|
HTML rendering created 2025-09-06 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
|
|
NAME | SYNOPSIS | DESCRIPTION | OPTIONS | COPYRIGHT | SEE ALSO | BUGS | AUTHORS | COLOPHON |
|
|
|
DEPMOD(8) depmod DEPMOD(8)
depmod - Generate modules.dep and map files.
depmod [-b basedir] [-m moduledir] [-o outdir] [-e]
[-E Module.symvers]
[-F System.map] [-n] [-v] [-A] [-P prefix] [-w] [version]
depmod [-e] [-E Module.symvers] [-F System.map] [-n] [-v] [-P
prefix]
[-w] [version] [filename...]
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 <BASEDIR>/<MODULEDIR>/version. By default <MODULEDIR>
is /lib/modules and <BASEDIR> is empty. See options below to
override when needed. It determines what symbols each module
exports and needs. 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).
-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
Override the base directory <BASEDIR> where modules are
located. 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.
If a relative path is given, it's relative to the current
working directory.
Example:
depmod -b /my/build/staging/dir/
This expects all input files under
/my/build/staging/dir/lib/modules/$(uname -r) and generates
index files under that same directory.
-m moduledir, --moduledir moduledir
Override the module directory <MODULEDIR>, which defaults to
/lib/modules prefix set at build time. This is useful when
building modules.dep file in basedir for a system that uses a
different prefix, e.g. /usr/lib/modules vs /lib/modules.
Relative and absolute paths are accepted, but they are always
relative to the basedir.
Examples:
depmod -b /tmp/build -m /kernel-modules
depmod -b /tmp/build -m kernel-modules
This expects all input files under /tmp/build/kernel-
modules/$(uname -r) and generates index files under that same
directory.
Without an accompanying -b argument, the moduledir is relative
to /. Example:
depmod -m foo/bar
This expects all input files under /foo/bar/$(uname -r) and
generates index files under the same directory. Unless libkmod
is prepared to handle that arbitrary location, it won't work
in runtime.
-o outdir, --outdir outdir
Set the output directory where depmod will store any generated
file. outdir serves as a root to that location, similar to how
basedir is used. Also this setting takes precedence and if
used together with basedir it will result in the input being
that directory, but the output being the one set by outdir.
If a relative path is given, it's relative to the current
working directory.
Example:
depmod -o /my/build/staging/dir/
This expects all input files under /lib/modules/$(uname -r)
and generates index files under
/my/build/staging/dir/lib/modules/$(uname -r).
-C file or directory, --config file or directory
This option overrides the default configuration files. See
depmod.d(5).
-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 Module.symvers, --symvers Module.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 System.map, --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.
This manual page originally Copyright 2002, Rusty Russell, IBM
Corporation. Portions Copyright Jon Masters, and others.
depmod.d(5), modprobe(8), modules.dep(5)
Please direct any bug reports to kmod's issue tracker at
https://github.com/kmod-project/kmod/issues/ alongside with
version used, steps to reproduce the problem and the expected
outcome.
Numerous contributions have come from the linux-modules mailing
list <linux-modules@vger.kernel.org> and Github. If you have a
clone of kmod.git itself, the output of git-shortlog(1) and
git-blame(1) can show you the authors for specific parts of the
project.
Lucas De Marchi <lucas.de.marchi@gmail.com> is the current
maintainer of the project.
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 man-pages@man7.org] If you
have a bug report for this manual page, send it to
linux-modules@vger.kernel.org. This page was obtained from the
project's upstream Git repository
⟨git://git.kernel.org/pub/scm/utils/kernel/kmod/kmod.git⟩ on
2025-08-11. (At that time, the date of the most recent commit
that was found in the repository was 2025-07-13.) 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 man-pages@man7.org
kmod 2025-08-11 DEPMOD(8)
Pages that refer to this page: depmod.d(5), modules.dep(5), insmod(8), kernel-install(8), kmod(8), lsmod(8), modprobe(8), rmmod(8)
|
HTML rendering created 2025-09-06 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
|