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MODULES.CONF (5)

configuration file for loading kernel modules

DESCRIPTION

    The behaviour of modprobe(8) (and depmod(8) ) can be modified by the (optional) configuration file /etc/modules.conf.

    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 following formats:

    [add] above module module_list alias alias_name real_name [add] below module module_list define VARIABLE WORD depfile=A_PATH else elseif EXPRESSION endif if EXPRESSION include PATH_TO_CONFIG_FILE insmod_opt=GENERIC_OPTIONS_TO_INSMOD install module command ... keep [add] options module MODULE_SPECIFIC_OPTIONS path=A_PATH path[TAG]=A_PATH [add] probe name module_list [add] probeall name module_list post-install module command ... post-remove module command ... pre-install module command ... pre-remove module command ... remove module command ...

    All arguments to a directive will be processed to handle shell meta-characters, which means that "shell tricks" like wild-cards and commands enclosed in back-quotes can be used:

    path[misc]=/lib/modules/1.1.5?/local path[net]=/lib/modules/`uname -r`/net

    Directives may be repeated multiple times. Note that some directives can have an optional prefix: add. When this prefix is used, the new module_list will be added to the previous module_list instead of replacing it.

SEMANTICS

    A_PATH is the fully qualified path to the target. It is possible to use shell meta-characters in A_PATH including command output, such as \`uname -r\` and \`kernelversion\`. These two commands are also understood internally in these utilities as meaning the version number of the current kernel and the current kernel version respectively (e.g.: 2.2.3 and 2.2).

    WORD is a sequence if non-white characters. If ' " or ` is found in the string, all characters up to the matching ' " or ` will also be included, even whitespace. Every WORD will then be expanded w.r.t. meta-characters. If the expanded result gives more than one word then only the first word of the result will be used.

    EXPRESSION below can be:

    WORD compare_op WORD

      where compare_op is one of ==, !=, <, <=, >= or >. The string values of the WORDs are compared.

    -n WORD compare_op WORD

      where compare_op is one of ==, !=, <, <=, >= or >. The numeric values of the WORDs are compared.

    WORD

      If the expansion of WORD fails, or if the expansion is "0" (zero), "false" or "" (empty) then the expansion has the value FALSE. Otherwise the expansion has the value TRUE

    -f FILENAME

      Test if the file FILENAME exists.

    -k

      Test if "autoclean" is enabled (i.e. called from the kernel).

    ! EXPRESSION

      A negated expression is also an expression.

SYNTAX

    This is a description of the legal directives.

    define VARIABLE WORD

      Do a putenv("VARIABLE=WORD"). Variables can be created and modified by this directive. The variables will be available in the environment, which makes them usable for all commands executed in the current session.

    depfile=A_PATH

      This is the path to the dependency file that will be created by depmod and used by modprobe to find the modules and their dependent modules. Normally the default value should be used, see below.

    if EXPRESSION

      If the expression is evaluated to be TRUE then all directives up to the matching else, elseif or endif are processed. Otherwise they are ignored. if directives may be nested up to an internal maximum of 20. Note: please avoid having any path directives conditionally processed. Since modprobe has enough built-in "smarts", a conditionally processed path directive will gain you nothing but confusion. Really.

    else

      If the previous matching if or elseif directive evaluated its expression to be FALSE then the directives enclosed by the (optional) else directive and its matching endif directive will be processed.

    elseif EXPRESSION

      If the previous matching if or elseif directives evaluated their expression to be FALSE and if the expression for this directive evaluates to TRUE then the directives up to the next matching elseif, else or endif directive will be processed.

    endif

      This directive ends the chain of matching if, elseif or else directive(s) controlling the conditional processing of configuration file directives.

    if EXPRESSION any config lines elseif EXPRESSION any config lines else any config lines endif

    The else and elseif directives are optional.

    include PATH_TO_CONFIG_FILE

      To handle different platforms or configurations with a single configuration file can be quite complex. With the use of the include directive, conditionally processed by if directives, this is now easier to handle.

    insmod_opt=GENERIC_OPTIONS_TO_INSMOD

      If insmod should need some special options, not specified elsewhere, this directive makes it possible to add such an option, to be used for every invocation. The standard default options to insmod does normally not have to be modified unless some special situation needs to be handled.

