added config for nvidia/intel gpus and settings file

hardware/amdgpu.nix

@@ -1,8 +1,14 @@
-{ pkgs, config, ... }: {
+{ pkgs, lib, ... }:
+{
+    # Adapted from: https://github.com/NixOS/nixos-hardware/blob/master/common/gpu/amd/default.nix
 
     # Make the kernel use the correct driver early
     boot.initrd.kernelModules = [ "amdgpu" ];
 
+    # Make sure Xserver uses the `amdgpu` driver
+    services.xserver.enable = true;
+    services.xserver.videoDrivers = [ "amdgpu" ];
+
     # For 32 bit applications
     hardware.opengl.driSupport32Bit = true;
 
@@ -12,6 +18,11 @@
         rocmPackages.clr.icd
     ];
 
+    # For 32 bit applications 
+    hardware.opengl.extraPackages32 = with pkgs; [
+        driversi686Linux.amdvlk
+    ];
+
     environment.systemPackages = with pkgs; [
         nvtop-amd
         clinfo

hardware/default.nix

@@ -1,5 +1,11 @@
+{ lib, ... }:
+let
+    settings = import ./../settings.nix;
+in
 {
-    imports = [
+    # Optionally import modules for specific hardware
-        ./amdgpu.nix
+    imports = 
-    ];
+        lib.optionals settings.hardware.amdgpu [ ./amdgpu.nix ]
+        ++ lib.optionals settings.hardware.intelgpu [ ./intelgpu.nix ]
+        ++ lib.optionals settings.hardware.nvidiagpu [ ./nvidiagpu.nix ];
 }

hardware/intelgpu.nix

@@ -0,0 +1,16 @@
+{ pkgs, lib, ... }:
+{
+    # Excerpt: https://github.com/NixOS/nixos-hardware/blob/master/common/gpu/intel/default.nix
+
+    boot.initrd.kernelModules = [ "i915" ];
+
+    environment.variables = {
+        VDPAU_DRIVER = lib.mkIf config.hardware.opengl.enable (lib.mkDefault "va_gl");
+    };
+
+    hardware.opengl.extraPackages = with pkgs; [
+        (if (lib.versionOlder (lib.versions.majorMinor lib.version) "23.11") then vaapiIntel else intel-vaapi-driver)
+        libvdpau-va-gl
+        intel-media-driver
+    ];
+}

hardware/nvidia.nix

@@ -0,0 +1,8 @@
+{ pkgs, lib, ... }:
+{
+    # Excerpt from: https://github.com/NixOS/nixos-hardware/blob/master/common/gpu/nvidia/default.nix
+    services.xserver.videoDrivers = lib.mkDefault [ "nvidia" ];
+    hardware.opengl.extraPackages = with pkgs; [
+        vaapiVdpau
+    ];
+}

settings.nix

@@ -0,0 +1,7 @@
+{
+    hardware = {
+        amdgpu = true;
+        intelgpu = false;
+        nvidiagpu = false;
+    };
+}