source: bootable/x86/kernel.xml @ 2d5272d

Last change on this file since 2d5272d was 2d5272d, checked in by Jim Gifford <clfs@…>, 17 years ago

r2916@server (orig r1394): chris | 2006-04-17 01:08:22 -0700
Missed a couple references to the sun disklabel patches.

  • Property mode set to 100644
File size: 10.0 KB
1<?xml version="1.0" encoding="ISO-8859-1"?>
2<!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.4//EN"
3  "" [
4  <!ENTITY % general-entities SYSTEM "../../general.ent">
5  %general-entities;
8<sect1 id="ch-bootable-kernel" role="wrap">
9  <?dbhtml filename="kernel.html"?>
11  <title>Linux-&linux-version;</title>
13  <indexterm zone="ch-bootable-kernel">
14    <primary sortas="a-Linux">Linux</primary>
15  </indexterm>
17  <sect2 role="package"><title/>
18    <para>The Linux package contains the Linux kernel.</para>
20    <segmentedlist>
21      <segtitle>&dependencies;</segtitle>
23      <seglistitem>
24        <seg>Bash, Binutils, Coreutils, Findutils, GCC, Glibc, Grep,
25        Gzip, Kbd, Make, Module-Init-Tools, Perl, and Sed</seg>
26      </seglistitem>
27    </segmentedlist>
29  </sect2>
31  <sect2 role="installation">
32    <title>Installation of the kernel</title>
34    <para os="p1">Util-linux does not compute the checksum of a sun disklabel
35    properly with gcc-&gcc-version;. The following patch fixes this issue:</para>
37<screen os="p2"><userinput>patch -Np1 -i ../&linux-sun_disklabel_fix-patch;</userinput></screen>
39    <para os="a">Building the kernel involves a few steps&mdash;configuration,
40    compilation, and installation. Read the <filename>README</filename>
41    file in the kernel source tree for alternative methods to the way this
42    book configures the kernel.</para>
44    <para os="b">Prepare for compilation by running the following command:</para>
46<screen os="c"><userinput>make mrproper</userinput></screen>
48    <para os="d">This ensures that the kernel tree is absolutely clean. The
49    kernel team recommends that this command be issued prior to each
50    kernel compilation. Do not rely on the source tree being clean after
51    un-tarring.</para>
53    <para os="e">If, in <xref linkend="ch-scripts-console" role=","/> it was
54    decided to compile the keymap into the kernel, issue the command
55    below:</para>
57<screen os="f"><userinput>loadkeys -m /usr/share/kbd/keymaps/<replaceable>[path to  keymap]</replaceable> &gt; \
58    drivers/char/defkeymap.c</userinput></screen>
60    <para os="g">For example, if using a Dutch keyboard, use
61    <filename>/usr/share/kbd/keymaps/i386/qwerty/</filename>.</para>
63    <para os="h">Configure the kernel via a menu-driven interface.
64    Please note that the udev bootscript requires "rtc" and "tmpfs" to be
65    enabled and built into the kernel, not as modules. BLFS has
66    some information regarding particular kernel configuration requirements of
67    packages outside of LFS at <ulink
68    url="&blfs-root;view/svn/longindex.html#kernel-config-index"/>:</para>
70<screen os="i"><userinput>make menuconfig</userinput></screen>
72    <para os="j">Alternatively, <command>make oldconfig</command> may be more
73    appropriate in some situations. See the <filename>README</filename>
74    file for more information.</para>
76    <para os="k">If desired, skip kernel configuration by copying the kernel
77    config file, <filename>.config</filename>, from the host system
78    (assuming it is available) to the root directory of the unpacked kernel
79    sources. However, we do not recommend this option. It is often better
80    to explore all the configuration menus and create the kernel configuration
81    from scratch.</para>
83    <para os="m">Compile the kernel image and modules:</para>
85<screen os="n"><userinput>make</userinput></screen>
87    <para os="o">If using kernel modules, an
88    <filename>/etc/modprobe.conf</filename> file may be needed.
89    Information pertaining to modules and kernel configuration is
90    located in the kernel documentation in the <filename
91    class="directory">Documentation</filename> directory of the kernel
92    sources tree. Also, <filename>modprobe.conf(5)</filename> may
93    be of interest.</para>
95    <para os="p">Be very careful when reading other documentation relating to
96    kernel modules because it usually applies to 2.4.x kernels only. As
97    far as we know, kernel configuration issues specific to Hotplug and
98    Udev are not documented. The problem is that Udev will create a device
99    node only if Hotplug or a user-written script inserts the corresponding
100    module into the kernel, and not all modules are detectable by Hotplug.
101    Note that statements like the one below in the
102    <filename>/etc/modprobe.conf</filename> file do not work with Udev:</para>
104<screen os="q"><literal>alias char-major-XXX some-module</literal></screen>
106    <para os="r">Because of the complications with Hotplug, Udev, and modules,
107    we strongly recommend starting with a completely non-modular kernel
108    configuration, especially if this is the first time using Udev.</para>
110    <para os="s">Install the modules, if the kernel configuration uses
111    them:</para>
113<screen os="t"><userinput>make modules_install</userinput></screen>
115    <para os="u">After kernel compilation is complete, additional steps are
116    required to complete the installation. Some files need to be copied to
