Plymouth / greeter theme notes (lab)

Updated

July 30, 2026

Goal

Visible product identity on boot/login without shipping megabytes of third-party themes you do not license.

Practical path on 26.05

  1. Console first — console.colors, console.font, /etc/issue (Projects 5–6). Cheap and reliable in QEMU.
  2. Plymouth — boot.plymouth.enable = true with a stock theme (spinner, etc.) while learning. Custom themes = package a theme derivation later.
  3. Greeter logo — option names depend on GDM/SDDM/LightDM and nixpkgs revision. Verify on your pin; if missing, set wallpaper via Home Manager on installed systems.
  4. ISO volume label — isoImage.volumeID / isoImage.isoName when using installer profiles.

Custom Plymouth (stretch)

  • Theme = directory of script + images under the Plymouth theme path.
  • Package with stdenv.mkDerivation installing into $out/share/plymouth/themes/....
  • Reference via boot.plymouth.themePackages + boot.plymouth.theme.
  • Test only in a VM with enough RAM; Plymouth failures are painful on metal.

Assets in this folder

Use logo.svg as a greeter/docs mark. Convert to PNG if a greeter requires bitmap:

# if rsvg-convert available
rsvg-convert -w 256 logo.svg -o logo.png