Edit /etc/grub.d/40_custom file to add custom entry in grub2 menu (this is just an example):
menuentry "Live" {
set root='(hd0,1)'
linux /boot/vmlinuz-3.2.0-24-generic boot=live toram=fs.squashfs
initrd /boot/initrd.img-3.2.0-24-generic
}
After applying changes update grub configuration:
# update-grub
To print kernel release use uname command:
$ uname -r
3.2.0-24-generic