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Schedulability analysis of hierarchical real-time systems is based in the previous knowledge of the scheduling algorithms both in the local and the global levels. In a partitioned system with safety and security issues and certification assurance levels, the global scheduling is usually generated using a static table. Therefore, each partition must allocate task jobs only in the temporal windows reserved for that partition. Even if the static table can come originally from a periodic server or other scheduling policy, the final plan can suffer from modifications due to changes in the system requirements. As a consequence, the CPU assignment to a partition does not have to correspond to any known policy. In this case, it is not possible to use existing scheduling analysis for hierarchical systems. This paper provides a schedulability analysis when the global level policy is not known but provided as a set of arbitrary time windows. The paper also provides a method to determine the more restrictive CPU assignment for a task set, as a mean of stablishing minimum temporal requirements for the partition.

International audience; The transition from conventional federated archi-tectures to integrated architectures enables the integration of functionalities with different criticality (such as safety, security and real-time) on a single embedded computing platform. Many embedded mixed-criticality systems require distributed subsystems with networks to satisfy computational resource demands and installation requirements and ensure fault-tolerance. The broad trend of the integration of functionalities with different crit-icality on a multi-core embedded computing platform increases the complexity and challenges to certification, which is supported by the fact that today's safety-related standards are mostly focused on single-core devices and not on multi-core devices where resources are shared between more than one component. This paper analyses the commonly occurring problems in today's mixed-criticality systems and presents reusable generic solutions to tackle them, including solutions for hypervisors, commercial-off-the-self multi-core devices and mixed-criticality networks.

International audience; In a context of complexification of embedded systems within satellites, CNES is an actor in the will to promote standardization and reuse from a mission to another.By definition, in the frame of satellites payloads, the flight software is mission specific and therefore developed from scratch for each instrument. This is due to the fact that most of the payload developments in the scope of scientific missions are contracted to national institutes (each time a different one), those have generally poor background in embedded real time software engineering. But even in this case, a certain number of subsets can be considered as generic and would benefit in not being redeveloped for each mission.

International audience; ARINC 653 defines a partitioned framework where the partitions are scheduled according to a predefined cyclic plan and the processes of each partition are scheduled with a fixed priority policy. The timing characteristics defined in ARINC (period and duration) can hardly be used to precisely represent the timing requirements of the applications. We extend the timing model of ARINC 653 to consider deadlines and the periodic behaviour of the individual processes. A novel definition of how to model periodic activities and how this new model is specially useful in an heterogeneous partitioned system is also presented. The new model and the set of scheduling algorithms have been implemented in a scheduling tool (called Xoncrete) to assist the designer to generate the cyclic plan table. Although founded on solid theoretical results, Xoncrete is not a general purpose tool, it is a tool designed to provide real help to the system designer.