Manual Pages  — LOADER.4TH

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 (seeloader(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 flag on the stack to indicate if any configuration files were successfully loaded.
read-conf filename	Reads and processes a loader.conf(5) file. Does not proceed to boot.
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.

include /boot/loader.4th
start

set kernel="kernel.old"
unload
boot-conf

unload
read-conf /boot/special.conf
boot-conf

unload
disable-module splash_bmp
disable-module bitmap
boot-conf

loader.conf(5), loader(8)