    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. Otherwise the normal behaviour is that the default set will be replaced by the set of paths in the configuration file.

    path=A_PATH

    path[TAG]=A_PATH

      The A_PATH argument specifies an additional directory to search for modules. The path directive 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 enclosed 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 directories containing modules that should be loaded at boot-time.

    alias alias_name real_name

      The "alias" directive can be used to give alias names to modules. A line in /etc/modules.conf that looks like this:

    alias iso9660 isofs

    makes it possible to write modprobe iso9660 although there is no object file for such a module available. Note that the line:

    alias some_module off

    will make modprobe ignore requests to load that module. Another special alias is:

    alias some_module null

    which will make requests for some_module always succeed, but no module will actually be installed. This can be used as a base for stacks created via the above and below directives. It is possible to have an unlimited number of levels of alias directives, since all aliases will be recursively expanded in order to find the physical module actually referred to.

    7 It is legal for an alias to map module A to module B and for module A to exist at the same time but this construct is ambiguous and is not recommended. For historical reasons, the kernel sound system has a module called sound.o but the sound developers also want an alias from sound to the module for the user's sound card, e.g. "alias\ sound\ sb". In an attempt to support this requirement but still maintain the defined behaviour where options can be applied to aliases, modprobe bypasses alias expansion when processing a module name if the name was obtained via modules.dep, otherwise aliases are expanded. This is not guaranteed to give the expected behaviour on all combinations of aliases and real modules, you should avoid using an alias with the same name as a real module.

    [add] probe name module_list

    [add] probeall name module_list

      These directives can only be used when name is the name of the module requested on the command line of modprobe. The effect is that when a request for name is made, the modules in module_list will be tried, in the specified order. The difference between the directives is that probe will continue until the first successful module insertion, while probeall will continue until the end of the list. The exit status reflects whether any module has been successfully installed or not. The optional add prefix adds the new list to the previous list instead of replacing it.

    [add] options [-k] module [MODULE_SPECIFIC_OPTIONS]

      All module names, including aliased names, can have their own options directives. Options specified for an alias have higher priority than the options specified for more "basic" names. This rule is used to resolve conflicting options directives. Options given on the command line have the highest priority. If there is -k before the module name, then the module won't be autocleaned even if modprobe has been invoked with the -k autoclean option. The optional add prefix adds the new list to the previous list instead of replacing it.

    [add] above module module_list

      This directive makes it possible for one module to "pull in" another set of modules on top of itself in a module stack, as seen in the output of the lsmod(8) command. The above directive is useful for those circumstances when the dependencies are more complex than what can be described in the modules.dep dependency file. This is an optimized case of the post-install and pre-remove directives. Note that failure of installing the module will not influence the exit status of modprobe. The optional add prefix adds the new list to the previous list instead of replacing it.

    [add] below module module_list

      This directive makes it possible for one module to "push" another set of modules below itself in a module stack, as seen in the output of the lsmod(8) command. The below directive is useful for those circumstances when the dependencies are more complex than what can be described in the modules.dep dependency file. This is an optimized case of the pre-install and post-remove directives. Note that failure of installing the module will not influence the exit status of modprobe. The optional add prefix adds the new list to the previous list instead of replacing it.

    The following directives are useful for (optionally) executing specific commands when loading and unloading a module. Note that even aliased module names can have these directives, which will be executed in the proper order together with any directives for the unaliased module name.

    pre-install module command

      Execute command before installing the specified module. See the below directive as well.

    install module command

      Execute command instead of the default insmod when installing the specified module.

    post-install module command

      Execute command after installing the specified module. See the above directive as well.

    pre-remove module command

      Execute command before removing the specified module. See the above directive as well.

    remove module command

      Execute command instead of the default (built-in) rmmod when removing the specified module.

    post-remove module command

      Execute command after removing the specified module. See the below directive as well.

