u-boot-update - program to generate u-boot menu files
u-boot-update is a tool used to generate the menu files used by the U-BOOT
bootloader. Options can be configured in /etc/default/u-boot.
- This variable specifies if u-boot-update is allowed to modify the
configuration files in /boot/extlinux. Values are either 'true' or
'false', default is 'true'.
- U_BOOT_ALTERNATIVES="default recovery"
- This variable specifies which entries u-boot-update is populating. Values
are 'default', 'recovery', 'live', default is 'default recovery'.
- This variable specifies the default entry to boot. The name of an entry
consists of two or three characters. Linux kernel images start with the
letter 'l', followed by an integer started by '0' for the first kernel
version (which is numerically the highest one in case kernel images of
more than one linux version are installed) and, optionally, the mode (r
for rescue mode, l for live mode). Memdisk entries start with the letter
'm', followed by an integer, no optional modes available. The default is
- This variables specifies how many kernel versions should be used to
populate the boot configuration. Value is an integer starting with 1, or
'all' to populate for all kernels, default is 'all'.
- U_BOOT_MENU_LABEL="Debian GNU/Linux, kernel"
- This variable specifies the text that is used as a description in the boot
menu. Value is an arbitrary string. If lsb_release is installed, the
distributors id is automatically determined. If lsb_release is not
available, it defaults to 'Debian GNU/Linux, kernel'.
- U_BOOT_PARAMETERS="ro quiet"
- This variable specifies additional boot parameters that are appended to
each kernel entry. Value is an arbitrary string, default is 'ro quiet'
(except for recovery entries, where quiet is avoided).
- This variable specifies the root partition. It is automatically extracted
from /etc/fstab. U-BOOT supports both devices and UUIDs.
- This variable specifies the time that U-BOOT should wait for user input
during boot. Values are in decisecond greater than 0 (e.g. '10' for a 1
second timeout), 0 specifies to wait forever. The default is 50.
More information about U-BOOT can be found at
u-boot-update and this manual page was written by Daniel Baumann
<firstname.lastname@example.org> for extlinux. Riku
Voipio <email@example.com> updated them for u-boot.