[673b0d8] | 1 | <?xml version="1.0" encoding="ISO-8859-1"?>
|
---|
| 2 | <!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.3//EN" "http://www.oasis-open.org/docbook/xml/4.3/docbookx.dtd" [
|
---|
| 3 | <!ENTITY % general-entities SYSTEM "../general.ent">
|
---|
| 4 | %general-entities;
|
---|
| 5 | ]>
|
---|
[76a4fc3] | 6 | <sect1 id="ch-bootable-kernel" role="wrap">
|
---|
[673b0d8] | 7 | <title>Linux-&linux-version;</title>
|
---|
| 8 | <?dbhtml filename="kernel.html"?>
|
---|
| 9 |
|
---|
| 10 | <indexterm zone="ch-bootable-kernel"><primary sortas="a-Linux">Linux</primary></indexterm>
|
---|
[6370fa6] | 11 |
|
---|
[a001133] | 12 | <sect2 role="package"><title/>
|
---|
[5888299] | 13 | <para>The Linux package contains the kernel and the header files.</para>
|
---|
| 14 |
|
---|
[a001133] | 15 | <segmentedlist>
|
---|
| 16 | <segtitle>&buildtime;</segtitle>
|
---|
| 17 | <segtitle>&diskspace;</segtitle>
|
---|
[69993f4] | 18 | <seglistitem><seg>4.20 SBU</seg>
|
---|
| 19 | <seg>181 MB</seg></seglistitem>
|
---|
[a001133] | 20 | </segmentedlist>
|
---|
| 21 |
|
---|
| 22 | <segmentedlist>
|
---|
| 23 | <segtitle>Linux installation depends on</segtitle>
|
---|
| 24 | <seglistitem><seg>Bash, Binutils, Coreutils, Findutils,
|
---|
[69993f4] | 25 | GCC, Glibc, Grep, Gzip, Make, Modutils, Perl, and Sed</seg></seglistitem>
|
---|
[a001133] | 26 | </segmentedlist>
|
---|
| 27 | </sect2>
|
---|
| 28 |
|
---|
| 29 | <sect2 role="installation">
|
---|
[2081905] | 30 | <title>Installation of the kernel</title>
|
---|
| 31 |
|
---|
[69993f4] | 32 | <para>Building the kernel involves a few steps—configuration,
|
---|
[1dc34de7] | 33 | compilation, and installation. Read the <filename>README</filename>
|
---|
[4ea4bc4] | 34 | file in the kernel source tree for alternate methods to the way this
|
---|
[1dc34de7] | 35 | book configures the kernel.</para>
|
---|
[2081905] | 36 |
|
---|
| 37 | <para>Prepare for compilation by running the following command:</para>
|
---|
| 38 |
|
---|
| 39 | <screen><userinput>make mrproper</userinput></screen>
|
---|
| 40 |
|
---|
[1dc34de7] | 41 | <para>This ensures that the kernel tree is absolutely clean. The
|
---|
| 42 | kernel team recommends that this command be issued prior to each
|
---|
| 43 | kernel compilation. Do not rely on the source tree being clean after
|
---|
[673b0d8] | 44 | un-tarring.</para>
|
---|
[2081905] | 45 |
|
---|
[1dc34de7] | 46 | <para>Also, ensure that the kernel does not attempt to pass
|
---|
| 47 | hotplugging events to userspace until userspace specifies that it is
|
---|
| 48 | ready:</para>
|
---|
[b9e738a] | 49 |
|
---|
| 50 | <screen><userinput>sed -i 's@/sbin/hotplug@/bin/true@' kernel/kmod.c</userinput></screen>
|
---|
| 51 |
|
---|
[c17fc85] | 52 | <para>If, in <xref linkend="ch-scripts-console" role=","/> it was decided to
|
---|
[5fc710e] | 53 | compile the keymap into the kernel, issue the command below:</para>
|
---|
[89d204ea] | 54 |
|
---|
[0c012ac] | 55 | <screen><userinput>loadkeys -m /usr/share/kbd/keymaps/<replaceable>[path to keymap]</replaceable> > \
|
---|
[76a4fc3] | 56 | drivers/char/defkeymap.c</userinput></screen>
|
---|
[89d204ea] | 57 |
|
---|
[1dc34de7] | 58 | <para>For example, if using a Dutch keyboard, use
|
---|
[2256873] | 59 | <phrase
|
---|
| 60 | condition="html"><filename>/usr/share/kbd/keymaps/i386/qwerty/nl.map.gz</filename></phrase><phrase
|
---|
| 61 | condition="pdf"><filename>/usr/share/kbd/keymaps/i386/
|
---|
| 62 | qwerty/nl.map.gz</filename></phrase>.</para>
