NAME

delay.4th — FreeBSD debugging boot module

DESCRIPTION

The file that goes by the name of delay.4th is a set of commands designed to add debugging capabilities to loader(8). The commands of delay.4th by themselves are not enough for most uses. Please refer to the examples below for the most common situations, and to loader(8) for additional commands.

Before using any of the commands provided in delay.4th, it must be included through the command:

include delay.4th

This line is present in /boot/beastie.4th file, so it is not needed (and should not be re-issued) in a normal setup.

The commands provided by it are:

delay_execute

Executes the [string] procedure stored in the delay_command environment variable after loader_delay seconds.

If the optional delay_showdots environment variable is set, a continuous series of dots is printed.

During the duration, the user can either press Ctrl-C (or Esc) to abort or ENTER to proceed immediately.

The environment variables that effect its behavior are:

delay_command: The command to be executed by delay_execute.
loader_delay: The duration (in seconds) to delay before executing delay_command.
delay_showdots: If set, will cause delay_execute to print a continuous series of dots during the delay duration.

FILES

/boot/loader: The loader(8).
/boot/delay.4th: delay.4th itself.
/boot/loader.rc: loader(8) bootstrapping script.

EXAMPLES

Introducing a 5-second delay before including another file from /boot/loader.rc:

include /boot/delay.4th
set delay_command="include /boot/other.4th"
set delay_showdots
set loader_delay=5
delay_execute

HISTORY

The delay.4th set of commands first appeared in FreeBSD 9.0.

AUTHORS

The delay.4th set of commands was written by Devin Teske ⟨dteske@FreeBSD.org⟩.