config/hardware/gpu/rocm.nix

{ pkgs, lib, ... }:
{
  # assumes common-gpu-amd from nixos-hardware is also added
  # TODO: should we move it from flake.nix to here?

  # nixos-hardware common-amd options
  # https://github.com/NixOS/nixos-hardware/blob/master/common/gpu/amd/default.nix
  hardware.amdgpu.opencl = true;
  hardware.amdgpu.amdvlk = true;

  hardware.opengl.enable = true;
  # https://libreddit.noximilien.pbsds.net/r/archlinux/comments/nih9c9/amdgpu_vs_modesetting_in_current_510_kernels_xorg/
  services.xserver.videoDrivers = [ "amdgpu" ]; # use gpu, adaptive sync and and hardware page flipping
  #services.xserver.videoDrivers = [ "modesetting" ]; # integrated (non-accelerated) framebuffer, KMS
  hardware.opengl.driSupport = true;
  hardware.opengl.driSupport32Bit = true;
  hardware.opengl.extraPackages = [
    pkgs.rocm-opencl-icd
    (if (lib.versionOlder (lib.versions.majorMinor lib.version) "23.11")
      then pkgs.rocm-runtime#-ext
      else pkgs.rocmPackages.rocm-runtime
    )
  ];

  nixpkgs.config.openglSupport = true; # why is this not set by hardware.opengl.enable ?
  nixpkgs.config.rocmSupport = true;
  nixpkgs.config.vdpauSupport  = true;
  nixpkgs.config.vaapiSupport  = true;

  # https://nixos.wiki/wiki/AMD_GPU#HIP
  systemd.tmpfiles.rules = let
    hip = if (lib.versionOlder (lib.versions.majorMinor lib.version) "23.11")
      then pkgs.hip
      else pkgs.rocmPackages.clr;
  in [
    "L+    /opt/rocm/hip   -    -    -     -    ${hip}"
  ];

  environment.systemPackages = with pkgs; [
    nvtop-amd
  ];
}