nixos/modules/kernel/default.nix

inputs:
{
  options.nixos.kernel = let inherit (inputs.lib) mkOption types; in
  {
    patches = mkOption { type = types.listOf (types.enum [ "cjktty" "preempt" ]); default = []; };
    modules =
    {
      install = mkOption { type = types.listOf types.str; default = []; };
      load = mkOption { type = types.listOf types.str; default = []; };
      initrd = mkOption { type = types.listOf types.str; default = []; };
      modprobeConfig = mkOption { type = types.listOf types.str; default = []; };
    };
  };
  config = let inherit (inputs.lib) mkMerge mkIf; inherit (inputs.localLib) mkConditional; in mkMerge
  [
    # generic
    {
      boot =
      {
        kernelModules = [ "br_netfilter" ];
        initrd.availableKernelModules =
        [
          "ahci" "ata_piix" "bfq" "failover" "net_failover" "nls_cp437" "nls_iso8859-1" "nvme" "sdhci_acpi" "sd_mod"
          "sr_mod" "usbcore" "usbhid" "usbip-core" "usb-common" "usb_storage" "vhci-hcd" "virtio" "virtio_blk"
          "virtio_net" "virtio_pci" "xhci_pci" "virtio_ring" "virtio_scsi" "cryptd" "crypto_simd" "libaes"
        ];
        kernelParams = [ "delayacct" "acpi_osi=Linux" ];
        kernelPackages = inputs.pkgs.linuxPackagesFor (inputs.pkgs.linuxPackages_xanmod.kernel.override rec
        {
          src = inputs.pkgs.fetchFromGitHub
          {
            owner = "xanmod";
            repo = "linux";
            rev = modDirVersion;
            sha256 = "sha256-rvSQJb9MIOXkGEjHOPt3x+dqp1AysvQg7n5yYsg95fk=";
          };
          version = "6.4.12";
          modDirVersion = "6.4.12-xanmod1";
        });
      };
    }
    # patches
    {
      boot.kernelPatches =
      (
        let
          patches =
          {
            cjktty =
            {
              patch = inputs.pkgs.fetchurl
              {
                url = "https://raw.githubusercontent.com/zhmars/cjktty-patches/master/v6.x/cjktty-6.3.patch";
                sha256 = "sha256-QnsWruzhtiZnqzTUXkPk9Hb19Iddr4VTWXyV4r+iLvE=";
              };
              extraStructuredConfig =
                { FONT_CJK_16x16 = inputs.lib.kernel.yes; FONT_CJK_32x32 = inputs.lib.kernel.yes; };
            };
            preempt =
            {
              patch = null;
              extraStructuredConfig =
              {
                PREEMPT_VOLUNTARY = inputs.lib.mkForce inputs.lib.kernel.no;
                PREEMPT = inputs.lib.mkForce inputs.lib.kernel.yes;
                HZ_500 = inputs.lib.mkForce inputs.lib.kernel.no;
                HZ_1000 = inputs.lib.mkForce inputs.lib.kernel.yes;
                HZ = inputs.lib.mkForce (inputs.lib.kernel.freeform "1000");
              };
            };
          };
        in
          builtins.map (name: { inherit name; } // patches.${name}) inputs.config.nixos.kernel.patches
      );
    }
    # modules
    {
      boot =
      {
        extraModulePackages = inputs.config.nixos.kernel.modules.install;
        kernelModules = inputs.config.nixos.kernel.modules.load;
        initrd.availableKernelModules = inputs.config.nixos.kernel.modules.initrd;
        extraModprobeConfig = builtins.concatStringsSep "\n" inputs.config.nixos.kernel.modules.modprobeConfig;
      };
    }
  ];
}

# modprobe --show-depends