.\"/* Copyright 1999 Bjorn Ekwall <bj0rn@blox.se>
.\" This program is distributed according to the Gnu General Public License.
.\" See the file COPYING in the base distribution directory
.\"
.TH MODULES.CONF 5 "07 December 1999"
.UC 4
.SH NAME
modules.conf \- configuration file for loading kernel modules
.SH DESCRIPTION
The behaviour of
.B modprobe(8)
(and
.B depmod(8)
)
can be modified by the (optional) configuration file
.B /etc/modules.conf.
.PP
The configuration file consists of a set of lines.
.br
All empty lines, and all text on a line after a '#', will be ignored.
.br
Lines may be continued by ending the line with a '\\'.
.br
The remaining lines should all conform to one of the following formats:
.nf

  [add] above module module_list
  alias alias_name result
  [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 ...
.fi
.PP
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:
.nf

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

.fi
Directives may be repeated multiple times.
Note that some directives can have an optional prefix:
.I add.
When this prefix is used, the new module_list will be
.B added
to the previous module_list instead of replacing it.
.SH SEMANTICS
.B A_PATH
is the fully qualified path to the target.
It is possible to use shell meta-characters in
.B A_PATH
including command output, such as
.I \`uname \-r\`
and
.I \`kernelversion\`.
.br
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).
.PP
.B 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
.B 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.
.PP
EXPRESSION below can be:
.TP
.I "WORD compare_op WORD"
where compare_op is one of ==, !=, <, <=, >= or >.
The string values of the WORDs are compared.
.TP
.I "\-n WORD compare_op WORD"
where compare_op is one of ==, !=, <, <=, >= or >.
The numeric values of the WORDs are compared.
.TP
.I 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
.TP
.I "\-f FILENAME"
Test if the file FILENAME exists.
.TP
.I \-k
Test if "autoclean" is enabled (i.e. called from the kernel).
.TP
.I "! EXPRESSION"
A negated expression is also an expression.
.SH SYNTAX
This is a description of the legal directives.
.TP
.I "define VARIABLE WORD"
Do a
.I 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.
.TP
.I "depfile=A_PATH"
This is the path to the dependency file that will be created by
.B depmod
and used by
.B modprobe
to find the modules and their dependent modules.
Normally the default value should be used, see below.
.TP
.I "if EXPRESSION"
If the expression is evaluated to be
.B TRUE
then all directives up to the matching
.I "else, elseif"
or
.I endif
are processed.  Otherwise they are ignored.
.I if
directives may be nested up to an internal maximum of 20.
.br
Note: please avoid having any
.B path
directives conditionally processed.
Since
.B modprobe
has enough built-in "smarts", a conditionally processed
.B path
directive will gain you nothing but confusion.  Really.
.TP
.I "else"
If the previous matching
.I if
or
.I elseif
directive evaluated its expression to be
.B FALSE
then the directives enclosed by the (optional)
.I else
directive and its matching
.I endif
directive will be processed.
.TP
.I "elseif EXPRESSION"
If the previous matching
.I if
or
.I elseif
directives evaluated their expression to be
.B FALSE
and if the expression for this directive evaluates to
.B TRUE
then the directives up to the next matching
.I "elseif, else"
or
.I endif
directive will be processed.
.TP
.I "endif"
This directive ends the chain of matching
.I "if, elseif"
or
.I else
directive(s) controlling the conditional processing of configuration
file directives.
.nf

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

.fi
The
.I else
and
.I elseif
directives are optional.
.TP
.I "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
.I include
directive, conditionally processed by
.I if
directives, this is now easier to handle.
.TP
.I "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.
.TP
.I "keep"
If this word is found on a line
.B before
any lines that contain the
.B 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
.B replaced
by the set of paths in the configuration file.
.TP
.I "path=A_PATH"
.TP
.I "path[TAG]=A_PATH"
The
.B A_PATH
argument specifies an additional directory to search for modules.
The
.B 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
.B modprobe.
The tag is appended to the "path" keyword enclosed in square brackets.
If the tag is missing, the tag "misc" is assumed.
.br
One very useful tag is
.B boot,
which can be used to mark all directories containing modules
that should be loaded at boot-time.
.TP
.I "alias alias_name result"
The "alias" directive can be used to give alias names to modules.
A line in /etc/modules.conf that looks like this:
.nf

  alias iso9660 isofs

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

  alias some_module off

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

  alias some_module null

.fi
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
.I above
and
.I below
directives.
.br
.nf

