alqueva/hosts/micronix/system.nix

# Edit this configuration file to define what should be installed on
# your system.  Help is available in the configuration.nix(5) man page
# and in the NixOS manual (accessible by running ‘nixos-help’).
{pkgs, ...}: {
  imports = [
    ./config/sysctl.d/performance.nix
    ./config/sysctl.d/hardening.nix
  ];

  boot.loader = {
    generationsDir.copyKernels = true;
  };

  boot.kernelPackages = pkgs.linuxPackages_cachyos-lto;

  boot.kernelParams = [
    "default_hugepagesz=1G"
    "hugepagesz=1G"
    "slab_nomerge"
    "init_on_alloc=1"
    "randomize_kstack_offset=on"
    "init_on_free=1"
    "page_alloc.shuffle=1"
    "pti=on"
    "vsyscall=none"
    "debugfs=off"
    "oops=panic"
    "module.sig_enforce=1"
    "lockdown=confidentiality"
    "mce=0"
    "quiet"
    "splash"
    "loglevel=0"
  ];

  services.scx = {
    enable = true;
    scheduler = "scx_lavd";
    extraArgs = ["--performance"];
  };

  boot.runSize = "100%";
  boot.devSize = "100%";
  boot.devShmSize = "100%";
  boot.tmp.useTmpfs = true;
  boot.tmp.tmpfsSize = "100%";
  boot.tmp.cleanOnBoot = true;

  fileSystems."/" = {
    fsType = "btrfs";
    options = ["compress=zstd:6" "discard" "flushoncommit" "subvol=@"];
  };

  services.btrfs.autoScrub = {
    fileSystems = ["/"]; # Assuming root is formatted with Btrfs.
    interval = "daily";
    enable = true;
  };

  zramSwap = {
    enable = true;
    priority = 100;
    memoryPercent = 100;
  };

  nix.gc = {
    automatic = true;
    options = "-d";
  };

  nix.optimise.automatic = true;

  nix.settings = {
    experimental-features = "cgroups dynamic-derivations flakes nix-command recursive-nix";
    auto-optimise-store = true;
    http-connections = 0;
    download-buffer-size = 671088640;
    max-jobs = "auto";
    sync-before-registering = true;
    use-cgroups = true;
  };

  boot.initrd.kernelModules = ["amdgpu"];

  # Processor settings for AMD
  hardware.cpu.amd = {
    sev.enable = true;
    updateMicrocode = true;
  };

  # Bootloader.
  boot.loader.systemd-boot = {
    enable = true;
    edk2-uefi-shell = {enable = true;};
    memtest86 = {enable = true;};
    configurationLimit = 3;
  };

  networking.tempAddresses = "default";

  # Load AMD GPU drivers early
  hardware.amdgpu.initrd = {
    enable = true;
  };

  hardware.amdgpu.opencl = {
    enable = true;
  };

  # Graphics
  hardware.graphics = {
    enable = true;
    enable32Bit = true;
  };

  # Enable the X11 windowing system.
  services.xserver.enable = true;
  services.xserver.videoDrivers = ["amdgpu"];
  services.xserver.updateDbusEnvironment = true;
  services.xserver.enableTearFree = true;

  # TLP
  services.power-profiles-daemon.enable = false; # We disable this because it sucks
  services.tlp.enable = true;
  services.tlp.settings = {
    CPU_DRIVER_OPMODE_ON_AC = "active";
    CPU_DRIVER_OPMODE_ON_BAT = "active";
    CPU_SCALING_GOVERNOR_ON_AC = "performance";
    CPU_SCALING_GOVERNOR_ON_BAT = "schedutil";
    CPU_BOOST_ON_AC = 1;
    CPU_BOOST_ON_BAT = 0;
    PLATFORM_PROFILE_ON_AC = "performance";
    PLATFORM_PROFILE_ON_BAT = "low-power";
    DISK_IOSCHED = "kyber";
    RADEON_DPM_PERF_LEVEL_ON_AC = "high";
    WIFI_PWR_ON_AC = "off";
    WIFI_PWR_ON_BAT = "off";
  };

  security.rtkit.enable = true;

  programs.dconf.enable = true;

  xdg.portal = {
    enable = true;
    xdgOpenUsePortal = true;
    extraPortals = with pkgs; [
      xdg-desktop-portal
      xdg-desktop-portal-gtk
      xdg-desktop-portal-gnome
    ];
    config.common.default = "*";
  };

  environment.sessionVariables.NIXOS_OZONE_WL = "1";

  services.dbus = {
    implementation = "broker";
  };

  # SECURITY
  security = {
    tpm2 = {
      enable = true;
    }; # Having TPM2 is nice.
    polkit = {
      enable = true;
    };
    protectKernelImage = true;
    forcePageTableIsolation = true;
  };

  systemd.tpm2.enable = true;

  fonts = {
    enableGhostscriptFonts = true;
    enableDefaultPackages = true;
    fontDir = {
      enable = true;
      decompressFonts = true;
    };
  };
}