Systemd-boot

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Gummiboot is a UEFI boot loader 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.

Installing

Note: /usr/bin/gummiboot requires efivarfs support in the kernel and requires it to be mounted at /sys/firmware/efi/efivars. Mounting of efivarfs at this path is done automatically by systemd if the kernel supports efivarfs. LTS kernels do not support efivarfs. In such cases, the user needs to use efibootmgr to create a boot entry for gummiboot.
Note: If gummiboot fails to create a boot entry, check for existence of /sys/firmware/efi/efivars/dump-* files. If they exist, delete them, reboot and retry gummiboot again. If even this fails, retry gummiboot after booting with efi_no_storage_paranoia kernel parameter. If all these fail, try creating the boot entry using efibootmgr or UEFI Shell v2 bcfg command.

Install gummiboot from [extra] and run the following to install gummiboot:

First, we should enable efivarfs and disable sysfs-efivars interface (for more info refer link):

Note: The below commands should be run BEFORE chroot, if any.
# umount /sys/firmware/efi/efivars
# modprobe -r efivars
# modprobe efivarfs
# mount -t efivarfs efivarfs /sys/firmware/efi/efivars
Note: The below commands should be run AFTER chroot, if any.
# pacman -S gummiboot
# gummiboot install
Note: The gummiboot command assumes that your EFI System Partition is mounted on /boot. If your ESP is mounted on /boot/efi you have to call the following gummiboot install command with the additional --path switch. This also means that gummiboot will not be able to update itself automatically and you will have to call gummiboot --path=/boot/efi update after every package update. Additionally you will have to make sure that the kernel and initramfs are copied onto the ESP as gummiboot can't load EFI binaries from other partitions. It is therefore strongly recommended to mount your ESP to /boot if you use gummiboot. The rest of this article will assume that your ESP is mounted on /boot.

This will automatically copy the gummiboot binary to your EFI System Partition and create a boot entry in the EFI Boot Manager. You should however still be able to boot gummiboot as it copies the binary to the default EFI binary location on your ESP (/boot/EFI/BOOT/BOOTX64.EFI on x64 systems). Note that the installation process has to be done only once, updating will happen automatically by the post_install script of gummiboot during package updates.

Configuring

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

  • default – default entry to select (without the .conf suffix); can be a wildcard like arch-*
  • timeout – menu timeout in seconds. If this is not set, the menu will only be shown when you hold the space key while booting.

Example:

/boot/loader/loader.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

Gummiboot searches for boot menu items in /boot/loader/entries/*.conf – each file found must contain exactly one boot entry. 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 (/boot); e.g. /vmlinuz-linux. Either this or linux (see below) is required.
  • options – Command-line options to pass to the EFI program. Optional, but you will need at least initrd=efipath and root=dev if booting Linux.

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.

An example entry for Arch Linux:

/boot/loader/entries/arch.conf
title          Arch Linux
linux          /vmlinuz-linux
initrd         /initramfs-linux.img
options        root=PARTUUID=14420948-2cea-4de7-b042-40f67c618660 rw

You can also add other EFI programs such as \EFI\arch\grub.efi.

Note: Gummiboot will automatically check for binaries of a Windows Installation (\EFI\Microsoft\Boot\Bootmgfw.efi) or an UEFI Shell (\shellx64.efi) and display entries for them, so you don't have to create these manually.

Inside the boot menu

TODO: document keybindings from http://freedesktop.org/wiki/Software/gummiboot

Troubleshooting

Manual entry using efibootmgr

If gummiboot install command failed you can create a EFI boot entry manually with efibootmgr utility:

# efibootmgr -c -w -d /dev/sdX -p Y -l '\EFI\gummiboot\gummibootx64.efi' -L "Gummiboot"