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 LinuxFromScratch system completed,
we need to ensure we can boot it.  To do this, we will run the grub program.</para>

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

<para>Grub uses it's own naming structure for drives, in the form of hd(a,b),
where a is the hard drive number, and b is the partition number, both of which
start from zero.  So, partition hda1 would be hd(0,0) to grub, and hdb2 would
be hd(1,2).  Also, Grub doesn't pay attention to CDROM drives at all, so if,
for example, if you have a CD on hdb, and a second hard drive on hdc, partitions
on that second hard drive would still be hd(1,b).</para>

<para>So, using the information above, select the appropriate designator for
your root partition.  For the purposes of this, we will assume hd(0,3) for
your root partition.  First, we tell grub where to find it's files:</para>

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

<para>This tells grub to look for it's 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 it's 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
kernel (hd0,3)/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
kernel (hd0,2)/boot/kernel-2.4.20 root=/dev/hda3 ro
initrd (hd0,2)/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
chainloader (hd0,0)+1
EOF</userinput></screen></para>

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

</sect1>