Architectures for mixed-criticality systems based on networked multi-core chips

Mixed-criticality architectures with support for modular certification make the integration of application subsystems with different safety assurance levels both technically and economically feasible. Strict segregation of these subsystems is a key requirement to avoid fault propagation and unintended side-effects due to integration. Also, mixed-criticality architectures must deal with the heterogeneity of subsystems that differ not only in their criticality, but also in the underlying computational models and the timing requirements. Non safety-critical subsystems often demand adaptability and support for dynamic system structures, while certification standards impose static configurations for safety-critical subsystems. Several aspects such as time and space partitioning, heterogeneous computational models and adaptability were individually addressed at different integration levels including distributed systems, the chip-level and software execution environments. However, a holistic architecture for the seamless mixed-criticality integration encompassing distributed systems, multi-core chips, operating systems and hypervisors is an open research problem. This paper describes the state-of-the-art of mixed-criticality systems and discusses the ongoing research within the European project DREAMS on a hierarchical mixed-criticality platform with support for strict segregation of subsystems, heterogeneity and adaptability.