Files
nixfiles/hosts/T400/README.md
T
Emma Thorpe 10cc6cceed refactor(flake): add user registry and multi-user host support
Separate user identity (data) from the reusable modules, and let a host
declare any number of users instead of exactly one.

- users/registry.nix: per-user identity (name, email, groups, authorized
  and signing keys) as the single source of identity; no user data is
  hardcoded in the modules.
- mkHost takes a `users` set keyed by username; per-user identity is
  injected into each home config via the `identity` module arg
  (extraSpecialArgs is per-host, so it cannot carry per-user data).
- modules/users.nix builds accounts from the registry; modules/ssh.nix no
  longer defines authorized keys (the registry owns them); home/git.nix
  and home/desktop.nix read `identity`; users/emmathorpe/work.nix drops
  its now-redundant git identity override.
- Restructure the tree: users/, home/, modules/, hosts/, lib/ replace the
  former lyrathorpe/ and system/ layout.
- Add standalone homeConfigurations (the portable subset: shell, git,
  editor, claude) and an exported homeModules output for use on machines
  not managed by this flake, or as an input to other flakes.

Behaviour-preserving for existing hosts: lyrathorpe-mbp and
emmathorpe-edaas evaluate to identical derivations; lyrathorpe-t400,
lyrathorpe-macpro31 and lyrathorpe-rpi5 differ only by de-duplicating a
repeated authorized_keys entry. Fixes the SSH authorized-key leak (one
user's key was applied to every account), the hardcoded default git
identity, and the hardcoded EDaaS linger setting.
2026-06-29 12:27:52 +01:00

3.4 KiB

ThinkPad T400 — install notes

Flake host: lyrathorpe-t400. Files: configuration.nix, the boot-*.nix variants, and hardware-configuration.nix.

Hardware configuration

hardware-configuration.nix here is a hand-written placeholder. On the real machine, run nixos-generate-config, replace the file, and commit it. It assumes by-label partitions — root nixos (ext4) and swap — so either label them at install time or swap in the generated UUIDs.

Bootloader — import the module matching the flashed firmware

configuration.nix imports exactly one boot module. Default is boot-bios.nix; switch by commenting it out and uncommenting the relevant alternative.

Firmware Module Notes
Stock Lenovo BIOS, or coreboot + SeaBIOS payload boot-bios.nix GRUB on the MBR. Set device to the real install disk (/dev/sda by default). MBR/legacy layout.
coreboot + GRUB payload boot-coreboot-grub.nix GRUB is config-only (device = "nodev"); NixOS does not write to a disk. Your coreboot grub.cfg (in the flash chip) must search for and configfile the on-disk /boot/grub/grub.cfg, or chainload the disk's GRUB.
coreboot + Tianocore/edk2 (UEFI) payload boot-coreboot-uefi.nix systemd-boot. canTouchEfiVariables = true (coreboot honours NVRAM writes). The module declares its own ESP (/boot vfat, label ESP) — when you regenerate hardware-configuration.nix, do not let it also define /boot. Create + label an ESP vfat partition (GPT).

Graphics

This unit has the optional discrete ATI Mobility Radeon HD 3470 (RV620). The open radeon KMS driver is loaded in the initrd for early modesetting; firmware comes from enableRedistributableFirmware.

The T400 has switchable graphics (discrete ATI + Intel GMA 4500MHD). Select Discrete in the firmware's graphics setting so only the ATI is live. If you run Integrated instead, the Intel i915 driver takes over with no config change and radeon stays idle.

Login

Graphical login via a Wayland greeter — greetd running ReGreet inside the cage kiosk compositor — configured centrally in lyrathorpe/swaywm.nix for every Sway host (gated on features.swayDesktop.enable). The greeter is forced to the Dvorak layout to match the console and Sway session. Set the user password (passwd lyrathorpe) after install, or the greeter cannot authenticate. Requires working radeon/i915 KMS (see Graphics).

Apply

sudo nixos-rebuild switch --flake .#lyrathorpe-t400