diff --git a/overlay/default.nix b/overlay/default.nix
index 3dad0df..cdf42a0 100644
--- a/overlay/default.nix
+++ b/overlay/default.nix
@@ -25,6 +25,8 @@ in {
   # disable firmware compression so that brcm firmware can be found at
   # the path expected by raspberry pi firmware/device tree
   compressFirmwareXz = x: x;
+
+  # A recent known working version of libcamera-apps
   libcamera-apps = final.callPackage ./libcamera-apps.nix { };
 
   # provide generic rpi arm64 u-boot
@@ -37,14 +39,16 @@ in {
       url = "ftp://ftp.denx.de/pub/u-boot/u-boot-${version}.tar.bz2";
       sha256 = "03wm651ix783s4idj223b0nm3r6jrdnrxs1ncs8s128g72nknhk9";
     };
-    # In raspberry pi products the firmware manipulates the device
-    # tree in a variety of ways before handing it off to the linux
-    # kernel. Since we have installed u-boot in place of a linux
-    # kernel we have the option of passing this device tree passed by
-    # the firmware to the kernel, or providing our own. This
+    # In raspberry pi sbcs the firmware manipulates the device tree in
+    # a variety of ways before handing it off to the linux kernel. [1]
+    # Since we have installed u-boot in place of a linux kernel we may
+    # pass the device tree passed by the firmware onto the kernel, or
+    # we may provide the kernel with a device tree of our own. This
     # configuration uses the device tree provided by firmware so that
     # we don't have to be aware of all manipulation done by the
     # firmware and attempt to mimic it.
+    #
+    # 1. https://forums.raspberrypi.com/viewtopic.php?t=329799#p1974233
     extraConfig = ''
       CONFIG_OF_HAS_PRIOR_STAGE=y
       CONFIG_OF_BOARD=y
@@ -54,6 +58,10 @@ in {
   raspberrypifw = final.rpi-kernels.v5_15_87.firmware;
 
 } // {
+  # rpi kernels and firmware are available at
+  # `pkgs.rpi-kernels.<VERSION>.{kernel,firmware,wireless-firmware}'. 
+  #
+  # For example: `pkgs.rpi-kernels.v5_15_87.kernel'
   rpi-kernels = rpi-kernels [
     {
       version = "5.15.36";
diff --git a/rpi-3b-plus/default.nix b/rpi-3b-plus/default.nix
deleted file mode 100644
index f3f7de2..0000000
--- a/rpi-3b-plus/default.nix
+++ /dev/null
@@ -1,14 +0,0 @@
-rpi:
-{ lib, pkgs, config, ... }:
-
-{
-  imports = [ rpi ];
-  hardware.raspberry-pi.deviceTree = {
-    base-dtb = "bcm2710-rpi-3-b-plus.dtb";
-    # 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
deleted file mode 100644
index c9141e2..0000000
--- a/rpi-4b/default.nix
+++ /dev/null
@@ -1,8 +0,0 @@
-rpi:
-{ lib, pkgs, config, ... }:
-
-{
-  imports = [ rpi ];
-  hardware.raspberry-pi.deviceTree.base-dtb = "bcm2711-rpi-4-b.dtb";
-}
-
diff --git a/rpi-zero-2-w/default.nix b/rpi-zero-2-w/default.nix
deleted file mode 100644
index 13a649b..0000000
--- a/rpi-zero-2-w/default.nix
+++ /dev/null
@@ -1,13 +0,0 @@
-rpi:
-{ lib, pkgs, config, ... }:
-
-{
-  imports = [ rpi ];
-  hardware.raspberry-pi.deviceTree.base-dtb = "bcm2710-rpi-zero-2.dtb";
-  # 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 $out/broadcom/bcm2837-rpi-zero-2.dtb
-  '';
-}
diff --git a/rpi/audio.nix b/rpi/audio.nix
deleted file mode 100644
index 1d2f79b..0000000
--- a/rpi/audio.nix
+++ /dev/null
@@ -1,17 +0,0 @@
