loader.conf - Configuration file for systemd-boot
ESP/loader/loader.conf,
ESP/loader/entries/*.conf
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).
Each configuration file must consist 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.
Boolean arguments may be written as
"yes"/"y"/"true"/"1" or
"no"/"n"/"false"/"0".
The following configuration options in loader.conf are
understood:
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.
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 the timeout is disabled, the default entry will be booted
immediately. The menu can be shown by pressing and holding a key before
systemd-boot is launched.
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
Takes a boolean argument. Enable (the default) or disable
the "Reboot into firmware" entry.
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[1] for further information.
# /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.
- 1.
- Random Seeds
https://systemd.io/RANDOM_SEEDS