{ system ? builtins.currentSystem,
  config ? {},
  pkgs ? import ../.. { inherit system config; }
}:

with import ../lib/testing-python.nix { inherit system pkgs; };
with pkgs.lib;

let

  # The configuration to install.
  makeConfig = { bootLoader, grubVersion, grubDevice, grubIdentifier, grubUseEfi
               , extraConfig, forceGrubReinstallCount ? 0
               }:
    pkgs.writeText "configuration.nix" ''
      { config, lib, pkgs, modulesPath, ... }:

      { imports =
          [ ./hardware-configuration.nix
            <nixpkgs/nixos/modules/testing/test-instrumentation.nix>
          ];

        # To ensure that we can rebuild the grub configuration on the nixos-rebuild
        system.extraDependencies = with pkgs; [ stdenvNoCC ];

        ${optionalString (bootLoader == "grub") ''
          boot.loader.grub.version = ${toString grubVersion};
          ${optionalString (grubVersion == 1) ''
            boot.loader.grub.splashImage = null;
          ''}

          boot.loader.grub.extraConfig = "serial; terminal_output serial";
          ${if grubUseEfi then ''
            boot.loader.grub.device = "nodev";
            boot.loader.grub.efiSupport = true;
            boot.loader.grub.efiInstallAsRemovable = true; # XXX: needed for OVMF?
          '' else ''
            boot.loader.grub.device = "${grubDevice}";
            boot.loader.grub.fsIdentifier = "${grubIdentifier}";
          ''}

          boot.loader.grub.configurationLimit = 100 + ${toString forceGrubReinstallCount};
        ''}

        ${optionalString (bootLoader == "systemd-boot") ''
          boot.loader.systemd-boot.enable = true;
        ''}

        users.users.alice = {
          isNormalUser = true;
          home = "/home/alice";
          description = "Alice Foobar";
        };

        hardware.enableAllFirmware = lib.mkForce false;

        ${replaceChars ["\n"] ["\n  "] extraConfig}
      }
    '';


  # The test script boots a NixOS VM, installs NixOS on an empty hard
  # disk, and then reboot from the hard disk.  It's parameterized with
  # a test script fragment `createPartitions', which must create
  # partitions and filesystems.
  testScriptFun = { bootLoader, createPartitions, grubVersion, grubDevice, grubUseEfi
                  , grubIdentifier, preBootCommands, postBootCommands, extraConfig
                  , testSpecialisationConfig
                  }:
    let iface = if grubVersion == 1 then "ide" else "virtio";
        isEfi = bootLoader == "systemd-boot" || (bootLoader == "grub" && grubUseEfi);
        bios  = if pkgs.stdenv.isAarch64 then "QEMU_EFI.fd" else "OVMF.fd";
    in if !isEfi && !(pkgs.stdenv.isi686 || pkgs.stdenv.isx86_64) then
      throw "Non-EFI boot methods are only supported on i686 / x86_64"
    else ''
      def assemble_qemu_flags():
          flags = "-cpu max"
          ${if (system == "x86_64-linux" || system == "i686-linux")
            then ''flags += " -m 1024"''
            else ''flags += " -m 768 -enable-kvm -machine virt,gic-version=host"''
          }
          return flags


      qemu_flags = {"qemuFlags": assemble_qemu_flags()}

      hd_flags = {
          "hdaInterface": "${iface}",
          "hda": "vm-state-machine/machine.qcow2",
      }
      ${optionalString isEfi ''
        hd_flags.update(
            bios="${pkgs.OVMF.fd}/FV/${bios}"
        )''
      }
      default_flags = {**hd_flags, **qemu_flags}


      def create_machine_named(name):
          return create_machine({**default_flags, "name": name})


      machine.start()

      with subtest("Assert readiness of login prompt"):
          machine.succeed("echo hello")

      with subtest("Wait for hard disks to appear in /dev"):
          machine.succeed("udevadm settle")

