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LOADER.4TH(8) FreeBSD System Manager's Manual LOADER.4TH(8)
NAME
loader.4th - loader.conf processing tools
DESCRIPTION
The file that goes by the name of loader.4th is a set of commands
designed to manipulate loader.conf(5) files. The default /boot/loader.rc
includes loader.4th and uses one of its commands to automatically read
and process the standard loader.conf(5) files. Other commands exists to
help the user specify alternate configurations.
The commands of loader.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 loader.4th, it must be
included through the command:
include loader.4th
This line is present in the default /boot/loader.rc file, so it is not
needed (and should not be re-issued) in a normal setup.
The commands provided by it are:
boot
boot kernelname [...]
boot directory [...]
boot -flag ... Boot as specified by the loader.conf(5)
files read.
Depending on the arguments passed, it can
override boot flags and either the kernel
name or the search path for kernel and
modules.
boot-conf
boot-conf kernelname [...]
boot-conf directory [...]
boot-conf -flag ... Works like boot described above, but instead
of booting immediately, uses autoboot, so it
can be stopped.
start Reads /boot/defaults/loader.conf, all other
loader.conf(5) files specified in it, then
loads the desired kernel and modules (if not
already loaded). After which you can use
the boot or autoboot commands or simply exit
(provided autoboot_delay is not set to NO)
to boot the system. start is the command
used in the default /boot/loader.rc file
(see loader(8)).
initialize Initialize the support library so commands
can be used without executing start first.
Like start, it reads
/boot/defaults/loader.conf and all other
loader.conf(5) files specified in it (but
does not load kernel or modules). Returns a
enable-module module Enables the loading of module.
disable-module module Disables the loading of module.
toggle-module module Toggles the loading of module on and off.
show-module module Shows the information gathered in the
loader.conf(5) files about the module
module.
retry Used inside loader.conf(5) files to specify
the action after a module loading fails.
ignore Used inside loader.conf(5) files to specify
the action after a module loading fails.
try-include file [file ...]
Process script files if they exist. Each
file, in turn, is completely read into
memory, and then each of its lines is passed
to the command line interpreter. If any
error is returned by the interpreter, the
try-include command aborts immediately,
without reading any other files, and
silently returns without error.
FILES
/boot/loader The loader(8).
/boot/loader.4th loader.4th itself.
/boot/loader.rc loader(8) bootstrapping script.
/boot/defaults/loader.conf
File loaded by the start command.
EXAMPLES
Standard /boot/loader.rc:
include /boot/loader.4th
start
Load a different kernel with the standard configuration:
set kernel="kernel.old"
unload
boot-conf
Read an additional configuration file and then proceed to boot:
unload
read-conf /boot/special.conf
boot-conf
Disable the loading of the splash screen module and bitmap and then
proceed to boot:
unload
disable-module splash_bmp
disable-module bitmap
boot-conf
SEE ALSO
<dcs@FreeBSD.org>.
BUGS
A British espionage series.
FreeBSD 14.0-RELEASE-p11 November 13, 2013 FreeBSD 14.0-RELEASE-p11