dotfiles/nixos/systems/liveusb/default.nix

# SPDX-FileCopyrightText: 2022 Richard Brežák <richard@brezak.sk>
#
# SPDX-License-Identifier: LGPL-3.0-or-later
{
  inputs,
  lib',
  config,
  ...
}: let
  inherit
    (lib')
    flip
    mapAttrs
    singleton
    ;

  config' = config;
in {
  flake.nixosConfigurations.liveusb = inputs.nixpkgs.lib.nixosSystem {
    system = "x86_64-linux";
    lib = lib';

    specialArgs = {
      config' = config';
      inputs' = inputs;
      secret = lib'.loadSecrets inputs.secrets;
    };

    modules =
      singleton
      ({
        pkgs,
        config,
        ...
      }: {
        imports = [
          "${inputs.nixpkgs}/nixos/modules/installer/cd-dvd/installation-cd-graphical-base.nix"
          ./nixpkgs.nix
        ];

        environment.systemPackages = [
          (pkgs.writeShellScriptBin "test-s0ix" ''
            _cpu_residency="/sys/devices/system/cpu/cpuidle/low_power_idle_cpu_residency_us"
            _system_residency="/sys/devices/system/cpu/cpuidle/low_power_idle_system_residency_us"

            echo '> '"$_system_residency before"
            _residency_before=$(cat "$_system_residency")
            echo "$_residency_before"

            echo "Suspending to RAM and resuming in 30 seconds..."
            rtcwake -u -s 30 -m mem -n && systemctl suspend

            echo '> '"$_system_residency after"
            _residency_after=$(cat "$_system_residency")
            echo "$_residency_after"

            if [ $_residency_before -lt $_residency_after ] ; then
              echo "Suspend successful"
            elso
              echo "Suspend unsuccessful"
            fi

            ${lib'.getExe pkgs.smartmontools} -a $(echo /dev/nvme?n? | tr ' ' '\n' | head -n 1)
          '')
        ];

        isoImage.edition = "xfce";

        services.xserver.videoDrivers = ["nvidia"];

        boot.supportedFilesystems = singleton "zfs";

        boot.kernelPackages = pkgs.linuxKernel.packages.linux_6_1;
        boot.kernelParams = [
          "nvidia.NVreg_EnableS0ixPowerManagement=1"
          "nvidia.NVreg_S0ixPowerManagementVideoMemoryThreshold=2048"
        ];

        hardware.nvidia = {
          powerManagement.enable = true;
          package = config.boot.kernelPackages.nvidia_x11_beta;
        };

        services.xserver = {
          desktopManager = {
            xterm.enable = false;
            xfce.enable = true;
          };
          displayManager.defaultSession = "xfce";
        };
      });
  };
}