7.2.12 GRUB Configuration

The operating system uses GNU GRUB as its boot loader (see overview of GRUB in GNU GRUB Manual). It is configured using grub-configuration declarations. This data type is exported by the (gnu system grub) module, and described below.

Data Type: grub-configuration

The type of a GRUB configuration declaration.

device

This is a string denoting the boot device. It must be a device name understood by the grub-install command, such as /dev/sda or (hd0) (see Invoking grub-install in GNU GRUB Manual).

menu-entries (default: ())

A possibly empty list of menu-entry objects (see below), denoting entries to appear in the GRUB boot menu, in addition to the current system entry and the entry pointing to previous system generations.

default-entry (default: 0)

The index of the default boot menu entry. Index 0 is for the current system’s entry.

timeout (default: 5)

The number of seconds to wait for keyboard input before booting. Set to 0 to boot immediately, and to -1 to wait indefinitely.

theme (default: %default-theme)

The grub-theme object describing the theme to use.

Should you want to list additional boot menu entries via the menu-entries field above, you will need to create them with the menu-entry form:

Data Type: menu-entry

The type of an entry in the GRUB boot menu.

label

The label to show in the menu—e.g., "GNU".

linux

The Linux kernel to boot.

linux-arguments (default: ())

The list of extra Linux kernel command-line arguments—e.g., ("console=ttyS0").

initrd

A G-Expression or string denoting the file name of the initial RAM disk to use (see G-Expressions).

Themes are created using the grub-theme form, which is not documented yet.

Scheme Variable: %default-theme

This is the default GRUB theme used by the operating system, with a fancy background image displaying the GNU and Guix logos.