Restoring UEFI boot entries after motherboard change

My ThinkPad 460p motherboard got changed due hardware failure and now I’m struggling the restore the uefi boot entries. Prior motherboard change system had working dualboot setup (Windows 10 and Leap 42.2).
What I’ve learned is that this is because motherboard NVRAM had the boot entries and they’re now gone and need to be restored.

I’ve got the Leap 42.2 installation USB. Problem is that with UEFI boot I get kernel 11 panics. I suspect it’s due videocard.

Here’s what works and what doesn’t work:

  1. With legacy boot I can boot using USB to rescue or my Leap 42.2 using Kernel safe settings or setting video to no KMS. Without either of these, kernel will panic 11 and boot fails. Since this is in legacy, efimanager etc cannot see the boot entries. I can use this to mount EFI partition and tweak that.
  2. With UEFI boot & usb, I’ve not managed to find grub2-efi options/settings that would work. Adding “nomodeset” to linuxefi or set gfxplayload=text do not seem to have any effect.
  3. Trying to use grub2-efi “Boot from Harddisk”, I booted in legacy mode, mounted EFI partition and copied EFI/opensuse/grubx64.efi to EFI/Boot/fallback.efi. Booting to this fails as linux or initrd are not found.

Any advice how to boot system in UEFI and after that how to restore the boot entries?

Hi
You need to boot in efi mode, try a tumbleweed live system, try using nomodeset, as long as you get to the command line you will be fine to create the efi entries with efibootmgr.

Thanks for quick reply!

I tried Thumleweed live dvd but with same result as with Leap 42.2 USB (kernel panic 11). Here’s that I did:

  1. Set UEFI mode in BIOS
  2. Boot from USB
  3. Select “Rescue system” from grub-efi
  4. Press e to modify parameters
  5. Change following line
    from “linuxefi /boot/x84_64/loader/linux/ splash=silent rescue=1” to “linuxefi /boot/x84_64/loader/linux/ splash=silent rescue=1 nomodeset”
  6. ctrl-x
  7. System loads kernel and boots and panics while green bars are “loading” at the bottom of the screen

I know need to boot in efi-mode, but haven’t found a way to do that without that kernel panic. Maybe I’m doing something wrong?

Hi
So it’s booting into windows ok?

There is no CSM compatibility mode or such in the BIOS?

Are you plugged into a USB 2 or USB 3 (Blue connector), can you disable USB 3, can you select USB Legacy support in the BIOS. Is the USB device 2 or 3?

Yes.

There is and it’s enabled.

It’s USB 3. ThinkPad t460p doesn’t have any USB 2 ports. I didn’t find any related settings (USB legacy) in the BIOS.

When I boot in legacy mode, I can get to Rescue system when using video mode “no kms” or “safe settings” kernel options. Any idea what I should try to use instead or in addition to the “nomodeset” to have same effect with grub-efi ? Was I applying “nomodeset” correctly?

Hi
Maybe it’s plymouth then and add some verbose output;


nomodeset plymouth.enable=0 splash=verbose