117    the <filename class="directory">/boot</filename> directory.</para>
119    <para os="v">Issue the following command to install the kernel:</para>
121<screen><userinput>cp arch/i386/boot/bzImage /boot/lfskernel-&linux-version;</userinput></screen>
123    <para os="w"><filename></filename> is a symbol file for the kernel.
124    It maps the function entry points of every function in the kernel API,
125    as well as the addresses of the kernel data structures for the running
126    kernel. Issue the following command to install the map file:</para>
128<screen os="w1"><userinput>cp /boot/;</userinput></screen>
130    <para os="x">The kernel configuration file <filename>.config</filename>
131    produced by the <command>make menuconfig</command> step above contains
132    all the configuration selections for the kernel that was just compiled.
133    It is a good idea to keep this file for future reference:</para>
135<screen os="x1"><userinput>cp .config /boot/config-&linux-version;</userinput></screen>
137    <para os="y">It is important to note that the files in the kernel source
138    directory are not owned by <systemitem class="username">root</systemitem>.
139    Whenever a package is unpacked as user <systemitem
140    class="username">root</systemitem> (like we did
141    inside chroot), the files have the user and group IDs of whatever
142    they were on the packager's computer. This is usually not a problem
143    for any other package to be installed because the source tree is
144    removed after the installation. However, the Linux source tree is
145    often retained for a long time.  Because of this, there is a chance
146    that whatever user ID the packager used will be assigned to somebody
147    on the machine. That person would then have write access to the kernel
148    source.</para>
150    <para os="y1">If the kernel source tree is going to retained, run
151    <command>chown -R 0:0</command> on the <filename
152    class="directory">linux-&linux-version;</filename> directory to
153    ensure all files are owned by user <systemitem
154    class="username">root</systemitem>.</para>
156    <warning os="z">
157      <para>Some kernel documentation recommends creating a symlink from
158      <filename class="symlink">/usr/src/linux</filename> pointing to the
159      kernel source directory. This is specific to kernels prior to the
160      2.6 series and <emphasis>must not</emphasis> be created on an LFS
161      system as it can cause problems for packages you may wish to build
162      once your base LFS system is complete.</para>
164      <para>Also, the headers in the system's <filename
165      class="directory">include</filename> directory should
166      <emphasis>always</emphasis> be the ones against which Glibc was
167      compiled, that is, the ones from the Linux-Libc-Headers package,
168      and therefore, should <emphasis>never</emphasis> be replaced by
169      the kernel headers.</para>
170    </warning>
172  </sect2>
174  <sect2 id="contents-kernel" role="content">
175    <title>Contents of Linux</title>
177    <segmentedlist>
178      <segtitle>Installed files</segtitle>
180      <seglistitem>
181        <seg>config-[linux-version], lfskernel-[linux-version],
182        and[linux-version]</seg>
183      </seglistitem>
184    </segmentedlist>
186    <variablelist>
187      <bridgehead renderas="sect3">Short Descriptions</bridgehead>
188      <?dbfo list-presentation="list"?>
189      <?dbhtml list-presentation="table"?>
191      <varlistentry id="config">
192        <term><filename>config-[linux-version]</filename></term>
193        <listitem>
194          <para>Contains all the configuration selections for the kernel</para>
195          <indexterm zone="ch-bootable-kernel config">
196            <primary sortas="e-/boot/config">/boot/config-[linux-version]</primary>
197          </indexterm>
198        </listitem>
199      </varlistentry>
201      <varlistentry id="lfskernel">
202        <term><filename>lfskernel-[linux-version]</filename></term>
203        <listitem>
204          <para>The engine of the Linux system. When turning on the
205          computer, the kernel is the first part of the operating system
206          that gets loaded. It detects and initializes all components of
207          the computer's hardware, then makes these components available
208          as a tree of files to the software and turns a single CPU into
209          a multitasking machine capable of running scores of programs
210          seemingly at the same time.</para>
211          <indexterm zone="ch-bootable-kernel lfskernel">
212            <primary sortas="b-lfskernel">lfskernel-[linux-version]</primary>
213          </indexterm>
214        </listitem>
215      </varlistentry>
217      <varlistentry id="">
218        <term><filename>[linux-version]</filename></term>
219        <listitem>
220          <para>A list of addresses and symbols; it maps the entry points
221          and addresses of all the functions and data structures in the
222          kernel</para>
223          <indexterm zone="ch-bootable-kernel">
224            <primary sortas="e-/boot/">/boot/[linux-version]</primary>
225          </indexterm>
226        </listitem>
227      </varlistentry>
229    </variablelist>
231  </sect2>
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