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1<?xml version='1.0'?>
2<!--*-nxml-*-->
3<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
4        "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
5<refentry id="depmod">
6  <refentryinfo>
7    <title>depmod</title>
8    <productname>kmod</productname>
9
10    <authorgroup>
11      <author>
12        <contrib>Developer</contrib>
13        <firstname>Jon</firstname>
14        <surname>Masters</surname>
15        <email>jcm@jonmasters.org</email>
16      </author>
17      <author>
18        <contrib>Developer</contrib>
19        <firstname>Robby</firstname>
20        <surname>Workman</surname>
21        <email>rworkman@slackware.com</email>
22      </author>
23      <author>
24        <contrib>Developer</contrib>
25        <firstname>Lucas</firstname>
26        <surname>De Marchi</surname>
27        <email>lucas.de.marchi@gmail.com</email>
28      </author>
29    </authorgroup>
30  </refentryinfo>
31
32  <refmeta>
33    <refentrytitle>depmod</refentrytitle>
34    <manvolnum>8</manvolnum>
35  </refmeta>
36
37  <refnamediv>
38    <refname>depmod</refname>
39    <refpurpose>
40      Generate <filename>modules.dep</filename> and map files.
41    </refpurpose>
42  </refnamediv>
43
44  <refsynopsisdiv>
45    <cmdsynopsis>
46      <command>depmod</command>
47      <arg><option>-b <replaceable>basedir</replaceable></option></arg>
48      <arg><option>-e</option></arg>
49      <arg><option>-E <replaceable>Module.symvers</replaceable></option></arg>
50      <arg><option>-F <replaceable>System.map</replaceable></option></arg>
51      <arg><option>-n</option></arg>
52      <arg><option>-v</option></arg>
53      <arg><option>-A</option></arg>
54      <arg><option>-P <replaceable>prefix</replaceable></option></arg>
55      <arg><option>-w</option></arg>
56      <arg><option><replaceable>version</replaceable></option></arg>
57    </cmdsynopsis>
58
59    <cmdsynopsis>
60      <command>depmod</command>
61      <arg><option>-e</option></arg>
62      <arg><option>-E <replaceable>Module.symvers</replaceable></option></arg>
63      <arg><option>-F <replaceable>System.map</replaceable></option></arg>
64      <arg><option>-m</option></arg>
65      <arg><option>-n</option></arg>
66      <arg><option>-v</option></arg>
67      <arg><option>-P <replaceable>prefix</replaceable></option></arg>
68      <arg><option>-w</option></arg>
69      <arg><option><replaceable>version</replaceable></option></arg>
70      <arg rep='repeat'><option><replaceable>filename</replaceable></option></arg>
71    </cmdsynopsis>
72  </refsynopsisdiv>
73
74  <refsect1><title>DESCRIPTION</title>
75    <para>
76      Linux kernel modules can provide services (called "symbols") for other
77      modules to use (using one of the EXPORT_SYMBOL variants in the code).  If
78      a second module uses this symbol, that second module clearly depends on
79      the first module.  These dependencies can get quite complex.
80    </para>
81    <para> <command>depmod</command> creates a list of module dependencies by
82      reading each module under
83      <filename>/lib/modules/</filename><replaceable>version</replaceable> and
84      determining what symbols it exports and what symbols it needs.  By
85      default, this list is written to <filename>modules.dep</filename>, and a
86      binary hashed version named <filename>modules.dep.bin</filename>, in the
87      same directory.  If filenames are given on the command line, only those
88      modules are examined (which is rarely useful unless all modules are
89      listed).  <command>depmod</command> also creates a list of symbols
90      provided by modules in the file named
91      <filename>modules.symbols</filename> and its binary hashed version,
92      <filename>modules.symbols.bin</filename>.  Finally,
93      <command>depmod</command> will output a file named
94      <filename>modules.devname</filename> if modules supply special device
95      names (devname) that should be populated in /dev on boot (by a utility
96      such as systemd-tmpfiles).
97    </para>
98    <para> If a <replaceable>version</replaceable> is provided, then that kernel
99      version's module directory is used rather than the current kernel version
100      (as returned by <command>uname -r</command>).
101    </para>
102  </refsect1>
103  <refsect1><title>OPTIONS</title>
104    <variablelist>
105      <varlistentry>
106        <term>
107          <option>-a</option>
108        </term>
109        <term>
110          <option>--all</option>
111        </term>
112        <listitem>
113          <para>
114            Probe all modules. This option is enabled by default if no
115            file names are given in the command-line.
116          </para>
117        </listitem>
118      </varlistentry>
119      <varlistentry>
120        <term>
121          <option>-A</option>
122        </term>
123        <term>
124          <option>--quick</option>
125        </term>
126        <listitem>
127          <para>
128            This option scans to see if any modules are newer than the
129            <filename>modules.dep</filename> file before any work is done:
130            if not, it silently exits rather than regenerating the files.
