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HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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BOOTCTL(1) bootctl BOOTCTL(1)
bootctl - Control EFI firmware boot settings and manage boot
loader
bootctl [OPTIONS...] {COMMAND}
bootctl can check the EFI firmware and boot loader status, list
and manage available boot loaders and boot loader entries, and
install, update, or remove the systemd-boot(7) boot loader on the
current system.
These commands are available on any EFI system, regardless of the
boot loader used.
status
Shows brief information about the system firmware, the boot
loader that was used to boot the system, the boot loaders
currently available in the ESP, the boot loaders listed in
the firmware's list of boot loaders and the current default
boot loader entry. If no command is specified, this is the
implied default.
See the example below for details of the output.
Added in version 239.
reboot-to-firmware [BOOL]
Query or set the "Reboot-Into-Firmware-Setup" flag of the EFI
firmware. Takes a boolean argument which controls whether to
show the firmware setup on next system reboot. If the
argument is omitted shows the current status of the flag, or
whether the flag is supported. This controls the same flag as
systemctl reboot --firmware-setup, but is more low-level and
allows setting the flag independently from actually
requesting a reboot.
Hint: use systemctl reboot --firmware-setup to reboot into
firmware setup once. See systemctl(1) for details.
Added in version 251.
These commands are available for all boot loaders that implement
the Boot Loader Specification[1], such as systemd-boot.
list
Shows all available boot loader entries implementing the Boot
Loader Specification[1], as well as any other entries
discovered or automatically generated by a boot loader
implementing the Boot Loader Interface[2]. JSON output may be
requested with --json=.
See the example below for details of the output.
Added in version 239.
unlink ID
Removes a boot loader entry including the files it refers to.
Takes a single boot loader entry ID string or a glob pattern
as argument. Referenced files such as kernel or initrd are
only removed if no other entry refers to them.
Added in version 253.
cleanup
Removes files from the ESP and XBOOTLDR partitions that
belong to the entry token but are not referenced in any boot
loader entries.
Added in version 253.
These commands are available for all boot loaders that implement
the Boot Loader Specification[1] and the Boot Loader
Interface[2], such as systemd-boot.
set-default ID, set-oneshot ID
Sets the default boot loader entry. Takes a single boot
loader entry ID string or a glob pattern as argument. The
set-oneshot command will set the default entry only for the
next boot, the set-default will set it persistently for all
future boots.
bootctl list can be used to list available boot loader
entries and their IDs.
In addition, the boot loader entry ID may be specified as one
of: @default, @oneshot or @current, which correspond to the
current default boot loader entry for all future boots, the
current default boot loader entry for the next boot, and the
currently booted boot loader entry. These special IDs are
resolved to the current values of the EFI variables
LoaderEntryDefault, LoaderEntryOneShot and
LoaderEntrySelected, see Boot Loader Specification[1] for
details. These special IDs are primarily useful as a quick
way to persistently make the currently booted boot loader
entry the default choice, or to upgrade the default boot
loader entry for the next boot to the default boot loader
entry for all future boots, but may be used for other
operations too.
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.
When an empty string ("") is specified as the ID, then the
corresponding EFI variable will be unset.
Hint: use systemctl reboot --boot-loader-entry=ID to reboot
into a specific boot entry and systemctl reboot
--boot-loader-menu=timeout to reboot into the boot loader
menu once. See systemctl(1) for details.
Added in version 240.
set-timeout TIMEOUT, set-timeout-oneshot TIMEOUT
Sets the boot loader menu timeout in seconds. The
set-timeout-oneshot command will set the timeout only for the
next boot. See systemd.time(7) for details about the syntax
of time spans.
If this is set to menu-disabled or menu-hidden or 0, no menu
is shown and the default entry will be booted immediately,
while setting this to menu-force disables the timeout while
always showing the menu. When an empty string ("") is
specified the bootloader will revert to its default menu
timeout.
Added in version 250.
These commands manage the systemd-boot EFI boot loader, and do
not work in conjunction with other boot loaders.
install
Installs systemd-boot into the EFI system partition. A copy
of systemd-boot will be stored as the EFI default/fallback
loader at ESP/EFI/BOOT/BOOT*.EFI. The boot loader is then
added to the top of the firmware's boot loader list.
Added in version 239.
update
Updates all installed versions of systemd-boot(7), if the
available version is newer than the version installed in the
EFI system partition. This also includes the EFI
default/fallback loader at ESP/EFI/BOOT/BOOT*.EFI. The boot
loader is then added to end of the firmware's boot loader
list if missing.
Added in version 239.
remove
Removes all installed versions of systemd-boot from the EFI
system partition and the firmware's boot loader list.
