The sintra live ISO (live.nix) had no serial support — ftdi_sio and the
ttyJ5/ttyJ7 udev symlinks were only in hardware/upboard.nix (installed), so
booting iso-sintra on real hardware failed on the validator + F56 dispenser
while the disk image worked. The two definitions had already drifted (live's
tejo block lacked ttyS4).
Extract the UP Board serial peripherals (usbserial/ftdi_sio/cp210x, the
ttyJ4/ttyJ5/ttyJ7 udev symlinks + permissions, console=tty0) into
hardware/upboard-serial.nix and import it from both upboard.nix (installed
tejo + sintra) and live.nix (sintra only). Single source of truth — the two
artifacts can't drift again. Named upboard-serial (not sintra-serial) since
upboard.nix serves both tejo-installed and sintra-installed.
Camera + LED/SPI rules stay inline in upboard.nix (installed-specific; the
pairing camera works via getUserMedia without the scanner symlink). Verified
by eval: live sintra now carries ftdi_sio + console=tty0 + ttyJ7; installed
sintra/tejo unchanged (serial present, camera present, no console dupe).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The USB disk image was systemd-boot (UEFI-only) with make-disk-image's "efi"
table (pure GPT + ESP, protective MBR). The Sintra's Aaeon UP Board firmware
USB-boots in Legacy/BIOS mode — it boots the live ISO via that ISO's isolinux
(BIOS) El Torito image, not the UEFI ESP — so a dd'd systemd-boot image has no
BIOS boot code to execute and the firmware won't list it (a hand-added hybrid
MBR didn't help: nothing to run).
Switch the USB target to GRUB with BIOS + UEFI on make-disk-image's "hybrid"
table: it adds a bios_grub partition, GRUB writes its BIOS stage to the MBR AND
a removable /EFI/BOOT/BOOTX64.EFI — mirroring the live ISO's dual boot. The
Aaeon now lists it (as two "ia android" entries, BIOS + UEFI) and boots it.
Scoped to disk-image-sintra-usb only; the eMMC install keeps systemd-boot.
ESP stays partition 1 so the ESP-USB relabel step is unchanged.
Verified on hardware: booted from USB into the wizard with the full upboard.nix
hardware config.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The disk image was ~6.2 GiB of closure, largely desktop/multimedia baggage a
single-purpose Electron kiosk never uses. Cut the clearly-unused stacks:
- services.speechd off → drops speech-dispatcher's espeak-ng + mbrola voices
(~1 GB text-to-speech). An ATM does not talk.
- v4l-utils built withGUI=false → drops the entire Qt6 stack (~0.5 GB) that only
backed the qv4l2 GUI; the v4l2-ctl CLI we actually use for the camera stays.
- documentation off (man/info/NixOS manual) — nobody reads them on a kiosk.
Closure 6.2 → 5.0 GiB. The remaining bulk is electron's own runtime (gtk4/
gstreamer/pipewire, unavoidable), mesa+llvm (GPU), and linux-firmware — those
need heavier / riskier work to touch. Distribute the image as .img.zst.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
