revise deck system config

hosts/nixos/deck/system.nix

@@ -7,6 +7,9 @@
     ../../../modules/desktop.nix
   ];
 
+  # Desktop module configuration (disable GDM for Jovian autoStart mode)
+  desktop-custom.enableDisplayManager = false;
+
   # Bootloader - standard UEFI setup
   boot.loader = {
     systemd-boot.enable = true;
@@ -33,10 +36,8 @@
     enableRedistributableFirmware = true;
 
     # Graphics configuration for AMD
-    graphics = {
-      enable = true;
-      enable32Bit = true;
-    };
+    # Note: enable32Bit is set by jovian.steam.enable
+    graphics.enable = true;
 
     # Bluetooth support
     bluetooth = {
@@ -50,18 +51,10 @@
     };
   };
 
-  # Sound configuration with PipeWire
-  services.pulseaudio.enable = false;
-  security.rtkit.enable = true;
-  services.pipewire = {
-    enable = true;
-    alsa.enable = true;
-    alsa.support32Bit = true;
-    pulse.enable = true;
-  };
-
   # Jovian Steam Deck configuration
   jovian = {
+    hardware.has.amd.gpu = true;  # Enables backlight control and early modesetting
+
     steam = {
       enable = true;
       autoStart = true;
@@ -71,6 +64,13 @@
     devices.steamdeck = {
       enable = true;
       autoUpdate = true;
+      enableSoundSupport = true;  # Steam Deck-optimized PipeWire with DSP
+      enableVendorDrivers = true;  # Uses Valve's driver branches instead of upstream
+    };
+    steamos = {
+      useSteamOSConfig = true;  # Enable SteamOS optimizations (zram, OOM, sysctl, etc.)
+      enableBluetoothConfig = true;  # SteamOS bluetooth defaults
+      enableAutoMountUdevRules = true;  # Auto-mount SD cards
     };
   };
 

modules/desktop.nix

@@ -1,9 +1,24 @@
 { config, pkgs, lib, ... }:
 
+with lib;
+
+let
+  cfg = config.desktop-custom;
+in
+
 {
+  options.desktop-custom = {
+    enableDisplayManager = mkOption {
+      type = types.bool;
+      default = true;
+      description = "Enable GDM display manager (conflicts with jovian.steam.autoStart)";
+    };
+  };
+
+  config = {
     # GNOME Desktop Environment
     services.xserver.enable = true;
-  services.displayManager.gdm.enable = true;
+    services.displayManager.gdm.enable = mkIf cfg.enableDisplayManager true;
     services.desktopManager.gnome.enable = true;
 
     # Keyboard layout
@@ -65,4 +80,5 @@
     environment.systemPackages = with pkgs; [
       hicolor-icon-theme  # Fallback icon theme
     ];
+  };
 }