nix-config/modules/desktop/xserver.nix

{
  flake.modules.nixos.xserver = {
    config,
    lib,
    ...
  }:
    with lib; let
      cfg = config.mySystem.desktop.xserver;
    in {
      options.mySystem.desktop.xserver = {
        videoDrivers = mkOption {
          type = types.listOf types.str;
          default = [];
          example = ["amdgpu"];
          description = "Extra X11 video drivers to load";
        };
      };
      config.services.xserver = {
        enable = true;
        videoDrivers = cfg.videoDrivers;
        xkb = {
          layout = "fr";
          variant = "bepo_afnor";
        };
      };
    };
}