M2OS-Mc: An RTOS for Many-Core Processors

A current trend of industrial systems is reducing space, weight and power (SWaP) through the allocation of different applications on a single chip. This is enabled by the continued improvement of semiconductor technology which allows the integration of multiple cores in a single processor chip, as the processors are prevented to continue increasing their clock rate due to the "power-wall". The use of Commercial-Off-The-Shelf (COTS) multi-core processors for real-time purposes presents issues due to the shared bus used to access the shared memory. An alternative to the use of multi-core processors are the many-core processors with tens to hundreds of processors in the same chip, using different scalable ways to interconnect their cores. This paper presents the adaptation of the M2OS Real-Time Operating System (RTOS) and its simplified Ada run-time for mesh-based many-core processors. This RTOS is called M2OS-mc and has been tested on the Epiphany III many-core processor (referred in this paper simply as Epiphany), a many-core which has 16 cores connected by a Network-on-Chip (NoC) consisting of a 4x4 2D mesh. In order to have a synchronized way to send messages between tasks through the NoC independently of the core where they are being executed, we provide sampling port communication primitives