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I recently updated the firmware on my Asus Sabertooth 990fx, and now the UEFI bios won't boot my ubuntu install, which boots off of EFI. EFI boot works for the livecd, but the BIOS doesn't seem to recognize the ubuntu install anymore, which it did before.

Any help would be welcome.

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1 Answer 1

Your update may have removed the Ubuntu boot loader from the NVRAM settings. If the CD boots in EFI mode, you should be able to type the following commands (or some variant of them) to correct the problem:

sudo apt-get install efibootmgr
efibootmgr -c -l \\EFI\\ubuntu\\grubx64.efi -L Ubuntu

I'm not 100% positive of the path to GRUB on the EFI System Partition (ESP), so you may need to adjust that. Also, that path is specified using EFI-style backslashes rather than forward slashes, and since backslashes are escape characters in Linux shells, they must be doubled up -- hence \\EFI\\ubuntu\\grubx64.efi rather than /EFI/ubuntu/grubx64.efi. However it's expressed, this filename is relative to the root of the ESP, which is the partition that's identified by the boot flag in GParted or by a partition type code of EF00 in gdisk.

Another option is to move and rename grubx64.efi to /EFI/boot/bootx64.efi on the ESP; that's a sort of default/backup boot loader filename. A variant of this option is to install some other boot manager, such as rEFIt or rEFInd, under that name. This option might be appealing if you dual-boot with Windows or some other OS; rEFIt and rEFInd can both detect any EFI boot loader stored in conventional locations on the ESP and redirect the boot process to them. rEFIt has been abandoned, though, and the version on its Web site doesn't work on UEFI PCs; rEFInd is a fork of rEFIt that provides updates and that does work on UEFI PCs.

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