0

This is more than likely my fault for messing with UEFI in the first place.

tl;dr: I can't boot my Samsung RV520, the boot order is set in the BIOS/UEFI and I can neither boot from USB or DVD. What can I do?

I decided to upgrade from Ubuntu 18.04 to Ubuntu 20.04. After the installation my laptop would boot to the boot device selection screen and the wrong boot device was highlighted, so I wanted to change that. I couldn't in the BIOS (after a reboot the old boot order was back), so I decided to use efibootmgr.

I ran sudo efibootmgr -o A,B,C, which was "grub", "ubuntu" and "Windows Boot Manager".

This is now the fixed boot order in BIOS. It doesn't boot anything though, but just boot loops. I can still enter the BIOS, but new boot devices don't appear (USB or DVD) and changing the boot order doesn't do anything.

I also can't get to the Boot Menu to select a new boot device on the fly. I tried all the F keys, but the boot menu doesn't show.

  • F2: starts the BIOS (works)
  • F4: should start the recovery, but I removed that partition years ago.
  • F8/12: one of them should show the boot menu, but they don't.
  • F9: If a HDD is connected to laptop it turns off. If no HDD is connected the screen turns black (loop stops) and the CPU Fan starts spinning up.

I removed the BIOS battery over night, which did reset the BIOS, but the boot order persists.

It's a Samsung RV520 running a Phoenix SecureCore Tiano-BIOS. The HDD is GPT formatted and the uefi-partition is sda1 (ubuntu / is sda4).

BIOS2

BIOS3

BIOS4

BIOS5

BIOS6

karel
  • 114,770
dakes
  • 101
  • Post this: sudo efibootmgr -v. That will show boot order also. – oldfred Feb 18 '21 at 14:15
  • @oldfred I don't know where to put this in. I can neither boot from any installed OS or from USB/DVD – dakes Feb 18 '21 at 14:20
  • That is an Ubuntu command using terminal. You need to be able to boot from live installer and after reset, you should be able to select USB flash drive. Unless you damaged flash drive during some other changes. Then recreate new Ubuntu live installer flash drive. – oldfred Feb 18 '21 at 14:22
  • My problem is that ai can't reach any terminal at all. I can't change the boot order and the primary option doesn't boot. Putting a DVD or USB key into the laptop doesn't show up on boot options. – dakes Feb 18 '21 at 15:36
  • I think your original entries of A,B,C were probably the issue. They normally are 4 char hex and first ones are like 0001, 0002. Some can be 000A, and last char can work for many. – oldfred Feb 18 '21 at 18:54
  • So game over for this laptop? – dakes Feb 18 '21 at 19:56
  • With UEFI you always should be able to boot a flash drive, if flash drive is correct. Not sure of a way to erase UEFI entries, unless you can boot a recovery drive or get into UEFI & remove all entries. Once I did totally reinstall UEFI to reset mine as it seemed to lock up. And then I had to boot with rEFInd which I had as another recovery mode boot drive. You also can try Super grub. http://www.rodsbooks.com/refind/ & https://askubuntu.com/questions/908677/want-to-view-contents-of-boot-efi-in-xubuntu-dont-have-permissions & https://www.supergrubdisk.org/super-grub2-disk/ – oldfred Feb 18 '21 at 22:26

1 Answers1

0

So I got this fixed luckily. In short: I was able to boot by using an undocumented function of my bios which was that F3 always tries to boot from DVD. Using this I was able to boot WinPE and from there I was able to reset my bios.

The procedure is described in detail here. It also describes (in the links) how to obtain the necessary files.

http://forum.notebookreview.com/threads/samsung-series-7-np700z5c-s03ca-my-last-hope.762595/

Thanks to the people at notebookreview.com!

dakes
  • 101