DEFAULT CONFIGURATION

    If the configuration file '/etc/modules.conf' is missing, or if any directive is not overridden, the following defaults are assumed:

    depfile=/lib/modules/`uname -r`/modules.dep

    path[boot]=/lib/modules/boot path[fs]=/lib/modules/`uname -r`/fs path[net]=/lib/modules/`uname -r`/net path[scsi]=/lib/modules/`uname -r`/scsi path[block]=/lib/modules/`uname -r`/block path[cdrom]=/lib/modules/`uname -r`/cdrom path[ipv4]=/lib/modules/`uname -r`/ipv4 path[ipv6]=/lib/modules/`uname -r`/ipv6 path[sound]=/lib/modules/`uname -r`/sound path[fc4]=/lib/modules/`uname -r`/fc4 path[video]=/lib/modules/`uname -r`/video path[misc]=/lib/modules/`uname -r`/misc path[pcmcia]=/lib/modules/`uname -r`/pcmcia path[atm]=/lib/modules/`uname -r`/atm path[usb]=/lib/modules/`uname -r`/usb

    path[fs]=/lib/modules/`kernelversion`/fs path[net]=/lib/modules/`kernelversion`/net path[scsi]=/lib/modules/`kernelversion`/scsi path[block]=/lib/modules/`kernelversion`/block path[cdrom]=/lib/modules/`kernelversion`/cdrom path[ipv4]=/lib/modules/`kernelversion`/ipv4 path[ipv6]=/lib/modules/`kernelversion`/ipv6 path[sound]=/lib/modules/`kernelversion`/sound path[fc4]=/lib/modules/`kernelversion`/fc4 path[video]=/lib/modules/`kernelversion`/video path[misc]=/lib/modules/`kernelversion`/misc path[pcmcia]=/lib/modules/`kernelversion`/pcmcia path[atm]=/lib/modules/`kernelversion`/atm path[usb]=/lib/modules/`kernelversion`/usb

    path[fs]=/lib/modules/default/fs path[net]=/lib/modules/default/net path[scsi]=/lib/modules/default/scsi path[block]=/lib/modules/default/block path[cdrom]=/lib/modules/default/cdrom path[ipv4]=/lib/modules/default/ipv4 path[ipv6]=/lib/modules/default/ipv6 path[sound]=/lib/modules/default/sound path[fc4]=/lib/modules/default/fc4 path[video]=/lib/modules/default/video path[misc]=/lib/modules/default/misc path[pcmcia]=/lib/modules/default/pcmcia path[atm]=/lib/modules/default/atm path[usb]=/lib/modules/default/usb

    path[fs]=/lib/modules/fs path[net]=/lib/modules/net path[scsi]=/lib/modules/scsi path[block]=/lib/modules/block path[cdrom]=/lib/modules/cdrom path[ipv4]=/lib/modules/ipv4 path[ipv6]=/lib/modules/ipv6 path[sound]=/lib/modules/sound path[fc4]=/lib/modules/fc4 path[video]=/lib/modules/video path[misc]=/lib/modules/misc path[pcmcia]=/lib/modules/pcmcia path[atm]=/lib/modules/atm path[usb]=/lib/modules/usb

    There are also a set of default alias and options directives. Since this set is continously extended, no list will be given here. The (current) default set can be viewed by using the modprobe -c command with an empty /etc/modules.conf file.

    All options directives specify the options needed for a module, as in:

    modprobe de620 bnc=1

    These options will be overridden by any options given in the /etc/modules.conf file, and on the modprobe command line.

    Remember that it is possible to have an options directive 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

ALTERNATIVE CONFIGURATION FILE

    For historical reasons, if /etc/modules.conf does not exist, modutils will read /etc/conf.modules instead. However the use of this historical name is depreciated and it should be replaced with /etc/modules.conf.

SEE ALSO

AUTHOR

    Bjorn Ekwall <bj0rn@blox.se>
    Keith Owens <kaos@ocs.com.au>