CXL IP Debug Toolkit

Hi WZ,

The issue evolved into 2 phases of debugging.

The first, and original, situation was the failure to boot the OS in the AMD system. With the Intel CXL Type 3 Example Design image in the DK-DEV-AGI027R1BES development kit plugged into the system, the handoff from firmware (EFI) boot to the OS causes the system to reboot itself. It happens in a very early stage of the boot, so no logs are created by the OS. By forcing the CXL to be treated as Special Purpose Memory in the BIOS settings, the OS is able to boot, but the device is not seen as a CXL device. Which leads to phase 2 of the investigation.

In the second situation, as stated earlier, the OS is able to boot, but the card does not appear as a CXL device to the OS. daxctl is invoked in order to make the device usable to the OS as a memory one. A simple C program was written so that a single byte can be written to the device. However, as soon as the write operation is executed, the system reboots itself.

The file attached to the start of the thread shows the CXL IP registers status extracted using the Debug Toolkit, after the write has been executed and the system rebooted.

Could you provide details on the meaning of the Debug Toolkit registers?

Thank you,

Ricardo