Hi Eugene:
The MPU API interface is defined in
devices/[MCU]/drivers/fsl_sysmpu.c
devices/[MCU]/drivers/fsl_sysmpu.h
There is a SYSMPU example defines protected/unprotected memory region for the core access
boards\frdmk82f\driver_examples\sysmpu
These APIs can also used in a FreeRTOS projects.
Regards
Daniel