Added in version 239.
is-installed
Checks whether systemd-boot is installed in the ESP. Note
that a single ESP might host multiple boot loaders; this
hence checks whether systemd-boot is one (of possibly many)
installed boot loaders — and neither whether it is the
default nor whether it is registered in any EFI variables.
Added in version 243.
random-seed
Generates a random seed and stores it in the EFI System
Partition (ESP), for use by the systemd-boot boot loader. If
a random seed already exists in the ESP it is refreshed. Also
generates a random 'system token' and stores it persistently
as an EFI variable, if one has not been set before. If the
boot loader finds the random seed in the ESP and the system
token in the EFI variable it will derive a random seed to
pass to the OS and a new seed to store in the ESP from the
combination of both. The random seed passed to the OS is
credited to the kernel's entropy pool by the system manager
during early boot, and permits userspace to boot up with an
entropy pool fully initialized very early on. Also see
systemd-boot-random-seed.service(8).
See Random Seeds[3] for further information.
Added in version 243.
kernel-identify kernel
Takes a kernel image as argument. Checks what kind of kernel
the image is. Returns one of "uki", "pe", and "unknown".
Added in version 253.
kernel-inspect kernel
Takes a kernel image as argument. Prints details about the
image.
Added in version 253.
The following options are understood:
--esp-path=
Path to the EFI System Partition (ESP). If not specified,
/efi/, /boot/, and /boot/efi/ are checked in turn. It is
recommended to mount the ESP to /efi/, if possible.
--boot-path=
Path to the Extended Boot Loader partition, as defined in the
Boot Loader Specification[1]. If not specified, /boot/ is
checked. It is recommended to mount the Extended Boot Loader
partition to /boot/, if possible.
--root=root
Takes a directory path as an argument. All paths will be
prefixed with the given alternate root path, including config
search paths.
Added in version 252.
--image=image
Takes a path to a disk image file or block device node. If
specified, all operations are applied to file system in the
indicated disk image. This option is similar to --root=, but
operates on file systems stored in disk images or block
devices. The disk image should either contain just a file
system or a set of file systems within a GPT partition table,
following the Discoverable Partitions Specification[4]. For
further information on supported disk images, see
systemd-nspawn(1)'s switch of the same name.
Added in version 252.
--image-policy=policy
Takes an image policy string as argument, as per
systemd.image-policy(7). The policy is enforced when
operating on the disk image specified via --image=, see
above. If not specified defaults to the "*" policy, i.e. all
recognized file systems in the image are used.
--install-source=
When installing binaries with --root= or --image=, selects
where to source them from. Takes one of "auto" (the default),
"image" or "host". With "auto" binaries will be picked from
the specified directory or image, and if not found they will
be picked from the host. With "image" or "host" no fallback
search will be performed if the binaries are not found in the
selected source.
Added in version 252.
-p, --print-esp-path
This option modifies the behaviour of status. Only prints the
path to the EFI System Partition (ESP) to standard output and
exits.
Added in version 236.
-x, --print-boot-path
This option modifies the behaviour of status. Only prints the
path to the Extended Boot Loader partition if it exists, and
the path to the ESP otherwise to standard output and exit.
This command is useful to determine where to place boot
loader entries, as they are preferably placed in the Extended
Boot Loader partition if it exists and in the ESP otherwise.
Boot Loader Specification Type #1 entries should generally be
placed in the directory "$(bootctl -x)/loader/entries/".
Existence of that directory may also be used as indication
that boot loader entry support is available on the system.
Similarly, Boot Loader Specification Type #2 entries should
be placed in the directory "$(bootctl -x)/EFI/Linux/".
Note that this option (similarly to the --print-esp-path
option mentioned above), is available independently from the
boot loader used, i.e. also without systemd-boot being
installed.
Added in version 242.
-R, --print-root-device
Print the path to the block device node backing the root file
system of the local OS. This prints a path such as
/dev/nvme0n1p5. If the root file system is backed by
dm-crypt/LUKS or dm-verity the underlying block device is
returned. If the root file system is backed by multiple block
devices (as supported by btrfs) the operation will fail. If
the switch is specified twice (i.e. -RR) and the discovered
block device is a partition device the "whole" block device
it belongs to is determined and printed (e.g. /dev/nvme0n1).
If the root file system is "tmpfs" (or a similar in-memory
file system), the block device backing /usr/ is returned if
applicable. If the root file system is a network file system
(e.g. NFS, CIFS) the operation will fail.
Added in version 254.
--no-variables
Do not touch the firmware's boot loader list stored in EFI
variables.
Added in version 220.
--graceful
Ignore failure when the EFI System Partition cannot be found,
when EFI variables cannot be written, or a different or newer
boot loader is already installed. Currently only applies to
is-installed, update, and random-seed verbs.
