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.
-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 <[email protected]>
Developer
Robby Workman <[email protected]>
Developer
Lucas De Marchi <[email protected]>
Developer
kmod 03/01/2015 DEPMOD(8)
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