BOOT.CONFIG(5) FreeBSD File Formats Manual BOOT.CONFIG(5)


boot.configConfiguration file for the boot blocks


The boot.config file contains options for the FreeBSD boot block code.

When the FreeBSD boot loader runs, it searches the “ a” slice of the boot partition for a boot.config file (as a result, slices which are missing an “ a” partition require user intervention during the boot process). If the boot.config file is found, its contents are used as the default configuration options for the boot block code and are echoed to the system console.

A valid format of this file is to put BIOS drive number, a controller type, a unit number, a partition, a kernel file name, and any other valid boot(8) option on a single line, as it is done at the “ boot:” prompt.

The options related to the boot image selection described below and all the other options available for boot.config are documented in detail in the boot(8) manual page.


parameters for the boot blocks (optional)


The command:

# echo "-P" > /boot.config

will activate the serial console of FreeBSD.

The command:

# echo "1:ad(1,a)/boot/loader" > /boot.config

will instruct the second stage of boot(8) on the first disk to boot with the third boot(8) stage from the second disk.

The command:

# echo "1:ad(1,a)/boot/loader -P" > /boot.config

will do both of the above.


boot(8), loader(8)


This manual page was written by Daniel Gerzo <danger@FreeBSD.org>.
May 13, 2007 FreeBSD