sudo update-grub
Generating grub configuration file ...
Warning: Setting GRUB_TIMEOUT to a non-zero value when GRUB_HIDDEN_TIMEOUT is set is no longer supported.
Found linux image: /boot/vmlinuz-3.13.6-031306-generic
Found initrd image: /boot/initrd.img-3.13.6-031306-generic
Found linux image: /boot/vmlinuz-3.13.4-031304-generic
Found initrd image: /boot/initrd.img-3.13.4-031304-generic
Found linux image: /boot/vmlinuz-3.13.0-031300-generic
Found initrd image: /boot/initrd.img-3.13.0-031300-generic
Found linux image: /boot/vmlinuz-3.12.3.old
Found initrd image: /boot/initrd.img-3.12.3
Adding boot menu entry for EFI firmware configuration
done