refactor: move system modules into proper directories

systems/default.nix

@@ -1,13 +1,8 @@
 {
   lib,
   hostname,
-  pkgs,
   type,
   modulesPath,
-  inputs,
-  config,
-  specialArgs,
-  username,
   ...
 }:
 {
@@ -15,13 +10,14 @@
     # Common options for all machines.
     [
       (modulesPath + "/installer/scan/not-detected.nix")
-      ./modules/bootloaders/systemd-boot.nix
+      ./modules/boot.nix
+      ./modules/networking.nix
+      ./modules/nix.nix
       ./modules/programs/zsh.nix
-      ./modules/hardware/networking.nix
       ./modules/security.nix
       ./modules/users.nix
     ]
-    # Options for desktops.
+    # Options for graphical systems.
     (lib.optionals (type == "desktop") [
       ./modules/hardware/audio.nix
       ./modules/hardware/bluetooth.nix
@@ -33,66 +29,9 @@
     # Options for specific hostnames.
     (lib.optionals (hostname == "nemesis") [
       ./hw-nemesis.nix
-      ./modules/hardware/nvidia.nix
+      ./modules/bootloaders/systemd-boot.nix
       ./modules/hardware/cpu_amd.nix
+      ./modules/hardware/nvidia.nix
     ])
   ];
-
-  boot = {
-    loader = {
-      timeout = 5;
-      efi.canTouchEfiVariables = true;
-    };
-    kernelPackages = pkgs.linuxPackages_latest;
-    initrd.availableKernelModules = [
-      "nvme"
-      "xhci_pci"
-      "ahci"
-      "usbhid"
-      "usb_storage"
-      "sd_mod"
-    ];
-  };
-
-  home-manager = {
-    useGlobalPkgs = true;
-    useUserPackages = true;
-    extraSpecialArgs = specialArgs;
-  };
-
-  system.stateVersion = "24.11";
-
-  users.mutableUsers = false; # Always reset users on system activation
-
-  nixpkgs.config.allowUnfree = true;
-  nix = {
-    settings.experimental-features = [
-      "nix-command"
-      "flakes"
-      "pipe-operators"
-    ];
-
-    # Add binary caches to avoid having to compile them
-    settings = {
-      substituters = [
-        "https://hyprland.cachix.org"
-        "https://cuda-maintainers.cachix.org"
-        "https://nix-community.cachix.org"
-        "https://nvf.cachix.org"
-        "https://yazi.cachix.org"
-      ];
-      trusted-public-keys = [
-        "hyprland.cachix.org-1:a7pgxzMz7+chwVL3/pzj6jIBMioiJM7ypFP8PwtkuGc="
-        "cuda-maintainers.cachix.org-1:0dq3bujKpuEPMCX6U4WylrUDZ9JyUG0VpVZa7CNfq5E="
-        "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
-        "nvf.cachix.org-1:GMQWiUhZ6ux9D5CvFFMwnc2nFrUHTeGaXRlVBXo+naI="
-        "yazi.cachix.org-1:Dcdz63NZKfvUCbDGngQDAZq6kOroIrFoyO064uvLh8k="
-      ];
-    };
-  };
-
-  time.timeZone = "Asia/Singapore";
-
-  i18n.defaultLocale = "en_SG.UTF-8";
-
 }

systems/modules/boot.nix

@@ -0,0 +1,18 @@
+{ pkgs, ... }:
+{
+  boot = {
+    loader = {
+      timeout = 5;
+      efi.canTouchEfiVariables = true;
+    };
+    kernelPackages = pkgs.linuxPackages_latest;
+    initrd.availableKernelModules = [
+      "nvme"
+      "xhci_pci"
+      "ahci"
+      "usbhid"
+      "usb_storage"
+      "sd_mod"
+    ];
+  };
+}

systems/modules/bootloaders/extlinux.nix

@@ -1,6 +0,0 @@
-{
-  # Use the extlinux boot loader. (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;
-}