      ${createPartitions}

      with subtest("Create the NixOS configuration"):
          machine.succeed("nixos-generate-config --root /mnt")
          machine.succeed("cat /mnt/etc/nixos/hardware-configuration.nix >&2")
          machine.copy_from_host(
              "${ makeConfig {
                    inherit bootLoader grubVersion grubDevice grubIdentifier
                            grubUseEfi extraConfig;
                  }
              }",
              "/mnt/etc/nixos/configuration.nix",
          )

      with subtest("Perform the installation"):
          machine.succeed("nixos-install < /dev/null >&2")

      with subtest("Do it again to make sure it's idempotent"):
          machine.succeed("nixos-install < /dev/null >&2")

      with subtest("Shutdown system after installation"):
          machine.succeed("umount /mnt/boot || true")
          machine.succeed("umount /mnt")
          machine.succeed("sync")
          machine.shutdown()

      # Now see if we can boot the installation.
      machine = create_machine_named("boot-after-install")

      # For example to enter LUKS passphrase.
      ${preBootCommands}

      with subtest("Assert that /boot get mounted"):
          machine.wait_for_unit("local-fs.target")
          ${if bootLoader == "grub"
              then ''machine.succeed("test -e /boot/grub")''
              else ''machine.succeed("test -e /boot/loader/loader.conf")''
          }

      with subtest("Check whether /root has correct permissions"):
          assert "700" in machine.succeed("stat -c '%a' /root")

      with subtest("Assert swap device got activated"):
          # uncomment once https://bugs.freedesktop.org/show_bug.cgi?id=86930 is resolved
          machine.wait_for_unit("swap.target")
          machine.succeed("cat /proc/swaps | grep -q /dev")

      with subtest("Check that the store is in good shape"):
          machine.succeed("nix-store --verify --check-contents >&2")

      with subtest("Check whether the channel works"):
          machine.succeed("nix-env -iA nixos.procps >&2")
          assert ".nix-profile" in machine.succeed("type -tP ps | tee /dev/stderr")

      with subtest(
          "Check that the daemon works, and that non-root users can run builds "
          "(this will build a new profile generation through the daemon)"
      ):
          machine.succeed("su alice -l -c 'nix-env -iA nixos.procps' >&2")

      with subtest("Configure system with writable Nix store on next boot"):
          # we're not using copy_from_host here because the installer image
          # doesn't know about the host-guest sharing mechanism.
          machine.copy_from_host_via_shell(
              "${ makeConfig {
                    inherit bootLoader grubVersion grubDevice grubIdentifier
                            grubUseEfi extraConfig;
                    forceGrubReinstallCount = 1;
                  }
              }",
              "/etc/nixos/configuration.nix",
          )

      with subtest("Check whether nixos-rebuild works"):
          machine.succeed("nixos-rebuild switch >&2")

      with subtest("Test nixos-option"):
          kernel_modules = machine.succeed("nixos-option boot.initrd.kernelModules")
          assert "virtio_console" in kernel_modules
          assert "List of modules" in kernel_modules
          assert "qemu-guest.nix" in kernel_modules

      machine.shutdown()

      # Check whether a writable store build works
      machine = create_machine_named("rebuild-switch")
      ${preBootCommands}
      machine.wait_for_unit("multi-user.target")

      # we're not using copy_from_host here because the installer image
      # doesn't know about the host-guest sharing mechanism.
      machine.copy_from_host_via_shell(
          "${ makeConfig {
                inherit bootLoader grubVersion grubDevice grubIdentifier
                grubUseEfi extraConfig;
                forceGrubReinstallCount = 2;
              }
          }",
          "/etc/nixos/configuration.nix",
      )
      machine.succeed("nixos-rebuild boot >&2")
      machine.shutdown()

      # And just to be sure, check that the machine still boots after
      # "nixos-rebuild switch".
      machine = create_machine_named("boot-after-rebuild-switch")
      ${preBootCommands}
      machine.wait_for_unit("network.target")
      ${postBootCommands}
      machine.shutdown()

