Hello everyone,

I am trying to  build an Intel platform's customized UEFI.

I have extracted the microcode and FSP binaries from the vendors UEFI image successfully. I also changed the PlatformPkg and FspFlashOffset FDF files. Execution goes on fine up until the last line of this subroutine:

FspHeaderFound:

  ; Get the fsp TempRamInit Api address

  mov eax, dword [edi + FSP_HEADER_IMAGEBASE_OFFSET]

  add eax, dword [edi + FSP_HEADER_TEMPRAMINIT_OFFSET]

  ; Setup the hardcode stack

  mov esp, TempRamInitStack

  ; Call the fsp TempRamInit Api

  jmp eax

I have checked the address of TempRamInit Entry which matched the address inside the FSP header.

but somehow it doesn't return to the TempRamInitDone subroutine. I have no idea why this happens. I also changed the UPD parameters to match the signature of the target platform.
Any thoughts on this?