try to get cedar module working

build.sh

@@ -3,4 +3,5 @@
 nix-build "<nixpkgs/nixos>" \
     -I nixpkgs=https://github.com/danielfullmer/nixpkgs/archive/e69838e006a7271006ab834b521187891bf93ff4.tar.gz \
     -I nixos-config=./sd-image.nix \
-    -A config.system.build.sdImage
+    -A config.system.build.sdImage \
+    --keep-failed

configuration.nix

@@ -27,7 +27,20 @@
   ];
 
   boot.kernelModules = [ "spi-nor" ]; # Not sure why this doesn't autoload. Provides SPI NOR at /dev/mtd0
-  boot.extraModulePackages = [ config.boot.kernelPackages.rtl8189es ];
+  boot.extraModulePackages = [
+    config.boot.kernelPackages.rtl8189es
+    config.boot.kernelPackages.sunxi-cedar
+  ];
+
+  nixpkgs.overlays = [
+    # add sunxi-cedar kernel module
+    (self: super: {
+      linuxPackages_5_9 = super.linuxPackages_5_9.extend (lpself: lpsuper: {
+        sunxi-cedar = lpself.callPackage ./kernel/sunxi-cedar.nix {};
+      });
+    })
+  ];
+
 
   zramSwap.enable = true; # 128MB is not much to work with
 

kernel/sunxi-cedar.nix

@@ -0,0 +1,33 @@
+{ lib, stdenv, fetchFromGitHub, kernel }:
+
+stdenv.mkDerivation rec {
+  pname = "sunxi-cedar";
+  version = "8bfe1150ea24537523465a77df56cd78076cda4a";
+
+  src = fetchFromGitHub {
+    owner = "uboborov";
+    repo = "sunxi-cedar-mainline";
+    rev = "${version}";
+    sha256 = "s/Cxr1GlmvORBvoJvU0LCpezacuQv5qT/9GyJYcAtq4=";
+  };
+
+  makeFlags = [
+    # For Makefile.linux
+    #"KDIR=${kernel.dev}/lib/modules/${kernel.modDirVersion}/build"
+    #"INSTALL_MOD_PATH=$(out)"
+    #"KERNELRELEASE=${kernel.modDirVersion}"
+
+    # For Makefile
+    "KERNEL_SOURCE=${kernel.dev}/lib/modules/${kernel.modDirVersion}/build"
+  ];
+  nativeBuildInputs = kernel.moduleBuildDependencies;
+
+  hardeningDisable = [ "pic" ];
+
+  meta = with lib; {
+    description = "sunxi cedar kernel module - device: /dev/cedar_dev - targeting mainline kernel - linux-4.11.y and higher ";
+    homepage = "https://github.com/uboborov/sunxi-cedar-mainline";
+    platforms = platforms.linux;
+    license = licenses.gpl2Plus;
+  };
+}