nix-dotfiles/modules/boot.nix

{ config, lib, libS, ... }:

let cfg = config.boot;
in {
  options = {
    boot = {
      default = libS.mkOpinionatedOption "enable the boot builder";
      cpuType = lib.mkOption {
        type = lib.types.str;
        example = "amd";
        default = "";
        description = "The cpu-type installed on the server.";
      };
      amdGPU = libS.mkOpinionatedOption "the system contains a AMD GPU";
      filesystem = lib.mkOption {
        type = lib.types.str;
        example = "btrfs";
        default = "ext4";
        description = "The filesystem installed.";
      };
      fullDiskEncryption = libS.mkOpinionatedOption "use luks full disk encrytion";
      useSystemdBoot = libS.mkOpinionatedOption "use systemd boot";
    };
  };

  config.boot = lib.mkIf cfg.default {
    initrd = {
      # networking for netcard kernelModules = [ "e1000e" ];
      kernelModules = lib.mkIf cfg.amdGPU [ "amdgpu" ];

      network = lib.mkIf cfg.fullDiskEncryption {
        enable = true;
        ssh = {
          enable = true;
          port = 2222;
        };
      };
    };

    supportedFilesystems = [ cfg.filesystem ];
    tmp.useTmpfs = true;
    kernelPackages = config.boot.zfs.package.latestCompatibleLinuxPackages;
    kernelParams = [ "nordrand" ] ++ lib.optional (cfg.cpuType == "amd") "kvm-amd" ++ lib.optional cfg.fullDiskEncryption "ip=<ip-addr>::<ip-gateway>:<netmask>";

    zfs = lib.mkIf (cfg.filesystem == "zfs") {
      enableUnstable = true;
      devNodes = "/dev/disk/by-id/";
      forceImportRoot = true;
    };

    loader = {
      efi = { canTouchEfiVariables = false; };
      generationsDir.copyKernels = true;
      systemd-boot.enable = lib.mkIf cfg.useSystemdBoot true;
      grub = lib.mkIf (!cfg.useSystemdBoot) {
        enable = true;
        copyKernels = true;
        zfsSupport = lib.mkIf (cfg.filesystem == "zfs") true;
        efiSupport = true;
        efiInstallAsRemovable = true;
        fsIdentifier = "uuid";
        enableCryptodisk = lib.mkIf cfg.fullDiskEncryption true;
      };
    };
  };
}