systemd-boot

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systemd-boot, previously called gummiboot (German for: 'rubber dinghy'), is a simple UEFI boot manager which executes configured EFI images. The default entry is selected by a configured pattern (glob) or an on-screen menu to be navigated via arrow-keys. It is included with systemd, which is installed on an Arch system by default.

It is simple to configure but it can only start EFI executables such as the Linux kernel EFISTUB, UEFI Shell, GRUB, or the Windows Boot Manager.

Installation

Installing the EFI boot manager

To install the systemd-boot EFI boot manager, first make sure the system has booted in UEFI mode and that UEFI variables are accessible. This can be checked by running the command efivar --list.

It should be noted that systemd-boot is only able to load the EFISTUB kernel from the EFI system partition (ESP). To keep the kernel updated, it is simpler and therefore recommended to mount the ESP to /boot. If the ESP is not mounted to /boot, the kernel and initramfs files must be copied onto that ESP. See EFI system partition#Alternative mount points for details.

esp will be used throughout this page to denote the ESP mountpoint, e.g. /boot.

With the ESP mounted to esp, use bootctl(1) to install systemd-boot into the EFI system partition by running:

# bootctl --path=esp install

This will copy the systemd-boot boot loader to the EFI partition: on a x64 architecture system the two identical binaries esp/EFI/systemd/systemd-bootx64.efi and esp/EFI/BOOT/BOOTX64.EFI will be transferred to the ESP. It will then set systemd-boot as the default EFI application (default boot entry) loaded by the EFI Boot Manager.

To conclude the installation, configure systemd-boot.

Updating the EFI boot manager

Whenever there is a new version of systemd-boot, the boot manager can be optionally reinstalled by the user. This can be performed manually or the update can be automatically triggered using pacman hooks. The two approaches are described thereafter.

Note: The boot manager is a standalone EFI executable and any version can be used to boot the system (partial updates do not apply, since pacman only installs the systemd-boot installer, not systemd-boot itself). However, new versions may add new features or fix bugs, so it is probably a good idea to update it anyway.

Manual update

bootctl must be used to update systemd-boot. If the path parameter is not specified, /efi, /boot, and /boot/efi are checked in turn.

# bootctl update

If the ESP is mounted on a different location, the path option can be passed as follows:

# bootctl --path=esp update
Note: This is also the command to use when migrating from gummiboot, before removing that package. If that package has already been removed, however, run bootctl --path=esp install.

Automatic update

The package systemd-boot-pacman-hookAUR provides a Pacman hook to automate the update process. Installing the package will add a hook which will be executed every time the systemd package is upgraded. Alternatively, to replicate what the systemd-boot-pacman-hook package does without installing it, place the following pacman hook in the /etc/pacman.d/hooks/ directory:

/etc/pacman.d/hooks/100-systemd-boot.hook
[Trigger]
Type = Package
Operation = Upgrade
Target = systemd

[Action]
Description = Updating systemd-boot
When = PostTransaction
Exec = /usr/bin/bootctl update

Configuration

Loader configuration

The loader configuration is stored in the file esp/loader/loader.conf. The following settings can be specified:

  • default – default entry to select as defined in #Adding loaders; it is given without the .conf suffix and it can be a wildcard like arch-*.
  • timeout – menu timeout in seconds before the default entry is booted. If this is not set, the menu will only be shown on Space key (or most other keys actually work too) press during boot.
  • editor – whether to enable the kernel parameters editor or not. yes (default) is enabled, no is disabled; since the user can add init=/bin/bash to bypass root password and gain root access, it is strongly recommended to set this option to no if the machine can be accessed by unauthorized persons.
  • auto-entries – shows automatic entries for Windows, EFI Shell, and Default Loader if set to 1 (default), 0 to hide;
  • auto-firmware – shows entry for rebooting into UEFI firmware settings if set to 1 (default), 0 to hide;
  • console-mode – changes UEFI console mode: 0 for 80x25, 1 for 80x50, 2 and above for non-standard modes provided by the device firmware, if any, auto picks a suitable mode automatically, max for highest available mode, keep (default) for the firmware selected mode.
  • random-seed-mode - controls whether to read the random seed from the file esp/loader/random-seed. If set to with-system-token (default), it loads the seed from file only if the EFI variable LoaderSystemToken is set; if set to always, it loads the seed from file even if the EFI variable is unset; and if set to off, the file is ignored.