-{ config, lib, pkgs, ... }:
-
-let cfg = config.hardware.raspberry-pi.audio;
-in {
-  options.hardware.raspberry-pi.audio = {
-    enable = lib.mkEnableOption "configuration for audio";
-  };
-  config = lib.mkIf cfg.enable {
-    hardware = {
-      raspberry-pi.deviceTree.base-dtb-params = [ "audio=on" ];
-      pulseaudio.configFile = lib.mkOverride 990
-        (pkgs.runCommand "default.pa" { } ''
-          sed 's/module-udev-detect$/module-udev-detect tsched=0/' ${config.hardware.pulseaudio.package}/etc/pulse/default.pa > $out
-        '');
-    };
-  };
-}
diff --git a/rpi/default.nix b/rpi/default.nix
index 3d7f886..46ac142 100644
--- a/rpi/default.nix
+++ b/rpi/default.nix
@@ -2,14 +2,7 @@
 { lib, pkgs, config, ... }:
 
 {
-  imports = [
-    ../sd-image
-    ./device-tree.nix
-    ./audio.nix
-    ./i2c.nix
-    ./i2s.nix
-    ./modesetting.nix
-  ];
+  imports = [ ../sd-image ];
 
   nixpkgs = { overlays = [ overlay ]; };
   boot = {
diff --git a/rpi/device-tree.nix b/rpi/device-tree.nix
deleted file mode 100644
index fc79365..0000000
--- a/rpi/device-tree.nix
+++ /dev/null
@@ -1,102 +0,0 @@
-{ config, lib, pkgs, ... }:
-
-let cfg = config.hardware.raspberry-pi.deviceTree;
-in {
-  options.hardware.raspberry-pi.deviceTree = {
-    base-dtb = lib.mkOption {
-      type = lib.types.str;
-      example = "bcm2711-rpi-4-b.dtb";
-      description = "base dtb to apply";
-    };
-    base-dtb-params = lib.mkOption {
-      type = lib.types.listOf lib.types.string;
-      default = [ ];
-      example = [ "i2c1=on" "audio=on" ];
-      description = "parameters to pass to the base dtb";
-    };
-    dt-overlays = lib.mkOption {
-      type = with lib.types;
-        listOf (submodule {
-          options = {
-            overlay = lib.mkOption { type = oneOf [ str path ]; };
-            args = lib.mkOption {
-              type = listOf str;
-              default = [ ];
-            };
-          };
-        });
-      default = [ ];
-      example = [{
-        overlay = "vc4-fkms-v3d";
-        args = [ "cma-512" ];
-      }];
-      description = "dtb overlays to apply";
-    };
-    postInstall = lib.mkOption {
-      type = lib.types.str;
-      default = "";
-      description = "bash command to run after building dtb";
-    };
-  };
-  config = {
-    hardware = {
-      deviceTree = {
-        enable = true;
-        filter = cfg.base-dtb;
-        package = let
-          dtbsWithSymbols = pkgs.stdenv.mkDerivation {
-            name = "dtbs-with-symbols";
-            inherit (config.boot.kernelPackages.kernel)
-              src nativeBuildInputs depsBuildBuild;
-            patches = map (patch: patch.patch)
-              config.boot.kernelPackages.kernel.kernelPatches;
-            buildPhase = ''
-              patchShebangs scripts/*
-              substituteInPlace scripts/Makefile.lib \
-                --replace 'DTC_FLAGS += $(DTC_FLAGS_$(basetarget))' 'DTC_FLAGS += $(DTC_FLAGS_$(basetarget)) -@'
-              make ${pkgs.stdenv.hostPlatform.linux-kernel.baseConfig} ARCH="${pkgs.stdenv.hostPlatform.linuxArch}"
-              make dtbs ARCH="${pkgs.stdenv.hostPlatform.linuxArch}"
-            '';
