'\" t
.\"     Title: depmod
.\"    Author: Jon Masters <jcm@jonmasters.org>
.\" Generator: DocBook XSL Stylesheets vsnapshot <http://docbook.sf.net/>
.\"      Date: 01/29/2021
.\"    Manual: depmod
.\"    Source: kmod
.\"  Language: English
.\"
.TH "DEPMOD" "8" "01/29/2021" "kmod" "depmod"
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.SH "NAME"
depmod \- Generate modules\&.dep and map files\&.
.SH "SYNOPSIS"
.HP \w'\fBdepmod\fR\ 'u
\fBdepmod\fR [\fB\-b\ \fR\fB\fIbasedir\fR\fR] [\fB\-e\fR] [\fB\-E\ \fR\fB\fIModule\&.symvers\fR\fR] [\fB\-F\ \fR\fB\fISystem\&.map\fR\fR] [\fB\-n\fR] [\fB\-v\fR] [\fB\-A\fR] [\fB\-P\ \fR\fB\fIprefix\fR\fR] [\fB\-w\fR] [\fB\fIversion\fR\fR]
.HP \w'\fBdepmod\fR\ 'u
\fBdepmod\fR [\fB\-e\fR] [\fB\-E\ \fR\fB\fIModule\&.symvers\fR\fR] [\fB\-F\ \fR\fB\fISystem\&.map\fR\fR] [\fB\-n\fR] [\fB\-v\fR] [\fB\-P\ \fR\fB\fIprefix\fR\fR] [\fB\-w\fR] [\fB\fIversion\fR\fR] [\fB\fIfilename\fR\fR...]
.SH "DESCRIPTION"
.PP
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\&.
.PP
\fBdepmod\fR
creates a list of module dependencies by reading each module under
/lib/modules/\fIversion\fR
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)\&.
\fBdepmod\fR
also creates a list of symbols provided by modules in the file named
modules\&.symbols
and its binary hashed version,
modules\&.symbols\&.bin\&. Finally,
\fBdepmod\fR
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)\&.
.PP
If a
\fIversion\fR
is provided, then that kernel version\*(Aqs module directory is used rather than the current kernel version (as returned by
\fBuname \-r\fR)\&.
.SH "OPTIONS"
.PP
\fB\-a\fR, \fB\-\-all\fR
.RS 4
Probe all modules\&. This option is enabled by default if no file names are given in the command\-line\&.
.RE
.PP
\fB\-A\fR, \fB\-\-quick\fR
.RS 4
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\&.
.RE
.PP
\fB\-b \fR\fB\fIbasedir\fR\fR, \fB\-\-basedir \fR\fB\fIbasedir\fR\fR
.RS 4
If your modules are not currently in the (normal) directory
/lib/modules/\fIversion\fR, but in a staging area, you can specify a
\fIbasedir\fR
which is prepended to the directory name\&. This
\fIbasedir\fR
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\&.
.RE
.PP
\fB\-C\fR, \fB\-\-config \fR\fB\fIfile or directory\fR\fR
.RS 4
This option overrides the default configuration directory at
/etc/depmod\&.d/\&.
.RE
.PP
\fB\-e\fR, \fB\-\-errsyms\fR
.RS 4
When combined with the
\fB\-F\fR
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\&.
.RE
.PP
\fB\-E\fR, \fB\-\-symvers\fR
.RS 4
When combined with the
\fB\-e\fR
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
\fB\-F\fR\&.
.RE
.PP
\fB\-F\fR, \fB\-\-filesyms \fR\fB\fISystem\&.map\fR\fR
.RS 4
Supplied with the
System\&.map
produced when the kernel was built, this allows the
\fB\-e\fR
option to report unresolved symbols\&. This option is mutually incompatible with
\fB\-E\fR\&.
.RE
.PP
\fB\-h\fR, \fB\-\-help\fR
.RS 4
Print the help message and exit\&.
.RE
.PP
\fB\-n\fR, \fB\-\-show\fR, \fB\-\-dry\-run\fR
.RS 4
This sends the resulting modules\&.dep and the various map files to standard output rather than writing them into the module directory\&.
.RE
.PP
\fB\-P\fR
.RS 4
Some architectures prefix symbols with an extraneous character\&. This specifies a prefix character (for example \*(Aq_\*(Aq) to ignore\&.
.RE
.PP
\fB\-v\fR, \fB\-\-verbose\fR
.RS 4
In verbose mode,
\fBdepmod\fR
will print (to stdout) all the symbols each module depends on and the module\*(Aqs file name which provides that symbol\&.
.RE
.PP
\fB\-V\fR, \fB\-\-version\fR
.RS 4
Show version of program and exit\&. See below for caveats when run on older kernels\&.
.RE
.PP
\fB\-w\fR
.RS 4
Warn on duplicate dependencies, aliases, symbol versions, etc\&.
.RE
.SH "COPYRIGHT"
.PP
This manual page originally Copyright 2002, Rusty Russell, IBM Corporation\&. Portions Copyright Jon Masters, and others\&.
.SH "SEE ALSO"
.PP
\fBdepmod.d\fR(5),
\fBmodprobe\fR(8),
\fBmodules.dep\fR(5)
.SH "AUTHORS"
.PP
\fBJon Masters\fR <\&jcm@jonmasters\&.org\&>
.RS 4
Developer
.RE
.PP
\fBRobby Workman\fR <\&rworkman@slackware\&.com\&>
.RS 4
Developer
.RE
.PP
\fBLucas De Marchi\fR <\&lucas\&.de\&.marchi@gmail\&.com\&>
.RS 4
Developer
.RE