modprobe.conf(5) - phpMan

modprobe.conf(5) modprobe.conf(5)

NAME
modprobe.conf -- 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 mod-
ules. /etc/modprobe.conf (or, if that does not exist, 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 "mod-
probe 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 mod-
ule, 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 mod-
ule.

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 com-
mand can be any shell command: this allows you to do any kind of complex pro-
cessing 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 "mod-
probe -r" is run. The removal counterparts to the two examples above would be:
"remove fred /sbin/modprobe -r --ignore-remove fred && /sbin/modprobe -r bar-
ney", 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 directo-
ries, 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 that 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.