diff options
Diffstat (limited to 'chapter08')
| -rw-r--r-- | chapter08/fstab.xml | 42 | ||||
| -rw-r--r-- | chapter08/grub.xml | 86 | ||||
| -rw-r--r-- | chapter08/introduction.xml | 6 | ||||
| -rw-r--r-- | chapter08/kernel.xml | 197 |
4 files changed, 295 insertions, 36 deletions
diff --git a/chapter08/fstab.xml b/chapter08/fstab.xml index 015e26bc6..969d306fb 100644 --- a/chapter08/fstab.xml +++ b/chapter08/fstab.xml @@ -7,6 +7,13 @@ <title>Creating the /etc/fstab File</title> <?dbhtml filename="fstab.html"?> +<indexterm zone="ch-bootable-fstab"><primary sortas="e-/etc/fstab">/etc/fstab</primary></indexterm> + +<para>The <filename>/etc/fstab</filename> file is used by some +programs to determine where file systems are to be mounted by default, +which must be checked, and in which order. Create a new file systems +table like this:</para> + <screen><userinput>cat > /etc/fstab << "EOF" <literal># Begin /etc/fstab @@ -22,4 +29,39 @@ shm /dev/shm tmpfs defaults 0 0 # End /etc/fstab</literal> EOF</userinput></screen> +<para>Replace <replaceable>[xxx]</replaceable>, +<replaceable>[yyy]</replaceable>, and <replaceable>[fff]</replaceable> +with the values appropriate for the system, for example, <filename +class="partition">hda2</filename>, <filename +class="partition">hda5</filename>, and <systemitem +class="filesystem">ext2</systemitem>. For details on the six +fields in this file, see <command>man 5 fstab</command>.</para> + +<para>When using a journalling file system, the <parameter>1 +1</parameter> at the end of the line should be replaced with +<parameter>0 0</parameter> because such a partition does not need to +be dumped or checked.</para> + +<para>The <filename class="directory">/dev/shm</filename> mount point +for <systemitem class="filesystem">tmpfs</systemitem> is included to +allow enabling POSIX-shared memory. The kernel must have the required +support built into it for this to work (more about this is in the next +section). Please note that very little software currently uses +POSIX-shared memory. Therefore, consider the <filename +class="directory">/dev/shm</filename> mount point optional. For more +information, see +<filename>Documentation/filesystems/tmpfs.txt</filename> in the kernel +source tree.</para> + +<para>There are other lines which may be added to the +<filename>/etc/fstab</filename> file. One example is a line for USB +devices:</para> + +<screen>usbfs /proc/bus/usb usbfs devgid=14,devmode=0660 0 0 </screen> + +<para>This option will only work if <quote>Support for Host-side +USB</quote> and <quote>USB device filesystem</quote> are compiled into +the kernel (not as a module).</para> + </sect1> + diff --git a/chapter08/grub.xml b/chapter08/grub.xml index 4d50002a0..12487ec71 100644 --- a/chapter08/grub.xml +++ b/chapter08/grub.xml @@ -7,35 +7,82 @@ <title>Making the LFS System Bootable</title> <?dbhtml filename="grub.html"?> - -<para>We highly recommend that you create a Grub boot floppy diskette just in case. -Insert a blank floppy diskette and run the following commands:</para> +<indexterm zone="ch-bootable-grub"> +<primary sortas="a-Grub">Grub</primary> +<secondary>configuring</secondary></indexterm> + +<para>Your shiny new LFS system is almost complete. One of the last +things to do is to ensure that the system can be properly booted. The +instructions below apply only to computers of IA-32 architecture, +meaning mainstream PCs. Information on <quote>boot loading</quote> for +other architectures should be available in the usual resource-specific +locations for those architectures.</para> + +<para>Boot loading can be a complex area, so a few cautionary +words are in order. Be familiar with the current boot loader and any other +operating systems present on the hard drive(s) that need to be +bootable. Make sure that an emergency boot disk is ready to +<quote>rescue</quote> the computer if the computer becomes +unusable (un-bootable).