DEPMOD

DEPMOD(8)                          depmod                          DEPMOD(8)

NAME

depmod – Generate modules.dep and map files.

SYNOPSIS

depmod [-b basedir] [-e] [-E Module.symvers] [-F System.map] [-n]
[-v] [-A] [-P prefix] [-w] [version]

depmod [-e] [-E Module.symvers] [-F System.map] [-m] [-n] [-v]
[-P prefix] [-w] [version] [filename…]

DESCRIPTION

Linux kernel modules can provide services (called “symbols”) for
other modules to use (using one of the EXPORT_SYMBOL variants in the
code). If a second module uses this symbol, that second module
clearly depends on the first module. These dependencies can get quite
complex.

depmod creates a list of module dependencies by reading each module
under /lib/modules/version and determining what symbols it exports
and what symbols it needs. By default, this list is written to
modules.dep, and a binary hashed version named modules.dep.bin, in
the same directory. If filenames are given on the command line, only
those modules are examined (which is rarely useful unless all modules
are listed).  depmod also creates a list of symbols provided by
modules in the file named modules.symbols and its binary hashed
version, modules.symbols.bin. Finally, depmod will output a file
named modules.devname if modules supply special device names
(devname) that should be populated in /dev on boot (by a utility such
as systemd-tmpfiles).

If a version is provided, then that kernel version’s module directory
is used rather than the current kernel version (as returned by uname
-r).

OPTIONS

-a, –all
Probe all modules. This option is enabled by default if no file
names are given in the command-line.

-A, –quick
This option scans to see if any modules are newer than the
modules.dep file before any work is done: if not, it silently
exits rather than regenerating the files.

-b basedir, –basedir basedir
If your modules are not currently in the (normal) directory
/lib/modules/version, but in a staging area, you can specify a
basedir which is prepended to the directory name. This basedir is
stripped from the resulting modules.dep file, so it is ready to
be moved into the normal location. Use this option if you are a
distribution vendor who needs to pre-generate the meta-data files
rather than running depmod again later.

-C, –config file or directory
This option overrides the default configuration directory at
/etc/depmod.d/.

-e, –errsyms
When combined with the -F option, this reports any symbols which
a module needs which are not supplied by other modules or the
kernel. Normally, any symbols not provided by modules are assumed
to be provided by the kernel (which should be true in a perfect
world), but this assumption can break especially when
additionally updated third party drivers are not correctly
installed or were built incorrectly.

-E, –symvers
When combined with the -e option, this reports any symbol
versions supplied by modules that do not match with the symbol
versions provided by the kernel in its Module.symvers. This
option is mutually incompatible with -F.

-F, –filesyms System.map
Supplied with the System.map produced when the kernel was built,
this allows the -e option to report unresolved symbols. This
option is mutually incompatible with -E.

-h, –help
Print the help message and exit.

-n, –show, –dry-run
This sends the resulting modules.dep and the various map files to
standard output rather than writing them into the module
directory.

-P
Some architectures prefix symbols with an extraneous character.
This specifies a prefix character (for example ‘_’) to ignore.

-v, –verbose
In verbose mode, depmod will print (to stdout) all the symbols
each module depends on and the module’s file name which provides
that symbol.

-V, –version
Show version of program and exit. See below for caveats when run
on older kernels.

-w
Warn on duplicate dependencies, aliases, symbol versions, etc.

COPYRIGHT

This manual page originally Copyright 2002, Rusty Russell, IBM
Corporation. Portions Copyright Jon Masters, and others.

SEE ALSO

depmod.d(5), modprobe(8), modules.dep(5)

AUTHORS

Jon Masters <[email protected]>
Developer

Robby Workman <[email protected]>
Developer

Lucas De Marchi <[email protected]>
Developer

COLOPHON

This page is part of the kmod (userspace tools for managing kernel
modules) project.  Information about the project can be found at
[unknown — if you know, please contact [email protected]] If you
have a bug report for this manual page, send it to
[email protected].  This page was obtained from the
project’s upstream Git repository
(git://git.kernel.org/pub/scm/utils/kernel/kmod/kmod.git) on
2014-12-30.  If you discover any rendering problems in this HTML
version of the page, or you believe there is a better or more up-to-
date source for the page, or you have corrections or improvements to
the information in this COLOPHON (which is not part of the original
manual page), send a mail to [email protected]

kmod                             12/30/2014                        DEPMOD(8)