nixos-config/profiles/boot.nix

{ lib, pkgs, config, ... }:
with config.deviceSpecific; {
  zramSwap = {
    enable = true;
    algorithm = "zstd";
    priority = 100;
    memoryPercent = 100; # around 25% of memory
  };

  persist.state.files = [ "/etc/machine-id" ];

  services.earlyoom = {
    enable = devInfo.ram < 16;
    freeMemThreshold = 5;
    freeSwapThreshold = 100;
  };

  services.fstrim = lib.mkIf (devInfo.fileSystem != "zfs") {
    enable = isSSD;
    interval = "weekly";
  };

  services.zfs = lib.mkIf (devInfo.fileSystem == "zfs") {
    autoScrub.enable = true;
    autoScrub.interval = "weekly";
    trim.enable = isSSD;
    trim.interval = "weekly";
  };

  boot = {
    loader = {
      timeout = lib.mkForce 4;
      systemd-boot.enable = lib.mkDefault
        pkgs.hostPlatform.system == "x86_64-linux";
    };

    kernelParams =
      [ "zswap.enabled=0" "quiet" "scsi_mod.use_blk_mq=1" "modeset" "nofb" ]
      ++ lib.optionals (pkgs.hostPlatform.system == "x86_64-linux") [
        "rd.systemd.show_status=auto"
        "rd.udev.log_priority=3"
        "pti=off"
        "spectre_v2=off"
        "kvm.ignore_msrs=1"
      ];

    kernelPackages = lib.mkDefault pkgs.linuxPackages_lqx;

    consoleLogLevel = 3;
    kernel.sysctl = {
      "vm.swappiness" = if config.deviceSpecific.isSSD then 1 else 10;
    };

    cleanTmpDir = !config.boot.tmpOnTmpfs;
    zfs.forceImportAll = lib.mkDefault false;
  };
}