</para> + +<para>Earlier, we compiled and installed the Grub boot loader software +in preparation for this step. The procedure involves writing some +special Grub files to specific locations on the hard drive. We highly +recommend creating a Grub boot floppy diskette as a backup. Insert a +blank floppy diskette and run the following commands:</para> <screen><userinput>dd if=/boot/grub/stage1 of=/dev/fd0 bs=512 count=1 dd if=/boot/grub/stage2 of=/dev/fd0 bs=512 seek=1</userinput></screen> -<para>Remove the diskette and store it somewhere safe. Now we'll run the +<para>Remove the diskette and store it somewhere safe. Now, run the <command>grub</command> shell:</para> <screen><userinput>grub</userinput></screen> -<para>First, tell Grub where to search for its <filename>stage{1,2}</filename> -files -- you can use the Tab key everywhere to make Grub show the alternatives:</para> +<para>Grub uses its own naming structure for drives and partitions in +the form of <emphasis>(hdn,m)</emphasis>, where <emphasis>n</emphasis> +is the hard drive number and <emphasis>m</emphasis> is the partition +number, both starting from zero. For example, partition <filename +class="partition">hda1</filename> is <emphasis>(hd0,0)</emphasis> to +Grub and <filename class="partition">hdb3</filename> is +<emphasis>(hd1,2)</emphasis>. In contrast to Linux, Grub does not +consider CD-ROM drives to be hard drives. For example, if using a CD +on <filename class="partition">hdb</filename> and a second hard drive +on <filename class="partition">hdc</filename>, that second hard drive +would still be <emphasis>(hd1)</emphasis>.</para> + +<para>Using the above information, determine the appropriate +designator for the root partition (or boot partition, if a separate +one is used). For the following example, it is assumed that the root +(or separate boot) partition is <filename +class="partition">hda4</filename>.</para> + +<para>Tell Grub where to search for its +<filename>stage{1,2}</filename> files. The Tab key can be used +everywhere to make Grub show the alternatives:</para> <screen><userinput>root (hd0,3)</userinput></screen> -<para>Tell Grub to install itself into the MBR (Master Boot Record) of +<warning><para>The following command will overwrite the current boot +loader. Do not run the command if this is not desired, for example, if +using a third party boot manager to manage the Master Boot Record +(MBR). In this scenario, it would make more sense to install +Grub into the <quote>boot sector</quote> of the LFS partition. In this +case, this next command would become <userinput>setup +(hd0,3)</userinput>.</para></warning> + +<para>Tell Grub to install itself into the MBR of <filename class="partition">hda</filename>:</para> <screen><userinput>setup (hd0)</userinput></screen> -<para>If all is well, Grub will have reported finding its files in -<filename class="directory">/boot/grub</filename>. That's all there is to it:</para> +<para>If all went well, Grub will have reported finding its files in +<filename class="directory">/boot/grub</filename>. That's all there is +to it. Quit the <command>grub</command> shell:</para> <screen><userinput>quit</userinput></screen> -<para>Now we need to create a <quote>menu list</quote> file, defining Grub's -boot menu:</para> +<para>Create a <quote>menu list</quote> file defining Grub's boot menu:</para> <screen><userinput>cat > /boot/grub/menu.lst << "EOF" <literal># Begin /boot/grub/menu.lst @@ -55,7 +102,7 @@ root (hd0,3) kernel /boot/lfskernel-&linux-version; root=/dev/hda4</literal> EOF</userinput></screen> -<para>You may want to add an entry for your host distribution. It might look +<para>Add an entry for the host distribution if desired. It might look like this:</para> <screen><userinput>cat >> /boot/grub/menu.lst << "EOF" @@ -65,8 +112,8 @@ kernel /boot/kernel-2.4.20 root=/dev/hda3 initrd /boot/initrd-2.4.20</literal> EOF</userinput></screen> -<para>Also, if you happen to dual-boot Windows, the following entry should -allow booting it:</para> +<para>If dual-booting Windows, the following entry will allow +booting it:</para> <screen><userinput>cat >> /boot/grub/menu.lst << "EOF" <literal>title Windows @@ -74,11 +121,16 @@ rootnoverify (hd0,0) chainloader +1</literal> EOF</userinput></screen> -<para>The FHS stipulates that Grub's menu.lst file should be symlinked to -/etc/grub/menu.lst. To satisfy this requirement, issue the following -command:</para> +<para>If <command>info grub</command> does not provide all necessary material, additional +information regarding Grub is located on its website at: +<ulink url="http://www.gnu.org/software/grub/"/>.