refactor(system): fix conflicts between desktop environment login managers

chore: Prep for PR

system/host/configuration.nix

@@ -116,7 +116,7 @@ in
 
       # Enable the KDE desktop environment.
       # https://kde.org/
-      kde.enable = false;
+      kde.useX11 = false;
 
       # Enable the XFCE desktop environment.
       # https://xfce.org/

system/modules/system/bootloader.nix

@@ -45,6 +45,13 @@ in
 
       # Set up TPM if enabled. See https://nixos.wiki/wiki/TPM
       (lib.mkIf (cfg.tpm2.enable) {
+        boot.initrd = {
+          # Enable systemd for TPM auto-unlocking
+          systemd.enable = true;
+
+          availableKernelModules = [ "tpm_crb" ];
+          kernelModules = [ "tpm_crb" ];
+        };
         # After installing and rebooting, set it up via https://wiki.archlinux.org/title/Systemd-cryptenroll#Trusted_Platform_Module
         environment.systemPackages = with pkgs; [ tpm2-tss ];
         security.tpm2 = {

system/modules/system/gpu/amd.nix

@@ -15,15 +15,12 @@ in
 
   config = lib.mkIf cfg.enable {
     boot.initrd.kernelModules = [ "amdgpu" ];
-    services.xserver = {
-      enable = true;
-      videoDrivers = [ "amdgpu" ];
-    };
+    services.xserver.videoDrivers = [ "amdgpu" ];
 
-    hardware.opengl = {
+    hardware.graphics = {
       extraPackages = [ pkgs.amdvlk ];
       # 32-bit application compatibility
-      driSupport32Bit = true;
+      enable32Bit = true;
       extraPackages32 = with pkgs; [ driversi686Linux.amdvlk ];
     };
   };

system/modules/system/gpu/intel.nix

@@ -19,7 +19,7 @@ in
 
     environment.variables.VDPAU_DRIVER = "va_gl";
 
-    hardware.opengl.extraPackages = with pkgs; [
+    hardware.graphics.extraPackages = with pkgs; [
       (
         if (lib.versionOlder (lib.versions.majorMinor lib.version) "23.11") then
           vaapiIntel
@@ -30,7 +30,7 @@ in
       intel-media-driver
     ];
 
-    hardware.opengl.extraPackages32 = with pkgs.driversi686Linux; [
+    hardware.graphics.extraPackages32 = with pkgs.driversi686Linux; [
       (
         if (lib.versionOlder (lib.versions.majorMinor lib.version) "23.11") then
           vaapiIntel

system/modules/system/system.nix

@@ -3,7 +3,6 @@
   pkgs,
   config,
   lib,
-  inputs,
   ...
 }:
 let
@@ -19,6 +18,9 @@ in
     };
   };
   config = {
+    # Install the latest kernel
+    boot.kernelPackages = lib.mkDefault pkgs.linuxPackages_latest;
+
     # Set up the environment
     environment = {
       # Install base packages

system/modules/ui/audio.nix

@@ -35,7 +35,7 @@ in
       pulse.enable = true;
       jack.enable = true;
 
-      # Reduce audio latency per https://wiki.nixos.org/wiki/PipeWire#Low-latency_setup
+      # Reduce audio latency per https://nixos.wiki/wiki/PipeWire#Low-latency_setup
       extraConfig.pipewire = lib.mkIf cfg.enableLowLatency {
         "92-low-latency.conf" = {
           "context.properties" = {

system/modules/ui/desktops/budgie.nix

@@ -16,17 +16,18 @@ in
   };
 
   config = lib.mkIf cfg.enable {
-    aux.system.ui.desktops.enable = true;
+    aux.system.ui.desktops = {
+      enable = true;
+      displayManager = lib.mkOptionDefault "lightdm";
+    };
 
     services.xserver = {
       enable = true;
-      desktopManager.budgie.enable = true;
-      displayManager.lightdm.enable = lib.mkIf (
-        !(
-          config.services.xserver.displayManager.gdm.enable
-          || config.services.xserver.displayManager.sddm.enable
-        )
-      ) true;
+      desktopManager.budgie.enable =
+        if config.services.xserver.desktopManager.gnome.enable then
+          builtins.abort "Budgie and Gnome cannot be enabled at the same time due to a bug. For details and a possible workaround, please see https://discourse.nixos.org/t/help-i-cant-have-pantheon-gnome-and-plasma-installed-on-my-system-at-the-same-time/47346"
+        else
+          true;
     };
   };
 }

system/modules/ui/desktops/common.nix

@@ -21,13 +21,23 @@ in
           variant = "";
         };
       };
+      displayManager = lib.mkOption {
+        description = "The display manager to use to start a desktop session.";
+        type = lib.types.enum [
+          "gdm"
+          "lightdm"
+          "sddm"
+          "sddm_wayland"
+        ];
+      };
     };
   };
 
   config = lib.mkIf cfg.enable {
-    aux.system.ui.audio.enable = true;
-
-    hardware.bluetooth.enable = true;
+    aux.system = {
+      bluetooth.enable = true;
+      ui.audio.enable = true;
+    };
 
     boot = {
       # Enable Plymouth for graphical bootsplash.
@@ -37,7 +47,7 @@ in
       };
 
