pkg megi's kernel

this won't likely build cleanly: it uses floats in places, which isn't
supported in kernel build well.

pkgs/linux-megous/default.nix

@@ -0,0 +1,21 @@
+{ lib, buildPackages, fetchFromGitHub, perl, buildLinux, nixosTests, modDirVersionArg ? null, ... } @ args:
+
+with lib;
+
+buildLinux (args // rec {
+  version = "5.18.14";
+
+  # modDirVersion needs to be x.y.z, will automatically add .0 if needed
+  modDirVersion = if (modDirVersionArg == null) then concatStringsSep "." (take 3 (splitVersion "${version}.0")) else modDirVersionArg;
+
+  # branchVersion needs to be x.y
+  extraMeta.branch = versions.majorMinor version;
+
+  src = fetchFromGitHub {
+    owner = "megous";
+    repo = "linux";
+    # branch: orange-pi-5.18
+    rev = "3ef835b665191e4833ae1363245be48e96013df6";
+    sha256 = "sha256-nQsBXeGLZhpem1p7Vnc8z7XB354AO1mn7VTj/hH5twY=";
+  };
+} // (args.argsOverride or { }))

pkgs/overlay.nix

@@ -13,6 +13,12 @@
     pkgs = prev // { inherit ubootRaspberryPi4_64bit; };
   };
   rtl8723cs-firmware = prev.callPackage ./rtl8723cs-firmware { };
+  linux-megous = prev.callPackage ./linux-megous {
+    kernelPatches = [
+      prev.kernelPatches.bridge_stp_helper
+      prev.kernelPatches.request_key_helper
+    ];
+  };
 
   #### customized packages
   # nixos-unstable pleroma is too far out-of-date for our db