      # Tests for validating clone configuration entries in grub menu
    ''
    + optionalString testSpecialisationConfig ''
      # Reboot Machine
      machine = create_machine_named("clone-default-config")
      ${preBootCommands}
      machine.wait_for_unit("multi-user.target")

      with subtest("Booted configuration name should be 'Home'"):
          # This is not the name that shows in the grub menu.
          # The default configuration is always shown as "Default"
          machine.succeed("cat /run/booted-system/configuration-name >&2")
          assert "Home" in machine.succeed("cat /run/booted-system/configuration-name")

      with subtest("We should **not** find a file named /etc/gitconfig"):
          machine.fail("test -e /etc/gitconfig")

      with subtest("Set grub to boot the second configuration"):
          machine.succeed("grub-reboot 1")

      ${postBootCommands}
      machine.shutdown()

      # Reboot Machine
      machine = create_machine_named("clone-alternate-config")
      ${preBootCommands}

      machine.wait_for_unit("multi-user.target")
      with subtest("Booted configuration name should be Work"):
          machine.succeed("cat /run/booted-system/configuration-name >&2")
          assert "Work" in machine.succeed("cat /run/booted-system/configuration-name")

      with subtest("We should find a file named /etc/gitconfig"):
          machine.succeed("test -e /etc/gitconfig")

      ${postBootCommands}
      machine.shutdown()
    '';


  makeInstallerTest = name:
    { createPartitions, preBootCommands ? "", postBootCommands ? "", extraConfig ? ""
    , extraInstallerConfig ? {}
    , bootLoader ? "grub" # either "grub" or "systemd-boot"
    , grubVersion ? 2, grubDevice ? "/dev/vda", grubIdentifier ? "uuid", grubUseEfi ? false
    , enableOCR ? false, meta ? {}
    , testSpecialisationConfig ? false
    }:
    makeTest {
      inherit enableOCR;
      name = "installer-" + name;
      meta = with pkgs.lib.maintainers; {
        # put global maintainers here, individuals go into makeInstallerTest fkt call
        maintainers = (meta.maintainers or []);
      };
      nodes = {

        # The configuration of the machine used to run "nixos-install".
        machine = { pkgs, ... }: {
          imports = [
            ../modules/profiles/installation-device.nix
            ../modules/profiles/base.nix
            extraInstallerConfig
          ];

          # builds stuff in the VM, needs more juice
          virtualisation.diskSize = 8 * 1024;
          virtualisation.cores = 8;
          virtualisation.memorySize = 1536;

          # Use a small /dev/vdb as the root disk for the
          # installer. This ensures the target disk (/dev/vda) is
          # the same during and after installation.
          virtualisation.emptyDiskImages = [ 512 ];
          virtualisation.bootDevice =
            if grubVersion == 1 then "/dev/disk/by-id/scsi-0QEMU_QEMU_HARDDISK_drive2" else "/dev/vdb";
          virtualisation.qemu.diskInterface =
            if grubVersion == 1 then "scsi" else "virtio";

          boot.loader.systemd-boot.enable = mkIf (bootLoader == "systemd-boot") true;

          hardware.enableAllFirmware = mkForce false;

          # The test cannot access the network, so any packages we
          # need must be included in the VM.
          system.extraDependencies = with pkgs; [
            desktop-file-utils
            docbook5
            docbook_xsl_ns
            libxml2.bin
            libxslt.bin
            nixos-artwork.wallpapers.simple-dark-gray-bottom
            ntp
            perlPackages.ListCompare
            perlPackages.XMLLibXML
            shared-mime-info
            sudo
            texinfo
            unionfs-fuse
            xorg.lndir

            # add curl so that rather than seeing the test attempt to download
            # curl's tarball, we see what it's trying to download
            curl
          ]
          ++ optional (bootLoader == "grub" && grubVersion == 1) pkgs.grub
          ++ optionals (bootLoader == "grub" && grubVersion == 2) (let
            zfsSupport = lib.any (x: x == "zfs")
              (extraInstallerConfig.boot.supportedFilesystems or []);
          in [
            (pkgs.grub2.override { inherit zfsSupport; })
            (pkgs.grub2_efi.override { inherit zfsSupport; })
          ]);

          nix.binaryCaches = mkForce [ ];
          nix.extraOptions = ''
            hashed-mirrors =
            connect-timeout = 1
          '';
        };

