NAME

       u-boot-update - program to generate u-boot menu files

SYNOPSIS

       u-boot-update

DESCRIPTION

       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.

OPTIONS

       U_BOOT_UPDATE="true|false"
           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'.

       U_BOOT_DEFAULT="l0"
           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 'l0'.

       U_BOOT_ENTRIES="all"
           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).

       U_BOOT_ROOT="root=DEVICE"
           This variable specifies the root partition. It is automatically  extracted  from  /etc/fstab.  U-BOOT
           supports both devices and UUIDs.

       U_BOOT_TIMEOUT="50"
           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.

FILES

       /etc/default/u-boot

HOMEPAGE

       More information about U-BOOT can be found at <http://www.denx.de/wiki/U-Boot>.

       u-boot-update   and   this   manual   page   was  written  by  Daniel  Baumann  <daniel.baumann@progress-
       technologies.net> for extlinux. Riku Voipio <riku.voipio@linaro.org> updated them for u-boot.

1.00                                               2017-10-18                                   U-BOOT-UPDATE(8)