Ubuntu Manpage: depmod - Generate modules.dep and map files.

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] [-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.

AUTHORS