<< Solved >> BIOS/UEFI disappeared!!! Please help me...

[crybbio]

After tons of hours spent I finally managed to install Big Sur. Then I copied the EFI folder of the USB installer in the Big Sur drive EFI partition to manage the boot. I don't know what is happened... Now, if I try to enter in the BIOS/UEFI screen, pressing canc or F2, nothing is happening and the screen remains black indeed, after a while, the screen turns off while the keyboard and mouse remain on. I have to reboot with cntr-alt-canc. If I do nothing, the Open Core boot appears as if the drive containing Macos had become the default. What can I do to bring up the BIOS menu again?

 

[crybbio]

I tried everything but with no luck. To give it another try, I checked my motherboard data on CPU-Z and ... I discovered an amazing thing: the Big Sur installation changed something on the board! It no longer appears as ASUS Rog Strix H370-I Gaming but as Acidantera, iMac model! How is it possible?? Could this be why the Del and F2 keys no longer work to enter the BIOS / UEFI?

 

[trs96]

IF you are using OC 0.6.3 or older try doing this:

Go to Misc -> Security -> BootProtect
Change the String from Bootstrap to a value of None

 

[crybbio]

I'll try, thanks a lot

 

[Bustycat]

I tried everything but with no luck. To give it another try, I checked my motherboard data on CPU-Z and ... I discovered an amazing thing: the Big Sur installation changed something on the board! It no longer appears as ASUS Rog Strix H370-I Gaming but as Acidantera, iMac model! How is it possible?? Could this be why the Del and F2 keys no longer work to enter the BIOS / UEFI?

Set CustomSMBIOSGuid to true (boolean) and UpdateSMBIOSMode to Custom (string).

 

[crybbio]

Change the String from Bootstrap to a value of None

Set CustomSMBIOSGuid to true (boolean)

UpdateSMBIOSMode to Custom (string)

Just did them: nothing changed...I'm not still able to enter the Bios/UEFI screen

 

[trs96]

Just did them: nothing changed...I'm not still able to enter the Bios/UEFI screen

You should read this and follow the directions 100 %. You'll need a BIOS reflash to gain access again.

Bootstrap causes BIOS corruption on Gigabyte Z87 if to make reset CMOS · Issue #1222 · acidanthera/bugtracker

Configuration: OpenCore 0.6.2, Haswell CPU, Gigabyte Z87-UD3H motherboard with "F7" BIOS Setup: Bootstrap enabled <key>BootProtect</key> <string>Bootstrap</string> Symptoms: "OpenCore" shows as fir...

github.com

This is a problem with more than just Z87 Haswell boards. It's why Acidanthera has changed BootProtect to None instead of Bootstrap with their latest OpenCore.

 

[crybbio]

You should read this and follow the directions 100 %. You'll need a BIOS reflash to gain access again.

Bootstrap causes BIOS corruption on Gigabyte Z87 if to make reset CMOS · Issue #1222 · acidanthera/bugtracker

Configuration: OpenCore 0.6.2, Haswell CPU, Gigabyte Z87-UD3H motherboard with "F7" BIOS Setup: Bootstrap enabled <key>BootProtect</key> <string>Bootstrap</string> Symptoms: "OpenCore" shows as fir...

github.com

This is a problem with more than just Z87 Haswell boards. It's why Acidanthera has changed BootProtect to None instead of Bootstrap with their latest OpenCore.

Thanks so much. I assume I will get the default Bios settings that I'll have to modify again.

 

[trs96]

I will get the default Bios settings that I'll have to modify again.

yep

 

[crybbio]

You should read this and follow the directions 100 %. You'll need a BIOS reflash to gain access again.

Bootstrap causes BIOS corruption on Gigabyte Z87 if to make reset CMOS · Issue #1222 · acidanthera/bugtracker

Configuration: OpenCore 0.6.2, Haswell CPU, Gigabyte Z87-UD3H motherboard with "F7" BIOS Setup: Bootstrap enabled <key>BootProtect</key> <string>Bootstrap</string> Symptoms: "OpenCore" shows as fir...

github.com

This is a problem with more than just Z87 Haswell boards. It's why Acidanthera has changed BootProtect to None instead of Bootstrap with their latest OpenCore.

I was reflecting on another problem that appeared after installing Big Sur and the disappearance of the Bios / UEFI (https://www.tonymacx86.com/threads/usb-issue-and-sudden-reboot.308824/): could the two be connected?