diff --git a/overlay/default.nix b/overlay/default.nix
index 9142720..890f211 100644
--- a/overlay/default.nix
+++ b/overlay/default.nix
@@ -22,6 +22,9 @@ let
   rpi-kernels = builtins.foldl' (b: a: b // rpi-kernel a) { };
 in {
 
+  # disable firmware compression so that brcm firmware can be found at
+  # the path expected by raspberry pi firmware/device tree
+  compressFirmwareXz = x: x;
   libcamera-apps = final.callPackage ./libcamera-apps.nix { };
 
   # provide generic rpi arm64 u-boot
@@ -35,6 +38,8 @@ in {
       sha256 = "0png7p8k6rwbmmcyhc22xczcaz7kx0dafw5zmp0i9ni4kjs8xc4j";
     };
   };
+  raspberrypiWirelessFirmware = final.rpi-kernels.v5_15_87.wireless-firmware;
+  raspberrypifw = final.rpi-kernels.v5_15_87.firmware;
 
   # raspberrypiWirelessFirmware = prev.raspberrypiWirelessFirmware.overrideAttrs
   #   (old: {
diff --git a/rpi-3b-plus/default.nix b/rpi-3b-plus/default.nix
index b378229..f3f7de2 100644
--- a/rpi-3b-plus/default.nix
+++ b/rpi-3b-plus/default.nix
@@ -3,22 +3,10 @@ rpi:
 
 {
   imports = [ rpi ];
-  nixpkgs = {
-    overlays = [
-      (final: prev: {
-        raspberrypiWirelessFirmware =
-          final.rpi-kernels.v5_15_87.wireless-firmware;
-        raspberrypifw = final.rpi-kernels.v5_15_87.firmware;
-      })
-    ];
-  };
-  boot.kernelPackages =
-    pkgs.linuxPackagesFor (pkgs.rpi-kernels.v5_15_87.kernel);
   hardware.raspberry-pi.deviceTree = {
     base-dtb = "bcm2710-rpi-3-b-plus.dtb";
-    # u-boot expects bcm2837-rpi-3-b-plus.dtb for the 3b+ (as of
-    # 2020.04), although the kernel has 2710. We rename it to satisfy
-    # u-boot for now.
+    # u-boot expects bcm2837-rpi-3-b-plus.dtb for the 3b+ Rename the
+    # raspberry pi dtb to match mainline linux and satisfy u-boot.
     postInstall = ''
       mv $out/broadcom/bcm2710-rpi-3-b-plus.dtb $out/broadcom/bcm2837-rpi-3-b-plus.dtb
     '';
diff --git a/rpi-4b/default.nix b/rpi-4b/default.nix
index 1c3c825..c9141e2 100644
--- a/rpi-4b/default.nix
+++ b/rpi-4b/default.nix
@@ -2,18 +2,7 @@ rpi:
 { lib, pkgs, config, ... }:
 
 {
-  nixpkgs = {
-    overlays = [
-      (final: prev: {
-        raspberrypiWirelessFirmware =
-          final.rpi-kernels.v5_15_87.wireless-firmware;
-        raspberrypifw = final.rpi-kernels.v5_15_87.firmware;
-      })
-    ];
-  };
   imports = [ rpi ];
   hardware.raspberry-pi.deviceTree.base-dtb = "bcm2711-rpi-4-b.dtb";
-  boot.kernelPackages =
-    pkgs.linuxPackagesFor (pkgs.rpi-kernels.v5_15_87.kernel);
 }
 
diff --git a/rpi-zero-2-w/default.nix b/rpi-zero-2-w/default.nix
index 93dd016..13a649b 100644
--- a/rpi-zero-2-w/default.nix
+++ b/rpi-zero-2-w/default.nix
@@ -3,22 +3,11 @@ rpi:
 
 {
   imports = [ rpi ];
-  nixpkgs = {
-    overlays = [
-      (final: prev: {
-        raspberrypiWirelessFirmware =
-          final.rpi-kernels.v5_15_36.wireless-firmware;
-        raspberrypifw = final.rpi-kernels.v5_15_36.firmware;
-      })
-    ];
-  };
   hardware.raspberry-pi.deviceTree.base-dtb = "bcm2710-rpi-zero-2.dtb";
-  # u-boot expects bcm2837-rpi-zero-2.dtb for the zero 2 w (as of
-  # 2020.04), although the kernel has 2710. We rename it to satisfy
-  # u-boot for now.
+  # u-boot expects bcm2837-rpi-zero-2.dtb for the zero 2 w (this is
+  # the device tree name in the upstream kernel), Rename the raspberry
+  # pi dtb to the expected name to satisfy u-boot.
   hardware.raspberry-pi.deviceTree.postInstall = ''
     mv $out/broadcom/bcm2710-rpi-zero-2.dtb $out/broadcom/bcm2837-rpi-zero-2.dtb
   '';
-  boot.kernelPackages =
-    pkgs.linuxPackagesFor (pkgs.rpi-kernels.v5_15_36.kernel);
 }
diff --git a/rpi/default.nix b/rpi/default.nix
index 9969816..1ee75e9 100644
--- a/rpi/default.nix
+++ b/rpi/default.nix
@@ -14,6 +14,7 @@
   nixpkgs = { overlays = [ overlay ]; };
   boot = {
     initrd.availableKernelModules = [ "usbhid" "usb_storage" "vc4" ];
+    kernelPackages = pkgs.linuxPackagesFor (pkgs.rpi-kernels.v5_15_87.kernel);
 
     loader = {
       grub.enable = lib.mkDefault false;