mirror of https://github.com/tLDP/LDP
119 lines
4.7 KiB
XML
119 lines
4.7 KiB
XML
<sect1 id="ch08-grub">
|
|
<title>Making the LFS system bootable</title>
|
|
<?dbhtml filename="grub.html" dir="chapter08"?>
|
|
|
|
<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, i.e. mainstream PC's. Information on "boot loading" 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
|
|
(unbootable).</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. For the following example, we'll assume your root
|
|
partition is <filename>hda4</filename>.</para>
|
|
|
|
<para>First, tell Grub where to search for its <filename>stage{1,2}</filename>
|
|
files -- you can use Tab everywhere to make Grub show the alternatives:</para>
|
|
|
|
<screen><userinput>root (hd0,3)</userinput></screen>
|
|
|
|
<!-- HACK - Force some whitespace to appease tidy -->
|
|
<literallayout></literallayout>
|
|
|
|
<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
|
|
"boot sector" of the LFS partition, in which case the command would become:
|
|
<userinput>setup (hd0,3)</userinput>.</para></warning>
|
|
|
|
<!-- HACK - Force some whitespace to appease tidy -->
|
|
<literallayout></literallayout>
|
|
|
|
<para>Then tell it 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 "menu list" 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 &milestone;
|
|
root (hd0,3)
|
|
kernel /boot/lfskernel root=/dev/hda4 ro
|
|
<userinput>EOF</userinput></screen>
|
|
|
|
<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 ro
|
|
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 <userinput>info grub</userinput> 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>
|
|
|