DEPMOD(8)			    depmod			     DEPMOD(8)

NAME
       depmod - Generate modules.dep and map files.

SYNOPSIS
       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...]

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 <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).

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
	   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.

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)

BUGS
       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.

AUTHORS
       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.

kmod				  2025-03-28			     DEPMOD(8)