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 (registration required) various documents highlighting:

System Workbench for STM32

AC6 OpenOCD not working with STM32CubeMX import



Did you try killing all existing openocd sessions before starting the debugger? sometimes openocd sessions are running in the background thus disturbing the normal debug session startup. If the session refuses to disapear you may try to exit Eclipse then restart.

Bernard (Ac6)