Encapsulating Application Subsystems Using the DECOS Core OS

This paper presents an approach to structured integration of different application subsystems on the same embedded hardware, as currently developed in DECOS (Dependable Embedded Components and Systems), an integrated project within the Sixth Framework Programme of the European Commission. Those application subsystems can have different criticality levels and vendors. Furthermore, reliable communication among application subsystems is a major concern. Focusing on the Encapsulated Execution Environment (EEE), which separates application subsystems in the space AND the time domain, this approach outlines the concepts and principles of an exokernel operating system, of partitioning, and of virtualization. The Core Operating System (COS) is described as a case study, including the hardware used, the current feature set, and benchmark values of central COS operations. This paper also presents a model for a platform-independent application interface layer. Parts of this interface layer are generated from task specification to provide tasks with tailored communication services.