      };

      testScript = testScriptFun {
        inherit bootLoader createPartitions preBootCommands postBootCommands
                grubVersion grubDevice grubIdentifier grubUseEfi extraConfig
                testSpecialisationConfig;
      };
    };

    makeLuksRootTest = name: luksFormatOpts: makeInstallerTest name {
      createPartitions = ''
        machine.succeed(
            "flock /dev/vda parted --script /dev/vda -- mklabel msdos"
            + " mkpart primary ext2 1M 50MB"  # /boot
            + " mkpart primary linux-swap 50M 1024M"
            + " mkpart primary 1024M -1s",  # LUKS
            "udevadm settle",
            "mkswap /dev/vda2 -L swap",
            "swapon -L swap",
            "modprobe dm_mod dm_crypt",
            "echo -n supersecret | cryptsetup luksFormat ${luksFormatOpts} -q /dev/vda3 -",
            "echo -n supersecret | cryptsetup luksOpen --key-file - /dev/vda3 cryptroot",
            "mkfs.ext3 -L nixos /dev/mapper/cryptroot",
            "mount LABEL=nixos /mnt",
            "mkfs.ext3 -L boot /dev/vda1",
            "mkdir -p /mnt/boot",
            "mount LABEL=boot /mnt/boot",
        )
      '';
      extraConfig = ''
        boot.kernelParams = lib.mkAfter [ "console=tty0" ];
      '';
      enableOCR = true;
      preBootCommands = ''
        machine.start()
        machine.wait_for_text("Passphrase for")
        machine.send_chars("supersecret\n")
      '';
    };

  # The (almost) simplest partitioning scheme: a swap partition and
  # one big filesystem partition.
  simple-test-config = {
    createPartitions = ''
      machine.succeed(
          "flock /dev/vda parted --script /dev/vda -- mklabel msdos"
          + " mkpart primary linux-swap 1M 1024M"
          + " mkpart primary ext2 1024M -1s",
          "udevadm settle",
          "mkswap /dev/vda1 -L swap",
          "swapon -L swap",
          "mkfs.ext3 -L nixos /dev/vda2",
          "mount LABEL=nixos /mnt",
      )
    '';
  };

  simple-uefi-grub-config = {
    createPartitions = ''
      machine.succeed(
          "flock /dev/vda parted --script /dev/vda -- mklabel gpt"
          + " mkpart ESP fat32 1M 100MiB"  # /boot
          + " set 1 boot on"
          + " mkpart primary linux-swap 100MiB 1024MiB"
          + " mkpart primary ext2 1024MiB -1MiB",  # /
          "udevadm settle",
          "mkswap /dev/vda2 -L swap",
          "swapon -L swap",
          "mkfs.ext3 -L nixos /dev/vda3",
          "mount LABEL=nixos /mnt",
          "mkfs.vfat -n BOOT /dev/vda1",
          "mkdir -p /mnt/boot",
          "mount LABEL=BOOT /mnt/boot",
      )
    '';
    bootLoader = "grub";
    grubUseEfi = true;
  };

  specialisation-test-extraconfig = {
    extraConfig = ''
      environment.systemPackages = [ pkgs.grub2 ];
      boot.loader.grub.configurationName = "Home";
      specialisation.work.configuration = {
        boot.loader.grub.configurationName = lib.mkForce "Work";

        environment.etc = {
          "gitconfig".text = "
            [core]
              gitproxy = none for work.com
              ";
        };
      };
    '';
    testSpecialisationConfig = true;
  };


in {

  # !!! `parted mkpart' seems to silently create overlapping partitions.


  # The (almost) simplest partitioning scheme: a swap partition and
  # one big filesystem partition.
  simple = makeInstallerTest "simple" simple-test-config;

