About GDB debug AP Cores for Morello_FVP

Hi everyone.

I have build and run morello_fvp by following below guide.

https://git.morello-project.org/morello/docs/-/blob/morello/release-1.6/firmware/user-guide.rst?ref_type=heads#running-the-software-on-fvp

When i try to append "--plugin ~/FVP_Morello_install/plugins/Linux64_GCC-6.4/GDBRemoteConnection.so -D" , 

and use gdb-multiarch <scp_elf> then connect port 31627 , it can debug the core which running SCP firmware normally.

But i didnt find any way to debug AP cores , i have tried to find any useful information in FVP help message or FVP list parameter, but doesnt find any clue yet.

Could you please help to give some advice about it?

Thanks a lot.