{
  pkgs,
  tiny-dfr ? pkgs.tiny-dfr
}:
  assert tiny-dfr.version == "0.3.1";
{
  services.udev.packages = [ tiny-dfr ];
  systemd.services.tiny-dfr = {
    enable = true;
    description = "tiny-dfr";
    after = ["systemd-user-sessions.service" "getty@tty1.service" "plymouth-quit.service" "systemd-logind.service" "dev-tiny_dfr_display.device" "dev-tiny_dfr_backlight.device" "dev-tiny_dfr_display_backlight.device"];
    wantedBy = ["multi-user.target"];
    bindsTo = ["dev-tiny_dfr_display.device" "dev-tiny_dfr_backlight.device" "dev-tiny_dfr_display_backlight.device"];
    startLimitIntervalSec = 30;
    startLimitBurst = 2;
    serviceConfig = {
      ExecStart = "${tiny-dfr}/bin/tiny-dfr";
      Restart = "always";
    };
  };
  environment.etc."tiny-dfr/next-workspace.svg".source = ./tiny-dfr-icons/next-workspace.svg;
  environment.etc."tiny-dfr/prev-workspace.svg".source = ./tiny-dfr-icons/prev-workspace.svg;
  environment.etc."tiny-dfr/brightness_high.svg".source = ./tiny-dfr-icons/brightness_high.svg;
  environment.etc."tiny-dfr/brightness_low.svg".source = ./tiny-dfr-icons/brightness_low.svg;
  environment.etc."tiny-dfr/backlight_high.svg".source = ./tiny-dfr-icons/backlight_high.svg;
  environment.etc."tiny-dfr/backlight_low.svg".source = ./tiny-dfr-icons/backlight_low.svg;
  environment.etc."tiny-dfr/play_pause.svg".source = ./tiny-dfr-icons/play_pause.svg;
  environment.etc."tiny-dfr/fast_forward.svg".source = ./tiny-dfr-icons/fast_forward.svg;
  environment.etc."tiny-dfr/fast_rewind.svg".source = ./tiny-dfr-icons/fast_rewind.svg;
  environment.etc."tiny-dfr/volume_up.svg".source = ./tiny-dfr-icons/volume_up.svg;
  environment.etc."tiny-dfr/volume_down.svg".source = ./tiny-dfr-icons/volume_down.svg;
  environment.etc."tiny-dfr/volume_off.svg".source = ./tiny-dfr-icons/volume_off.svg;
  environment.etc."tiny-dfr/config.toml".source = (pkgs.formats.toml {}).generate "tiny-dfr-config" {
    FontTemplate = "monospace-12";
    ActiveBrightness = 255;
    ShowButtonOutlines = false;
    MediaLayerDefault = true;

    MediaLayerKeys = [
      { Icon = "prev-workspace";  Action = "Finance"; } # bind me in the window manager!
      { Icon = "next-workspace";  Action = "Sport"; }   # bind me in the window manager!
      { Icon = "brightness_low";  Action = "BrightnessDown"; }
      { Icon = "brightness_high"; Action = "BrightnessUp";   }
      { Icon = "backlight_low";   Action = "IllumDown";      }
      { Icon = "backlight_high";  Action = "IllumUp";        }
      { Icon = "fast_rewind";     Action = "PreviousSong";   }
      { Icon = "play_pause";      Action = "PlayPause";      }
      { Icon = "fast_forward";    Action = "NextSong";       }
      { Icon = "volume_off";      Action = "Mute";           }
      { Icon = "volume_down";     Action = "VolumeDown";     }
      { Icon = "volume_up";       Action = "VolumeUp";       }
    ];
    PrimaryLayerKeys = [
      { Text = "F1";  Action = "F1";       }
      { Text = "F2";  Action = "F2";       }
      { Text = "F3";  Action = "F3";       }
      { Text = "F4";  Action = "F4";       }
      { Text = "F5";  Action = "F5";       }
      { Text = "F6";  Action = "F6";       }
      { Text = "F7";  Action = "F7";       }
      { Text = "F8";  Action = "F8";       }
      { Text = "3";  Action = "Num3";       }
      { Text = "F10"; Action = "F10";      }
      { Text = "F11"; Action = "F11";      }
      { Text = "F12"; Action = "F12";      }
    ];
  };
}