NetBSD/sbin/modload/modload.8

.\" $NetBSD: modload.8,v 1.25 2003/09/06 20:09:26 wiz Exp $
.\"
.\" Copyright (c) 1993 Christopher G. Demetriou
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"          This product includes software developed for the
.\"          NetBSD Project.  See http://www.NetBSD.org/ for
.\"          information about NetBSD.
.\" 4. The name of the author may not be used to endorse or promote products
.\"    derived from this software without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
.\"
.\" <<Id: LICENSE,v 1.2 2000/06/14 15:57:33 cgd Exp>>
.\"
.Dd September 6, 2003
.Dt MODLOAD 8
.Os
.Sh NAME
.Nm modload
.Nd load a kernel module
.Sh SYNOPSIS
.Nm
.Op Fl dfnsSv
.Op Fl A Ar kernel
.Op Fl e Ar entry
.Op Fl p Ar postinstall
.Op Fl o Ar output_file
.Op Fl T Ar linker_script
.Ar input_file
.Sh DESCRIPTION
The
.Nm
utility loads a loadable kernel module into a running system.
The input file is an object file (.o file).
.Pp
The options to
.Nm
are as follows:
.Bl -tag -width indent
.It Fl d
Debug.
Used to debug
.Nm
itself.
.It Fl f
This forces load of the module, even if it doesn't match the
currently running kernel.
When LKM is loaded, the kernel normally checks if the LKM is
compatible with the running kernel.
This option disables this check.
.Em Note
an incompatible LKM can cause system instability, including data
loss or corruption.
Don't use this option unless you are sure what you are doing.
.It Fl n
Do everything, except calling the module entry point (and any
post-install program).
.It Fl v
Print comments about the loading process.
.It Fl s
Load the symbol table.
.It Fl S
Do not remove the temporary object file.
By default, the
.Xr ld 1
output is removed after being loaded into the kernel.
.It Fl A Ar kernel
Specify the file that is passed to the linker
to resolve module references to external symbols.
The symbol file must be for the currently running
kernel or the module is likely to crash the system.
.It Fl e Ar entry
Specify the module entry point.
This is passed by
.Nm
to
.Xr ld 1
when the module is linked.
The default module entry point name is `xxxinit'.
If `xxxinit' cannot be found, an attempt to
use `\*[Lt]module_name\*[Gt]_lkmentry' will be made, where
\*[Lt]module_name\*[Gt] is the filename being loaded without the `.o'.
.It Fl p Ar postinstall
Specify the name of a shell script or program that will
be executed if the module is successfully loaded.
It is always passed the module id (in decimal) and module
type (in hexadecimal) as the first two arguments.
For loadable drivers, the third argument is the character major device number
and the fourth argument is the block major device number.
For a loadable system call, the third argument is the system call number.
.It Fl o Ar output_file
Specify the name of the output file that is produced by the linker.
.It Fl T Ar linker_script
Specify the name of the linker script use to link against the kernel.
.El
.Sh FILES
.Bl -tag -width /usr/include/sys/lkm.h -compact
.It Pa /netbsd
default file passed to the linker to resolve external
references in the module
.It Pa /usr/include/sys/lkm.h
file containing definitions of module types
.\" .It Pa output file.
.\" default output file name
.El
.Sh DIAGNOSTICS
The
.Nm
utility exits with a status of 0 on success
and with a nonzero status if an error occurs.
.Sh SEE ALSO
.Xr ld 1 ,
.Xr lkm 4 ,
.Xr modstat 8 ,
.Xr modunload 8
.Sh HISTORY
The
.Nm
command was designed to be similar in functionality
to the corresponding command in
.Tn "SunOS 4.1.3" .
.Sh AUTHORS
.An Terrence R. Lambert
.Aq terry@cs.weber.edu .
.Sh BUGS
Loading the symbol table is expensive in terms of space:
it presently duplicates all the kernel symbols for each lkm loaded
with
.Fl s .