Software/gummiboot

gummiboot Simple UEFI Boot Manager

gummiboot 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.

gummiboot operates on the EFI System Partition (ESP) only. Configuration file fragments, kernels, initrds, other EFI images need to reside on the ESP. Linux kernels need to be built with CONFIG_EFI_STUB to be able to be directly executed as an EFI image.

gummiboot reads simple and entirely generic boot loader configuration files; one file per boot loader entry to select from. All files need to reside on the ESP.

Pressing the Space key (or most other keys actually work too) during bootup will show an on-screen menu with all configured loader entries to select from. Pressing Enter on the selected entry loads and starts the EFI image.

If no timeout is configured, which is the default setting, and no key pressed during bootup, the default entry is executed right away.

All configuration files are expected to be 7-bit ASCII or valid UTF8. The loader configuration file understands the following keywords:

configuration keywords
default	pattern to select the default entry in the list of entries
timeout	timeout in seconds for how long to show the menu

The entry configuration files understand the following keywords:

entry config keywords
title	text to show in the menu
version	version string to append to the title when the title is not unique
machine-id	machine identifier to append to the title when the title is not unique
efi	executable EFI image
options	options to pass to the EFI image / kernel command line
linux	linux kernel image (gummiboot still requires the kernel to have an EFI stub)
initrd	initramfs image (gummiboot just adds this as option initrd=)