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<refentry id="depmod">
<refentryinfo>
<title>depmod</title>
<productname>kmod</productname>
<authorgroup>
<author>
<contrib>Developer</contrib>
<firstname>Jon</firstname>
<surname>Masters</surname>
<email>jcm@jonmasters.org</email>
</author>
<author>
<contrib>Developer</contrib>
<firstname>Robby</firstname>
<surname>Workman</surname>
<email>rworkman@slackware.com</email>
</author>
<author>
<contrib>Developer</contrib>
<firstname>Lucas</firstname>
<surname>De Marchi</surname>
<email>lucas.de.marchi@gmail.com</email>
</author>
</authorgroup>
</refentryinfo>
<refmeta>
<refentrytitle>depmod</refentrytitle>
<manvolnum>8</manvolnum>
</refmeta>
<refnamediv>
<refname>depmod</refname>
<refpurpose>
Generate <filename>modules.dep</filename> and map files.
</refpurpose>
</refnamediv>
<refsynopsisdiv>
<cmdsynopsis>
<command>depmod</command>
<arg><option>-b <replaceable>basedir</replaceable></option></arg>
<arg><option>-e</option></arg>
<arg><option>-E <replaceable>Module.symvers</replaceable></option></arg>
<arg><option>-F <replaceable>System.map</replaceable></option></arg>
<arg><option>-n</option></arg>
<arg><option>-v</option></arg>
<arg><option>-A</option></arg>
<arg><option>-P <replaceable>prefix</replaceable></option></arg>
<arg><option>-w</option></arg>
<arg><option><replaceable>version</replaceable></option></arg>
</cmdsynopsis>
<cmdsynopsis>
<command>depmod</command>
<arg><option>-e</option></arg>
<arg><option>-E <replaceable>Module.symvers</replaceable></option></arg>
<arg><option>-F <replaceable>System.map</replaceable></option></arg>
<arg><option>-m</option></arg>
<arg><option>-n</option></arg>
<arg><option>-v</option></arg>
<arg><option>-P <replaceable>prefix</replaceable></option></arg>
<arg><option>-w</option></arg>
<arg><option><replaceable>version</replaceable></option></arg>
<arg rep='repeat'><option><replaceable>filename</replaceable></option></arg>
</cmdsynopsis>
</refsynopsisdiv>
<refsect1><title>DESCRIPTION</title>
<para>
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.
</para>
<para> <command>depmod</command> creates a list of module dependencies by
reading each module under
<filename>/lib/modules/</filename><replaceable>version</replaceable> and
determining what symbols it exports and what symbols it needs. By
default, this list is written to <filename>modules.dep</filename>, and a
binary hashed version named <filename>modules.dep.bin</filename>, 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). <command>depmod</command> also creates a list of symbols
provided by modules in the file named
<filename>modules.symbols</filename> and its binary hashed version,
<filename>modules.symbols.bin</filename>. Finally,
<command>depmod</command> will output a file named
<filename>modules.devname</filename> if modules supply special device
names (devname) that should be populated in /dev on boot (by a utility
such as systemd-tmpfiles).
</para>
<para> If a <replaceable>version</replaceable> is provided, then that kernel
version's module directory is used rather than the current kernel version
(as returned by <command>uname -r</command>).
</para>
</refsect1>
<refsect1><title>OPTIONS</title>
<variablelist>
<varlistentry>
<term>
<option>-a</option>
</term>
<term>
<option>--all</option>
</term>
<listitem>
<para>
Probe all modules. This option is enabled by default if no
file names are given in the command-line.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<option>-A</option>
</term>
<term>
<option>--quick</option>
</term>
<listitem>
<para>
This option scans to see if any modules are newer than the
<filename>modules.dep</filename> file before any work is done:
if not, it silently exits rather than regenerating the files.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<option>-b <replaceable>basedir</replaceable></option>
</term>
<term>
<option>--basedir <replaceable>basedir</replaceable></option>
</term>
<listitem>
<para>
If your modules are not currently in the (normal) directory
<filename>/lib/modules/</filename><replaceable>version</replaceable>,
but in a staging area, you can specify a
<replaceable>basedir</replaceable> which is prepended to the
directory name. This <replaceable>basedir</replaceable> is
stripped from the resulting <filename>modules.dep</filename> 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.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<option>-C</option>
</term>
<term>
<option>--config <replaceable>file or directory</replaceable></option>
</term>
<listitem>
<para>
This option overrides the default configuration directory at
<filename>/etc/depmod.d/</filename>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<option>-e</option>
</term>
<term>
<option>--errsyms</option>
</term>
<listitem>
<para>
When combined with the <option>-F</option> 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.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<option>-E</option>
</term>
<term>
<option>--symvers</option>
</term>
<listitem>
<para>
When combined with the <option>-e</option> option, this
reports any symbol versions supplied by modules that do
not match with the symbol versions provided by the
kernel in its <filename>Module.symvers</filename>.
This option is mutually incompatible with <option>-F</option>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<option>-F</option>
</term>
<term>
<option>--filesyms <replaceable>System.map</replaceable></option>
</term>
<listitem>
<para>
Supplied with the <filename>System.map</filename> produced when the
kernel was built, this allows the <option>-e</option> option to
report unresolved symbols. This option is mutually incompatible
with <option>-E</option>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<option>-h</option>
</term>
<term>
<option>--help</option>
</term>
<listitem>
<para>
Print the help message and exit.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<option>-n</option>
</term>
<term>
<option>--show</option>
</term>
<term>
<option>--dry-run</option>
</term>
<listitem>
<para>
This sends the resulting modules.dep and the various map files to
standard output rather than writing them into the module directory.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<option>-P</option>
</term>
<listitem>
<para>
Some architectures prefix symbols with an extraneous character.
This specifies a prefix character (for example '_') to ignore.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<option>-v</option>
</term>
<term>
<option>--verbose</option>
</term>
<listitem>
<para>
In verbose mode, <command>depmod</command> will print (to stdout)
all the symbols each module depends on and the module's file name
which provides that symbol.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<option>-V</option>
</term>
<term>
<option>--version</option>
</term>
<listitem>
<para>
Show version of program and exit. See below for caveats when
run on older kernels.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<option>-w</option>
</term>
<listitem>
<para>
Warn on duplicate dependencies, aliases, symbol versions, etc.
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1><title>COPYRIGHT</title>
<para>
This manual page originally Copyright 2002, Rusty Russell,
IBM Corporation. Portions Copyright Jon Masters, and others.
</para>
</refsect1>
<refsect1><title>SEE ALSO</title>
<para>
<citerefentry>
<refentrytitle>depmod.d</refentrytitle><manvolnum>5</manvolnum>
</citerefentry>,
<citerefentry>
<refentrytitle>modprobe</refentrytitle><manvolnum>8</manvolnum>
</citerefentry>,
<citerefentry>
<refentrytitle>modules.dep</refentrytitle><manvolnum>5</manvolnum>
</citerefentry>
</para>
</refsect1>
</refentry>