source: chapter08/kernel.xml@ 28b40e2

Last change on this file since 28b40e2 was 28b40e2, checked in by Manuel Canales Esparcia <manuel@…>, 18 years ago

Finished the PDF fixes.

git-svn-id: http://svn.linuxfromscratch.org/LFS/branches/6.2/BOOK@7737 4aa44e1e-78dd-0310-a6d2-fbcd4c07a689

  • Property mode set to 100644
File size: 8.9 KB
Line 
1<?xml version="1.0" encoding="ISO-8859-1"?>
2<!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.4//EN"
3 "http://www.oasis-open.org/docbook/xml/4.4/docbookx.dtd" [
4 <!ENTITY % general-entities SYSTEM "../general.ent">
5 %general-entities;
6]>
7
8<sect1 id="ch-bootable-kernel" role="wrap">
9 <?dbhtml filename="kernel.html"?>
10
11 <title>Linux-&linux-version;</title>
12
13 <indexterm zone="ch-bootable-kernel">
14 <primary sortas="a-Linux">Linux</primary>
15 </indexterm>
16
17 <sect2 role="package">
18 <title/>
19
20 <para>The Linux package contains the Linux kernel.</para>
21
22 <segmentedlist>
23 <segtitle>&buildtime;</segtitle>
24 <segtitle>&diskspace;</segtitle>
25
26 <seglistitem>
27 <seg>&linux-ch8-sbu;</seg>
28 <seg>&linux-ch8-du;</seg>
29 </seglistitem>
30 </segmentedlist>
31
32 </sect2>
33
34 <sect2 role="installation">
35 <title>Installation of the kernel</title>
36
37 <para>Building the kernel involves a few steps&mdash;configuration,
38 compilation, and installation. Read the <filename>README</filename> file
39 in the kernel source tree for alternative methods to the way this book
40 configures the kernel.</para>
41
42 <para>By default, the Linux kernel generates wrong sequences of bytes when
43 dead keys are used in UTF-8 keyboard mode. Also, one cannot copy and paste
44 non-ASCII characters when UTF-8 mode is active. Fix these issues with the
45 patch:</para>
46
47<screen><userinput>patch -Np1 -i ../&linux-utf8-patch;</userinput></screen>
48
49 <para>Prepare for compilation by running the following command:</para>
50
51<screen><userinput>make mrproper</userinput></screen>
52
53 <para>This ensures that the kernel tree is absolutely clean. The
54 kernel team recommends that this command be issued prior to each
55 kernel compilation. Do not rely on the source tree being clean after
56 un-tarring.</para>
57
58 <!-- Support for compiling a keymap into the kernel is deliberately removed -->
59
60 <para>Configure the kernel via a menu-driven interface. BLFS has some
61 information regarding particular kernel configuration requirements of
62 packages outside of LFS at <ulink
63 url="&blfs-root;view/svn/longindex.html#kernel-config-index"/>:</para>
64
65<screen role="nodump"><userinput>make menuconfig</userinput></screen>
66
67 <para>Alternatively, <command>make oldconfig</command> may be more
68 appropriate in some situations. See the <filename>README</filename>
69 file for more information.</para>
70
71 <para>If desired, skip kernel configuration by copying the kernel
72 config file, <filename>.config</filename>, from the host system
73 (assuming it is available) to the unpacked <filename
74 class="directory">linux-&linux-version;</filename> directory. However,
75 we do not recommend this option. It is often better to explore all the
76 configuration menus and create the kernel configuration from
77 scratch.</para>
78
79 <para>Compile the kernel image and modules:</para>
80
81<screen><userinput>make</userinput></screen>
82
83 <para>If using kernel modules, an <filename>/etc/modprobe.conf</filename>
84 file may be needed. Information pertaining to modules and kernel
85 configuration is located in <xref linkend="ch-scripts-udev"/> and in the
86 kernel documentation in the <filename
87 class="directory">linux-&linux-version;/Documentation</filename> directory.
88 Also, <filename>modprobe.conf(5)</filename> may be of interest.</para>
89
90 <para>Install the modules, if the kernel configuration uses them:</para>
91
92<screen><userinput>make modules_install</userinput></screen>
93
94 <beginpage/>
95
96 <para>After kernel compilation is complete, additional steps are
97 required to complete the installation. Some files need to be copied to
98 the <filename class="directory">/boot</filename> directory.</para>
99
100 <para>The path to the kernel image may vary depending on the platform
101 being used. The following command assumes an x86 architecture:</para>
102
103<screen><userinput>cp -v arch/i386/boot/bzImage /boot/lfskernel-&linux-version;</userinput></screen>
104
105 <para><filename>System.map</filename> is a symbol file for the kernel.
106 It maps the function entry points of every function in the kernel API,
107 as well as the addresses of the kernel data structures for the running
108 kernel. Issue the following command to install the map file:</para>
