Can't get to BIOS after setting UMA Frame Buffer to Auto

wsanders

Problem: I can't get to the BIOS after setting the UMA Frame Buffer size in the BIOS to "Auto". When I hold down "delete" after a power cycle the system goes through an extra boot step or two compared to when it was set to the factory default of 3G, then I get a black screen. This is an SER6 with the 6600H CPU.


If I don't hit any keys, the system eventually boots into Fedora 38. but I don't see the GRUB menu. I have a dual boot system with the factory Windows 11 on another partition. So, for now, I can't go back to Windows 11.

How can I get to the BIOS?

More questions:

Is there a kernel option I can edit in GRUB to override the UMA Frame Buffer BIOS setting?
Is there a newer verson the BIOS I can upgrade to without booting into the BIOS?
Can I factory reset the BIOS somehow without booting into it?

I set the UMA buffer size to Auto because there are some bugs inthe Fedora amdgpu driver I'm tryng to work around. Every few days my system locks up.  I can't use Ctrl-Alt-Delete to reset, but I can ssh into the box and work with it that way.

Any other ideas?

These are the current options for my default GRUB boot entry:

kernel="/boot/vmlinuz-6.4.14-200.fc38.x86_64"
args="ro rootflags=subvol=root rhgb quiet"
root="UUID=cc96eaa8-054d-449b-b047-3c649b75c068"
initrd="/boot/initramfs-6.4.14-200.fc38.x86_64.img"
title="Fedora Linux (6.4.14-200.fc38.x86_64) 38 (KDE Plasma)"
id="0c5a3abaf6aa4371a69e8f1ae1605403-6.4.14-200.fc38.x86_64"

wsanders

I had never noticed the CLR CMOS hole before reading about it an another post. Very handy. After resetting the CMOS as per instructions the SER6 boots normally, and I see the GRUB menu.

It's still a bug that merits looking into, that setting the UMA Buffer Size to Auto makes the BIOS unusable. Since I am not a gamer, I have reduced the UMA Buffer Size to 1G from the default 3G with no detrimental effects - I can still get to BIOS, GRUB, etc.

I also noticed that the CPU TDP setting is set to 35W from the factory. I did some stress tests with the TDP set to 45W and found it had a minimal effect of the maximum CPU temperature. The CPU temp maxed out at 89C in 35W mode and 91C in 45W (the CPU rated power) mode. Perhaps there might be a difference in fan noise, but in my non-gamer use I rarely see the CPU temp rise about 56C except at boot.

tuiguang7

Hello ,thanks for your sharing.