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 <jcm AT jonmasters.org>
Developer
Robby Workman <rworkman AT slackware.com>
Developer
Lucas De Marchi <lucas.de.marchi AT gmail.com>
Developer
kmod 01/08/2018 DEPMOD(8)