</para> + +<para>The FHS stipulates that Grub's <filename>menu.lst</filename> file should be symlinked to +<filename class="symlink">/etc/grub/menu.lst</filename>. To satisfy this requirement, issue the +following command:</para> <screen><userinput>mkdir /etc/grub && ln -s /boot/grub/menu.lst /etc/grub</userinput></screen> </sect1> + diff --git a/chapter08/introduction.xml b/chapter08/introduction.xml index d936cf2ed..6fa80cadc 100644 --- a/chapter08/introduction.xml +++ b/chapter08/introduction.xml @@ -7,6 +7,10 @@ <title>Introduction</title> <?dbhtml filename="introduction.html"?> -<para>See testing</para> +<para>It is time to make the LFS system bootable. This chapter +discusses creating an <filename>fstab</filename> file, building a +kernel for the new LFS system, and installing the Grub boot loader so +that the LFS system can be selected for booting at startup.</para> </sect1> + diff --git a/chapter08/kernel.xml b/chapter08/kernel.xml index 9fe3bc889..4b775a3d9 100644 --- a/chapter08/kernel.xml +++ b/chapter08/kernel.xml @@ -3,26 +3,37 @@ <!ENTITY % general-entities SYSTEM "../general.ent"> %general-entities; ]> -<sect1 id="ch-bootable-kernel" xreflabel="Linux" role="wrap"> +<sect1 id="ch-bootable-kernel" role="wrap"> <title>Linux-&linux-version;</title> <?dbhtml filename="kernel.html"?> <indexterm zone="ch-bootable-kernel"><primary sortas="a-Linux">Linux</primary></indexterm> <sect2 role="package"><title/> +<para>The Linux package contains the kernel and the header files.</para> <segmentedlist> <segtitle>&buildtime;</segtitle> <segtitle>&diskspace;</segtitle> -<seglistitem><seg>All default options: 4.20 SBU</seg> -<seg>All default options: 181 MB</seg></seglistitem> +<seglistitem><seg>4.20 SBU</seg> +<seg>181 MB</seg></seglistitem> </segmentedlist> +<segmentedlist> +<segtitle>Linux installation depends on</segtitle> +<seglistitem><seg>Bash, Binutils, Coreutils, Findutils, +GCC, Glibc, Grep, Gzip, Make, Modutils, Perl, and Sed</seg></seglistitem> +</segmentedlist> </sect2> <sect2 role="installation"> <title>Installation of the kernel</title> +<para>Building the kernel involves a few steps—configuration, +compilation, and installation. Read the <filename>README</filename> +file in the kernel source tree for alternate methods to the way this +book configures the kernel.</para> + <para>Kernel version 2.6.10 has a security vulnerability that will allow user processes to gain root privledges upon loading of a kernel module. See: <ulink url="http://www.uwsg.iu.edu/hypermail/linux/kernel/0412.3/0679.html"/> for more information. The following patch fixes this problem:</para> @@ -33,50 +44,200 @@ processes to gain root privledges upon loading of a kernel module. See: <screen><userinput>make mrproper</userinput></screen> -<!--NEW: the sed command has been removed--> +<para>This ensures that the kernel tree is absolutely clean. The +kernel team recommends that this command be issued prior to each +kernel compilation. Do not rely on the source tree being clean after +un-tarring.</para> -<para>If, in <xref linkend="ch-scripts-console"/>, you decided you want -to compile the keymap into the kernel, issue the command below:</para> +<para>If, in <xref linkend="ch-scripts-console" role=","/> it was decided to +compile the keymap into the kernel, issue the command below:</para> <screen><userinput>loadkeys -m /usr/share/kbd/keymaps/<replaceable>[path to keymap]</replaceable> > \ drivers/char/defkeymap.c</userinput></screen> -<para>Configure the kernel via a menu-driven interface. BLFS has some -information regarding particular kernel configuration requirements of -packages outside of LFS at -<ulink url="&blfs-root;view/svn/longindex.html#kernel-config-index"/>.</para> +<para>For example, if using a Dutch keyboard, use +<phrase +condition="html"><filename>/usr/share/kbd/keymaps/i386/qwerty/nl.map.gz</filename></phrase><phrase +condition="pdf"><filename>/usr/share/kbd/keymaps/i386/ +qwerty/nl.map.gz</filename></phrase>.