source: chapter08/udev.xml@ 6be4bf1

xry111/loongarch xry111/loongarch-12.1 xry111/loongarch-12.2
Last change on this file since 6be4bf1 was 289f284, checked in by Xi Ruoyao <xry111@…>, 8 months ago

Merge remote-tracking branch 'origin/trunk' into xry111/loongarch

  • Property mode set to 100644
File size: 11.3 KB
Line 
1<?xml version="1.0" encoding="UTF-8"?>
2<!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
3 "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
4 <!ENTITY % general-entities SYSTEM "../general.ent">
5 %general-entities;
6]>
7
8<sect1 id="ch-system-udev" role="wrap" revision="sysv">
9 <?dbhtml filename="udev.html"?>
10
11 <sect1info condition="script">
12 <productname>udev</productname>
13 <productnumber>&systemd-version;</productnumber>
14 <address>&systemd-url;</address>
15 </sect1info>
16
17 <title>Udev from Systemd-&systemd-version;</title>
18
19 <indexterm zone="ch-system-udev">
20 <primary sortas="a-Udev">Udev</primary>
21 </indexterm>
22
23 <sect2 role="package">
24 <title/>
25
26 <para>The Udev package contains programs for dynamic creation of device
27 nodes.</para>
28
29 <segmentedlist>
30 <segtitle>&buildtime;</segtitle>
31 <segtitle>&diskspace;</segtitle>
32
33 <seglistitem>
34 <seg>&udev-fin-sbu;</seg>
35 <seg>&udev-fin-du;</seg>
36 </seglistitem>
37 </segmentedlist>
38 </sect2>
39
40 <sect2 role="installation">
41 <title>Installation of Udev</title>
42
43 <para>Udev is part of the systemd-&systemd-version; package. Use
44 the systemd-&systemd-version;.tar.xz file as the source tarball.</para>
45
46 <para>Remove two unneeded groups,
47 <systemitem class="groupname">render</systemitem> and
48 <systemitem class="groupname">sgx</systemitem>, from the default udev
49 rules:</para>
50
51 <screen><userinput remap="pre">sed -i -e 's/GROUP="render"/GROUP="video"/' \
52 -e 's/GROUP="sgx", //' rules.d/50-udev-default.rules.in</userinput></screen>
53
54 <para>Remove one udev rule requiring a full Systemd installation:</para>
55
56 <screen><userinput remap="pre">sed '/systemd-sysctl/s/^/#/' -i rules.d/99-systemd.rules.in</userinput></screen>
57
58 <para>Adjust the hardcoded paths to network configuration files for the
59 standalone udev installation:</para>
60
61 <screen><userinput remap="pre">sed '/NETWORK_DIRS/s/systemd/udev/' -i src/basic/path-lookup.h</userinput></screen>
62
63 <para>Prepare Udev for compilation:</para>
64
65<screen><userinput remap="configure">mkdir -p build
66cd build
67
68CFLAGS+=" -Wno-format-overflow" \
69meson setup \
70 --prefix=/usr \
71 --buildtype=release \
72 -Dmode=release \
73 -Ddev-kvm-mode=0660 \
74 -Dlink-udev-shared=false \
75 -Dlogind=false \
76 -Dvconsole=false \
77 ..</userinput></screen>
78
79 <variablelist>
80 <title>The meaning of the meson options:</title>
81
82 <varlistentry>
83 <term><parameter>--buildtype=release</parameter></term>
84 <listitem>
85 <para>This switch overrides the default buildtype
86 (<quote>debug</quote>), which produces unoptimized
87 binaries.</para>
88 </listitem>
89 </varlistentry>
90
91 <varlistentry>
92 <term><parameter>-Dmode=release</parameter></term>
93 <listitem>
94 <para>Disable some features considered experimental by upstream.
95 </para>
96 </listitem>
97 </varlistentry>
98
99 <varlistentry>
100 <term><parameter>-Ddev-kvm-mode=0660</parameter></term>
101 <listitem>
102 <para>The default udev rule would allow all users to access
103 <filename class='devicefile'>/dev/kvm</filename>. The editors
104 consider it dangerous. This option overrides it.</para>
105 </listitem>
106 </varlistentry>
107
108 <varlistentry>
109 <term><parameter>-Dlink-udev-shared=false</parameter></term>
110 <listitem>
111 <para>This option prevents udev from linking to the internal
112 systemd shared library,
113 <systemitem class='library'>libsystemd-shared</systemitem>.
