DEPMOD(1)
NAME
depmod, modprobe - handle loadable modules automatically
SYNOPSIS
depmod [ -a ]
depmod [ -a version ]
depmod module1.o module2.o ...
modprobe module.o [symbol=value ...]
modprobe -t tag pattern
modprobe -a -t tag pattern
modprobe -l [ -t tag ] pattern
modprobe -r module
modprobe -c
DESCRIPTION
These utilities are intended to make a Linux modular ker-
nel manageable for all users, administrators and distribu-
tion maintainers.
Depmod creates a "Makefile"-like dependency file, based on
the symbols it finds in the set of modules mentioned on
the command line (or in a default place). This dependency
file can later be used by modprobe to automatically load
the relevant module(s).
Modprobe is used to load a set of modules, either a single
module, a stack of dependant modules, or all modules that
are marked with a specified tag.
Modprobe will automatically load all base modules needed
in a module stack, as described by the dependency file
modules.dep. If the loading of one of these modules
fails, the whole current stack of modules will be unloaded
(by rmmod) automatically.
Modprobe has two ways of loading modules. One way (the
probe mode) will try to load a module out of a list
(defined by pattern ). It stops loading as soon as one
module load successfully. This can be used to autoload
one ethernet driver out of a list for example. The other
way, is to load all modules from a list. This can be used
to load some modules at boot time.
With the option -r, modprobe will automatically unload a
stack of modules, similar to the way rmmod -r does.
Option -l combined with option -t list all available mod-
ules of a certain type. An enhanced mount command could
use the command
modprobe -l -t fs
to get the list of all file system drivers available and
on request load the proper one. So, the mount command
could become more generic as well... (The kerneld solve
this without changing the mount utility)
Option -c will print all configuration (default + configu-
ration file).
The normal use of depmod is to include the line
"/sbin/depmod -a" in one of the rc-files in /etc/rc.d, so
that the correct module dependencies will be available
immediately after booting the system.
Note that it is also possible to create the dependency
file immediately after compiling a new kernel. If you do
"depmod -a 1.3.99" when you have compiled kernel 1.3.99
and its modules the first time, while still running e.g.
1.3.98, the file will be created in the correct place.
Note however that the dependencies on the kernel will not
be guaranteed to be correct in this case!
Option -d put depmod in debug mode. It outputs all command
it is issuing. Option -e output the list of unresolved
symbol for each module, Normally depmod only output the
list of unloadable modules. Option -v output the list of
all processed modules. Modules may be located at differ-
ent place in the filesystem, but there will always be some
need to override this, especially for module developers.
We expect some official standard will emerge, defined by
the FSSTND. Until that time you might as well use this
suggested directory structure.
CONFIGURATION
The behaviour of depmod and modprobe can be adjusted by
the (optional) configuration file /etc/conf.modules
The configuration file consists of a set of lines.
All empty lines, and all text on a line after a '#', will
be ignored.
Lines may be continued by ending the line with a '\'.
The remaining lines should all conform to one of the fol-
lowing formats:
keep
parameter=value
options module symbol=value ...
alias module real_name
pre-install module command ...
install module command ...
post-install module command ...
pre-remove module command ...
remove module command ...
post-remove module command ...
All values in the "parameter" lines will be processed by a
shell, which means that "shell tricks" like wild-cards and
commands enclosed in back-quotes can be used:
path[misc]=/lib/modules/1.1.5?
path[net]=/lib/modules/`uname -r`
Parameters may be repeated multiple times.
These are the legal parameters:
keep If this word is found on a line before any lines
that contain the path descriptions, the default set
of paths will be saved, and thus added to. Other-
wise the normal behaviour is that the default set
will be replaced by the set of paths in the config-
uration file.
depfile=DEPFILE_PATH
This is the path to the dependency file that will
be created by depmod and used by modprobe.
path=SOME_PATH
The path parameter specifies a directory to search
for the modules.
path[tag]=SOME_PATH
The path parameter can carry an optional tag. This
tells us a little more about the purpose of the
modules in this directory and allows some automated
operations by modprobe. The tag is appended to the
"path" keyword enclose in square brackets. If the
tag is missing, the tag "misc" is assumed.
