Rescue – UEFI Revert To BIOS Boot – How?
hi guys
I have a box on which UEFI boot has gone haywire and instead of boot it power the box down, that is before even going to grub2. (displays some error message)
I if change to BIOS boot then I can start CentOS‘ rescue –
my question is: how can I rescue, re-build grub so it would boot from tradition BIOS?
many thanks, L.
3 thoughts on - Rescue – UEFI Revert To BIOS Boot – How?
If the OS was installed with UEFI enabled I would go back to UEFI mode.
Then re-add your OS boot configuration within the BIOS setup screen.
Most motherboard manufacturers detail this process on their website where you browse the disk to select somefilename.efi and give it a label “CentOS”.
CentOS mailing list CentOS@CentOS.org https://lists.CentOS.org/mailman/listinfo/CentOS
Hi,
I had the same sort of issue. My workstation with a Asrock motherboard suddenly decided to reset UEFI to defaults which caused my Fedora installation not to boot. I could boot with a Live USB stick and use efibootmgr to set the UEFI boot for Fedora but next time I powered on my machine the same issue happened (I remove AC power from my workstation when it is not in use). Turned out to be a flat battery for the BIOS
(coin cell). I replaced the coin cell and set the UEFI boot with the Live USB stick and all was well. The efibootmgr command was something like :
efibootmgr -c –part 2 –loader /EFI/Fedora/grubx64.efi –label Fedora
Please check the manpage of efibootmgr, the process of how to setup the UEFI boot is described very well.
Regards,
Michel
vanishing. Not enable faux BIOS legacy boot, which literally means UEFI
plus BIOS hacked on top.
As much a PITA UEFI is, adding more crap on top is asking for even more confusion.
An alternative is benevolent malware as the firmware+bootloader. E.g. https://lwn.net/Articles/748586/
Chris Murphy