114 This library is designed to be shared by many Systemd components
115 and it's too overkill for a udev-only installation.</para>
116 </listitem>
117 </varlistentry>
118
119 <varlistentry>
120 <term><parameter>-Dlogind=false -Dvconsole=false</parameter></term>
121 <listitem>
122 <para>These options prevent the generation of several udev rule
123 files belonging to the other Systemd components that we won't
124 install.</para>
125 </listitem>
126 </varlistentry>
127 </variablelist>
128
129 <para>Get the list of the shipped udev helpers and save it into an
130 environment variable (exporting it is not strictly necessary, but it makes
131 building as a regular user or using a package manager easier):</para>
132
133 <screen><userinput remap="make">export udev_helpers=$(grep "'name' :" ../src/udev/meson.build | \
134 awk '{print $3}' | tr -d ",'" | grep -v 'udevadm')</userinput></screen>
135
136 <para>Only build the components needed for udev:</para>
137
138 <screen><userinput remap="make">ninja udevadm systemd-hwdb \
139 $(ninja -n | grep -Eo '(src/(lib)?udev|rules.d|hwdb.d)/[^ ]*') \
140 $(realpath libudev.so --relative-to .) \
141 $udev_helpers</userinput></screen>
142
143 <para>Install the package:</para>
144
145 <screen><userinput remap="install">install -vm755 -d {/usr/lib,/etc}/udev/{hwdb.d,rules.d,network}
146install -vm755 -d /usr/{lib,share}/pkgconfig
147install -vm755 udevadm /usr/bin/
148install -vm755 systemd-hwdb /usr/bin/udev-hwdb
149ln -svfn ../bin/udevadm /usr/sbin/udevd
150cp -av libudev.so{,*[0-9]} /usr/lib/
151install -vm644 ../src/libudev/libudev.h /usr/include/
152install -vm644 src/libudev/*.pc /usr/lib/pkgconfig/
153install -vm644 src/udev/*.pc /usr/share/pkgconfig/
154install -vm644 ../src/udev/udev.conf /etc/udev/
155install -vm644 rules.d/* ../rules.d/README /usr/lib/udev/rules.d/
156install -vm644 $(find ../rules.d/*.rules \
157 -not -name '*power-switch*') /usr/lib/udev/rules.d/
158install -vm644 hwdb.d/* ../hwdb.d/{*.hwdb,README} /usr/lib/udev/hwdb.d/
159install -vm755 $udev_helpers /usr/lib/udev
160install -vm644 ../network/99-default.link /usr/lib/udev/network</userinput></screen>
161
162 <para>Install some custom rules and support files useful in an LFS
163 environment:</para>
164
165<screen><userinput remap="install">tar -xvf ../../&udev-lfs-version;.tar.xz
166make -f &udev-lfs-version;/Makefile.lfs install</userinput></screen>
167
168 <para>Install the man pages:</para>
169
170 <!-- Please make sure systemd man pages tarball has a common leading
171 component in the path. -->
172<screen><userinput remap="install">tar -xf ../../systemd-man-pages-&systemd-man-version;.tar.xz \
173 --no-same-owner --strip-components=1 \
174 -C /usr/share/man --wildcards '*/udev*' '*/libudev*' \
175 '*/systemd.link.5' \
176 '*/systemd-'{hwdb,udevd.service}.8
177
178sed 's|systemd/network|udev/network|' \
179 /usr/share/man/man5/systemd.link.5 \
180 > /usr/share/man/man5/udev.link.5
181
182sed 's/systemd\(\\\?-\)/udev\1/' /usr/share/man/man8/systemd-hwdb.8 \
183 > /usr/share/man/man8/udev-hwdb.8
184
185sed 's|lib.*udevd|sbin/udevd|' \
186 /usr/share/man/man8/systemd-udevd.service.8 \
187 > /usr/share/man/man8/udevd.8
188
189rm /usr/share/man/man*/systemd*</userinput></screen>
190
191 <para>Finally, unset the <envar>udev_helpers</envar> variable:</para>
192
193 <!-- remap="make" seems confusing but we don't have sth. like
194 remap="clean". -->
195 <screen><userinput remap="install">unset udev_helpers</userinput></screen>
196
197 </sect2>
198
199 <sect2 id="conf-udev" role="configuration">
200 <title>Configuring Udev</title>
201
202 <indexterm zone="conf-udev">
203 <primary sortas="a-Udev">Udev</primary>
204 <secondary>configuring</secondary>
205 </indexterm>
206
207 <indexterm zone="conf-udev">
208 <primary sortas="e-/etc/udev/hwdb.bin">/etc/udev/hwdb.bin</primary>
209 </indexterm>
210
211 <para>Information about hardware devices is maintained in the
212 <filename class="directory">/etc/udev/hwdb.d</filename> and
213 <filename class="directory">/usr/lib/udev/hwdb.d</filename> directories.