Added in version 244.
-q, --quiet
Suppress printing of the results of various commands and also
the hints about ESP being unavailable.
Added in version 251.
--make-entry-directory=yes|no
Controls creation and deletion of the Boot Loader
Specification[1] Type #1 entry directory on the file system
containing resources such as kernel and initrd images during
install and remove, respectively. The directory is named
after the entry token, as specified with --entry-token=
parameter described below, and is placed immediately below
the $BOOT root directory (i.e. beneath the file system
returned by the --print-boot-path option, see above).
Defaults to "no".
Added in version 251.
--entry-token=
Controls how to name and identify boot loader entries for
this OS installation. Accepted during install, and takes one
of "auto", "machine-id", "os-id", "os-image-id" or an
arbitrary string prefixed by "literal:" as argument.
If set to machine-id the entries are named after the machine
ID of the running system (e.g.
"b0e793a9baf14b5fa13ecbe84ff637ac"). See machine-id(5) for
details about the machine ID concept and file.
If set to os-id the entries are named after the OS ID of the
running system, i.e. the ID= field of os-release(5) (e.g.
"fedora"). Similarly, if set to os-image-id the entries are
named after the OS image ID of the running system, i.e. the
IMAGE_ID= field of os-release (e.g.
"vendorx-cashier-system").
If set to auto (the default), the /etc/kernel/entry-token
file will be read if it exists, and the stored value used.
Otherwise if the local machine ID is initialized it is used.
Otherwise IMAGE_ID= from os-release will be used, if set.
Otherwise, ID= from os-release will be used, if set.
Unless set to "machine-id", or when
--make-entry-directory=yes is used the selected token string
is written to a file /etc/kernel/entry-token, to ensure it
will be used for future entries. This file is also read by
kernel-install(8), in order to identify under which name to
generate boot loader entries for newly installed kernels, or
to determine the entry names for removing old ones.
Using the machine ID for naming the entries is generally
preferable, however there are cases where using the other
identifiers is a good option. Specifically: if the
identification data that the machine ID entails shall not be
stored on the (unencrypted) $BOOT partition, or if the ID
shall be generated on first boot and is not known when the
entries are prepared. Note that using the machine ID has the
benefit that multiple parallel installations of the same OS
can coexist on the same medium, and they can update their
boot loader entries independently. When using another
identifier (such as the OS ID or the OS image ID), parallel
installations of the same OS would try to use the same entry
name. To support parallel installations, the installer must
use a different entry token when adding a second
installation.
Added in version 251.
--all-architectures
Install binaries for all supported EFI architectures (this
implies --no-variables).
Added in version 252.
--efi-boot-option-description=
Description of the entry added to the firmware's boot option
list. Defaults to "Linux Boot Manager".
Using the default entry name "Linux Boot Manager" is
generally preferable as only one bootloader installed to a
single ESP partition should be used to boot any number of OS
installations found on the various disks installed in the
system. Specifically distributions should not use this flag
to install a branded entry in the boot option list. However
in situations with multiple disks, each with their own ESP
partition, it can be beneficial to make it easier to identify
the bootloader being used in the firmware's boot option menu.
Added in version 252.
--dry-run
Dry run for unlink and cleanup.
In dry run mode, the unlink and cleanup operations only print
the files that would get deleted without actually deleting
them.
Added in version 253.
--no-pager
Do not pipe output into a pager.
--json=MODE
Shows output formatted as JSON. Expects one of "short" (for
the shortest possible output without any redundant whitespace
or line breaks), "pretty" (for a pretty version of the same,
with indentation and line breaks) or "off" (to turn off JSON
output, the default).
-h, --help
Print a short help text and exit.
--version
Print a short version string and exit.
bootctl install and update will look for a systemd-boot file
ending with the ".efi.signed" suffix first, and copy that instead
of the normal ".efi" file. This allows distributions or end-users
to provide signed images for UEFI SecureBoot.
On success, 0 is returned, a non-zero failure code otherwise.
bootctl --print-root-device returns exit status 80 in case the
root file system is not backed by single block device, and other
non-zero exit statuses on other errors.
If $SYSTEMD_RELAX_ESP_CHECKS=1 is set the validation checks for
the ESP are relaxed, and the path specified with --esp-path= may
refer to any kind of file system on any kind of partition.
Similarly, $SYSTEMD_RELAX_XBOOTLDR_CHECKS=1 turns off some
validation checks for the Extended Boot Loader partition.