For a detailed explanation of the available settings and their corresponding arguments see the loader.conf(5) manual. A loader configuration example is provided below:

esp/loader/loader.conf
default  arch
timeout  4
console-mode max
editor   no
Tip:
  • default and timeout can be changed in the boot menu itself and changes will be stored as EFI variables, overriding these options.
  • bootctl set-default "" can be used to clear the EFI variable overriding the default option.
  • A basic loader configuration file is located at /usr/share/systemd/bootctl/loader.conf.

Adding loaders

bootctl searches for boot menu items in esp/loader/entries/*.conf – each file found must contain exactly one loader. The possible options are:

  • title – operating system name. Required.
  • version – kernel version, shown only when multiple entries with same title exist. Optional.
  • machine-id – machine identifier from /etc/machine-id, shown only when multiple entries with same title and version exist. Optional.
  • efi – EFI program to start, relative to your ESP (esp); e.g. /vmlinuz-linux. Either this parameter or linux (see below) is required.
  • options – command line options to pass to the EFI program or kernel parameters. Optional, but you will need at least root=dev if booting Linux. This parameter can be omitted if the root partition is assigned the correct Root Partition Type GUID as defined in Discoverable Partitions Specification, in which case it will be automatically selected.

For Linux boot, you can also use linux instead of efi. Or initrd in addition to options. The syntax is:

  • linux and initrd followed by the relative path of the corresponding files in the ESP; e.g. /vmlinuz-linux; this will be automatically translated into efi path and options initrd=path – this syntax is only supported for convenience and has no differences in function.
Note: If options is present in a boot entry and Secure Boot is disabled, the value of options will override any .cmdline string embedded in the EFI image that is specified by efi or linux (see #Preparing kernels for /EFI/Linux). With Secure Boot, however, options (and any edits made to the kernel command line in the bootloader UI) will be ignored, and only the embedded .cmdline will be used.

An example of a loader file to launch Arch from a partition with the label arch_os and loading the Intel CPU microcode is:

esp/loader/entries/arch.conf
title   Arch Linux
linux   /vmlinuz-linux
initrd  /intel-ucode.img
initrd  /initramfs-linux.img
options root=LABEL=arch_os rw

bootctl will automatically check at boot time for Windows Boot Manager at the location /EFI/Microsoft/Boot/Bootmgfw.efi, EFI Shell /shellx64.efi and EFI Default Loader /EFI/BOOT/bootx64.efi, as well as specially prepared kernel files found in /EFI/Linux. When detected, corresponding entries with titles auto-windows, auto-efi-shell and auto-efi-default, respectively, will be generated. These entries do not require manual loader configuration. However, it does not auto-detect other EFI applications (unlike rEFInd), so for booting the Linux kernel, manual configuration entries must be created.

Note:
  • If you dual-boot Windows, it is strongly recommended to disable its default Fast Start-Up option.
  • If you have an Intel or AMD CPU, load the microcode with initrd before other images, an example is provided in Microcode#systemd-boot.
  • The root partition can be identified with its LABEL, PARTUUID or UUID (see Persistent block device naming). This is required only to identify the root partition, not the esp.
Tip:
  • The available boot entries which have been configured can be listed with the command bootctl list.
  • An example entry file is located at /usr/share/systemd/bootctl/arch.conf.
  • The kernel parameters for scenarios such as LVM, LUKS or dm-crypt can be found on the relevant pages.

EFI Shells or other EFI apps

In case you installed EFI shells and other EFI application into the ESP, you can use the following snippets.

Note: The file path parameter for the efi line is relative to your esp mount point. If you are mounted on /boot and your EFI binaries reside at /boot/EFI/xx.efi and /boot/yy.efi, then you would specify the parameters as efi /EFI/xx.efi and efi /yy.efi respectively.

Examples of loading custom UEFI Shell loaders:

esp/loader/entries/uefi-shell-v1-x86_64.conf
title   UEFI Shell x86_64 v1
efi     /EFI/shellx64_v1.efi
esp/loader/entries/uefi-shell-v2-x86_64.conf
title   UEFI Shell x86_64 v2
efi     /EFI/shellx64_v2.efi

Booting into EFI Firmware Setup

Most system firmware configured for EFI booting will add its own efibootmgr entries to boot into UEFI Firmware Setup.

Preparing kernels for /EFI/Linux

Tango-go-next.pngThis article or section is a candidate for moving to Unified kernel image.Tango-go-next.png

Notes: Does not belong here, not specific to systemd-boot. (Discuss in Talk:Microcode#Addition in EFI Boot stub)

/EFI/Linux is searched for specially prepared kernel files, which bundle the kernel, the init RAM disk (initrd), the kernel command line and /etc/os-release into one single file. This file can be easily signed for secure boot.