.fi
.ne 7
It is possible to have a large number of levels of
.I alias
directives, since all aliases will be recursively expanded
in order to find the physical module actually referred to.  There is an
arbitrary limit of 1000 on alias depth to detect loops like:
.nf

  alias a b
  alias b a

.fi
.br
If the final result of an
.I alias
mapping does not match the name of any module then modprobe applies
probe and probeall mappings to the result.  If those do not succeed
then the module is not found.  This makes constructs like this give
sensible results (from devfs).
.br
.nf

  alias           /dev/sg*        /dev/sg
  probeall        /dev/sg         scsi-hosts sg

.fi
.ne 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
.B 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.
.TP
.I "[add] probe name module_list"
.TP
.I "[add] probeall name module_list"
These directives can only be used when
.I name
is the name of the module requested on the command line of
.B modprobe.
The effect is that when a request for
.I name
is made, the modules in module_list will be tried, in the specified order.
The difference between the directives is that
.I probe
will continue until the first successful module insertion, while
.I probeall
will continue until the end of the list.
The exit status reflects whether any module has been successfully
installed or not.
The optional
.I add
prefix adds the new list to the previous list instead of replacing it.
.TP
.I "[add] options module MODULE_SPECIFIC_OPTIONS"
All module names, including aliased names, can have their own
.I 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
.I options
directives.
Options given on the command line have the highest priority.
The optional
.I add
prefix adds the new list to the previous list instead of replacing it.
If the result of an
.I alias
is not a real module then any
.I options
that were constructed from the
.I alias
chain are discarded before invoking probe[all].
.TP
.I "[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
.B lsmod(8)
command.
The
.I above
directive is useful for those circumstances when the dependencies
are more complex than what can be described in the
.B modules.dep
dependency file.
This is an optimized case of the
.I post-install
and
.I pre-remove
directives.
Note that failure of installing the module will not influence the
exit status of
.B modprobe.
The optional
.I add
prefix adds the new list to the previous list instead of replacing it.
.TP
.I "[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
.B lsmod(8)
command.
The
.I below
directive is useful for those circumstances when the dependencies
are more complex than what can be described in the
.B modules.dep
dependency file.
This is an optimized case of the
.I pre-install
and
.I post-remove
directives.
Note that failure of installing the module will not influence the
exit status of
.B modprobe.
The optional
.I add
prefix adds the new list to the previous list instead of replacing it.
.PP
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.
.TP
.I "pre-install module command"
Execute
.I command
before installing the specified module.
See the
.I below
directive as well.
.TP
.I "install module command"
Execute
.I command
instead of the default
.B insmod
when installing the specified module.
.TP
.I "post-install module command"
Execute
.I command
after installing the specified module.
See the
.I above
directive as well.
.TP
.I "pre-remove module command"
Execute
.I command
before removing the specified module.
See the
.I above
directive as well.
.TP
.I "remove module command"
Execute
.I command
instead of the default (built-in)
.B rmmod
when removing the specified module.
.TP
.I "post-remove module command"
Execute
.I command
after removing the specified module.
See the
.I below
directive as well.
.PP
.SH DEFAULT CONFIGURATION
If the configuration file '/etc/modules.conf' is missing,
or if any directive is not overridden,
the following defaults are assumed:
.PP
  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[ide]=/lib/modules/`uname \-r`/ide
  path[ieee1394]=/lib/modules/`uname \-r`/ieee1394

  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[ide]=/lib/modules/`kernelversion`/ide
  path[ieee1394]=/lib/modules/`kernelversion`/ieee1394

  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[ide]=/lib/modules/default/ide
  path[ieee1394]=/lib/modules/default/ieee1394

  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
  path[ide]=/lib/modules/ide
  path[ieee1394]=/lib/modules/ieee1394
.PP
There are also a set of default
.I alias
and
.I options
directives.
Since this set is continously extended, no list will be given here.
The (current) default set can be viewed by using the
.B "modprobe \-c"
command with an empty
.B /etc/modules.conf
file.
.PP
All
.I options
directives specify the options needed for
a module, as in:
.nf

  modprobe de620 bnc=1

.fi
These options will be overridden by any options given
in the
.B /etc/modules.conf
file, and on the
.B modprobe
command line.
.PP
Remember that it is possible to have an
.I options
directive for aliased module names as well
as for the non-aliased name.
This is useful for e.g. the dummy module:
.nf

  alias dummy0 dummy
  options dummy0 \-o dummy0

.fi
.PP
.SH 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.
This version of modutils issues a warning message if /etc/conf.modules
exists, later versions will give an error message and refuse to load
modules.
.SH SEE ALSO
depmod(8), modprobe(8), insmod(8)
.SH AUTHOR
.nf
Bjorn Ekwall <bj0rn@blox.se>
Keith Owens <kaos@ocs.com.au>