  # Test cloned configurations with the simple grub configuration
  simpleSpecialised = makeInstallerTest "simpleSpecialised" (simple-test-config // specialisation-test-extraconfig);

  # Simple GPT/UEFI configuration using systemd-boot with 3 partitions: ESP, swap & root filesystem
  simpleUefiSystemdBoot = makeInstallerTest "simpleUefiSystemdBoot" {
    createPartitions = ''
      machine.succeed(
          "flock /dev/vda parted --script /dev/vda -- mklabel gpt"
          + " mkpart ESP fat32 1M 50MiB"  # /boot
          + " set 1 boot on"
          + " mkpart primary linux-swap 50MiB 1024MiB"
          + " mkpart primary ext2 1024MiB -1MiB",  # /
          "udevadm settle",
          "mkswap /dev/vda2 -L swap",
          "swapon -L swap",
          "mkfs.ext3 -L nixos /dev/vda3",
          "mount LABEL=nixos /mnt",
          "mkfs.vfat -n BOOT /dev/vda1",
          "mkdir -p /mnt/boot",
          "mount LABEL=BOOT /mnt/boot",
      )
    '';
    bootLoader = "systemd-boot";
  };

  simpleUefiGrub = makeInstallerTest "simpleUefiGrub" simple-uefi-grub-config;

  # Test cloned configurations with the uefi grub configuration
  simpleUefiGrubSpecialisation = makeInstallerTest "simpleUefiGrubSpecialisation" (simple-uefi-grub-config // specialisation-test-extraconfig);

  # Same as the previous, but now with a separate /boot partition.
  separateBoot = makeInstallerTest "separateBoot" {
    createPartitions = ''
      machine.succeed(
          "flock /dev/vda parted --script /dev/vda -- mklabel msdos"
          + " mkpart primary ext2 1M 50MB"  # /boot
          + " mkpart primary linux-swap 50MB 1024M"
          + " mkpart primary ext2 1024M -1s",  # /
          "udevadm settle",
          "mkswap /dev/vda2 -L swap",
          "swapon -L swap",
          "mkfs.ext3 -L nixos /dev/vda3",
          "mount LABEL=nixos /mnt",
          "mkfs.ext3 -L boot /dev/vda1",
          "mkdir -p /mnt/boot",
          "mount LABEL=boot /mnt/boot",
      )
    '';
  };

  # Same as the previous, but with fat32 /boot.
  separateBootFat = makeInstallerTest "separateBootFat" {
    createPartitions = ''
      machine.succeed(
          "flock /dev/vda parted --script /dev/vda -- mklabel msdos"
          + " mkpart primary ext2 1M 50MB"  # /boot
          + " mkpart primary linux-swap 50MB 1024M"
          + " mkpart primary ext2 1024M -1s",  # /
          "udevadm settle",
          "mkswap /dev/vda2 -L swap",
          "swapon -L swap",
          "mkfs.ext3 -L nixos /dev/vda3",
          "mount LABEL=nixos /mnt",
          "mkfs.vfat -n BOOT /dev/vda1",
          "mkdir -p /mnt/boot",
          "mount LABEL=BOOT /mnt/boot",
      )
    '';
  };

  # zfs on / with swap
  zfsroot = makeInstallerTest "zfs-root" {
    extraInstallerConfig = {
      boot.supportedFilesystems = [ "zfs" ];
    };

    extraConfig = ''
      boot.supportedFilesystems = [ "zfs" ];

      # Using by-uuid overrides the default of by-id, and is unique
      # to the qemu disks, as they don't produce by-id paths for
      # some reason.
      boot.zfs.devNodes = "/dev/disk/by-uuid/";
      networking.hostId = "00000000";
    '';

    createPartitions = ''
      machine.succeed(
          "flock /dev/vda parted --script /dev/vda -- mklabel msdos"
          + " mkpart primary linux-swap 1M 1024M"
          + " mkpart primary 1024M -1s",
          "udevadm settle",
          "mkswap /dev/vda1 -L swap",
          "swapon -L swap",
          "zpool create rpool /dev/vda2",
          "zfs create -o mountpoint=legacy rpool/root",
          "mount -t zfs rpool/root /mnt",
          "udevadm settle",
      )
    '';
  };

