Using the CAU of the K64F board with uVisor


I want to use the Cryptographic Acceleration Unit (CAU) of the NXP K64F development board together with uVisor. When I add the CAU memory region to the ACL of my box, I get this error:

HALT_ERROR(core/system/src/mpu/vmpu_freescale_k64.c#156): ACL in unhandled memory area

the CAU is located on the Private Peripheral Bus (PPB). I think this could be the problem, as I get the same error when specifying another memory region within its address range (eg. the MCM memory region). In the processor documentation it says that the external PPB is accessible from privileged mode only, but only uVisor itself runs in privileged mode. Can the CAU be used with uVisor anyway?