{ config, lib, pkgs, ... }: { options.boot.initrd.services.bcache.enable = (lib.mkEnableOption "bcache support in the initrd") // { visible = false; # only works with systemd stage 1 }; config = { environment.systemPackages = [ pkgs.bcache-tools ]; services.udev.packages = [ pkgs.bcache-tools ]; boot.initrd.extraUdevRulesCommands = lib.mkIf (!config.boot.initrd.systemd.enable) '' cp -v ${pkgs.bcache-tools}/lib/udev/rules.d/*.rules $out/ ''; boot.initrd.services.udev = lib.mkIf config.boot.initrd.services.bcache.enable { packages = [ pkgs.bcache-tools ]; binPackages = [ pkgs.bcache-tools ]; }; }; }