The goal of the IMICRASAR project is to create an isolated mixed criticality hard real‐time platform that can be used for avionics and similar applications. By isolated we mean time & space isolation, including fine grained memry management, so that there are no unexpected interferences between tasks and the system remains predictable.

The main part is the porting of the HIPPEROS RTOS on the Thales EuroCPS platform, and the development of the required extensions in the RTOS kernel to support isolated mixed-criticality directly handled by the RTOS scheduler. Mixed criticality applications appear whenever the same hardware is used for applications having different criticalities (DAL). The system can then run in several modes, depending on the current criticality level, or in transition modes while migrating from one mode to another mode. The scheduler needs to make sure that all tasks in a given mode always meet their deadlines. Then depending of the current mode of operation, the system needs to schedule only the tasks that are required at that mode. In particular, whenever the system is a low criticality mode and a condition is detected that indicates that a higher criticality mode is required (e.g. one higher criticality job overruns its WCET (Worst Case Execution Time) estimated at the lower criticality level) the system will automatically enter a transition mode and then the higher criticality mode, where only high criticality tasks will run. This scheduler is conceptually close to the ARINC653 standard (de facto standard for avionics) used mostly in this sector, but extended to a multicore platform, while having the required extensions in such a way that the system remains highly predictable. The RTOS is also small enough to fit in constrained platforms and to be cache resident and thus avoid speculative execution. The main innovation of our approach to mixed criticality compared to state-of-the-art is that it is not only based on time & space isolation but also on the RTOS mode awareness to detect criticality mode changes so that the scheduler can react in a way that satisfies the requirements of critical tasks without shutting down all the others.

The requirement to use a single multicore board for combining mixed criticality applications comes regularly in market studies in several markets. The main drive is to reduce the number of boards, thus drastically reducing hardware costs and overall complexity. The creation of this RTOS makes it possible for embedded electronics designers to integrate mode functionalities in the same hardware, avoiding unnecessary redundancies and thus costs. As there is so far no acceptable mixed-criticality COTS solution on the market, and there is a clear market demand for it, this new development will in turn open new market opportunities for the HIPPEROS product in avionics and also in other markets (e.g. UAVs, UGVs, robotics, …).

HIPPEROS S.A. is Belgium’s specialist in multicore RTOS. It provides software for real-time and embedded systems requiring high performance and high reliability. It develops and markets the HIPPEROS (High Performance Parallel Embedded Real-time Operating Systems) multicore RTOS. HIPPEROS was designed for optimal scalability to take advantage of new parallel platforms. HIPPEROS supports critical applications that need to perform under constraints (SWaP), and thus where optimality of resource usage , such as low power and reduced footprint, is important.