FYI: HAP (Alt Disable) Flag Descriptor Location Changed on Alder Lake (ADL)

[GeographicCone]

On Alder Lake (ADL; 12th Gen CPU / CSME 16.0/16.1), the reserve_hap flag is now at offset 0x017E in the descriptor, and the HAP (Alt Disable) mode is switched on by setting it to 0x01.

me_cleaner can't really deal with the image:

• % python me_cleaner.py -s Dump.bin
Full image detected
The ME/TXE region is valid but the firmware is corrupted or missing

Coreboot's ifdtool can but patches it in the wrong place, even if explicitly told the platform is ADL:

• % ifdtool -M 1 -p adl Dump.bin
  • Result is change at offset 0x0102: 0x00 → 0x01

Otherwise, with fallback settings:

• % ifdtool -M 1 Dump.bin
  • Result is change at offset 0x0128: 0x01 → 0x81

So the patch is probably best applied manually for the time being. The location might be different on different platforms. One way to find out is to… look it up with Intel's very own MFIT (Modular Flash Image Tool), part of CSME Tools. It's located at:

• Intel ME Kernel → Reserved → Reserved: (No|Yes)

Note however that there might be side effects. On the laptop I tested it with, the device INTELAUDIO\DSP_CTLR_DEV_51C Intel Audio Smart Sound Technology (SST) OED (VEN8086&DEV_0222) no longer works. The error is:

• "The device cannot start. (Code 10)"
• "FW did not sent [sic!] FW Ready notification"

This also causes the boot time to become unreasonably long. Perhaps a workaround is possible by tweaking the UEFI/BIOS settings but it's not immediately obvious as to which.