Systemd-boot

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Gummiboot

Gummiboot is a new UEFI bootloader written by Kay Sievers. It is simple to configure, but can boot only other EFI binaries, including Linux with CONFIG_EFI_STUB enabled.

Note:

In the following steps, replace $esp with your EFI System Partition. Some users have it on /boot/efi, others on /boot directly.

Building

Download gummiboot source:

$ git clone git://anongit.freedesktop.org/gummiboot
$ cd gummiboot

Compile:

$ make

This should be quick, as there is only one file and no configuration options.

Installing

Copy Gummiboot to the EFI partition:

# install -Dm0644 gummiboot.efi $esp/EFI/gummiboot/gummiboot.efi

Add it to the boot configuration: (only needs to be done once; skip this when upgrading)

# efibootmgr -c -L "Gummiboot" -l '\EFI\gummiboot\gummiboot.efi'
Note:

This can be done only when already booted in UEFI mode. If you do not have another UEFI bootloader set up, you can either run gummiboot.efi from the UEFI Shell, or copy it to the "default" location $esp/EFI/BOOT/BOOTX64.EFI for x86_64 systems.

Configuring

The basic configuration is kept in $esp/loader/default.conf, with just two possible configuration options:

  • default pattern – default entry to select (without the .conf suffix); can be a wildcard like arch-*
  • timeout seconds – menu timeout in seconds

Example:

$esp/loader/default.conf
default arch
timeout 4

Note that both options can be changed in the boot menu itself, which will store them as EFI variables.

Adding boot entries

Note:

If you have separate partitions for /boot and /boot/efi, you must copy the kernel and initramfs to the EFI partition. Gummiboot does not support loading kernels from other partitions than itself. See the section below on how to automate this.

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

  • title title – operating system name. Required.
  • title-version version – kernel version, shown only when multiple entries with same title exist. Optional.
  • title-machine id – machine identifier (usually first few letters from /etc/machine-id, shown only when multiple entries with same title+version exist. Optional.
  • efi path – EFI image to boot; e.g. \EFI\arch\vmlinuz-linux.efi. Required.
  • options path – Options to pass to the kernel or EFI image. For Linux, the initramfs is also configured here using initrd=path. Required.

An example entry for Arch Linux:

$esp/loader/entries/arch.conf
title          Arch Linux
title-version  3.5-1
efi            \EFI\arch\vmlinuz-linux.efi
options        initrd=\EFI\arch\initramfs-linux.img root=PARTUUID=14420948-2cea-4de7-b042-40f67c618660 ro

When using efi, the path to initrd is specified in options.

An alternate syntax is also supported, with linux and initrd keywords, but works exactly the same way otherwise:

$esp/loader/entries/arch-git.conf
title          Arch Linux
title-version  20120725-1-git
title-machine  067d8bfe
linux          \EFI\arch\vmlinuz-linux-git.efi
initrd         \EFI\arch\initramfs-linux.img
options        root=PARTUUID=14420948-2cea-4de7-b042-40f67c618660 ro

Separate boot and EFI partitions