refactor(nixos): move cpu and gpu config to modules

configs/hardware/nvidia.nix

@@ -1,45 +0,0 @@
-{
-  inputs,
-  pkgs,
-  config,
-  ...
-}:
-{
-  # Accept the license by default; needed for some packages.
-  nixpkgs.config.nvidia.acceptLicense = true;
-  nix.settings = {
-    substituters = [ "https://cuda-maintainers.cachix.org" ];
-    trusted-public-keys = [
-      "cuda-maintainers.cachix.org-1:0dq3bujKpuEPMCX6U4WylrUDZ9JyUG0VpVZa7CNfq5E="
-    ];
-  };
-  services.xserver.videoDrivers = [ "nvidia" ];
-  environment.variables = {
-    GBM_BACKEND = "nvidia-drm";
-    LIBVA_DRIVER_NAME = "nvidia";
-    __GLX_VENDOR_LIBRARY_NAME = "nvidia";
-  };
-  hardware = {
-    enableRedistributableFirmware = true;
-    nvidia-container-toolkit.enable = true;
-    graphics = {
-      enable = true;
-      extraPackages = with pkgs; [
-        nvidia-vaapi-driver # hardware acceleration
-      ];
-    };
-    nvidia = {
-      modesetting.enable = true;
-      open = false;
-      nvidiaSettings = true;
-      nvidiaPersistenced = true;
-      package = config.boot.kernelPackages.nvidiaPackages.latest;
-    };
-  };
-  boot.initrd.availableKernelModules = [
-    "nvidia"
-    "nvidia_modeset"
-    "nvidia_uvm"
-    "nvidia_drm"
-  ];
-}

hosts/apollo.nix

@@ -1,11 +1,8 @@
-{ lib, config, ... }:
 {
   imports = [
     ../configs/filesystems/impermanence.nix
     ../configs/services.nix
   ];
-  boot.kernelModules = [ "kvm-intel" ];
-  nixpkgs.hostPlatform = lib.mkDefault "x86_64-linux";
-  hardware.cpu.intel.updateMicrocode = lib.mkDefault config.hardware.enableRedistributableFirmware;
   boot-config.bootloader = "systemd-boot";
+  hardware-config.cpu = "intel";
 }

hosts/common.nix

@@ -15,4 +15,5 @@
   nixosModules.enable = true;
   nix-config.enable = true;
   boot-config.enable = true;
+  hardware-config.enable = true;
 }

hosts/nemesis.nix

@@ -1,18 +1,11 @@
-{
+{ inputs, ... }:
-  inputs,
-  lib,
-  config,
-  ...
-}:
 {
   imports = [
     ../configs/filesystems/hw-nemesis.nix
-    ../configs/hardware/nvidia.nix
     ../configs/hardware/powermanagement.nix
     inputs.nixos-hardware.nixosModules.gigabyte-b650
   ];
-  boot.kernelModules = [ "kvm-amd" ];
-  nixpkgs.hostPlatform = lib.mkDefault "x86_64-linux";
-  hardware.cpu.amd.updateMicrocode = lib.mkDefault config.hardware.enableRedistributableFirmware;
   boot-config.bootloader = "systemd-boot";
+  hardware-config.cpu = "amd";
+  hardware-config.gpu = "nvidia";
 }

nixosModules/default.nix

@@ -1,7 +1,6 @@
 {
   config,
   lib,
-  pkgs,
   ...
 }:
 let
@@ -10,8 +9,9 @@ let
 in
 {
   imports = [
-    ./nix-config.nix
     ./boot.nix
+    ./hardware.nix
+    ./nix-config.nix
   ];
 
   options = {
@@ -20,7 +20,5 @@ in
     };
   };
 
-  config = lib.mkIf cfg.enable {
+  config = lib.mkIf cfg.enable { };
-    environment.systemPackages = with pkgs; [ micro ];
-  };
 }

nixosModules/hardware.nix

@@ -0,0 +1,81 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+let
+  moduleName = "hardware-config";
+  cfg = config."${moduleName}";
+in
+{
+  options = {
+    "${moduleName}" = {
+      enable = lib.mkEnableOption "Enable ${moduleName}.";
+      cpu = lib.mkOption {
+        type = lib.types.str;
+        default = "";
+        example = "amd";
+        description = "What CPU is being used.";
+      };
+      gpu = lib.mkOption {
+        type = lib.types.str;
+        default = "";
+        example = "nvidia";
+        description = "What GPU is being used.";
+      };
+    };
+  };
+
+  config = lib.mkMerge [
+    (lib.mkIf (cfg.cpu != "") {
+      nixpkgs.hostPlatform = lib.mkIf (cfg.cpu == "amd" || cfg.cpu == "intel") "x86_64-linux";
+      # CPU Settings
+      boot.kernelModules =
+        lib.optionals (cfg.cpu == "intel") [ "kvm-intel" ]
+        ++ lib.optionals (cfg.cpu == "amd") [ "kvm-amd" ];
+      hardware.cpu =
+        lib.mkIf (cfg.cpu == "intel") { intel.updateMicrocode = true; }
+        // lib.mkIf (cfg.cpu == "amd") { amd.updateMicrocode = true; };
+    })
+    (lib.mkIf (cfg.gpu == "nvidia") {
+      # Accept the license by default; needed for some packages.
+      nixpkgs.config.nvidia.acceptLicense = true;
+      nix.settings = {
+        substituters = [ "https://cuda-maintainers.cachix.org" ];
+        trusted-public-keys = [
+          "cuda-maintainers.cachix.org-1:0dq3bujKpuEPMCX6U4WylrUDZ9JyUG0VpVZa7CNfq5E="
+        ];
+      };
+      services.xserver.videoDrivers = [ "nvidia" ];
+      environment.variables = {
+        GBM_BACKEND = "nvidia-drm";
+        LIBVA_DRIVER_NAME = "nvidia";
+        __GLX_VENDOR_LIBRARY_NAME = "nvidia";
+      };
+      hardware = {
+        enableRedistributableFirmware = true;
+        nvidia-container-toolkit.enable = true;
+        graphics = {
+          enable = true;
+          extraPackages = with pkgs; [
+            nvidia-vaapi-driver # hardware acceleration
+          ];
+        };
+        nvidia = {
+          modesetting.enable = true;
+          open = false;
+          nvidiaSettings = true;
+          nvidiaPersistenced = true;
+          package = config.boot.kernelPackages.nvidiaPackages.latest;
+        };
+      };
+      boot.initrd.availableKernelModules = [
+        "nvidia"
+        "nvidia_modeset"
+        "nvidia_uvm"
+        "nvidia_drm"
+      ];
+    })
+  ];
+}