usr/src/boot/sys/boot/forth/loader.4th.8

.\" Copyright (c) 1999 Daniel C. Sobral
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.Dd November 13, 2013
.Dt LOADER.4TH 8
.Os
.Sh NAME
.Nm loader.4th
.Nd loader.conf processing tools
.Sh DESCRIPTION
The file that goes by the name of
.Nm
is a set of commands designed to manipulate
.Xr loader.conf 5
files.
The default
.Pa /boot/loader.rc
includes
.Nm
and uses one of its commands to automatically read and process
the standard
.Xr loader.conf 5
files.
Other commands exists to help the user specify alternate
configurations.
.Pp
The commands of
.Nm
by themselves are not enough for most uses.
Please refer to the
examples below for the most common situations, and to
.Xr loader 8
for additional commands.
.Pp
Before using any of the commands provided in
.Nm ,
it must be included
through the command:
.Pp
.Dl include loader.4th
.Pp
This line is present in the default
.Pa /boot/loader.rc
file, so it is not needed (and should not be re-issued) in a normal setup.
.Pp
The commands provided by it are:
.Bl -tag -width disable-module_module -compact -offset indent
.It Ic boot
.It Ic boot Ar kernelname Op Cm ...
.It Ic boot Ar directory Op Cm ...
.It Ic boot Fl flag Cm ...
Boot as specified by the
.Xr loader.conf 5
files read.
.Pp
Depending on the arguments passed, it can override boot flags and
either the kernel name or the search path for kernel and modules.
.Pp
.It Ic boot-conf
.It Ic boot-conf Ar kernelname Op Cm ...
.It Ic boot-conf Ar directory Op Cm ...
.It Ic boot-conf Fl flag Cm ...
Works like
.Ic boot
described above, but instead of booting immediately, uses
.Ic autoboot ,
so it can be stopped.
.Pp
.It Ic start
Reads
.Pa /boot/defaults/loader.conf ,
all other
.Xr loader.conf 5
files specified in it, then loads the desired kernel and modules
.Pq if not already loaded .
After which you can use the
.Ic boot
or
.Ic autoboot
commmands or simply exit (provided
.Va autoboot_delay
is not set to NO) to boot the system.
.Ic start
is the command used in the default
.Pa /boot/loader.rc
file
.Pq see Xr loader 8 .
.Pp
.It Ic initialize
Initialize the support library so commands can be used without executing
.Ic start
first.
Like
.Ic start ,
it reads
.Pa /boot/defaults/loader.conf
and all other
.Xr loader.conf 5
files specified in it
.Pq but does not load kernel or modules .
Returns a flag on the stack to indicate
if any configuration files were successfully loaded.
.Pp
.It Ic read-conf Ar filename
Reads and processes a
.Xr loader.conf 5
file.
Does not proceed to boot.
.Pp
.It Ic enable-module Ar module
Enables the loading of
.Ar module .
.Pp
.It Ic disable-module Ar module
Disables the loading of
.Ar module .
.Pp
.It Ic toggle-module Ar module
Toggles the loading of
.Ar module
on and off.
.Pp
.It Ic show-module Ar module
Shows the information gathered in the
.Xr loader.conf 5
files about the module
.Ar module .
.Pp
.It Ic retry
Used inside
.Xr loader.conf 5
files to specify the action after a module loading fails.
.Pp
.It Ic ignore
Used inside
.Xr loader.conf 5
files to specify the action after a module loading fails.
.It Ic try-include Ar file Op Ar
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.
.El
.Sh FILES
.Bl -tag -width /boot/loader.4th -compact
.It Pa /boot/loader
The
.Xr loader 8 .
.It Pa /boot/loader.4th
.Nm
itself.
.It Pa /boot/loader.rc
.Xr loader 8
bootstrapping script.
.It Pa /boot/defaults/loader.conf
File loaded by the
.Ic start
command.
.El
.Sh EXAMPLES
Standard
.Pa /boot/loader.rc :
.Pp
.Bd -literal -offset indent -compact
include /boot/loader.4th
start
.Ed
.Pp
Load a different kernel with the standard configuration:
.Pp
.Bd -literal -offset indent -compact
set kernel="kernel.old"
unload
boot-conf
.Ed
.Pp
Read an additional configuration file and then proceed to boot:
.Pp
.Bd -literal -offset indent -compact
unload
read-conf /boot/special.conf
boot-conf
.Ed
.Pp
Disable the loading of the splash screen module and bitmap and then
proceed to boot:
.Pp
.Bd -literal -offset indent -compact
unload
disable-module splash_bmp
disable-module bitmap
boot-conf
.Ed
.Sh SEE ALSO
.Xr loader.conf 5 ,
.Xr loader 8
.Sh HISTORY
The
.Nm
set of commands first appeared in
.Fx 3.2 .
.Sh AUTHORS
The
.Nm
set of commands was written by
.An Daniel C. Sobral Aq dcs@FreeBSD.org .
.Sh BUGS
A British espionage series.