One very useful tag is boot, which can be used to
mark all modules that should be loaded at boot-
time.
If the configuration file '/etc/conf.modules' is missing,
or if any parameter is not overridden, the following
defaults are assumed:
depfile=/lib/modules/`uname -r`/modules.dep
path[boot]=/lib/modules
path[fs]=/lib/modules/`uname -r`
path[misc]=/lib/modules/`uname -r`
path[net]=/lib/modules/`uname -r`
path[scsi]=/lib/modules/`uname -r`
path[cdrom]=/lib/modules/`uname -r`
path[ipv4]=/lib/modules/`uname -r`
path[ipv6]=/lib/modules/`uname -r`
path[sound]=/lib/modules/`uname -r`
path[fs]=/lib/modules/default
path[misc]=/lib/modules/default
path[net]=/lib/modules/default
path[scsi]=/lib/modules/default
path[cdrom]=/lib/modules/default
path[ipv4]=/lib/modules/default
path[ipv6]=/lib/modules/default
path[sound]=/lib/modules/default
path[fs]=/lib/modules
path[misc]=/lib/modules
path[net]=/lib/modules
path[scsi]=/lib/modules
path[cdrom]=/lib/modules
path[ipv4]=/lib/modules
path[ipv6]=/lib/modules
path[sound]=/lib/modules
All "option" lines specify the default options that are
needed for a module, as in:
modprobe de620 bnc=1
These options will be overridden by any options given on
the modprobe command line.
It is possible to have an "option" line for aliased module
names as well as for the non-aliased name. This is useful
for e.g. the dummy module:
alias dummy0 dummy
options dummy0 -o dummy0
The "alias" lines can be used to give alias names to mod-
ules. A line in /etc/conf.modules that looks like this:
alias iso9660 isofs
makes it possible to write modprobe iso9660 although there
is no such module available.
Note that the line:
alias some_module off
will make modprobe ignore requests to load that module.
This is usually used in conjunction with kerneld.
Commands
The configuration lines
pre-install module command ...
install module command ...
post-install module command ...
pre-remove module command ...
remove module command ...
post-remove module command ...
can be used when one wants some specific commands
to be executed when a module is inserted or
removed. All text after the module name will be
interpreted as the command text.
Note that the pre- and post-remove commands will
not be executed if a module is "autocleaned" by
kerneld! Look for the up-coming support for per-
sistent module storage instead.
STRATEGY
The idea is that modprobe will look first at the directory
containing modules compiled for the current release of the
kernel. If the module is not found there, modprobe will
look in the directory containing modules for a default
release.
When you install a new linux, the modules should be moved
to a directory related to the release (and version) of the
kernel you are installing. Then you should do a symlink
from this directory to the "default" directory.
Each time you compile a new kernel, the command make mod-
ules_install will create a new directory, but won't change
the default.
When you get a module unrelated to the kernel distribution
you should place it in one of the version-independent
directories under /lib/modules.
This is the default strategy, which can be overridden in
/etc/conf.modules.
EXAMPLES
modprobe -t net
Load one of the modules that are stored in the
directory tagged "net". Each module are tried
until one succeed (default: /lib/modules/net).
modprobe -a -t boot
All modules that are stored in the directory tagged
"boot" will be loaded (default: /lib/modules/boot).
modprobe slip.o
This will attempt to load the module slhc.o if it
was not previously loaded, since the slip module
needs the functionality in the slhc module. This
dependency will be described in the file "mod-
ules.dep" that was created automatically by depmod
modprobe -r slip.o
will unload slip.o. It will also unload slhc.o
automatically, unless it is used by some other mod-
ule as well (like e.g. ppp.o).
FILES
/etc/conf.modules, (and /etc/modules.conf)
/lib/modules/*/modules.dep,
/lib/modules/*
SEE ALSO
lsmod(1) kerneld(8) ksyms(1) modules(2)
REQUIERED UTILITIES
insmod(1), nm(1) rmmod(1),
NOTES
The pattern supplied to modprobe will often be escaped to
ensure that it is evaluated in the proper context
AUTHOR
Jacques Gelinas jack@solucorp.qc.ca
Bjorn Ekwall bj0rn@blox.se
BUGS
Naah...