Grub2

To configure the GRUB2 bootloader on SUSE Linux, use the file /etc/grub2/grub.cfg. I can be generated by the command

grub2-mkconfig -o /boot/grub2/grub.cfg

from /etc/default/grub and the files in /etc/default/grub

/etc/grub.d/*____
                 \
                   --- (grub2-mkconfig -o /boot/grub2/grub.cfg --->  /etc/grub2/grub.cfg
                 /
/etc/default/grub

The best way to add a menu item to your grub2 boot menu is to add the command menuentry to the end of /etc/grub.d/40_custom like this:

• change /etc/grub.d/40_custom to look like:

#!/bin/sh
exec tail -n +3 $0
# This file provides an easy way to add custom menu entries.  Simply type the
# menu entries you want to add after this comment.  Be careful not to change
# the 'exec tail' line above.

menuentry linuxintro{
}

• call grub2-mkconfig:

# grub2-mkconfig -o /boot/grub2/grub.cfg 
Generating grub.cfg ...
Found theme: /boot/grub2/themes/openSUSE/theme.txt
Found linux image: /boot/vmlinuz-3.7.10-1.40-desktop
Found initrd image: /boot/initrd-3.7.10-1.40-desktop
Found linux image: /boot/vmlinuz-3.7.10-1.16-desktop
Found initrd image: /boot/initrd-3.7.10-1.16-desktop
  No volume groups found
error: syntax error.

• woops ;) Add a volume to the configuration in /etc/grub.d/40_custom:

#!/bin/sh
exec tail -n +3 $0
# This file provides an easy way to add custom menu entries.  Simply type the
# menu entries you want to add after this comment.  Be careful not to change
# the 'exec tail' line above.

menuentry linuxintro{
  set hd=(hd0,0)
}

• and run mkconfig again:

# grub2-mkconfig -o /boot/grub2/grub.cfg