xref: /aosp_15_r20/external/kmod/man/depmod.8.xml (revision cc4ad7da8cefe208cb129ac2aa9a357c7c72deb2)
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>[email protected]</email>
16      </author>
17      <author>
18        <contrib>Developer</contrib>
19        <firstname>Robby</firstname>
20        <surname>Workman</surname>
21        <email>[email protected]</email>
22      </author>
23      <author>
24        <contrib>Developer</contrib>
25        <firstname>Lucas</firstname>
26        <surname>De Marchi</surname>
27        <email>[email protected]</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>-o <replaceable>outdir</replaceable></option></arg>
49      <arg><option>-e</option></arg>
50      <arg><option>-E <replaceable>Module.symvers</replaceable></option></arg>
51      <arg><option>-F <replaceable>System.map</replaceable></option></arg>
52      <arg><option>-n</option></arg>
53      <arg><option>-v</option></arg>
54      <arg><option>-A</option></arg>
55      <arg><option>-P <replaceable>prefix</replaceable></option></arg>
56      <arg><option>-w</option></arg>
57      <arg><option><replaceable>version</replaceable></option></arg>
58    </cmdsynopsis>
59
60    <cmdsynopsis>
61      <command>depmod</command>
62      <arg><option>-e</option></arg>
63      <arg><option>-E <replaceable>Module.symvers</replaceable></option></arg>
64      <arg><option>-F <replaceable>System.map</replaceable></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>@MODULE_DIRECTORY@/</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>@MODULE_DIRECTORY@/</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>-o <replaceable>outdir</replaceable></option>
158        </term>
159        <term>
160          <option>--outdir <replaceable>outdir</replaceable></option>
161        </term>
162        <listitem>
163          <para>
164            Set the output directory where depmod will store any generated file.
165            <replaceable>outdir</replaceable> serves as a root to that location,
166            similar to how <replaceable>basedir</replaceable> is used. Also this
167            setting takes precedence and if used together with
168            <replaceable>basedir</replaceable> it will result in the input being
169            that directory, but the output being the one set by
170            <replaceable>outdir</replaceable>.
171          </para>
172        </listitem>
173      </varlistentry>
174      <varlistentry>
175        <term>
176          <option>-C</option>
177        </term>
178        <term>
179          <option>--config <replaceable>file or directory</replaceable></option>
180        </term>
181        <listitem>
182          <para>
183            This option overrides the default configuration directory at
184            <filename>/etc/depmod.d/</filename>.
185          </para>
186        </listitem>
187      </varlistentry>
188      <varlistentry>
189        <term>
190          <option>-e</option>
191        </term>
192        <term>
193          <option>--errsyms</option>
194        </term>
195        <listitem>
196          <para>
197            When combined with the <option>-F</option> option, this reports any
198            symbols which a module needs which are not supplied by other
199            modules or the kernel.  Normally, any symbols not provided by
200            modules are assumed to be provided by the kernel (which should be
201            true in a perfect world), but this assumption can break especially
202            when additionally updated third party drivers are not correctly
203            installed or were built incorrectly.
204          </para>
205        </listitem>
206      </varlistentry>
207      <varlistentry>
208        <term>
209          <option>-E</option>
210        </term>
211        <term>
212          <option>--symvers</option>
213        </term>
214          <listitem>
215            <para>
216              When combined with the <option>-e</option> option, this
217              reports any symbol versions supplied by modules that do
218              not match with the symbol versions provided by the
219              kernel in its <filename>Module.symvers</filename>.
220              This option is mutually incompatible with <option>-F</option>.
221            </para>
222          </listitem>
223      </varlistentry>
224      <varlistentry>
225        <term>
226          <option>-F</option>
227        </term>
228        <term>
229          <option>--filesyms <replaceable>System.map</replaceable></option>
230        </term>
231        <listitem>
232          <para>
233            Supplied with the <filename>System.map</filename> produced when the
234            kernel was built, this allows the <option>-e</option> option to
235            report unresolved symbols.  This option is mutually incompatible
236            with <option>-E</option>.
237          </para>
238        </listitem>
239      </varlistentry>
240      <varlistentry>
241        <term>
242          <option>-h</option>
243        </term>
244        <term>
245          <option>--help</option>
246        </term>
247        <listitem>
248          <para>
249            Print the help message and exit.
250          </para>
251        </listitem>
252      </varlistentry>
253      <varlistentry>
254        <term>
255          <option>-n</option>
256        </term>
257        <term>
258          <option>--show</option>
259        </term>
260        <term>
261          <option>--dry-run</option>
262        </term>
263        <listitem>
264          <para>
265            This sends the resulting modules.dep and the various map files to
266            standard output rather than writing them into the module directory.
267          </para>
268        </listitem>
269      </varlistentry>
270      <varlistentry>
271        <term>
272          <option>-P</option>
273        </term>
274        <listitem>
275          <para>
276            Some architectures prefix symbols with an extraneous character.
277            This specifies a prefix character (for example '_') to ignore.
278          </para>
279        </listitem>
280      </varlistentry>
281      <varlistentry>
282        <term>
283          <option>-v</option>
284        </term>
285        <term>
286          <option>--verbose</option>
287        </term>
288        <listitem>
289          <para>
290            In verbose mode, <command>depmod</command> will print (to stdout)
291            all the symbols each module depends on and the module's file name
292            which provides that symbol.
293          </para>
294        </listitem>
295      </varlistentry>
296      <varlistentry>
297        <term>
298          <option>-V</option>
299        </term>
300        <term>
301          <option>--version</option>
302        </term>
303        <listitem>
304          <para>
305            Show version of program and exit. See below for caveats when
306            run on older kernels.
307          </para>
308        </listitem>
309      </varlistentry>
310      <varlistentry>
311        <term>
312          <option>-w</option>
313        </term>
314        <listitem>
315          <para>
316            Warn on duplicate dependencies, aliases, symbol versions, etc.
317          </para>
318        </listitem>
319      </varlistentry>
320    </variablelist>
321  </refsect1>
322
323  <refsect1><title>COPYRIGHT</title>
324    <para>
325      This manual page originally Copyright 2002, Rusty Russell,
326      IBM Corporation. Portions Copyright Jon Masters, and others.
327    </para>
328  </refsect1>
329
330  <refsect1><title>SEE ALSO</title>
331    <para>
332      <citerefentry>
333        <refentrytitle>depmod.d</refentrytitle><manvolnum>5</manvolnum>
334      </citerefentry>,
335      <citerefentry>
336        <refentrytitle>modprobe</refentrytitle><manvolnum>8</manvolnum>
337      </citerefentry>,
338      <citerefentry>
339        <refentrytitle>modules.dep</refentrytitle><manvolnum>5</manvolnum>
340      </citerefentry>
341    </para>
342  </refsect1>
343</refentry>
344