LOADER.CONF(5)

NAME
loader.conf - Configuration file for systemd-boot

SYNOPSIS

ESP/loader/loader.conf, ESP/loader/entries/*.conf XBOOTLDR/loader/entries/*.conf

DESCRIPTION

systemd-boot(7) will read ESP/loader/loader.conf, and any files with the ".conf" extension under ESP/loader/entries/ on the EFI system partition (ESP), and XBOOTLDR/loader/entries/ on the extended boot loader partition (XBOOTLDR) as defined by Boot Loader Specification[1].

Each of these configuration files must consist of series of newline (i.e. ASCII code 10) separated lines, each consisting of an option name, followed by whitespace, and the option value. "#" may be used to start a comment line. Empty and comment lines are ignored. The files use UTF-8 encoding.

Boolean arguments may be written as "yes"/"y"/"true"/"t"/"on"/"1" or "no"/"n"/"false"/"f"/"off"/"0".

OPTIONS

The configuration options supported by ESP/loader/entries/*.conf and XBOOTLDR/loader/entries/*.conf files are defined as part of the Boot Loader Specification[1].

The following configuration are supported by the loader.conf configuration file:

default
    A glob pattern to select the default entry. The default entry may be changed in the boot menu itself, in which case the name of the selected entry will be stored as an EFI variable, overriding this option.

    If set to "@saved" the chosen entry will be saved as an EFI variable on every boot and automatically selected the next time the boot loader starts.

    Table 1. Automatically detected entries will use the following names:
    Name | Description
    auto-efi-default | EFI Default Loader
    auto-efi-shell | EFI Shell
    auto-osx | macOS
    auto-reboot-to-firmware-setup | Reboot Into Firmware Interface
    auto-windows | Windows Boot Manager

timeout
    How long the boot menu should be shown before the default entry is booted, in seconds. This may be changed in the boot menu itself and will be stored as an EFI variable in that case, overriding this option.

    If set to "menu-hidden" or "0" no menu is shown and the default entry will be booted immediately. The menu can be shown by pressing and holding a key before systemd-boot is launched. Setting this to "menu-force" disables the timeout while always showing the menu.

console-mode
    This option configures the resolution of the console. Takes a number or one of the special values listed below. The following values may be used:

    0
        Standard UEFI 80x25 mode

    1
        80x50 mode, not supported by all devices

    2
        the first non-standard mode provided by the device firmware, if any

    auto
        Pick a suitable mode automatically using heuristics

    max
        Pick the highest-numbered available mode

    keep
        Keep the mode selected by firmware (the default)

editor
    Takes a boolean argument. Enable (the default) or disable the editor. The editor should be disabled if the machine can be accessed by unauthorized persons.

auto-entries
    Takes a boolean argument. Enable (the default) or disable entries for other boot entries found on the boot partition. In particular, this may be useful when loader entries are created to show replacement descriptions for those entries.

auto-firmware
    A boolean controlling the presence of the "Reboot into firmware" entry (enabled by default). If this is disabled, the firmware interface may still be reached by using the f key.

beep
    Beep n times when the n-th entry in the boot menu is shown (default disabled). Currently, only x86 is supported, where it uses the PC speaker.

reboot-for-bitlocker
    Caveat: This feature is experimental, and is likely to be changed (or removed in its current form) in a future version of systemd.

    Work around BitLocker requiring a recovery key when the boot loader was updated (disabled by default).

    Try to detect BitLocker encrypted drives along with an active TPM. If both are found and Windows Boot Manager is selected in the boot menu, set the "BootNext" EFI variable and restart the system. The firmware will then start Windows Boot Manager directly, leaving the TPM PCRs in expected states so that Windows can unseal the encryption key. This allows systemd-boot to be updated without having to provide the recovery key for BitLocker drive unlocking.

    Note that the PCRs that Windows uses can be configured with the "Configure TPM platform validation profile for native UEFI firmware configurations" group policy under "Computer Configuration\Administrative Templates\Windows Components\BitLocker Drive Encryption". When secure boot is enabled, changing this to PCRs "0,2,7,11" should be safe. The TPM key protector needs to be removed and then added back for the PCRs on an already encrypted drive to change. If PCR 4 is not measured, this setting can be disabled to speed up booting into Windows.

random-seed-mode
    Takes one of "off", "with-system-token" and "always". If "off" no random seed data is read off the ESP, nor passed to the OS. If "with-system-token" (the default) systemd-boot will read a random seed from the ESP (from the file /loader/random-seed) only if the LoaderSystemToken EFI variable is set, and then derive the random seed to pass to the OS from the combination. If "always" the boot loader will do so even if LoaderSystemToken is not set. This mode is useful in environments where protection against OS image reuse is not a concern, and the random seed shall be used even with no further setup in place. Use bootctl random-seed to initialize both the random seed file in the ESP and the system token EFI variable.

    See Random Seeds[2] for further information.

EXAMPLE

    # /boot/efi/loader/loader.conf
    timeout 0
    default 01234567890abcdef1234567890abdf0-*
    editor no

The menu will not be shown by default (the menu can still be shown by pressing and holding a key during boot). One of the entries with files with a name starting with "01234567890abcdef1234567890abdf0-" will be selected by default. If more than one entry matches, the one with the highest priority will be selected (generally the one with the highest version number). The editor will be disabled, so it is not possible to alter the kernel command line.

SEE ALSO

systemd-boot(7), bootctl(1)

NOTES

1.  Boot Loader Specification
    https://systemd.io/BOOT_LOADER_SPECIFICATION

2.  Random Seeds
    https://systemd.io/RANDOM_SEEDS