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

OPENOCD Debug doesn't work, but on STM32 ST-LINK Software works

To make the debug work you can Erase the chip on the STM32 STLINK Software, it should work.

I had this problem. There was a configuration problem, I looked to the assert functions and it was to pointing to ‘0’ which I believe that resets the microcontroller. Then, I activated the FULL_ASSERT and then I could see what was wrong. In my case it was a GPIO configuration problem. I forgot to put the pulls (I thought that it was not necessary, it’s outputs) on the GPIO_InitTypeDef structure. After I did that, the debug was working.

You can try this solution, but don’t forget to Erase the chip before.