Example 1. Output from status and list
$ bootctl status
System:
Firmware: UEFI 2.40 (firmware-version) ← firmware vendor and version
Secure Boot: disabled (setup) ← Secure Boot status
TPM2 Support: yes
Boot into FW: supported ← does the firmware support booting into itself
Current Boot Loader: ← details about sd-boot or another boot loader
Product: systemd-boot version implementing the Boot Loader Interface[2]
Features: ✓ Boot counting
✓ Menu timeout control
✓ One-shot menu timeout control
✓ Default entry control
✓ One-shot entry control
✓ Support for XBOOTLDR partition
✓ Support for passing random seed to OS
✓ Load drop-in drivers
✓ Boot loader sets ESP information
✓ Menu can be disabled
ESP: /dev/disk/by-partuuid/01234567-89ab-cdef-dead-beef00000000
File: └─/EFI/systemd/systemd-bootx64.efi
Random Seed: ← random seed used for entropy in early boot
Passed to OS: yes
System Token: set
Exists: yes
Available Boot Loaders on ESP:
ESP: /boot/efi (/dev/disk/by-partuuid/01234567-89ab-cdef-dead-beef00000000)
File: └─/EFI/systemd/systemd-bootx64.efi (systemd-boot 251
File: └─/EFI/BOOT/BOOTX64.EFI (systemd-boot 251
Boot Loaders Listed in EFI Variables:
Title: Linux Boot Manager
ID: 0x0001
Status: active, boot-order
Partition: /dev/disk/by-partuuid/...
File: └─/EFI/systemd/systemd-bootx64.efi
Title: Fedora
ID: 0x0000
Status: active, boot-order
Partition: /dev/disk/by-partuuid/...
File: └─/EFI/fedora/shimx64.efi
Title: Linux-Firmware-Updater
ID: 0x0002
Status: active, boot-order
Partition: /dev/disk/by-partuuid/...
File: └─/EFI/fedora/fwupdx64.efi
Boot Loader Entries:
$BOOT: /boot/efi (/dev/disk/by-partuuid/01234567-89ab-cdef-dead-beef00000000)
Default Boot Loader Entry:
type: Boot Loader Specification Type #1 (.conf)
title: Fedora Linux 36 (Workstation Edition)
id: ...
source: /boot/efi/loader/entries/entry-token-kernel-version.conf
version: kernel-version
machine-id: ...
linux: /entry-token/kernel-version/linux
initrd: /entry-token/kernel-version/initrd
options: root=...
$ bootctl list
Boot Loader Entries:
type: Boot Loader Specification Type #1 (.conf)
title: Fedora Linux 36 (Workstation Edition) (default) (selected)
id: ...
source: /boot/efi/loader/entries/entry-token-kernel-version.conf
version: kernel-version
machine-id: ...
linux: /entry-token/kernel-version/linux
initrd: /entry-token/kernel-version/initrd
options: root=...
type: Boot Loader Specification Type #2 (.efi)
title: Fedora Linux 35 (Workstation Edition)
id: ...
source: /boot/efi/EFI/Linux/fedora-kernel-version.efi
version: kernel-version
machine-id: ...
linux: /EFI/Linux/fedora-kernel-version.efi
options: root=...
type: Automatic
title: Reboot Into Firmware Interface
id: auto-reboot-to-firmware-setup
source: /sys/firmware/efi/efivars/LoaderEntries-4a67b082-0a4c-41cf-b6c7-440b29bb8c4f
In the listing, "(default)" specifies the entry that will be used
by default, and "(selected)" specifies the entry that was
selected the last time (i.e. is currently running).
systemd-boot(7), Boot Loader Specification[1], Boot Loader
Interface[2], systemd-boot-random-seed.service(8)
1. Boot Loader Specification
https://uapi-group.org/specifications/specs/boot_loader_specification
2. Boot Loader Interface
https://systemd.io/BOOT_LOADER_INTERFACE
3. Random Seeds
https://systemd.io/RANDOM_SEEDS
4. Discoverable Partitions Specification
https://uapi-group.org/specifications/specs/discoverable_partitions_specification
This page is part of the systemd (systemd system and service
manager) project. Information about the project can be found at
⟨http://www.freedesktop.org/wiki/Software/systemd⟩. If you have
a bug report for this manual page, see
⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩.
This page was obtained from the project's upstream Git repository
⟨https://github.com/systemd/systemd.git⟩ on 2024-06-14. (At that
time, the date of the most recent commit that was found in the
repository was 2024-06-13.) If you discover any rendering
problems in this HTML version of the page, or you believe there
is a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
[email protected]
systemd 257~devel BOOTCTL(1)
Pages that refer to this page: systemctl(1), loader.conf(5), kernel-command-line(7), systemd-boot(7), systemd.directives(7), systemd.index(7), systemd-stub(7), systemd-boot-random-seed.service(8), systemd-pcrlock(8)
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HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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