NAME
modprobe.conf, modprobe.d - Configuration file/directory for modprobe
DESCRIPTION
Because the modprobe command can add or
remove extra more than one module, due to module dependencies,
we need a method of specifying what options are to be used with
those modules. /etc/modprobe.conf and all files under the
/etc/modprobe.d directory specifies those options, as required.
It can also be used to create
convenient aliases: alternate names for a module. Finally, it
can override the normal modprobe behavior
altogether, for those with very special requirements (such as
inserting more than one module).
Note that module and alias names (like other module names) can
have - or _ in them: both are interchangable throughout all the
module commands.
The format of modprobe.conf and files under modprobe.d is simple: one
command per line, with blank lines and lines starting with #
ignored (useful for adding comments). A \ at the end of a line
causes it to continue on the next line, which makes the file a
bit neater.
The syntax is a simplification of modules.conf, used in 2.4 kernels and earlier.
COMMANDS
alias wildcard modulename
This allows you to give alternate names for a module. For
example: "alias my-mod really_long_modulename"
means you can use "modprobe my-mod" instead of "modprobe
really_long_modulename". You can also use shell-style
wildcards, so "alias my-mod* really_long_modulename"
means that "modprobe my-mod-something" has the same
effect. You can't have aliases to other aliases (that
way lies madness), but aliases can have options, which
will be added to any other options.
Note that modules can also contain their own aliases,
which you can see using modinfo. These
aliases are used as a last resort (ie. if there is no real
module, install,
remove, or alias
command in the configuration).
options modulename option...
This command allows you to add options to the module
modulename (which might be an
alias) every time it is inserted into the kernel: whether
directly (using modprobe
modulename, or because the
module being inserted depends on this module.
All options are added together: they can come from an
option for the module itself, for an
alias, and on the command line.
install modulename command...
This is the most powerful primitive in
modprobe.conf: it tells
modprobe to run your command instead of
inserting the module in the kernel as normal. The command
can be any shell command: this allows you to do any kind
of complex processing you might wish. For example, if the
module "fred" worked better with the module "barney"
already installed (but it didn't depend on it, so
modprobe won't automatically load it),
you could say "install fred /sbin/modprobe barney;
/sbin/modprobe --ignore-install fred", which would do what
you wanted. Note the --ignore-install,
which stops the second modprobe from
re-running the same install command.
See also remove below.
You can also use install to make up
modules which don't otherwise exist. For example:
"install probe-ethernet /sbin/modprobe e100 ||
/sbin/modprobe eepro100", which will try first the e100
driver, then the eepro100 driver, when you do "modprobe
probe-ethernet".
If you use the string "$CMDLINE_OPTS" in the command, it
will be replaced by any options specified on the modprobe
command line. This can be useful because users expect
"modprobe fred opt=1" to pass the "opt=1" arg to the
module, even if there's an install command in the
configuration file. So our above example becomes "install
fred /sbin/modprobe barney; /sbin/modprobe
--ignore-install fred $CMDLINE_OPTS"
remove modulename command...
This is similar to the install command
above, except it is invoked when "modprobe -r" is run.
The removal counterparts to the two examples above would
be: "remove fred /sbin/modprobe -r --ignore-remove fred &&
/sbin/modprobe -r barney", and "remove probe-ethernet
/sbin/modprobe -r eepro100 || /sbin/modprobe -r e100".
include filename
Using this command, you can include other configuration
files, or whole directories, which is occasionally useful. Note that aliases in
the included file will override aliases previously
declared in the current file.
blacklist modulename
Modules can contain their own aliases: usually these are
aliases describing the devices they support, such as
"pci:123...". These "internal" aliases can be overridden
by normal "alias" keywords, but there are cases where two
or more modules both support the same devices, or a module
invalidly claims to support a device: the
blacklist keyword indicates that all of
a particular module's internal aliases are to be ignored.
BACKWARDS COMPATIBILITY
There is a generate_modprobe.conf program
which should do a reasonable job of generating
modprobe.conf from your current (2.4 or
2.2) modules setup.
Although the syntax is similar to the older
/etc/modules.conf, there are many features
missing. There are two reasons for this: firstly, install and
remove commands can do just about anything, and secondly, the
module-init-tools modprobe is designed to be simple enough that
it can be easily replaced.
With the complexity of actual module insertion reduced to three
system calls (open, read, init_module), and the
modules.dep file being simple and open,
producing a more powerful modprobe variant can be done
independently if there is a need.
COPYRIGHT
This manual page Copyright 2004, Rusty Russell, IBM Corporation.
SEE ALSO
modprobe(8),
modules.dep(5)