You've probably noticed that you need to type several commands to boot your
OS. There's a solution to that - GRUB provides a menu interface
(see Menu interface) from which you can select an item (using arrow
keys) that will do everything to boot an OS.
To enable the menu, you need a configuration file,
menu.lst under the boot directory. We'll analyze an example
The file first contains some general settings, the menu interface
related options. You can put these commands (see Menu-specific commands) before any of the items (starting with title
# Sample boot menu configuration file
As you may have guessed, these lines are comments. Lines starting with a
hash character (`#'), and blank lines, are ignored by GRUB.
# By default, boot the first entry.
The first entry (here, counting starts with number zero, not one!) will
be the default choice.
# Boot automatically after 30 secs.
As the comment says, GRUB will boot automatically in 30 seconds, unless
interrupted with a keypress.
# Fallback to the second entry.
If, for any reason, the default entry doesn't work, fall back to the
second one (this is rarely used, for obvious reasons).
Note that the complete descriptions of these commands, which are menu
interface specific, can be found in Menu-specific commands. Other descriptions can be found in Commands.
Now, on to the actual OS definitions. You will see that each entry
begins with a special command, title (see title), and the
action is described after it. Note that there is no command
boot (see boot) at the end of each item. That is because
GRUB automatically executes boot if it loads other commands
The argument for the command title is used to display a short
title/description of the entry in the menu. Since title
displays the argument as is, you can write basically anything there.
# For booting GNU/Hurd
kernel /boot/gnumach.gz root=hd0s1
This boots GNU/Hurd from the first hard disk.
# For booting GNU/Linux
kernel (hd1,0)/vmlinuz root=/dev/hdb1
This boots GNU/Linux, but from the second hard disk.
# For booting Mach (getting kernel from floppy)
title Utah Mach4 multiboot
pause Insert the diskette now^G!!
kernel (fd0)/boot/kernel root=hd0s3
This boots Mach with a kernel on a floppy, but the root filesystem at
hd0s3. It also contains a pause line (see pause), which
will cause GRUB to display a prompt and delay, before actually executing
the rest of the commands and booting.
# For booting FreeBSD
This item will boot FreeBSD kernel loaded from the `a' partition of
the third pc slice of the first hard disk.
# For booting OS/2
# chainload OS/2 bootloader from the first sector
# This is similar to "chainload", but loads a specific file
# For booting Windows NT or Windows95
title Windows NT / Windows 95 boot menu
# For loading DOS if Windows NT is installed
# chainload /bootsect.dos
The same as the above, but for Windows.
# For installing GRUB into the hard disk
title Install GRUB into the hard disk
This will just (re)install GRUB onto the hard disk.
# Change the colors.
title Change the colors
color light-green/brown blink-red/blue
In the last entry, the command color is used (see color),
to change the menu colors (try it!). This command is somewhat special,
because it can be used both in the command-line and in the menu. GRUB
has several such commands, see General commands.
We hope that you now understand how to use the basic features of
GRUB. To learn more about GRUB, see the following chapters.
Published under the terms of the GNU General Public License