checkpoint lol

modules/nixos/hardware/raspberry-pi/default.nix

@@ -7,6 +7,11 @@
 }:
 let
   cfg = config.${namespace}.hardware.raspberry-pi;
+  dt_ao_overlay = _final: prev: {
+    deviceTree = prev.deviceTree // {
+      applyOverlays = _final.callPackage ./apply-overlays-dtmerge.nix { };
+    };
+  };
 in
 {
   options.${namespace}.hardware.raspberry-pi = {
@@ -19,13 +24,40 @@ in
       ];
       description = "Raspberry Pi variant (4 or 5)";
     };
+    
+    apply-overlays-dtmerge = {
+      enable = lib.mkEnableOption "" // {
+        description = ''
+          Whether replace deviceTree.applyOverlays implementation to use dtmerge from libraspberrypi.
+          This can resolve issues with applying dtbs for the pi.
+        '';
+      };
+    };
   };
 
+  imports = [
+    ./leds.nix
+  ];
+
   config = lib.mkIf cfg.enable {
 
-    boot.initrd.availableKernelModules = lib.mkIf (cfg.variant == "5") [
-      "nvme"
-    ];
+    boot = {
+      initrd.availableKernelModules = [
+        "usbhid"
+        "usb-storage"
+      ] ++ (if (cfg.variant == "5") then [
+        "nvme"
+      ] else
+      [
+        "vc4"
+        "pcie-brcmstb" # required for the pcie bus to work
+        "reset-raspberrypi" # required for vl805 firmware to load
+      ]);
+      loader = {
+        generic-extlinux-compatible.enable = lib.mkDefault true;
+        grub.enable = lib.mkForce false;
+      };
+    };
 
     # Common Raspberry Pi packages
     environment.systemPackages = with pkgs; [
@@ -58,21 +90,65 @@ in
 
     # Common hardware settings
     hardware = {
-      i2c.enable = lib.mkDefault true;
+      deviceTree = {
+        filter = lib.mkDefault (if (cfg.variant == "5") then "bcm2712-rpi-*.dtb" else "bcm2711-rpi-*.dtb");
+        overlays = lib.mkIf (cfg.variant == "4") [
+          {
+            name = "rpi4-cpu-revision";
+            dtsText = ''
+              /dts-v1/;
+              /plugin/;
+
+              / {
+                compatible = "raspberrypi,4-model-b";
+
+                fragment@0 {
+                  target-path = "/";
+                  __overlay__ {
+                    system {
+                      linux,revision = <0x00d03114>;
+                    };
+                  };
+                };
+              };
+            '';
+          }
+          {
+            name = "enable-xhci";
+            dtsText = ''
+              /dts-v1/;
+              /plugin/;
+
+              / {
+                compatible = "brcm,bcm2711";
+                fragment@0 {
+                  //target-path = "/scb/xhci@7e9c0000";
+                  target = <&xhci>;
+                  __overlay__ {
+                    status = "okay";
+                  };
+                };
+              };
+            '';
+          }
+        ];
+      };
+      firmware = [ pkgs.${namespace}.raspberryPiWirelessFirmware ];
       graphics.enable32Bit = lib.mkForce false;
+      i2c.enable = lib.mkDefault true;
     };
 
     # Pi specific system tags
-    system.nixos.tags = (
-      let
-        bootCfg = config.boot.loader.raspberry-pi;
-      in
-      [
-        "raspberry-pi-${bootCfg.variant}"
-        bootCfg.bootloader
-        config.boot.kernelPackages.kernel.version
-      ]
-    );
+    # system.nixos.tags = (
+    #   let
+    #     bootCfg = config.boot.loader.raspberry-pi;
+    #   in
+    #   [
+    #     "raspberry-pi-${bootCfg.variant}"
+    #     bootCfg.bootloader
+    #     config.boot.kernelPackages.kernel.version
+    #   ]
+    # );
 
     # Common programs
     programs.kdeconnect.enable = lib.mkDefault false;
@@ -164,6 +240,7 @@ in
             ++ [ "${pageSizeFlag}=14" ];
         });
       })
-    ] else [ ]);
+    ] else [ ])
+    ++ (if cfg.apply-overlays-dtmerge.enable then [ dt_ao_overlay ] else [ ]);
   };
 }