Files
Emma Thorpe f41879710c feat(nixos): disk hygiene, dedupe shared options, fix MacPro docs
- common-nixos: nix.settings.auto-optimise-store + larger download buffer.
- workstation: fstrim, boot.tmp.cleanOnBoot, and the shared graphical
  options moved here from the per-host configs (pipewire, swaylock PAM
  stub, redistributable firmware) -- MBP-Asahi gains audio it lacked.
- T400: zramSwap for the low-RAM host.
- MBP-Asahi: nixos-apple-silicon binary cache substituter.
- MacPro31 README: describe the real (LVM/UUID) hardware config; it is no
  longer a placeholder.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-06-10 15:08:10 +01:00

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3.4 KiB
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# 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
```sh
sudo nixos-rebuild switch --flake .#lyrathorpe-t400
```