  # Create two physical LVM partitions combined into one volume group
  # that contains the logical swap and root partitions.
  lvm = makeInstallerTest "lvm" {
    createPartitions = ''
      machine.succeed(
          "flock /dev/vda parted --script /dev/vda -- mklabel msdos"
          + " mkpart primary 1M 2048M"  # PV1
          + " set 1 lvm on"
          + " mkpart primary 2048M -1s"  # PV2
          + " set 2 lvm on",
          "udevadm settle",
          "sleep 1",
          "pvcreate /dev/vda1 /dev/vda2",
          "sleep 1",
          "vgcreate MyVolGroup /dev/vda1 /dev/vda2",
          "sleep 1",
          "lvcreate --size 1G --name swap MyVolGroup",
          "sleep 1",
          "lvcreate --size 3G --name nixos MyVolGroup",
          "sleep 1",
          "mkswap -f /dev/MyVolGroup/swap -L swap",
          "swapon -L swap",
          "mkfs.xfs -L nixos /dev/MyVolGroup/nixos",
          "mount LABEL=nixos /mnt",
      )
    '';
    postBootCommands = ''
      assert "loaded active" in machine.succeed(
          "systemctl list-units 'lvm2-pvscan@*' -ql --no-legend | tee /dev/stderr"
      )
    '';
  };

  # Boot off an encrypted root partition with the default LUKS header format
  luksroot = makeLuksRootTest "luksroot-format1" "";

  # Boot off an encrypted root partition with LUKS1 format
  luksroot-format1 = makeLuksRootTest "luksroot-format1" "--type=LUKS1";

  # Boot off an encrypted root partition with LUKS2 format
  luksroot-format2 = makeLuksRootTest "luksroot-format2" "--type=LUKS2";

  # Test whether opening encrypted filesystem with keyfile
  # Checks for regression of missing cryptsetup, when no luks device without
  # keyfile is configured
  encryptedFSWithKeyfile = makeInstallerTest "encryptedFSWithKeyfile" {
    createPartitions = ''
      machine.succeed(
          "flock /dev/vda parted --script /dev/vda -- mklabel msdos"
          + " mkpart primary ext2 1M 50MB"  # /boot
          + " mkpart primary linux-swap 50M 1024M"
          + " mkpart primary 1024M 1280M"  # LUKS with keyfile
          + " mkpart primary 1280M -1s",
          "udevadm settle",
          "mkswap /dev/vda2 -L swap",
          "swapon -L swap",
          "mkfs.ext3 -L nixos /dev/vda4",
          "mount LABEL=nixos /mnt",
          "mkfs.ext3 -L boot /dev/vda1",
          "mkdir -p /mnt/boot",
          "mount LABEL=boot /mnt/boot",
          "modprobe dm_mod dm_crypt",
          "echo -n supersecret > /mnt/keyfile",
          "cryptsetup luksFormat -q /dev/vda3 --key-file /mnt/keyfile",
          "cryptsetup luksOpen --key-file /mnt/keyfile /dev/vda3 crypt",
          "mkfs.ext3 -L test /dev/mapper/crypt",
          "cryptsetup luksClose crypt",
          "mkdir -p /mnt/test",
      )
    '';
    extraConfig = ''
      fileSystems."/test" = {
        device = "/dev/disk/by-label/test";
        fsType = "ext3";
        encrypted.enable = true;
        encrypted.blkDev = "/dev/vda3";
        encrypted.label = "crypt";
        encrypted.keyFile = "/mnt-root/keyfile";
      };
    '';
  };

