[root@nixos:~]# cat /etc/nixos/configuration.nix
{ config, pkgs, lib, ... }:
{
  # NixOS wants to enable GRUB by default
  boot.loader.grub.enable = false;
  # Enables the generation of /boot/extlinux/extlinux.conf
  boot.loader.generic-extlinux-compatible.enable = true;

  # !!! If your board is a Raspberry Pi 1, select this:
  # boot.kernelPackages = pkgs.linuxPackages_rpi;
  # !!! Otherwise (even if you have a Raspberry Pi 2 or 3), pick this:
  boot.kernelPackages = pkgs.linuxPackages_latest;

  # !!! This is only for ARMv6 / ARMv7. Don't enable this on AArch64, cache.nixos.org works there.
  nix.binaryCaches = lib.mkForce [ "http://nixos-arm.dezgeg.me/channel" ];
  nix.binaryCachePublicKeys = [ "nixos-arm.dezgeg.me-1:xBaUKS3n17BZPKeyxL4JfbTqECsT+ysbDJz29kLFRW0=%" ];

  # !!! Needed for the virtual console to work on the RPi 3, as the default of 16M doesn't seem to be enough.
  boot.kernelParams = ["cma=32M"];

  # File systems configuration for using the installer's partition layout
  fileSystems = {
    "/boot" = {
      device = "/dev/disk/by-label/NIXOS_BOOT";
      fsType = "vfat";
    };
    "/" = {
      device = "/dev/disk/by-label/NIXOS_SD";
      fsType = "ext4";
    };
  };

  # !!! Adding a swap file is optional, but strongly recommended!
  # swapDevices = [ { device = "/swapfile"; size = 1024; } ];

  networking.hostName = "nixpie";

  time.timeZone = "Europe/Amsterdam";

    services.avahi = {
    enable = true;
    publish.enable = true;
    publish.addresses = true;
    publish.userServices = true;

    nssmdns = true;
    interfaces = ["eth0" ];
  };

  environment.systemPackages = with pkgs; [
     wget vim
  ];

  services.openssh.enable = true;

  users.extraUsers.michaelk = {
    isNormalUser = true;
    uid = 1000;
  };

  services.xserver.enable = true;
  services.xserver.layout = "us";
  services.xserver.xkbOptions = "eurosign:e";

  services.xserver.desktopManager.xfce.enable = true;

  services.xserver.displayManager.auto = {
    enable = true;
    user = "michaelk";
  };

  services.xserver.inputClassSections = [
    ''
	Identifier		"calibration"
	MatchProduct 		"eGalax Inc."
	Option	"Calibration"	"1522 191 362 1556"
	Option	"SwapAxes"	"1"
	Option	"InvertX" "1"
	Option	"InvertY" "1"
    '' ];

  services.xserver.videoDrivers = [ "modesetting" ];

}