109
110<screen><userinput>cp -v System.map /boot/System.map-&linux-version;</userinput></screen>
111
112 <para>The kernel configuration file <filename>.config</filename>
113 produced by the <command>make menuconfig</command> step
114 above contains all the configuration selections for the kernel
115 that was just compiled. It is a good idea to keep this file for future
116 reference:</para>
117
118<screen><userinput>cp -v .config /boot/config-&linux-version;</userinput></screen>
119
120 <para>Install the documentation for the Linux kernel:</para>
121
122<screen><userinput>install -d /usr/share/doc/linux-&linux-version; &amp;&amp;
123cp -r Documentation/* /usr/share/doc/linux-&linux-version;</userinput></screen>
124
125 <para>It is important to note that the files in the kernel source
126 directory are not owned by <emphasis>root</emphasis>. Whenever a
127 package is unpacked as user <emphasis>root</emphasis> (like we did
128 inside chroot), the files have the user and group IDs of whatever
129 they were on the packager's computer. This is usually not a problem
130 for any other package to be installed because the source tree is
131 removed after the installation. However, the Linux source tree is
132 often retained for a long time. Because of this, there is a chance
133 that whatever user ID the packager used will be assigned to somebody
134 on the machine. That person would then have write access to the kernel
135 source.</para>
136
137 <para>If the kernel source tree is going to be retained, run
138 <command>chown -R 0:0</command> on the <filename
139 class="directory">linux-&linux-version;</filename> directory to ensure
140 all files are owned by user <emphasis>root</emphasis>.</para>
141
142 <warning>
143 <para>Some kernel documentation recommends creating a symlink from
144 <filename class="symlink">/usr/src/linux</filename> pointing to the kernel
145 source directory. This is specific to kernels prior to the 2.6 series and
146 <emphasis>must not</emphasis> be created on an LFS system as it can cause
147 problems for packages you may wish to build once your base LFS system is
148 complete.</para>
149
150 <para>Also, the headers in the system's
151 <filename class="directory">include</filename> directory should
152 <emphasis>always</emphasis> be the ones against which Glibc was compiled,
153 that is, the ones from the Linux-Libc-Headers package, and therefore, should
154 <emphasis>never</emphasis> be replaced by the kernel headers.</para>
155 </warning>
156
157 <beginpage/>
158
159 </sect2>
160
161 <sect2 id="contents-kernel" role="content">
162 <title>Contents of Linux</title>
163
164 <segmentedlist>
165 <segtitle>Installed files</segtitle>
166
167 <seglistitem>
168 <seg>config-&linux-version;, lfskernel-&linux-version;, and
169 System.map-&linux-version;</seg>
170 </seglistitem>
171 </segmentedlist>
172
173 <variablelist>
174 <bridgehead renderas="sect3">Short Descriptions</bridgehead>
175 <?dbfo list-presentation="list"?>
176 <?dbhtml list-presentation="table"?>
177
178 <varlistentry id="config">
179 <term><filename>config-&linux-version;</filename></term>
180 <listitem>
181 <para>Contains all the configuration selections for the kernel</para>
182 <indexterm zone="ch-bootable-kernel config">
183 <primary sortas="e-/boot/config">/boot/config-&linux-version;</primary>
184 </indexterm>
185 </listitem>
186 </varlistentry>
187
188 <varlistentry id="lfskernel">
189 <term><filename>lfskernel-&linux-version;</filename></term>
190 <listitem>
191 <para>The engine of the Linux system. When turning on the computer,
192 the kernel is the first part of the operating system that gets loaded.
193 It detects and initializes all components of the computer's hardware,
194 then makes these components available as a tree of files to the
195 software and turns a single CPU into a multitasking machine capable
196 of running scores of programs seemingly at the same time</para>
197 <indexterm zone="ch-bootable-kernel lfskernel">
198 <primary sortas="b-lfskernel">lfskernel-&linux-version;</primary>
199 </indexterm>
200 </listitem>
201 </varlistentry>
202
203 <varlistentry id="System.map">
204 <term><filename>System.map-&linux-version;</filename></term>
205 <listitem>
206 <para>A list of addresses and symbols; it maps the entry points and
207 addresses of all the functions and data structures in the
208 kernel</para>
209 <indexterm zone="ch-bootable-kernel System.map">
210 <primary sortas="e-/boot/System.map">/boot/System.map-&linux-version;</primary>
211 </indexterm>
212 </listitem>
213 </varlistentry>
214
215 </variablelist>
216
217 </sect2>
218
219</sect1>
Note: See TracBrowser for help on using the repository browser.