem && rpiboot -d secure-boot-recovery

Use existing private.pem — never regenerate it.