root@ubuntu:~# update-grub
Generating grub.cfg ...
Found linux image: /boot/vmlinuz-2.6.32-22-generic
Found initrd image: /boot/initrd.img-2.6.32-22-generic
Found linux image: /boot/vmlinuz-2.6.32-21-generic
Found initrd image: /boot/initrd.img-2.6.32-21-generic
Found memtest86+ image: /boot/memtest86+.bin
Found Gentoo Base System release 1.12.13 on /dev/sda1
done