Sometimes after a kernel upgrade, I don’t know why, the grub is not updated properly and then it is not possible to boot the system. Here it comes the way to solve this problem quite easily.
Use a LiveCD or a Rescue Mode to have access to the hard drive that holds the OS you are not able to boot.
Once logged in, chroot your former system.
$ sudo -i # mkdir /mnt/chroot # mount /dev/sda1 /mnt/chroot <--- replace sda1 for your system partition # mount -o bind /dev /mnt/chroot/dev # mount -o bind /sys /mnt/chroot/sys # mount -o bind /proc /mnt/chroot/proc # chroot /mnt/chroot # grub-install --recheck /dev/sda1 # update-grub
Then reboot and cross-fingers.
As of my later post, you are not getting the Nexus S kernel source. And what is more it seems rather difficult to customize it (include new modules or facilities, etc.).
Next it is shown how to do so. It is not as difficult as expected and the procedure is quite similar to a kernel customization and build in a computer.