|
---|
[89d204ea] | 63 |
|
---|
[2081905] | 64 | <para>Configure the kernel via a menu-driven interface:</para>
|
---|
| 65 |
|
---|
| 66 | <screen><userinput>make menuconfig</userinput></screen>
|
---|
| 67 |
|
---|
[2256873] | 68 | <para>Alternatively, <command>make oldconfig</command> may be more appropriate in some
|
---|
[2081905] | 69 | situations. See the <filename>README</filename> file for more
|
---|
| 70 | information.</para>
|
---|
| 71 |
|
---|
[69993f4] | 72 | <note><para>When configuring the kernel, be sure to enable the
|
---|
[1dc34de7] | 73 | <quote>Support for hot-pluggable devices</quote> option under the
|
---|
| 74 | <quote>General Setup</quote> menu. This enables hotplug events that
|
---|
| 75 | are used by <command>udev</command> to populate the <filename
|
---|
| 76 | class="directory">/dev</filename> directory with device
|
---|
| 77 | nodes.</para></note>
|
---|
| 78 |
|
---|
| 79 | <para>If desired, skip kernel configuration by copying the kernel
|
---|
| 80 | config file, <filename>.config</filename>, from the host system
|
---|
| 81 | (assuming it is available) to the unpacked <filename
|
---|
| 82 | class="directory">linux-&linux-version;</filename> directory. However,
|
---|
| 83 | we do not recommend this option. It is often better to explore all the
|
---|
[69993f4] | 84 | configuration menus and create the kernel configuration from
|
---|
[2081905] | 85 | scratch.</para>
|
---|
| 86 |
|
---|
[69993f4] | 87 | <para>For POSIX-shared memory support, ensure that the kernel config
|
---|
[1dc34de7] | 88 | option <quote>Virtual memory file system support</quote> is enabled.
|
---|
| 89 | It resides within the <quote>File systems</quote> menu and is normally
|
---|
| 90 | enabled by default.</para>
|
---|
[2081905] | 91 |
|
---|
[1dc34de7] | 92 | <para>LFS bootscripts make the assumption that either both
|
---|
| 93 | <quote>Support for Host-side USB</quote> and <quote>USB device
|
---|
| 94 | filesystem</quote> have been compiled directly into the kernel, or
|
---|
| 95 | that neither is compiled at all. Bootscripts will not work properly
|
---|
| 96 | if it is a module (usbcore.ko).</para>
|
---|
[72b0264] | 97 |
|
---|
[1dc34de7] | 98 | <note><para>NPTL requires the kernel to be compiled with GCC 3.x, in
|
---|
| 99 | this case &gcc-version;. Compiling with 2.95.x is known to cause failures in
|
---|
[69993f4] | 100 | the glibc test suite, so it is not recommended to compile the kernel
|
---|
[1dc34de7] | 101 | with gcc 2.95.x.</para></note>
|
---|
[2081905] | 102 |
|
---|
[9dfc02f] | 103 | <para>Compile the kernel image and modules:</para>
|
---|
[2081905] | 104 |
|
---|
[9dfc02f] | 105 | <screen><userinput>make</userinput></screen>
|
---|
[2081905] | 106 |
|
---|
[1dc34de7] | 107 | <para>If using kernel modules, an
|
---|
| 108 | <filename>/etc/modprobe.conf</filename> file may be needed.
|
---|
[69993f4] | 109 | Information pertaining to modules and kernel configuration is
|
---|
[1dc34de7] | 110 | located in the kernel documentation in the <filename
|
---|
| 111 | class="directory">linux-&linux-version;/Documentation</filename>
|
---|
| 112 | directory. The <emphasis>modprobe.conf</emphasis> man page may also be
|
---|
| 113 | of interest.</para>
|
---|
| 114 |
|
---|
[69993f4] | 115 | <para>Be very careful when reading other documentation because it
|
---|
[1dc34de7] | 116 | usually applies to 2.4.x kernels only. As far as we know, kernel
|
---|
| 117 | configuration issues specific to Hotplug and Udev are not documented.
