prepping for plasma in my mainline config

flakes/common/hm_modules/de_plasma/default.nix

@@ -0,0 +1,5 @@
+{ ... }:
+{
+  imports = [ ];
+}
+

utilities/nixos-installers/examples/flake.nix

@@ -59,6 +59,7 @@
 
               ./hardware-configuration.nix
               ./impermanence.nix
+              ./plasma.nix
               (
                 {
                   config,
@@ -71,6 +72,12 @@
                   system.stateVersion = "25.05";
                   services.openssh.settings.PasswordAuthentication = lib.mkForce true;
 
+                  myPlasma = {
+                    enable = true;
+                    gpu.intel.enable = true;
+                    sddm.autologinUser = "luser";
+                  };
+
                   # Home Manager
                   home-manager = {
                     useUserPackages = true;
@@ -124,4 +131,3 @@
       };
     };
 }
-

utilities/nixos-installers/examples/plasma.nix

@@ -0,0 +1,233 @@
+{ lib, pkgs, config, ... }:
+
+let
+  inherit (lib) mkOption types mkEnableOption mkIf mkMerge;
+  cfg = config.myPlasma;
+
+  oneGpuEnabled =
+    (lib.length (lib.filter (x: x) [
+      cfg.gpu.nvidia.enable
+      cfg.gpu.amd.enable
+      cfg.gpu.intel.enable
+    ])) <= 1;
+in
+{
+  options.myPlasma = {
+    enable = mkEnableOption "KDE Plasma desktop";
+
+    appearance.breezeDark = {
+      enable = mkOption {
+        type = types.bool;
+        default = true;
+        description = "Apply Breeze Dark system-wide (defaults via /etc/xdg and GTK_THEME).";
+      };
+    };
+
+    wayland = mkOption {
+      type = types.bool;
+      default = true;
+      description = "Enable SDDM Wayland and Plasma Wayland session.";
+    };
+
+    flatpak.enable = mkOption {
+      type = types.bool;
+      default = false;
+      description = "Enable Flatpak.";
+    };
+
+    gpu = {
+      enable32Bit = mkOption {
+        type = types.bool;
+        default = true;
+        description = "Install 32-bit OpenGL/VA-API bits (useful for Steam/Wine).";
+      };
+
+      nvidia = {
+        enable = mkOption { type = types.bool; default = false; };
+        open = mkOption {
+          type = types.bool;
+          default = true;
+          description = "Use NVIDIA open kernel module when available.";
+        };
+        package = mkOption {
+          type = types.package;
+          default = pkgs.linuxPackages.nvidiaPackages.production;
+          description = "NVIDIA driver package.";
+        };
+      };
+
+      amd = {
+        enable = mkOption { type = types.bool; default = false; };
+        useAmdvlk = mkOption {
+          type = types.bool; default = false;
+          description = "Install AMDVLK alongside Mesa (RADV stays default).";
+        };
+      };
+
+      intel = {
+        enable = mkOption { type = types.bool; default = false; };
+        legacyVaapi = mkOption {
+          type = types.bool; default = false;
+          description = "Also add intel-vaapi-driver for very old Intel iGPUs.";
+        };
+      };
+    };
+
+    sddm.autologinUser = mkOption {
+      type = types.nullOr types.str;
+      default = null;
+      description = "Set an autologin user for SDDM (optional).";
+    };
+
+    powerManagement = mkOption {
+      type = types.bool;
+      default = true;
+      description = "Enable ";
+    };
+  };
+
+  config = mkIf cfg.enable (mkMerge [
+    {
+      # Core desktop
+      services.displayManager.sddm = {
+        enable = true;
+        wayland.enable = cfg.wayland;
+        theme = "breeze";
+        autoLogin = mkIf (cfg.sddm.autologinUser != null) {
+          enable = true;
+          user = cfg.sddm.autologinUser;
+        };
+      };
+
+      services.desktopManager.plasma6.enable = true;
+
+      # Portals for sandboxed apps (Wayland, Flatpak)
