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

ac6 cannot debug/program stm32F411RE after update .... yet again.


This error message makes me think that the ST-Link is busy (a debug session is already running?). Try to terminate every debug session before running a new one, unplug then replug the ST-Link USB to reload the driver.
Sometimes, if multiple debug session are started on the same target, the OpenOCD executable does not exit well which blocks access for new connection to the ST-Link (You can verify if there is no openocd.exe running in background in the Windows Process Explorer).

Hope it helps,