  swraid = makeInstallerTest "swraid" {
    createPartitions = ''
      machine.succeed(
          "flock /dev/vda parted --script /dev/vda --"
          + " mklabel msdos"
          + " mkpart primary ext2 1M 100MB"  # /boot
          + " mkpart extended 100M -1s"
          + " mkpart logical 102M 3102M"  # md0 (root), first device
          + " mkpart logical 3103M 6103M"  # md0 (root), second device
          + " mkpart logical 6104M 6360M"  # md1 (swap), first device
          + " mkpart logical 6361M 6617M",  # md1 (swap), second device
          "udevadm settle",
          "ls -l /dev/vda* >&2",
          "cat /proc/partitions >&2",
          "udevadm control --stop-exec-queue",
          "mdadm --create --force /dev/md0 --metadata 1.2 --level=raid1 "
          + "--raid-devices=2 /dev/vda5 /dev/vda6",
          "mdadm --create --force /dev/md1 --metadata 1.2 --level=raid1 "
          + "--raid-devices=2 /dev/vda7 /dev/vda8",
          "udevadm control --start-exec-queue",
          "udevadm settle",
          "mkswap -f /dev/md1 -L swap",
          "swapon -L swap",
          "mkfs.ext3 -L nixos /dev/md0",
          "mount LABEL=nixos /mnt",
          "mkfs.ext3 -L boot /dev/vda1",
          "mkdir /mnt/boot",
          "mount LABEL=boot /mnt/boot",
          "udevadm settle",
      )
    '';
    preBootCommands = ''
      machine.start()
      machine.fail("dmesg | grep 'immediate safe mode'")
    '';
  };

  bcache = makeInstallerTest "bcache" {
    createPartitions = ''
      machine.succeed(
          "flock /dev/vda parted --script /dev/vda --"
          + " mklabel msdos"
          + " mkpart primary ext2 1M 50MB"  # /boot
          + " mkpart primary 50MB 512MB  "  # swap
          + " mkpart primary 512MB 1024MB"  # Cache (typically SSD)
          + " mkpart primary 1024MB -1s ",  # Backing device (typically HDD)
          "modprobe bcache",
          "udevadm settle",
          "make-bcache -B /dev/vda4 -C /dev/vda3",
          "echo /dev/vda3 > /sys/fs/bcache/register",
          "echo /dev/vda4 > /sys/fs/bcache/register",
          "udevadm settle",
          "mkfs.ext3 -L nixos /dev/bcache0",
          "mount LABEL=nixos /mnt",
          "mkfs.ext3 -L boot /dev/vda1",
          "mkdir /mnt/boot",
          "mount LABEL=boot /mnt/boot",
          "mkswap -f /dev/vda2 -L swap",
          "swapon -L swap",
      )
    '';
  };

  # Test a basic install using GRUB 1.
  grub1 = makeInstallerTest "grub1" rec {
    createPartitions = ''
      machine.succeed(
          "flock ${grubDevice} parted --script ${grubDevice} -- mklabel msdos"
          + " mkpart primary linux-swap 1M 1024M"
          + " mkpart primary ext2 1024M -1s",
          "udevadm settle",
          "mkswap ${grubDevice}-part1 -L swap",
          "swapon -L swap",
          "mkfs.ext3 -L nixos ${grubDevice}-part2",
          "mount LABEL=nixos /mnt",
          "mkdir -p /mnt/tmp",
      )
    '';
    grubVersion = 1;
    # /dev/sda is not stable, even when the SCSI disk number is.
    grubDevice = "/dev/disk/by-id/scsi-0QEMU_QEMU_HARDDISK_drive1";
  };

  # Test using labels to identify volumes in grub
  simpleLabels = makeInstallerTest "simpleLabels" {
    createPartitions = ''
      machine.succeed(
          "sgdisk -Z /dev/vda",
          "sgdisk -n 1:0:+1M -n 2:0:+1G -N 3 -t 1:ef02 -t 2:8200 -t 3:8300 -c 3:root /dev/vda",
          "mkswap /dev/vda2 -L swap",
          "swapon -L swap",
          "mkfs.ext4 -L root /dev/vda3",
          "mount LABEL=root /mnt",
      )
    '';
    grubIdentifier = "label";
  };

