
Give Your Computer the Boot #1
Chapter 1, Booting Linux
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HACK
It’s important to note how GRUB deals with disks and partition numbers.
Unlike Linux, GRUB refers to the first disk as
hd0 and the first partition as par-
tition
0. In Linux this is designated as /dev/hda1. Basically, if the letters that des-
ignate the hard drive in Linux were numbers, you would subtract 1 from them.
Therefore, an a (1) becomes 0, a b (2) becomes 1, and so on. Also, you would
subtract 1 from the partition number itself. For example, a boot partition
located on /dev/hdb3 becomes
hd1,2 in GRUB parlance. In the previous stanza,
you refer to the location of the kernel (
root)ashd0,0, but on the kernel line,
you refer to the root partition as /dev/hda3. Because it is a kernel parameter, it
uses the normal Linux method of referring to disks and partitions. The final
part of the stanza uses
savedefault to make the stanza a default option in the
GRUB menu, and the command
boot actually boots the system.
If you want to add another operating system, simply add it elsewhere in the
configuration file. A Windows stanza looks like this:
title Windows 95/98/NT/2000
root (hd0,0)
makeactive
chainloader +1
When you are booting non-Linux operating systems (most likely Win-
dows), you usually will need to use the
makeactive and chainloader key-
words. The
makeactive keyword is used to set this partition as GRUB’s main
root filesystem device. The