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

how the variable of openstm32_compiler_path been set?

Eclipse variables such as openstm32_compiler_path can be changed by opening the property dialog (Project -> Properties) then selecting C/C++ Build -> Build Variables

Make sure to check the “Show System Variables” option on the bottom of the dialog.

I tried editing the variable mentioned above (which was marked as a “ECLIPSE DYNAMIC VARIABLE”) to point to a different location for the ARM GCC tools, the override was accepted, and shows in the Build Variables dialog with the changed value, but it did not appear to “take”; the AC6-bundled tools were still used.

It is possible that you might have to edit the PATH (same dialog) since the path to the AC6-provided toolchain appears here as well. I did not take my own experimentation that far.