Customize bootloader entry w/ systemd-boot?


I came across this reddit thread discussing the system.nixos.label option and the NIXOS_LABEL environment variable.

They seem to have no effect with systemd-boot, so I was wondering if anyone knows how I can customize how the generations appear in the bootloader. I’d like to include the git commit hash & message.


The script building the entries should be this and the entry is build specifically here. But it seems it does not have any support for having the NIXOS_LABEL thing.
Possibly that is somehow refering to that as i found code writing the system.nixos.label to nixos-version, but actually idk how they are connected :slight_smile:

edit x: actually it seems that config.system.nixos.label does match with what is written do the description, at least for my system.

 cat /boot/loader/entries/nixos-generation-699.conf
title NixOS
version Generation 699 NixOS iamatest, Linux Kernel 6.1.53-xanmod1, Built on 2023-09-21


  system.nixos.label = "iamatest";