Implementation of asymmetric multiprocessing using a practical example on the i.MX8X with OpenAMP
David Kauschke, Mixed Mode GmbH
Heterogenous multiprocessor systems on a chip (MPSoC) have become increasingly popular for industrial applications in recent years due to their high performance, lower cost and energy efficiency. In particular, the use of many different integrated processors running different operating systems poses multiple challenges. This architecture is also known as Asymmetric Multiprocessing (AMP). The two biggest challenges are lifecycle management (LCM) and inter-processor communication (IPC).
This article presents the design of heterogeneous MPSoCs and the use of different operating systems. A framework is selected as the proposed solution to the two challenges. This is followed by a presentation detailing the implementation of the developed AMP system with the selected OpenAMP framework on NXP i.MX8X MPSoC with embedded Linux on the ARM Cortex-A35 and FreeRTOS on the ARM Cortex-M4, using Variscite’s VAR-SOM-MX8X SoM. To evaluate the implemented system, the latency times on the iMX 8X are measured. The results show, among other things, that the maximum latency from Linux user space to FreeRTOS with the use of the RT patch is 628 µs. From the results, it can be concluded that the IPC between the processors is suitable for soft real-time.