Secure Boot on TR4 X399 - Bricked.

[mikearuba]

Hi,

Does anyone have any experience enabling Secure Boot on the Asrock Taichi X399 motherboard + Threadripper (2950x)?

I have followed the guide https://wiki.gentoo.org/wiki/Secure_Boot and all goes as instructed. sbctl shows that the setup mode is exited.
When I reboot with Secure Boot enabled (out of setup mode) it simply "bricks" the PC -> a black screen and BIOS can no longer be entered nor can the computer be booted; can't do anything with it.
The code on the Dr.Debug LED display on the motherboard indicates "0E", then, left long enough, "00" ( I think, 'normal' )

I wish I could provide more detail on my install but it's now a literal brick. Fresh Gentoo install (plasma systemd x64). Bios version is 4.0.3 (latest)
https://www.asrock.com/mb/amd/x399%20taichi/index.asp

I'm puzzled as to why it would no longer do anything at all, black screen regardless of powering on/off/waiting etc....

Just wondering if anyone has come across anything similar. Maybe a BIOS bug, but there again Win 11 secure boot works fine.

[NeddySeagoon]

mikearuba,

Welcome to Gentoo.

Reading your motherboard manual, you have a Clear CMOS switch, located just to the left of the Dr Debug display, when that's at the bottom of the motherboard.
At the very least, it will corrupt the CMOS settings, so that the checksum is invalid. That should force the system into the BIOS an next boot.

It will not boot with the Clear CMOS switch in the clear position, as that usually holds the CPU reset.

You also have a BIOS flashback facility but that's usually very scary to try to use, so don't do that until we have tried everything else.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

[Goverp]