-            installPhase = ''
-              make dtbs_install INSTALL_DTBS_PATH=$out/dtbs  ARCH="${pkgs.stdenv.hostPlatform.linuxArch}"
-            '';
-          };
-          compiled-overlays = map (x:
-            let
-              overlay-file = if builtins.isPath x.overlay then
-                pkgs.runCommand "overlay.dtbo" {
-                  buildInputs = with pkgs; [ dtc ];
-                } "dtc -I dts -O dtb -o $out ${x.overlay}"
-              else
-                "${config.boot.kernelPackages.kernel}/dtbs/overlays/${x.overlay}.dtbo";
-            in x // { overlay = overlay-file; }) cfg.dt-overlays;
-        in lib.mkForce (pkgs.runCommand "device-tree-overlays" {
-          buildInputs = with pkgs; [ findutils libraspberrypi ];
-        } ''
-          cd ${dtbsWithSymbols}/dtbs
-          for dtb in $(find . -type f -name "${config.hardware.deviceTree.filter}")
-          do
-            install -D $dtb $out/$dtb
-
-            ${
-              lib.concatMapStrings (param: ''
-                dtmerge -d $out/$dtb{,-merged} - ${param}
-                mv $out/$dtb{-merged,}
-              '') cfg.base-dtb-params
-            }
-
-            ${
-              lib.concatMapStrings (x: ''
-                dtmerge -d $out/$dtb{,-merged} ${x.overlay} ${
-                  builtins.concatStringsSep " " x.args
-                }
-                mv $out/$dtb{-merged,}
-              '') compiled-overlays
-            }
-          done
-          ${cfg.postInstall}
-        '');
-      };
-    };
-  };
-}
diff --git a/rpi/i2c.nix b/rpi/i2c.nix
deleted file mode 100644
index a59021f..0000000
--- a/rpi/i2c.nix
+++ /dev/null
@@ -1,14 +0,0 @@
-{ config, lib, pkgs, ... }:
-
-let cfg = config.hardware.raspberry-pi.i2c;
-in {
-  options.hardware.raspberry-pi.i2c = {
-    enable = lib.mkEnableOption "configuration for i2c";
-  };
-  config = lib.mkIf cfg.enable {
-    hardware = {
-      raspberry-pi.deviceTree.base-dtb-params = [ "i2c1=on" ];
-      i2c.enable = true;
-    };
-  };
-}
diff --git a/rpi/i2s.nix b/rpi/i2s.nix
deleted file mode 100644
index fc88deb..0000000
--- a/rpi/i2s.nix
+++ /dev/null
@@ -1,13 +0,0 @@
-{ config, lib, pkgs, ... }:
-
-let cfg = config.hardware.raspberry-pi.i2s;
-in {
-  options.hardware.raspberry-pi.i2s = {
-    enable = lib.mkEnableOption "configuration for i2s";
-  };
-  config = lib.mkIf cfg.enable {
-    hardware = {
-      raspberry-pi.deviceTree.base-dtb-params = [ "i2s=on" ];
-    };
-  };
-}
diff --git a/rpi/modesetting.nix b/rpi/modesetting.nix
deleted file mode 100644
index f967b58..0000000
--- a/rpi/modesetting.nix
+++ /dev/null
@@ -1,23 +0,0 @@
-{ config, lib, pkgs, ... }:
-
-let cfg = config.hardware.raspberry-pi.fkms-3d;
-in {
-  options.hardware.raspberry-pi.fkms-3d = {
-    enable = lib.mkEnableOption "Enable modesetting through fkms-3d";
-  };
-  config = lib.mkIf cfg.enable {
-    hardware = {
-      raspberry-pi.deviceTree.dt-overlays = [
-        {
-          overlay = "cma";
-          args = [ ];
-        }
-        {
-          overlay = "vc4-fkms-v3d";
-          args = [ ];
-        }
-      ];
-    };
-    services.xserver.videoDrivers = lib.mkBefore [ "modesetting" "fbdev" ];
-  };
-}