A safety concept for a railway Mixed-criticality embedded system based on multicore partitioning

Mixed-criticality systems integrating applications subject to different safety-criticality levels into the same multicore embedded platform can provide potential benefits over traditionally followed federated architectures. While these advantages encourage many safety related industries, such as transportation systems, to venture to consider the mixed-criticality paradigm, many challenges related to safety certification of multicore approaches may hinder their adoption. This paper describes a safety concept for a railway signalling mixed-criticality system based on multicore partitioning that meets IEC-61508 and EN-5012X industrial safety standards. To reduce the conceptual gap caused by the fact that multicore partitioning and virtualization are still not 'common practice in industry' the safety concept argumentation is developed incrementally. To this end, it starts by the description of the commonly followed federated approach and transforms it up to meet integrated mixed-criticality paradigm upon two analogous multicore implementations, a COTS and an FPGA based in-house solution.