My implementation of a kernel module overlay

kernel-module-overlay.nix

{
  nixpkgs.overlays = [(
    self: super: {
      libcedrus = super.callPackage ./packages/libcedrus.nix {};
      libvdpau-sunxi = super.callPackage ./packages/libvdpau-sunxi.nix {};
      linuxPackagesFor = kernel: (super.linuxPackagesFor kernel).extend (kself: ksuper: {
        sunxi-cedar-mainline = ksuper.callPackage ./packages/sunxi-cedar-mainline.nix {};
      });
    }
  )];
  
  boot.extraModulePackages = [
    config.boot.kernelPackages.sunxi-cedar-mainline
  ];  
}