[graphics] Modularizes graphics config. Applies it to vega.

system/features/graphics.nix

@@ -0,0 +1,50 @@
+{ config, lib, ... }:
+{
+  options =
+    with lib;
+    with types;
+    {
+      graphics = {
+        enable = mkEnableOption "graphics support";
+        driverChannel = mkOption {
+          type = str;
+          # Default to production because I often want new features, but I don't want bleeding edge.
+          default = "production";
+          description = "Driver channel to use (in order of oldest to newest): stable, beta, latest";
+        };
+      };
+    };
+
+  config = lib.mkIf config.graphics.enable {
+    # Graphics settings
+    hardware.graphics = {
+      enable = true;
+      enable32Bit = true;
+    };
+
+    services.xserver.videoDrivers = [ "nvidia" ];
+
+    hardware.nvidia = {
+      package = config.boot.kernelPackages.nvidiaPackages."${config.graphics.driverChannel}";
+
+      modesetting.enable = true;
+
+      # Nvidia power management. Experimental, and can cause sleep/suspend to fail.
+      # Enable this if you have graphical corruption issues or application crashes after waking
+      # up from sleep. This fixes it by saving the entire VRAM memory to /tmp/ instead
+      # of just the bare essentials.
+      powerManagement.enable = true;
+
+      # Fine-grained power management for PRIME. Turns off GPU when not in use.
+      # Experimental and only works on modern Nvidia GPUs (Turing or newer).
+      # Requires offload to be enabled.
+      # powerManagement.finegrained = false;
+
+      # Use the open-source driver?
+      open = false;
+
+      # Enable the nvidia-settings menu?
+      nvidiaSettings = true;
+    };
+  };
+}

system/hosts/vega/hardware-configuration.nix

@@ -1,11 +1,17 @@
 # Do not modify this file!  It was generated by ‘nixos-generate-config’
 # and may be overwritten by future invocations.  Please make changes
 # to /etc/nixos/configuration.nix instead.
-{ config, lib, pkgs, modulesPath, ... }:
+{
+  config,
+  lib,
+  modulesPath,
+  ...
+}:
 
 {
-  imports =
+  imports = [
-    [ (modulesPath + "/installer/scan/not-detected.nix")
+    (modulesPath + "/installer/scan/not-detected.nix")
+    ../../features/graphics.nix
   ];
 
   # Bootloader.
@@ -13,18 +19,26 @@
   boot.loader.grub.device = "/dev/sda";
   boot.loader.grub.useOSProber = true;
 
-  boot.initrd.availableKernelModules = [ "xhci_pci" "ehci_pci" "ata_piix" "ahci" "usbhid" "usb_storage" "sd_mod" ];
+  boot.initrd.availableKernelModules = [
+    "xhci_pci"
+    "ehci_pci"
+    "ata_piix"
+    "ahci"
+    "usbhid"
+    "usb_storage"
+    "sd_mod"
+  ];
   boot.initrd.kernelModules = [ ];
   boot.kernelModules = [ "kvm-intel" ];
   boot.extraModulePackages = [ ];
 
-  fileSystems."/" =
+  fileSystems."/" = {
-    { device = "/dev/disk/by-uuid/4981ad42-b108-4eb4-accb-b092813bd981";
+    device = "/dev/disk/by-uuid/4981ad42-b108-4eb4-accb-b092813bd981";
     fsType = "ext4";
   };
 
-  swapDevices =
+  swapDevices = [
-    [ { device = "/dev/disk/by-uuid/f8868dce-6b32-45b7-bdf3-c9a34df1441d"; }
+    { device = "/dev/disk/by-uuid/f8868dce-6b32-45b7-bdf3-c9a34df1441d"; }
   ];
 
   # Enables DHCP on each ethernet and wireless interface. In case of scripted networking
@@ -39,34 +53,6 @@
   hardware.cpu.intel.updateMicrocode = lib.mkDefault config.hardware.enableRedistributableFirmware;
 
   # Graphics settings
-  hardware.graphics = {
+  # Using the default production drivers.
-    enable = true;
+  graphics.enable = true;
-    enable32Bit = true;
-  };
-
-  services.xserver.videoDrivers = [ "nvidia" ];
-
-  hardware.nvidia = {
-    package = config.boot.kernelPackages.nvidiaPackages.beta;
-
-    modesetting.enable = true;
-
-    # Nvidia power management. Experimental, and can cause sleep/suspend to fail.
-    # Enable this if you have graphical corruption issues or application crashes after waking
-    # up from sleep. This fixes it by saving the entire VRAM memory to /tmp/ instead
-    # of just the bare essentials.
-    powerManagement.enable = true;
-
-    # Fine-grained power management for PRIME. Turns off GPU when not in use.
-    # Experimental and only works on modern Nvidia GPUs (Turing or newer).
-    # Requires offload to be enabled.
-    # powerManagement.finegrained = false;
-
-    # Use the open-source driver?
-    open = false;
-
-    # Enable the nvidia-settings menu?
-    nvidiaSettings = true;
-  };
-
 }