systemd-boot - ArchWiki

# systemd-boot

From ArchWiki
Jump to navigation Jump to search

Related articles

- Arch boot process
- Secure Boot
- Unified Extensible Firmware Interface

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 must be updated by the user. This can be performed manually or the update can be automatically triggered using pacman hooks. The two approaches are described thereafter.

#### 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.

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 `initrd=efipath` and `root=dev` if booting Linux.

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

This article or section needs language, wiki syntax or style improvements. See Help:Style for reference.

Reason: Does not belong here, not specific to systemd-boot. (Discuss in Talk:Systemd-boot#)

/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.

Note: `systemd-boot` requires that the `os-release` file contain either `VERSION_ID` or `BUILD_ID` to generate an ID and automatically add the entry, which the Arch `os-release` does not. Either maintain your own copy with one of them, or make your bundling script generate it automatically.

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

## 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

- http://www.freedesktop.org/wiki/Software/systemd/systemd-boot/
- https://github.com/systemd/systemd/tree/master/src/boot/efi

Category:

- Boot loaders

Hidden category:

- Pages or sections flagged with Template:Style