|
---|
| 118 | The problem is that Udev will create a device node only if Hotplug or
|
---|
| 119 | a user-written script inserts the corresponding module into the
|
---|
| 120 | kernel, and not all modules are detectable by Hotplug. Note that
|
---|
[2256873] | 121 | statements like the one below in the
|
---|
| 122 | <filename>/etc/modprobe.conf</filename> file do not work with
|
---|
| 123 | Udev:</para>
|
---|
| 124 |
|
---|
| 125 | <para><screen>alias char-major-XXX some-module</screen></para>
|
---|
[a56c4bb] | 126 |
|
---|
[1dc34de7] | 127 | <para>Because of the complications with Hotplug, Udev, and modules, we
|
---|
| 128 | strongly recommend starting with a completely non-modular kernel
|
---|
| 129 | configuration, especially if this is the first time using Udev.</para>
|
---|
[a56c4bb] | 130 |
|
---|
[69993f4] | 131 | <para>Install the modules, if the kernel configuration uses them:</para>
|
---|
[2081905] | 132 |
|
---|
[9dfc02f] | 133 | <screen><userinput>make modules_install</userinput></screen>
|
---|
[2081905] | 134 |
|
---|
[1dc34de7] | 135 | <para>If there are many modules and very little space, consider
|
---|
| 136 | stripping and compressing the modules. For most users, such
|
---|
| 137 | compression is not worth the time, but if the system is pressed for
|
---|
| 138 | space, see <ulink
|
---|
| 139 | url="http://www.linux-mips.org/archives/linux-mips/2002-04/msg00031.html"/>.</para>
|
---|
[b157558] | 140 |
|
---|
[1dc34de7] | 141 | <para>After kernel compilation is complete, additional steps are
|
---|
| 142 | required to complete the installation. Some files need to be copied to
|
---|
| 143 | the <filename class="directory">/boot</filename> directory.</para>
|
---|
[2081905] | 144 |
|
---|
[1dc34de7] | 145 | <para>The path to the kernel image may vary depending on the platform
|
---|
| 146 | being used. Issue the following command to install the kernel:</para>
|
---|
[2081905] | 147 |
|
---|
[9dfc02f] | 148 | <screen><userinput>cp arch/i386/boot/bzImage /boot/lfskernel-&linux-version;</userinput></screen>
|
---|
[2081905] | 149 |
|
---|
[1dc34de7] | 150 | <para><filename>System.map</filename> is a symbol file for the kernel.
|
---|
| 151 | It maps the function entry points of every function in the kernel API,
|
---|
| 152 | as well as the addresses of the kernel data structures for the running
|
---|
| 153 | kernel. Issue the following command to install the map file:</para>
|
---|
[2081905] | 154 |
|
---|
[9dfc02f] | 155 | <screen><userinput>cp System.map /boot/System.map-&linux-version;</userinput></screen>
|
---|
[2081905] | 156 |
|
---|
[2256873] | 157 | <para>The kernel configuration file <filename>.config</filename>
|
---|
| 158 | produced by the <command>make menuconfig</command> step
|
---|
| 159 | above contains all the configuration selections for the kernel
|
---|
[1dc34de7] | 160 | that was just compiled. It is a good idea to keep this file for future
|
---|
| 161 | reference:</para>
|
---|
[2081905] | 162 |
|
---|
[9dfc02f] | 163 | <screen><userinput>cp .config /boot/config-&linux-version;</userinput></screen>
|
---|
[2081905] | 164 |
|
---|
[1dc34de7] | 165 | <para>It is important to note that the files in the kernel source
|
---|
| 166 | directory are not owned by <emphasis>root</emphasis>. Whenever a
|
---|
| 167 | package is unpacked as user <emphasis>root</emphasis> (like we did
|
---|
[69993f4] | 168 | inside chroot), the files have the user and group IDs of whatever
|
---|
[1dc34de7] | 169 | they were on the packager's computer. This is usually not a problem
|
---|
| 170 | for any other package to be installed because the source tree is
|
---|
| 171 | removed after the installation. However, the Linux source tree is
|
---|
