Gummiboot is a UEFI boot manager written by Kay Sievers and Harald Hoyer. It is simple to configure, but can only start EFI executables, the Linux kernel (with CONFIG_EFI_STUB enabled), grub.efi, and such.
In the following steps replace
$esp with path to your EFI System Partition, which is normally mounted on
/boot/efi (although some users have it on
Installfrom [extra] and copy the bootloader to the EFI partition:
If you are on a 64-bit UEFI system:
# cp /usr/lib/gummiboot/gummibootx64.efi $esp/EFI/gummiboot/gummiboot.efi
If you are on a 32-bit UEFI system:
# cp /usr/lib/gummiboot/gummibootia32.efi $esp/EFI/gummiboot/gummiboot.efi
Then add it to the boot configuration: (only needs to be done once; skip this when upgrading)
# efibootmgr -c -d /dev/sdX -p Y -w -L "Gummiboot" -l '\EFI\gummiboot\gummiboot.efi'
where /dev/sdX is the drive and Y is the partition number of your UEFISYS partition.
efibootmgrcan be used only when already booted in UEFI mode. If you do not have another UEFI bootloader set up, you can either run
gummiboot.efifrom the UEFI Shell, or copy it to the "default" location
$esp/EFI/boot/bootx64.efifor x86_64 systems.
The basic configuration is kept in
$esp/loader/loader.conf, with just two possible configuration options:
default– default entry to select (without the
.confsuffix); can be a wildcard like
timeout– menu timeout in seconds. If this is not set, the menu will only be shows when you hold the space key while booting.
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
If you have separate partitions for
/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– operating system name. Required.
title-version– kernel version, shown only when multiple entries with same title exist. Optional.
title-machine– machine identifier (usually first few letters from
/etc/machine-id, shown only when multiple entries with same title+version exist. Optional.
efi– EFI program to start; e.g.
options– Command-line options to pass to the EFI program. Optional, but you will need at least
root=devif booting Linux.
An example entry for Arch Linux:
title Arch Linux linux /vmlinuz-linux.efi initrd /initramfs-linux.img options root=PARTUUID=14420948-2cea-4de7-b042-40f67c618660 ro
For Linux, you can specify
linux path-to-vmlinuz and
initrd path-to-initramfs; this will be automatically translated to
efi path and
options initrd=path – this syntax is only supported for convenience and has no differences in function.
You can also add other EFI programs such as
\EFI\Microsoft\Boot\Bootmgfw.efi (the Windows 7 boot manager). The EFI Shell, if installed, will be shown automatically.
title UEFI Shell efi /shellx64.efi
Automatic copy on update
The copying of the
/usr/lib/gummiboot/gummiboot*.efi to the EFI System partition can be automated with systemd (as can eg. be done for the EFISTUB kernel):
[Unit] Description=Copy new version of Gummiboot to UEFISYS Partition [Path] PathChanged=/usr/lib/gummiboot/gummibootx64.efi Unit=gummiboot_copy.service [Install] WantedBy=multi-user.target
[Unit] Description=Copy new version of Gummiboot to UEFISYS Partition [Service] Type=oneshot ExecStart=/bin/cp -f /usr/lib/gummiboot/gummibootx64.efi /boot/efi/EFI/gummiboot/gummiboot.efi
gummibootia32.efi for a 32-bit UEFI system.
After creating the files run:
# systemctl enable gummiboot_copy.path # systemctl start gummiboot_copy.path
Separate boot and EFI partitions
TODO: link my kernel-post-upgrade stuff, https://github.com/grawity/code/tree/master/os/arch
TODO: document keybindings from http://freedesktop.org/wiki/Software/gummiboot
Transferring to new HDD causes breakage
Twice now I have transferred my installation from one disk to another, ESP included, and both times this broke my gummiboot setup. With a lot of trial and error, I have discovered that gummiboot does not like configuration files that have been tranfserred from one disk to another (I used rsync).
To solve this, delete the $ESP/loader directory and all of its contents, and recreate the necessary configuration files.
Though it has no additional info, here is my relevent forum thread.