A headless aarch64 companion for a Psion 5MX: PPP over RS232 with NAT out to
wifi and a telnet login, plus a cleartext POP3/SMTP proxy for the Psion's mail
client.
- hosts/PiZero2W/: host config, serial-ppp.nix, email-proxy.nix, an SD-image
variant, and a hardware-configuration.nix placeholder.
- Host table entry on nixos-hardware's raspberry-pi-3 profile; the Zero 2 W is
the Pi 3's BCM2837 SoC. nixpkgs' linuxPackages_rpi02w is deprecated and warns
that the linux-rpi series is being removed in favour of nixos-hardware.
- The host owns its firmware partition (hardware.raspberry-pi.firmware), which
is what puts the disable-bt and uart0/ctsrts overlays in config.txt so
/dev/ttyAMA0 is the RS232 header rather than Bluetooth. uboot.enable keeps the
U-Boot -> extlinux boot path the rewritten config.txt would otherwise lose.
- packages.aarch64-linux.zero2w-sd-image: the host's own configuration as an
installable card. The board has no Ethernet and no free serial port, so a
generic image would leave no way in.
- The mail proxy comes from the legacy-email-proxy flake, which provides the
package and the NixOS module; nothing about it is vendored here.
- docs/hosts/pizero2w.md, plus README host table and shared-layer notes.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
