NixOSConfig/lib/modules/unfree.nix

{ lib, machine, ... }: {
  config = {
    nixpkgs = {
      config.allowUnfreePredicate = pkg: builtins.elem (lib.getName pkg) (
        let
          names =
            (lib.optional machine.config.xone "xow_dongle-firmware") ++
            (lib.optionals machine.config.nvidia [
              "cuda_cccl"
              "cuda_cudart"
              "cuda_cuobjdump"
              "cuda_cupti"
              "cuda_cuxxfilt"
              "cuda_gdb"
              "cuda-merged"
              "cuda_nvcc"
              "cuda_nvdisasm"
              "cuda_nvml_dev"
              "cuda_nvprune"
              "cuda_nvrtc"
              "cuda_nvtx"
              "cuda_profiler_api"
              "cuda_sanitizer_api"
              "libcublas"
              "libcufft"
              "libcurand"
              "libcusolver"
              "libcusparse"
              "libnpp"
              "libnvjitlink"
              "rar"
            ]);
        in
          names);
    };
  };
}