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