131          </para>
132        </listitem>
133      </varlistentry>
134      <varlistentry>
135        <term>
136          <option>-b <replaceable>basedir</replaceable></option>
137        </term>
138        <term>
139          <option>--basedir <replaceable>basedir</replaceable></option>
140        </term>
141        <listitem>
142          <para>
143            If your modules are not currently in the (normal) directory
144            <filename>/lib/modules/</filename><replaceable>version</replaceable>,
145            but in a staging area, you can specify a
146            <replaceable>basedir</replaceable> which is prepended to the
147            directory name.  This <replaceable>basedir</replaceable> is
148            stripped from the resulting <filename>modules.dep</filename> file,
149            so it is ready to be moved into the normal location. Use this
150            option if you are a distribution vendor who needs to pre-generate
151            the meta-data files rather than running depmod again later.
152          </para>
153        </listitem>
154      </varlistentry>
155      <varlistentry>
156        <term>
157          <option>-C</option>
158        </term>
159        <term>
160          <option>--config <replaceable>file or directory</replaceable></option>
161        </term>
162        <listitem>
163          <para>
164            This option overrides the default configuration directory at
165            <filename>/etc/depmod.d/</filename>.
166          </para>
167        </listitem>
168      </varlistentry>
169      <varlistentry>
170        <term>
171          <option>-e</option>
172        </term>
173        <term>
174          <option>--errsyms</option>
175        </term>
176        <listitem>
177          <para>
178            When combined with the <option>-F</option> option, this reports any
179            symbols which a module needs which are not supplied by other
180            modules or the kernel.  Normally, any symbols not provided by
181            modules are assumed to be provided by the kernel (which should be
182            true in a perfect world), but this assumption can break especially
183            when additionally updated third party drivers are not correctly
184            installed or were built incorrectly.
185          </para>
186        </listitem>
187      </varlistentry>
188      <varlistentry>
189        <term>
190          <option>-E</option>
191        </term>
192        <term>
193          <option>--symvers</option>
194        </term>
195          <listitem>
196            <para>
197              When combined with the <option>-e</option> option, this
198              reports any symbol versions supplied by modules that do
199              not match with the symbol versions provided by the
200              kernel in its <filename>Module.symvers</filename>.
201              This option is mutually incompatible with <option>-F</option>.
202            </para>
203          </listitem>
204      </varlistentry>
205      <varlistentry>
206        <term>
207          <option>-F</option>
208        </term>
209        <term>
210          <option>--filesyms <replaceable>System.map</replaceable></option>
211        </term>
212        <listitem>
213          <para>
214            Supplied with the <filename>System.map</filename> produced when the
215            kernel was built, this allows the <option>-e</option> option to
216            report unresolved symbols.  This option is mutually incompatible
217            with <option>-E</option>.
218          </para>
219        </listitem>
220      </varlistentry>
221      <varlistentry>
222        <term>
223          <option>-h</option>
224        </term>
225        <term>
226          <option>--help</option>
227        </term>
228        <listitem>
229          <para>
230            Print the help message and exit.
231          </para>
232        </listitem>
233      </varlistentry>
234      <varlistentry>
235        <term>
236          <option>-n</option>
237        </term>
238        <term>
239          <option>--show</option>
240        </term>
241        <term>
242          <option>--dry-run</option>
243        </term>
244        <listitem>
245          <para>
246            This sends the resulting modules.dep and the various map files to
247            standard output rather than writing them into the module directory.
248          </para>
249        </listitem>
250      </varlistentry>
251      <varlistentry>
252        <term>
253          <option>-P</option>
254        </term>
255        <listitem>
256          <para>
257            Some architectures prefix symbols with an extraneous character.
258            This specifies a prefix character (for example '_') to ignore.
259          </para>
260        </listitem>
261      </varlistentry>
262      <varlistentry>
263        <term>
264          <option>-v</option>
265        </term>
266        <term>
267          <option>--verbose</option>
268        </term>
269        <listitem>
270          <para>
271            In verbose mode, <command>depmod</command> will print (to stdout)
272            all the symbols each module depends on and the module's file name
273            which provides that symbol.
274          </para>
275        </listitem>
276      </varlistentry>
277      <varlistentry>
278        <term>
279          <option>-V</option>
280        </term>
281        <term>
282          <option>--version</option>
283        </term>
284        <listitem>
285          <para>
286            Show version of program and exit. See below for caveats when
287            run on older kernels.
288          </para>
289        </listitem>
290      </varlistentry>
291      <varlistentry>
292        <term>
293          <option>-w</option>
294        </term>
295        <listitem>
296          <para>
297            Warn on duplicate dependencies, aliases, symbol versions, etc.
298          </para>
299        </listitem>
300      </varlistentry>
301    </variablelist>
302  </refsect1>
303
304  <refsect1><title>COPYRIGHT</title>
305    <para>
306      This manual page originally Copyright 2002, Rusty Russell,
307      IBM Corporation. Portions Copyright Jon Masters, and others.
308    </para>
309  </refsect1>
310
311  <refsect1><title>SEE ALSO</title>
312    <para>
313      <citerefentry>
314        <refentrytitle>depmod.d</refentrytitle><manvolnum>5</manvolnum>
315      </citerefentry>,
316      <citerefentry>
317        <refentrytitle>modprobe</refentrytitle><manvolnum>8</manvolnum>
318      </citerefentry>,
319      <citerefentry>
320        <refentrytitle>modules.dep</refentrytitle><manvolnum>5</manvolnum>
321      </citerefentry>
322    </para>
323  </refsect1>
324</refentry>
325