Lenovo ideapad u410
2 hdds of which 1 ssd
2 graphic cards with optimus technology- intel and nvidia, but disabled
Ubuntu 12.10 fresh install with EFI partition
It started ok
Update info appeared
Ask for reboot
After reboot the GRUB prompt appears
Boot from Live cd
Mount the boot partition, aka sda2
In boot/grub are the files updated.
The old one has read permission for all, the new one not.
sudo chmod a+r theFile
Restart is ok.
Maybe this can be done from grub prompt too?