Ubuntu – Cannot boot after BIOS / UEFI reset to defaults

12.04bootgrub2resetuefi

I have a ThinkPad X130e. I installed Ubuntu 12.04 LTS amd64 on it. All worked fine until yesterday. While diagnosing another issue I reset the BIOS / UEFI to defaults. Afterwards Ubuntu did not boot any more. The ThinkPad shows Operating System not found and that's it.

Did the BIOS / UEFI reset somehow nuke GRUB? If so how is that possible? How do I fix it?

Best Answer

  • A BIOS reset, voluntary or through an update will wipe the EFI boot entries more often than not.

    To restore the boot entry one has to use a recovery disc and reinstall grub-efi or grub-efi-amd64. The entry can also be added manually.

    This question shows a couple of ways to fix it: https://superuser.com/questions/376470/how-to-reinstall-grub2-efi.