00_header
05_debian_theme
06_os-prober (default: 30_os-prober)
10_linux
20_linux_xen
20_memtest86+
30_uefi-firmware
40_custom
41_custom

GRUB_TIMEOUT=3

# update-grub2
Generating grub.cfg ... => /boot/grub/grub.cfg
Found Microsoft Windows XP Professional on /dev/sda1
Found linux image: /boot/vmlinuz-3.8.0-30-generic
Found initrd image: /boot/initrd.img-3.8.0-30-generic
Found linux image: /boot/vmlinuz-3.8.0-19-generic
Found initrd image: /boot/initrd.img-3.8.0-19-generic
Found memtest86+ image: /boot/memtest86+.bin
done