systems/modules/hardware/nvidia.nix

@@ -3,10 +3,17 @@
   pkgs,
   config,
   ...
-}: {
+}:
+{
   # Accept the license by default; needed for some packages.
   nixpkgs.config.nvidia.acceptLicense = true;
-  services.xserver.videoDrivers = ["nvidia"];
+  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";
@@ -17,19 +24,23 @@
     nvidia-container-toolkit.enable = true;
     graphics = {
       enable = true;
-      package = inputs.hyprland.inputs.nixpkgs.legacyPackages.${pkgs.stdenv.hostPlatform.system}.mesa.drivers;
+      package = inputs.hyprland.inputs.nixpkgs.legacyPackages.${pkgs.stdenv.hostPlatform.system}.mesa;
       extraPackages = with pkgs; [
         nvidia-vaapi-driver # hardware acceleration
       ];
     };
     nvidia = {
       modesetting.enable = true;
-      # powerManagement.enable = true;
       open = false;
       nvidiaSettings = true;
       nvidiaPersistenced = true;
       package = config.boot.kernelPackages.nvidiaPackages.latest;
     };
   };
-  boot.initrd.availableKernelModules = ["nvidia" "nvidia_modeset" "nvidia_uvm" "nvidia_drm"];
+  boot.initrd.availableKernelModules = [
+    "nvidia"
+    "nvidia_modeset"
+    "nvidia_uvm"
+    "nvidia_drm"
+  ];
 }

systems/modules/nix.nix

@@ -0,0 +1,28 @@
+{
+  system.stateVersion = "24.11";
+
+  nixpkgs.config.allowUnfree = true;
+  nix = {
+    settings = {
+      experimental-features = [
+        "nix-command"
+        "flakes"
+        "pipe-operators"
+      ];
+
+      # Add binary caches to avoid having to compile them
+      substituters = [
+        "https://hyprland.cachix.org"
+        "https://nix-community.cachix.org"
+        "https://nvf.cachix.org"
+        "https://yazi.cachix.org"
+      ];
+      trusted-public-keys = [
+        "hyprland.cachix.org-1:a7pgxzMz7+chwVL3/pzj6jIBMioiJM7ypFP8PwtkuGc="
+        "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
+        "nvf.cachix.org-1:GMQWiUhZ6ux9D5CvFFMwnc2nFrUHTeGaXRlVBXo+naI="
+        "yazi.cachix.org-1:Dcdz63NZKfvUCbDGngQDAZq6kOroIrFoyO064uvLh8k="
+      ];
+    };
+  };
+}

systems/modules/programs/tailscale.nix

@@ -1,2 +0,0 @@
-{
-}

systems/modules/security/sops.nix

@@ -1,8 +0,0 @@
-{ inputs, ... }:
-{
-  sops = {
-    defaultSopsFile = ../../../secrets/secrets.yaml;
-    age.sshKeyPaths = [ "/etc/ssh/ssh_host_ed25519_key" ];
-    secrets.password.neededForUsers = true;
-  };
-}

systems/modules/users.nix

@@ -1,5 +1,16 @@
-{ config, ... }:
+{ config, specialArgs, ... }:
 {
+  home-manager = {
+    useGlobalPkgs = true;
+    useUserPackages = true;
+    extraSpecialArgs = specialArgs;
+  };
+
+  users.mutableUsers = false; # Always reset users on system activation
+
+  time.timeZone = "Asia/Singapore";
+  i18n.defaultLocale = "en_SG.UTF-8";
+
   home-manager.users.rafiq.imports = [ ../../users/rafiq.nix ];
   users.users.rafiq = {
     isNormalUser = true;

systems/modules/users/rafiq.nix

@@ -1,16 +0,0 @@
-{ inputs, config, ... }:
-{
-  home-manager.users.rafiq.imports = [ ../../../users/rafiq.nix ];
-  users.users.rafiq = {
-    isNormalUser = true;
-    description = "rafiq";
-    hashedPasswordFile = config.sops.secrets.password.path;
-    extraGroups = [
-      "networkmanager"
-      "wheel"
-    ];
-    openssh.authorizedKeys.keys = [
-      "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAILdsZyY3gu8IGB8MzMnLdh+ClDxQQ2RYG9rkeetIKq8n"
-    ];
-  };
-}