</para> + +<para>Configure the kernel via a menu-driven interface:</para> <screen><userinput>make menuconfig</userinput></screen> +<para>Alternatively, <command>make oldconfig</command> may be more appropriate in some +situations. See the <filename>README</filename> file for more +information.</para> + +<note><para>When configuring the kernel, be sure to enable the +<quote>Support for hot-pluggable devices</quote> option under the +<quote>General Setup</quote> menu. This enables hotplug events that +are used by <command>udev</command> to populate the <filename +class="directory">/dev</filename> directory with device +nodes.</para></note> + +<para>If desired, skip kernel configuration by copying the kernel +config file, <filename>.config</filename>, from the host system +(assuming it is available) to the unpacked <filename +class="directory">linux-&linux-version;</filename> directory. However, +we do not recommend this option. It is often better to explore all the +configuration menus and create the kernel configuration from +scratch.</para> + +<para>For POSIX-shared memory support, ensure that the kernel config +option <quote>Virtual memory file system support</quote> is enabled. +It resides within the <quote>File systems</quote> menu and is normally +enabled by default.</para> + +<para>LFS bootscripts make the assumption that either both +<quote>Support for Host-side USB</quote> and <quote>USB device +filesystem</quote> have been compiled directly into the kernel, or +that neither is compiled at all. Bootscripts will not work properly +if it is a module (usbcore.ko).</para> + +<note><para>NPTL requires the kernel to be compiled with GCC 3.x, in +this case &gcc-version;. Compiling with 2.95.x is known to cause failures in +the glibc test suite, so it is not recommended to compile the kernel +with gcc 2.95.x.</para></note> + <para>Compile the kernel image and modules:</para> <screen><userinput>make</userinput></screen> -<para>Install the modules, if your kernel configuration uses them:</para> +<para>If using kernel modules, an +<filename>/etc/modprobe.conf</filename> file may be needed. +Information pertaining to modules and kernel configuration is +located in the kernel documentation in the <filename +class="directory">linux-&linux-version;/Documentation</filename> +directory. The <emphasis>modprobe.conf</emphasis> man page may also be +of interest.</para> + +<para>Be very careful when reading other documentation because it +usually applies to 2.4.x kernels only. As far as we know, kernel +configuration issues specific to Hotplug and Udev are not documented. +The problem is that Udev will create a device node only if Hotplug or +a user-written script inserts the corresponding module into the +kernel, and not all modules are detectable by Hotplug. Note that +statements like the one below in the +<filename>/etc/modprobe.conf</filename> file do not work with +Udev:</para> + +<para><screen>alias char-major-XXX some-module</screen></para> + +<para>Because of the complications with Hotplug, Udev, and modules, we +strongly recommend starting with a completely non-modular kernel +configuration, especially if this is the first time using Udev.</para> + +<para>Install the modules, if the kernel configuration uses them:</para> <screen><userinput>make modules_install</userinput></screen> -<para>The path to the kernel image may vary depending on the platform you're -using. Issue the following command to install the kernel:</para> +<para>If there are many modules and very little space, consider +stripping and compressing the modules. For most users, such +compression is not worth the time, but if the system is pressed for +space, see <ulink +url="http://www.linux-mips.org/archives/linux-mips/2002-04/msg00031.html"/>.</para> + +<para>After kernel compilation is complete, additional steps are +required to complete the installation. Some files need to be copied to +the <filename class="directory">/boot</filename> directory.