Open Access

Florian Kluge

• Technological advancements enable to integrate more and more processing cores on single chips. After several years of multicore processors, in the last years the first manycore processors with 64 and more cores have reached the markets. Concurrently, designers of safety-critical systems strive to integrate more and more powerful software in their systems. For example, advanced driver assistence system increase travelling comfort, but can also improve car safety. Manycore processors can deliver the performance needed by such applications. Due to special requirements in safety-critical systems, a direct use of these processors is mostly hindered. To make them usable in safety-critical domains, existing concepts for software design need to be rethought and new concepts need to be developed. The operating system plays a key role in this process, as it provides the "glue" between application software and hardware platform. This work investigates, how future operating systems for manycoreTechnological advancements enable to integrate more and more processing cores on single chips. After several years of multicore processors, in the last years the first manycore processors with 64 and more cores have reached the markets. Concurrently, designers of safety-critical systems strive to integrate more and more powerful software in their systems. For example, advanced driver assistence system increase travelling comfort, but can also improve car safety. Manycore processors can deliver the performance needed by such applications. Due to special requirements in safety-critical systems, a direct use of these processors is mostly hindered. To make them usable in safety-critical domains, existing concepts for software design need to be rethought and new concepts need to be developed. The operating system plays a key role in this process, as it provides the "glue" between application software and hardware platform. This work investigates, how future operating systems for manycore processors should be designed such that they can be deployed in safety-critical systems. A manycore operating system for safety-critical applications (MOSSCA) is designed and applied to several use-cases. Operating system functionalities of MOSSCA are distributed over the cores of a manycore processor as far as possible. MOSSCA provides means to develop applications accordingly. Also it provides the platform for further investigations of operating system mechanisms. One of these is a timing analysis of the boot process in a manycore processor. Further considerations on shared resources show that the timing behaviour of applications is often abstracted too far in scheduling models, thus prohibiting optimisations or the exploitation of existing tolerances. A generic timing model (GTM) is developed to capture timing properties and requirements in cyber-physical system (CPS) during their development. One outcome of GTM are history-cognisant utility functions that can be applied for scheduling. In this work, their ability to map the constraints of (m, k)-firm real-time tasks is examined more closely. Beyond these, a number of further aspects is still being investigated, for example the coordination between tasks in a manycore processor and the further exploitation of GTM. These, and issues still open, are discussed at the end of this work.…