| 172 | often retained for a long time. Because of this, there is a chance
|
---|
| 173 | that whatever user ID the packager used will be assigned to somebody
|
---|
| 174 | on the machine. That person would then have write access to the kernel
|
---|
| 175 | source.</para>
|
---|
| 176 |
|
---|
| 177 | <para>If the kernel source tree is going to retained, run
|
---|
| 178 | <command>chown -R 0:0</command> on the <filename
|
---|
| 179 | class="directory">linux-&linux-version;</filename> directory to ensure
|
---|
| 180 | all files are owned by user <emphasis>root</emphasis>.</para>
|
---|
[2081905] | 181 | </sect2>
|
---|
[6910868] | 182 |
|
---|
[673b0d8] | 183 |
|
---|
[c6cb3aa] | 184 | <sect2 id="contents-kernel" role="content"><title>Contents of Linux</title>
|
---|
[673b0d8] | 185 |
|
---|
[c6cb3aa] | 186 | <segmentedlist>
|
---|
| 187 | <segtitle>Installed files</segtitle>
|
---|
[69993f4] | 188 | <seglistitem><seg>kernel, kernel headers,
|
---|
| 189 | and System.map</seg></seglistitem>
|
---|
[c6cb3aa] | 190 | </segmentedlist>
|
---|
[673b0d8] | 191 |
|
---|
[2256873] | 192 | <variablelist><bridgehead renderas="sect3">Short Descriptions</bridgehead>
|
---|
[3ed279f] | 193 | <?dbfo list-presentation="list"?>
|
---|
[673b0d8] | 194 |
|
---|
[b8a819f] | 195 | <varlistentry id="kernel">
|
---|
[2256873] | 196 | <term><filename>kernel</filename></term>
|
---|
[c6cb3aa] | 197 | <listitem>
|
---|
[2256873] | 198 | <para>The engine of the Linux system. When turning on the computer,
|
---|
[1dc34de7] | 199 | the kernel is the first part of the operating system that gets loaded.
|
---|
| 200 | It detects and initializes all components of the computer's hardware,
|
---|
| 201 | then makes these components available as a tree of files to the
|
---|
[69993f4] | 202 | software and turns a single CPU into a multitasking machine capable
|
---|
[673b0d8] | 203 | of running scores of programs seemingly at the same time.</para>
|
---|
[3ed279f] | 204 | <indexterm zone="ch-bootable-kernel kernel"><primary sortas="b-kernel">kernel</primary></indexterm>
|
---|
[c6cb3aa] | 205 | </listitem>
|
---|
| 206 | </varlistentry>
|
---|
[673b0d8] | 207 |
|
---|
[b8a819f] | 208 | <varlistentry id="kernel-headers">
|
---|
[2256873] | 209 | <term><filename>kernel headers</filename></term>
|
---|
[c6cb3aa] | 210 | <listitem>
|
---|
[2256873] | 211 | <para>Defines the interface to the services that the kernel provides.
|
---|
[69993f4] | 212 | The headers in the system's <filename
|
---|
[1dc34de7] | 213 | class="directory">include</filename> directory should
|
---|
| 214 | <emphasis>always</emphasis> be the ones against which Glibc was
|
---|
| 215 | compiled and therefore, should <emphasis>not</emphasis> be replaced
|
---|
| 216 | when upgrading the kernel.</para>
|
---|
[3ed279f] | 217 | <indexterm zone="ch-bootable-kernel kernel-headers"><primary sortas="e-kernel-headers">kernel headers</primary></indexterm>
|
---|
[c6cb3aa] | 218 | </listitem>
|
---|
| 219 | </varlistentry>
|
---|
[673b0d8] | 220 |
|
---|
[b8a819f] | 221 | <varlistentry id="System.map">
|
---|
| 222 | <term><filename>System.map</filename></term>
|
---|
[c6cb3aa] | 223 | <listitem>
|
---|
[2256873] | 224 | <para>A list of addresses and symbols; it maps the entry points and
|
---|
[1dc34de7] | 225 | addresses of all the functions and data structures in the
|
---|
[2256873] | 226 | kernel</para>
|
---|
[3ed279f] | 227 | <indexterm zone="ch-bootable-kernel System.map"><primary sortas="e-/boot/System.map">/boot/System.map</primary></indexterm>
|
---|
[c6cb3aa] | 228 | </listitem>
|
---|
| 229 | </varlistentry>
|
---|
| 230 | </variablelist>
|
---|
[673b0d8] | 231 |
|
---|
| 232 | </sect2>
|
---|
| 233 |
|
---|
[6370fa6] | 234 | </sect1>
|
---|
[1dc34de7] | 235 |
|
---|