Put the kernel command line you want to use in a file, and create the bundle file like this:

Kernel packaging command:
objcopy \
    --add-section .osrel="/usr/lib/os-release" --change-section-vma .osrel=0x20000 \
    --add-section .cmdline="kernel-command-line.txt" --change-section-vma .cmdline=0x30000 \
    --add-section .linux="vmlinuz-file" --change-section-vma .linux=0x40000 \
    --add-section .initrd="initrd-file" --change-section-vma .initrd=0x3000000 \
    "/usr/lib/systemd/boot/efi/linuxx64.efi.stub" "linux.efi"

Optionally sign the linux.efi file produced above.

Copy linux.efi into esp/EFI/Linux.

Support hibernation

See Suspend and hibernate.

Kernel parameters editor with password protection

Alternatively you can install systemd-boot-passwordAUR which supports password basic configuration option. Use sbpctl generate to generate a value for this option.

Install systemd-boot-password with the following command:

# sbpctl install esp

With enabled editor you will be prompted for your password before you can edit kernel parameters.

Keys inside the boot menu

The following keys are used inside the menu:

  • Up/Down - select entry
  • Enter - boot the selected entry
  • d - select the default entry to boot (stored in a non-volatile EFI variable)
  • -/T - decrease the timeout (stored in a non-volatile EFI variable)
  • +/t - increase the timeout (stored in a non-volatile EFI variable)
  • e - edit the kernel command line. It has no effect if the editor config option is set to 0.
  • v - show the systemd-boot and UEFI version
  • Q - quit
  • P - print the current configuration
  • h/? - help

These hotkeys will, when pressed inside the menu or during bootup, directly boot a specific entry:

  • l - Linux
  • w - Windows
  • a - OS X
  • s - EFI Shell
  • 1-9 - number of entry

Tips and tricks

Grml on ESP

Note: The following instructions are not exclusive to Grml. With slight adjustments, installing other software (e.g., SystemRescueCD) is possible.

Grml is a small live system with a collection of software for system administration and rescue.

In order to install Grml on the ESP, we only need to copy the kernel vmlinuz, the initramfs initrd.img, and the squashed image grml64-small.squashfs from the iso file to the ESP. To do so, first download grml64-small.iso and mount the file (the mountpoint is henceforth denoted mnt); the kernel and initramfs are located in mnt/boot/grml64small/, and the squashed image resides in mnt/live/grml64-small/.

Next, create a directory for Grml in your ESP,

# mkdir -p esp/grml

and copy the above-mentioned files in there:

# cp mnt/boot/grml64small/vmlinuz esp/grml
# cp mnt/boot/grml64small/initrd.img esp/grml
# cp mnt/live/grml64-small/grml64-small.squashfs esp/grml

In the last step, create an entry for the systemd-boot loader: In esp/loader/entries create a grml.conf file with the following content:

esp/loader/entries/grml.conf
title   Grml Live Linux
linux   /grml/vmlinuz
initrd  /grml/initrd.img
options apm=power-off boot=live live-media-path=/grml/ nomce net.ifnames=0

For an overview of the avialable boot options, consult the cheatcode for Grml.

Troubleshooting

Installing after booting in BIOS mode

Warning: This is not recommended.

If booted in BIOS mode, you can still install systemd-boot, however this process requires you to tell firmware to launch systemd-boot's EFI file at boot, usually via two ways:

  • you have a working EFI Shell somewhere else.
  • your firmware interface provides a way of properly setting the EFI file that needs to be loaded at boot time.

If you can do it, the installation is easier: go into your EFI Shell or your firmware configuration interface and change your machine's default EFI file to esp/EFI/systemd/systemd-bootx64.efi (or systemd-bootia32.efi depending if your system firmware is 32 bit).

Note: The firmware interface of Dell Latitude series provides everything you need to setup EFI boot but the EFI Shell won't be able to write to the computer's ROM.

Manual entry using efibootmgr

If the bootctl install command failed, you can create a EFI boot entry manually using efibootmgr:

# efibootmgr -c -d /dev/sdX -p Y -l "\EFI\systemd\systemd-bootx64.efi" -L "Linux Boot Manager"

where /dev/sdXY is the EFI system partition.

Note: The path to the EFI image must use the backslash (\) as the separator

Menu does not appear after Windows upgrade

See UEFI#Windows changes boot order.

See also