       # Add kernel parameters
-      kernelParams = [ "quiet" "splash" ];
+      kernelParams = [ "quiet" ];
     };
 
     services = {
@@ -46,14 +56,25 @@ in
         # Enable the X11 windowing system.
         enable = true;
 
-        # Enable touchpad support (enabled by default in most desktop managers, buuuut just in case).
-        libinput.enable = true;
-
         # Configure keymap in X11
         xkb = config.aux.system.ui.desktops.xkb;
+
+        # Set the display manager
+        displayManager = {
+          gdm.enable = (cfg.displayManager == "gdm");
+          lightdm.enable = (cfg.displayManager == "lightdm");
         };
       };
 
+      displayManager = {
+        sddm.enable = (cfg.displayManager == "sddm");
+        sddm.wayland.enable = (cfg.displayManager == "sddm_wayland");
+      };
+
+      # Enable touchpad support (enabled by default in most desktop managers, buuuut just in case).
+      libinput.enable = true;
+    };
+
     # Support for AppImage files
     programs.appimage = {
       enable = true;

system/modules/ui/desktops/gnome.nix

@@ -16,15 +16,17 @@ in
   };
 
   config = lib.mkIf cfg.enable {
-    aux.system.ui.desktops.enable = true;
+    aux.system.ui.desktops = {
+      enable = true;
+      displayManager = lib.mkOverride 500 "gdm";
+    };
 
     # Enable Gnome
     services.xserver = {
       # Remove default packages that came with the install
       excludePackages = [ pkgs.xterm ];
 
-      desktopManager.gnome.enable = true;
-      displayManager.gdm.enable = true;
+      desktopManager.gnome.enable = lib.mkDefault true;
     };
 
     environment = {
@@ -44,6 +46,9 @@ in
       ];
     };
 
+    # Manually set askPassword to avoid a conflict with KDE
+    programs.ssh.askPassword = "${pkgs.gnome.seahorse}/libexec/seahorse/ssh-askpass";
+
     # Gnome UI integration for KDE apps
     qt = {
       enable = true;

system/modules/ui/desktops/kde.nix

@@ -18,7 +18,10 @@ in
   };
 
   config = lib.mkIf cfg.enable {
-    aux.system.ui.desktops.enable = true;
+    aux.system.ui.desktops = {
+      enable = true;
+      displayManager = if cfg.useX11 then lib.mkDefault "sddm" else lib.mkDefault "sddm_wayland";
+    };
 
     programs.dconf.enable = true;
 
@@ -30,18 +33,9 @@ in
     };
 
     services = {
-      displayManager.sddm.enable = true;
       desktopManager.plasma6.enable = true;
 
-      xserver.displayManager = lib.mkIf cfg.useX11 {
-        defaultSession = "plasmaX11";
-        sddm.wayland.enable = lib.mkIf (
-          !(
-            config.services.xserver.displayManager.gdm.enable
-            || config.services.xserver.displayManager.lightdm.enable
-          )
-        ) true;
-      };
+      xserver.displayManager = lib.mkIf cfg.useX11 { defaultSession = "plasmaX11"; };
     };
 
     # Enable Gnome integration

system/modules/ui/desktops/xfce.nix

@@ -16,15 +16,20 @@ in
   };
 
   config = lib.mkIf cfg.enable {
-    aux.system.ui.desktops.enable = true;
+    aux.system.ui.desktops = {
+      enable = true;
+      displayManager = lib.mkOptionDefault "lightdm";
+    };
 
-    services.xserver = {
+    services = {
+      displayManager.defaultSession = "xfce";
+      xserver = {
         enable = true;
         desktopManager = {
           xterm.enable = false;
           xfce.enable = true;
         };
-      displayManager.defaultSession = "xfce";
+      };
     };
   };
 }

system/modules/ui/flatpak.nix

@@ -66,8 +66,8 @@ with lib;
         aggregatedIcons = pkgs.buildEnv {
           name = "system-icons";
           paths = with pkgs; [
-            (lib.mkIf config.aux.system.ui.gnome.enable gnome.gnome-themes-extra)
-            (lib.mkIf config.aux.system.ui.kde.enable kdePackages.breeze-icons)
+            (lib.mkIf config.aux.system.ui.desktops.gnome.enable gnome.gnome-themes-extra)
+            (lib.mkIf config.aux.system.ui.desktops.kde.enable kdePackages.breeze-icons)
           ];
           pathsToLink = [ "/share/icons" ];
         };