  # Test using the provided disk name within grub
  # TODO: Fix udev so the symlinks are unneeded in /dev/disks
  simpleProvided = makeInstallerTest "simpleProvided" {
    createPartitions = ''
      uuid = "$(blkid -s UUID -o value /dev/vda2)"
      machine.succeed(
          "sgdisk -Z /dev/vda",
          "sgdisk -n 1:0:+1M -n 2:0:+100M -n 3:0:+1G -N 4 -t 1:ef02 -t 2:8300 "
          + "-t 3:8200 -t 4:8300 -c 2:boot -c 4:root /dev/vda",
          "mkswap /dev/vda3 -L swap",
          "swapon -L swap",
          "mkfs.ext4 -L boot /dev/vda2",
          "mkfs.ext4 -L root /dev/vda4",
      )
      machine.execute(f"ln -s ../../vda2 /dev/disk/by-uuid/{uuid}")
      machine.execute("ln -s ../../vda4 /dev/disk/by-label/root")
      machine.succeed(
          "mount /dev/disk/by-label/root /mnt",
          "mkdir /mnt/boot",
          f"mount /dev/disk/by-uuid/{uuid} /mnt/boot",
      )
    '';
    grubIdentifier = "provided";
  };

  # Simple btrfs grub testing
  btrfsSimple = makeInstallerTest "btrfsSimple" {
    createPartitions = ''
      machine.succeed(
          "sgdisk -Z /dev/vda",
          "sgdisk -n 1:0:+1M -n 2:0:+1G -N 3 -t 1:ef02 -t 2:8200 -t 3:8300 -c 3:root /dev/vda",
          "mkswap /dev/vda2 -L swap",
          "swapon -L swap",
          "mkfs.btrfs -L root /dev/vda3",
          "mount LABEL=root /mnt",
      )
    '';
  };

  # Test to see if we can detect /boot and /nix on subvolumes
  btrfsSubvols = makeInstallerTest "btrfsSubvols" {
    createPartitions = ''
      machine.succeed(
          "sgdisk -Z /dev/vda",
          "sgdisk -n 1:0:+1M -n 2:0:+1G -N 3 -t 1:ef02 -t 2:8200 -t 3:8300 -c 3:root /dev/vda",
          "mkswap /dev/vda2 -L swap",
          "swapon -L swap",
          "mkfs.btrfs -L root /dev/vda3",
          "btrfs device scan",
          "mount LABEL=root /mnt",
          "btrfs subvol create /mnt/boot",
          "btrfs subvol create /mnt/nixos",
          "btrfs subvol create /mnt/nixos/default",
          "umount /mnt",
          "mount -o defaults,subvol=nixos/default LABEL=root /mnt",
          "mkdir /mnt/boot",
          "mount -o defaults,subvol=boot LABEL=root /mnt/boot",
      )
    '';
  };

  # Test to see if we can detect default and aux subvolumes correctly
  btrfsSubvolDefault = makeInstallerTest "btrfsSubvolDefault" {
    createPartitions = ''
      machine.succeed(
          "sgdisk -Z /dev/vda",
          "sgdisk -n 1:0:+1M -n 2:0:+1G -N 3 -t 1:ef02 -t 2:8200 -t 3:8300 -c 3:root /dev/vda",
          "mkswap /dev/vda2 -L swap",
          "swapon -L swap",
          "mkfs.btrfs -L root /dev/vda3",
          "btrfs device scan",
          "mount LABEL=root /mnt",
          "btrfs subvol create /mnt/badpath",
          "btrfs subvol create /mnt/badpath/boot",
          "btrfs subvol create /mnt/nixos",
          "btrfs subvol set-default "
          + "$(btrfs subvol list /mnt | grep 'nixos' | awk '{print $2}') /mnt",
          "umount /mnt",
          "mount -o defaults LABEL=root /mnt",
          "mkdir -p /mnt/badpath/boot",  # Help ensure the detection mechanism
          # is actually looking up subvolumes
          "mkdir /mnt/boot",
          "mount -o defaults,subvol=badpath/boot LABEL=root /mnt/boot",
      )
    '';
  };
}