puzzlevision/modules/nixos/common/grub/default.nix

{
  lib,
  pkgs,
  inputs,

  namespace, # The flake namespace, set in flake.nix. If not set, defaults to "internal".
  system, # The system architecture for this host (eg. `x86_64-linux`).
  target, # The Snowfall Lib target for this system (eg. `x86_64-iso`).
  format, # A normalized name for the system target (eg. `iso`).
  virtual, # A boolean to determine whether this system is a virtual target using nixos-generators.
  systems, # An attribute map of your defined hosts.

  config,
  ...
}: with lib; with lib.${namespace};
let
  cfg = config.${namespace}.common.grub;
in {
  options.${namespace}.common.grub = { enable = mkEnableOption "grub"; };

  config = mkIf cfg.enable {
    boot.loader.grub = {
      enable = true;
      devices = [ "nodev" ];
      efiInstallAsRemovable = true;
      efiSupport = true;

      extraEntries = ''
        menuentry "Reboot" {
          reboot
        }
        menuentry "Poweroff" {
          halt
        }
      '';
    };
  }
}