+      xdg.portal.enable = true;
+      # KDE portal is pulled with Plasma; add GTK for broader app support
+      xdg.portal.extraPortals = [ pkgs.xdg-desktop-portal-gtk ];
+
+      # PipeWire + WirePlumber for audio
+      services.pipewire = {
+        enable = true;
+        alsa.enable = true;
+        pulse.enable = true;
+        wireplumber.enable = true;
+      };
+
+      # Good defaults for laptops/desktops
+      services.power-profiles-daemon.enable = lib.mkIf cfg.powerManagement true;
+
+      # Flatpak
+      services.flatpak.enable = cfg.flatpak.enable;
+
+      # Wayland-friendly Electron/Chromium (prefer Wayland Ozone)
+      environment.sessionVariables.NIXOS_OZONE_WL = "1";
+
+      # OpenGL/VA-API/Vulkan base
+      hardware.opengl = {
+        enable = true;
+        # driSupport = true;
+        driSupport32Bit = cfg.gpu.enable32Bit;
+      };
+
+      # KDEConnect
+      programs.kdeconnect.enable = true;
+
+      # Useful KDE tools (minimal)
+      environment.systemPackages = with pkgs; [
+        kdePackages.kde-gtk-config
+        kdePackages.konsole
+        kdePackages.dolphin
+        kdePackages.spectacle
+        kdePackages.plasma-browser-integration
+        kdePackages.plasma-workspace-wallpapers
+      ];
+    }
+
+    (mkIf cfg.appearance.breezeDark.enable {
+      # Ensure themes are present
+      environment.systemPackages = with pkgs; [
+        kdePackages.breeze
+        kdePackages.breeze-icons
+        kdePackages.breeze-gtk
+      ];
+
+      # KDE defaults for ALL users (users can still override in ~/.config)
+      environment.etc."xdg/kdeglobals".text = ''
+        [General]
+        ColorScheme=BreezeDark
+
+        [KDE]
+        LookAndFeelPackage=org.kde.breezedark.desktop
+        widgetStyle=Breeze
+
+        [Icons]
+        Theme=breeze-dark
+
+        [Theme]
+        cursorTheme=breeze_cursors
+      '';
+
+      # Make GTK apps dark too
+      environment.sessionVariables.GTK_THEME = "Breeze-Dark";
+      # Nice to have for cursors across toolkits
+      environment.sessionVariables.XCURSOR_THEME = "breeze_cursors";
+    })
+
+    # AMD GPU
+    (mkIf cfg.gpu.amd.enable {
+      services.xserver.videoDrivers = [ "amdgpu" ];
+      hardware.opengl.extraPackages = with pkgs; [
+        vaapiVdpau
+        libvdpau-va-gl
+      ];
+      hardware.opengl.extraPackages32 = with pkgs.pkgsi686Linux; [
+        libva
+        vaapiVdpau
+        libvdpau-va-gl
+      ];
+      environment.systemPackages = lib.optionals cfg.gpu.amd.useAmdvlk [ pkgs.amdvlk ];
+    })
+
+    # Intel GPU
+    (mkIf cfg.gpu.intel.enable {
+      services.xserver.videoDrivers = [ "modesetting" ];
+      hardware.opengl.extraPackages =
+        with pkgs; [
+          intel-media-driver
+          libvdpau-va-gl
+        ] ++ lib.optionals cfg.gpu.intel.legacyVaapi [ vaapiIntel ];
+      hardware.opengl.extraPackages32 = with pkgs.pkgsi686Linux; [
+        libva
+        libvdpau-va-gl
+      ] ++ lib.optionals cfg.gpu.intel.legacyVaapi [ vaapiIntel ];
+    })
+
+    # NVIDIA GPU
+    (mkIf cfg.gpu.nvidia.enable {
+      services.xserver.videoDrivers = [ "nvidia" ];
+      hardware.nvidia = {
+        package = cfg.gpu.nvidia.package;
+        modesetting.enable = true;
+        powerManagement.enable = true;
+        open = cfg.gpu.nvidia.open;
+        nvidiaSettings = true;
+      };
+      # Wayland helpers for wlroots/GBM stacks (harmless otherwise)
+      environment.sessionVariables = {
+        GBM_BACKEND = "nvidia-drm";
+        __GL_GSYNC_ALLOWED = "0";
+        __GL_VRR_ALLOWED = "0";
+      };
+    })
+
+    {
+      assertions = [
+        {
+          assertion = oneGpuEnabled;
+          message = "Enable at most one of myPlasma.gpu.{nvidia,amd,intel}.enable.";
+        }
+      ];
+    }
+  ]);
+}