ucode 06-cf-01 fails to boot machine

[fanchen2]

With ucode 06-cf-01, I failed to boot machine into OS. just hang with black screen.
I tried all 3 versions in this repo 21000200, 21000230, 21000283, none of them can boot machine up.
But the one in BIOS: 0x21000070 works well. But it seems like this version is not in this repo.
My CPU:
CPU family: 6
Model: 207
Thread(s) per core: 2
Core(s) per socket: 56
Socket(s): 2
Stepping: 1

[hmh]

As far as I can tell from public documentation, this should be stepping A1 of a Gen5 Xeon Scalable processor.

https://edc.intel.com/content/www/us/en/design/products-and-solutions/processors-and-chipsets/eagle-stream/emerald-rapids-specification-update/identification-information/

Stepping A1 is not listed as a production stepping on the above documentation, so it appears to be an ES/QS stepping ?

[fanchen2]

@hmh Thank you for your response, yes, it is stepping A1, not production stepping, I have no idea about ES/QS.
But we can get the ucode in this repo, so it is not expected to work? or not expected be included in this repo?

[hmh]

Apparently, it wasn't, and it has been removed on release 2025-05-12.

ES/QS processors have never been supported for end-users by Intel as far as I know, they are "early (ES) and late (QS) development steppings" of the processor, and will miss several hardware fixes (and sometimes updates to the factory-preloaded microcode) when compared to the production steppings of the same processor.

I have no business knowing how an ES/QS part come to your possession (and I don't care: I don't work for Intel), I can only tell you they are not supposed to be sold or distributed outside of hardware development partners in the first place. And I can only ask you to please never report any software bugs (especially to unpaid free software developers!) on anything running on an ES or QS processor.

"Undefined Behavior Hellholes" are how these processors are known among software developers, and users that report bugs while running on such processors are not appreciated...