mirror of
https://git.linuxfromscratch.org/lfs.git
synced 2025-01-19 13:37:39 +00:00
52216a8930
git-svn-id: http://svn.linuxfromscratch.org/LFS/trunk/BOOK@3467 4aa44e1e-78dd-0310-a6d2-fbcd4c07a689
131 lines
5.4 KiB
XML
131 lines
5.4 KiB
XML
<?xml version="1.0" encoding="ISO-8859-1"?>
|
|
<!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.3//EN" "http://www.oasis-open.org/docbook/xml/4.3/docbookx.dtd" [
|
|
<!ENTITY % general-entities SYSTEM "../general.ent">
|
|
%general-entities;
|
|
]>
|
|
<sect1 id="ch-bootable-grub">
|
|
<title>Making the LFS system bootable</title>
|
|
<?dbhtml filename="grub.html"?>
|
|
|
|
<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 ensure you can boot it. 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. First, a few cautionary words. You
|
|
really should be familiar with your current boot loader and any other
|
|
operating systems present on your hard drive(s) that you might wish to keep
|
|
bootable. Please make sure that you have an emergency boot disk ready, so that
|
|
you can rescue your computer if, by any chance, your 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. Before we get to that, 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>
|
|
|
|
<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
|
|
<userinput>grub</userinput> shell:</para>
|
|
|
|
<screen><userinput>grub</userinput></screen>
|
|
|
|
<para>Grub uses its own naming structure for drives and partitions, in the form
|
|
of (hdn,m), where <emphasis>n</emphasis> is the hard drive number, and
|
|
<emphasis>m</emphasis> the partition number, both starting from zero. This
|
|
means, for instance, that partition <filename>hda1</filename> is (hd0,0) to
|
|
Grub, and <filename>hdb2</filename> is (hd1,1). In contrast to Linux, Grub
|
|
doesn't consider CD-ROM drives to be hard drives, so if you have a CD on
|
|
<filename>hdb</filename>, for example, and a second hard drive on
|
|
<filename>hdc</filename>, that second hard drive would still be (hd1).</para>
|
|
|
|
<para>Using the above information, determine the appropriate designator for
|
|
your root partition (or boot partition, if you use a separate one). For the
|
|
following example, we'll assume your root (or separate boot) partition is
|
|
<filename>hda4</filename>.</para>
|
|
|
|
<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>
|
|
|
|
<screen><userinput>root (hd0,3)</userinput></screen>
|
|
|
|
|
|
<warning><para>The following command will overwrite your current boot loader.
|
|
Don't run the command if this is not what you want. For example, you may be
|
|
using a third party boot manager to manage your MBR (Master Boot Record). In
|
|
this scenario, it would probably make more sense to install Grub into the
|
|
<quote>boot sector</quote> of the LFS partition, in which case this next command
|
|
would become: <userinput>setup (hd0,3)</userinput>.</para></warning>
|
|
|
|
|
|
<para>Tell Grub to install itself into the MBR (Master Boot Record) of
|
|
<filename>hda</filename>:</para>
|
|
|
|
<screen><userinput>setup (hd0)</userinput></screen>
|
|
|
|
<para>If all is well, Grub will have reported finding its files in
|
|
<filename>/boot/grub</filename>. That's all there is to it:</para>
|
|
|
|
<screen><userinput>quit</userinput></screen>
|
|
|
|
<para>Now we need to create a <quote>menu list</quote> file, defining Grub's
|
|
boot menu:</para>
|
|
|
|
<screen><userinput>cat > /boot/grub/menu.lst << "EOF"</userinput>
|
|
# Begin /boot/grub/menu.lst
|
|
|
|
# By default boot the first menu entry.
|
|
default 0
|
|
|
|
# Allow 30 seconds before booting the default.
|
|
timeout 30
|
|
|
|
# Use prettier colors.
|
|
color green/black light-green/black
|
|
|
|
# The first entry is for LFS.
|
|
title LFS &version;
|
|
root (hd0,3)
|
|
kernel --no-mem-option /boot/lfskernel-&linux-version; root=/dev/hda4
|
|
<userinput>EOF</userinput></screen>
|
|
|
|
<note><para>By default, Grub will automatically pass a <quote>mem=xxx</quote>
|
|
command line argument to the kernel. However, Grub occasionally gets the amount
|
|
of memory wrong which can lead to problems in some circumstances. It's best to
|
|
disable this functionality and let the kernel determine the amount of memory
|
|
itself, hence the use of the <emphasis>--no-mem-option</emphasis> above.</para>
|
|
</note>
|
|
|
|
<para>You may want to add an entry for your host distribution. It might look
|
|
like this:</para>
|
|
|
|
<screen><userinput>cat >> /boot/grub/menu.lst << "EOF"</userinput>
|
|
title Red Hat
|
|
root (hd0,2)
|
|
kernel /boot/kernel-2.4.20 root=/dev/hda3
|
|
initrd /boot/initrd-2.4.20
|
|
<userinput>EOF</userinput></screen>
|
|
|
|
<para>Also, if you happen to dual-boot Windows, the following entry should
|
|
allow booting it:</para>
|
|
|
|
<screen><userinput>cat >> /boot/grub/menu.lst << "EOF"</userinput>
|
|
title Windows
|
|
rootnoverify (hd0,0)
|
|
chainloader +1
|
|
<userinput>EOF</userinput></screen>
|
|
|
|
<para>If <command>info grub</command> doesn't tell you all you want to
|
|
know, you can find more information regarding Grub on its website, located at:
|
|
<ulink url="http://www.gnu.org/software/grub/"/>.</para>
|
|
|
|
</sect1>
|