arm64 was the last image in the household whose identity was typed in by hand
after building — Raspberry Pi Imager's OS Customisation dialog set the hostname
per unit at flash time. That's the exact step CoreSystemConfig.json exists to
remove, and it failed quietly when mistyped: spotify-connect-start reads
$(hostname) at service start, so a typo doesn't error, it just puts a Spotify
Connect device with the wrong room name in the picker.
The builder now substitutes the endpoint's hostname from the audio_endpoints
array into a generated copy of config/audio-endpoint.yaml and builds one image
per room, published like every other image as
iso-out/smarthome-<hostname>-<pairid>.img. The substitution is targeted rather
than a YAML round-trip: that template is mostly comments explaining an
unverified schema, and a load/dump would strip every one of them. It fails loudly
if it doesn't match exactly once, rather than shipping an image named after the
wrong room.
The cost is honest and documented: one full rpi-image-gen run per arm64 room,
qemu-emulated on an x86 builder, instead of one for all of them.
build.arm64_prebake: false restores the single generic image for households with
several arm64 rooms and a slow builder. Wi-Fi and SSH keys are still set in
Imager on arm64 either way — only the hostname moved into the build.
Also fixes the image-publishing search, which used `find -newer $BUILD_CONFIG`
and silently found nothing when the build finished within the same filesystem
timestamp granularity as the config write. Newest .img wins instead.
Resolves the per-room-identity asymmetry in project-plan Phase 15.5.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Amir Alexander Abdelbaki
2a87996cbb