214 <application>Udev</application> needs that information to be compiled
215 into a binary database <filename>/etc/udev/hwdb.bin</filename>. Create the
216 initial database:</para>
217
218<screen><userinput>udev-hwdb update</userinput></screen>
219
220 <para>This command needs to be run each time the hardware information is
221 updated.</para>
222
223 </sect2>
224
225 <sect2 id="contents-udev" role="content">
226 <title>Contents of Udev</title>
227
228 <segmentedlist>
229 <segtitle>Installed programs</segtitle>
230 <segtitle>Installed libraries</segtitle>
231 <segtitle>Installed directories</segtitle>
232
233 <seglistitem>
234 <seg>udevadm, udevd (symlink to udevadm), and udev-hwdb</seg>
235
236 <seg>libudev.so</seg>
237
238 <seg>/etc/udev and /usr/lib/udev</seg>
239 </seglistitem>
240 </segmentedlist>
241
242 <variablelist>
243 <bridgehead renderas="sect3">Short Descriptions</bridgehead>
244 <?dbfo list-presentation="list"?>
245 <?dbhtml list-presentation="table"?>
246 <varlistentry id="udevadm" revision="sysv">
247 <term><command>udevadm</command></term>
248 <listitem>
249 <para>Generic udev administration tool: controls the udevd daemon,
250 provides info from the Udev database, monitors uevents, waits for
251 uevents to finish, tests Udev configuration, and triggers uevents
252 for a given device</para>
253 <indexterm zone="ch-system-udev udevadm">
254 <primary sortas="b-udevadm">udevadm</primary>
255 </indexterm>
256 </listitem>
257 </varlistentry>
258
259 <varlistentry id="udevd">
260 <term><command>udevd</command></term>
261 <listitem>
262 <para>A daemon that listens for uevents on the netlink socket,
263 creates devices and runs the configured external programs in
264 response to these uevents</para>
265 <indexterm zone="ch-system-udev udevd">
266 <primary sortas="b-udevd">udevd</primary>
267 </indexterm>
268 </listitem>
269 </varlistentry>
270
271 <varlistentry id="udev-hwdb">
272 <term><command>udev-hwdb</command></term>
273 <listitem>
274 <para>Updates or queries the hardware database.</para>
275 <indexterm zone="ch-system-udev udev-hwdb">
276 <primary sortas="b-udev-hwdb">udev-hwdb</primary>
277 </indexterm>
278 </listitem>
279 </varlistentry>
280
281 <varlistentry id="libudev">
282 <term><filename class="libraryfile">libudev</filename></term>
283 <listitem>
284 <para>A library interface to udev device information</para>
285 <indexterm zone="ch-system-udev libudev">
286 <primary sortas="c-libudev">libudev</primary>
287 </indexterm>
288 </listitem>
289 </varlistentry>
290
291 <varlistentry id="etc-udev">
292 <term><filename class="directory">/etc/udev</filename></term>
293 <listitem>
294 <para>Contains Udev configuration files,
295 device permissions, and rules for device naming</para>
296 <indexterm zone="ch-system-udev etc-udev">
297 <primary sortas="e-/etc/udev">/etc/udev</primary>
298 </indexterm>
299 </listitem>
300 </varlistentry>
301
302 </variablelist>
303
304 </sect2>
305
306</sect1>
Note: See TracBrowser for help on using the repository browser.