lfs-book/chapter08/grub.xml

<sect1 id="ch08-grub">
<title>Making the LFS system bootable</title>
<?dbhtml filename="grub.html" dir="chapter08"?>

<para>Now that we have our shiny new Linux-From-Scratch system completed,
we need to ensure we can boot it.  To do this, we will run the
<userinput>grub</userinput> program.</para>

<para><screen><userinput>grub</userinput></screen></para>

<para>Grub uses its own naming structure for drives, in the form of (hdn,m),
where n is the hard drive number, and m is the partition number, both of which
start from zero.  So, partition hda1 would be (hd0,0) to Grub, and hdb2 would
be (hd1,1).  Also, Grub doesn't pay attention to CD-ROM drives at all, so if,
for example, you have a CD on hdb, and a second hard drive on hdc, partitions
on that second hard drive would still be (hd1,m).</para>

<para>So, using the information above, select the appropriate designator for
your root partition.  For the purposes of this, we will assume (hd0,3) for
your root partition.  First, we tell grub where to find its files:</para>

<para><screen><userinput>root (hd0,3)
setup (hd0)
quit</userinput></screen></para>

<para>This tells Grub to look for its files on hda4 (hd0,3), and install itself
into the MBR (Master Boot Record) of hda.</para>

<para>Also, we need to create the <filename>menu.lst</filename> file, which
Grub uses to designate its boot menu:</para>

<para><screen><userinput>cat &gt; /boot/grub/menu.lst &lt;&lt; "EOF"
# Begin /boot/grub/menu.lst

# Default to first menu entry
default 0

# Allow 30 seconds before booting default
timeout 30

# Use prettier colors
color green/black light-green/black

# Default Entry for LFS
title LFS 5.0
root (hd0,3)
kernel /boot/lfskernel root=/dev/hda4 ro
EOF</userinput></screen></para>

<para>You might also want to add in an entry for your host distribution.  It
might look similar to this:</para>

<para><screen><userinput>cat &gt;&gt; /boot/grub/menu.lst &lt;&lt; "EOF"
# Redhat Linux
title Redhat
root (hd0,2)
kernel /boot/kernel-2.4.20 root=/dev/hda3 ro
initrd /boot/initrd-2.4.20
EOF</userinput></screen></para>

<para>Also, if you happen to dual-boot Windows, the following entry should
allow booting it:</para>

<para><screen><userinput>cat &gt;&gt; /boot/grub/menu.lst &lt;&lt; "EOF"
# Windows
title Windows
rootnoverify (hd0,0)
chainloader +1
EOF</userinput></screen></para>

<para>You can find more info regarding Grub on its web site, located at:
<ulink url="http://www.gnu.org/software/grub"/>, as well as in the LFS Grub
HOWTO located at:
<ulink url="http://www.linuxfromscratch.org/hints/downloads/files/grub-howto.txt"/>.</para>

</sect1>