</para> + +<para>The path to the kernel image may vary depending on the platform +being used. Issue the following command to install the kernel:</para> <screen><userinput>cp arch/i386/boot/bzImage /boot/lfskernel-&linux-version;</userinput></screen> +<para><filename>System.map</filename> is a symbol file for the kernel. +It maps the function entry points of every function in the kernel API, +as well as the addresses of the kernel data structures for the running +kernel. Issue the following command to install the map file:</para> + <screen><userinput>cp System.map /boot/System.map-&linux-version;</userinput></screen> +<para>The kernel configuration file <filename>.config</filename> +produced by the <command>make menuconfig</command> step +above contains all the configuration selections for the kernel +that was just compiled. It is a good idea to keep this file for future +reference:</para> + <screen><userinput>cp .config /boot/config-&linux-version;</userinput></screen> -<para>If you are going to keep the kernel source tree around, you may want to -run <command>chown -R 0:0</command> on the -<filename class="directory">linux-&linux-version;</filename> directory to ensure all files are -owned by user <emphasis>root</emphasis>.</para> +<para>It is important to note that the files in the kernel source +directory are not owned by <emphasis>root</emphasis>. Whenever a +package is unpacked as user <emphasis>root</emphasis> (like we did +inside chroot), the files have the user and group IDs of whatever +they were on the packager's computer. This is usually not a problem +for any other package to be installed because the source tree is +removed after the installation. However, the Linux source tree is +often retained for a long time. Because of this, there is a chance +that whatever user ID the packager used will be assigned to somebody +on the machine. That person would then have write access to the kernel +source.</para> + +<para>If the kernel source tree is going to be retained, run +<command>chown -R 0:0</command> on the <filename +class="directory">linux-&linux-version;</filename> directory to ensure +all files are owned by user <emphasis>root</emphasis>.</para> + +<warning><para>Some kernel documentation recommends creating a symlink from +<filename class="symlink">/usr/src/linux</filename> pointing to the kernel +source directory. This is specific to kernels prior to the 2.6 series and +<emphasis>must not</emphasis> be created on an LFS system as it can cause +problems for packages you may wish to build once your base LFS system is +complete.</para></warning> </sect2> <sect2 id="contents-kernel" role="content"><title>Contents of Linux</title> -<para>See testing</para> +<segmentedlist> +<segtitle>Installed files</segtitle> +<seglistitem><seg>kernel, kernel headers, +and System.map</seg></seglistitem> +</segmentedlist> + +<variablelist><bridgehead renderas="sect3">Short Descriptions</bridgehead> +<?dbfo list-presentation="list"?> + +<varlistentry id="kernel"> +<term><filename>kernel</filename></term> +<listitem> +<para>The engine of the Linux system. When turning on the computer, +the kernel is the first part of the operating system that gets loaded. +It detects and initializes all components of the computer's hardware, +then makes these components available as a tree of files to the +software and turns a single CPU into a multitasking machine capable +of running scores of programs seemingly at the same time.</para> +<indexterm zone="ch-bootable-kernel kernel"><primary sortas="b-kernel">kernel</primary></indexterm> +</listitem> +</varlistentry> + +<varlistentry id="kernel-headers"> +<term><filename>kernel headers</filename></term> +<listitem> +<para>Defines the interface to the services that the kernel provides. +The headers in the system's <filename +class="directory">include</filename> directory should +<emphasis>always</emphasis> be the ones against which Glibc was +compiled and therefore, should <emphasis>not</emphasis> be replaced +when upgrading the kernel.</para> +<indexterm zone="ch-bootable-kernel kernel-headers"><primary sortas="e-kernel-headers">kernel headers</primary></indexterm> +</listitem> +</varlistentry> + +<varlistentry id="System.map"> +<term><filename>System.map</filename></term> +<listitem> +<para>A list of addresses and symbols; it maps the entry points and +addresses of all the functions and data structures in the +kernel</para> +<indexterm zone="ch-bootable-kernel System.map"><primary sortas="e-/boot/System.map">/boot/System.map</primary></indexterm> +</listitem> +</varlistentry> +</variablelist> </sect2> </sect1> + |