SW4STM32 and SW4Linux fully supports the STM32MP1 asymmetric multicore Cortex/A7+M4 MPUs

   With System Workbench for Linux, Embedded Linux on the STM32MP1 family of MPUs from ST was never as simple to build and maintain, even for newcomers in the Linux world.
And, if you install System Workbench for Linux in System Workbench for STM32 you can seamlessly develop and debug asymmetric applications running partly on Linux, partly on the Cortex-M4.
You can get more information from the ac6-tools website and download two short videos (registration required) highlighting:

System Workbench for STM32

STLINK v2 reset not working, unable to program/debug

I feel for you having jumped through hoops the last few days with something like this myself.

Have a close look at your .cfg file for OpenOCD... also if you change stuff in your debug configurations you will overwrite changes in the .cfg file for some reason, so rename your modified .cfg and choose that instead.

I’m a newbie to OpenOCD myself but if you put the contents up here then someone might know.