Multi-source and multicore automotive ECUs - OS protection mechanisms and scheduling

Abstract

Abstract-As the demand for computing power is quickly increasing in the automotive domain, car manufacturers and tier-one suppliers are gradually introducing multicore ECUs in their electronic architectures. Additionally, these multicore ECUs offer new features such as higher levels of parallelism which ease the respect of the safety requirements such as the ISO 26262 and the implementation of other automotive use-cases. These new features involve also more complexity in the design, development and verification of the software applications. Hence, OEMs and suppliers will require new tools and methodologies for deployment and validation. In this paper, we review the operating system protection mechanisms (e.g., memory, timing), needed for multi-source software in a safety critical context, with a clear focus on AUTOSAR OS which is the upcoming defacto standard for automotive ECUs. Then, we identify the main use-cases for automotive multicore ECUs and present solutions for the scheduling in a context where there are hundreds of software components and only a few OS tasks are allowed. Finally, experiments aim to assess the load level that can be reached on realistic case-studies.

An Efficient Hybrid Scheduler Using Dynamic Slack for Real-Time Critical Task Scheduling in Multicore Automotive ECUs

“…Each task of a task cluster is mapped to an OS Application. The OS Application is then mapped to a core by OS configuration [11]. Within a task, there will be a chain of nunnables to be executed sequentially.…”

“…At any releasing instant at the partitioned queue, the higher priority task get scheduled for execution. So at higher load conditions, low priority tasks do not get a CPU slot and because of strict partitioning, they are unable to migrate to other core even though the consequence is missing the deadlines [1,11]. CPU utilization is also not balanced with task partitioning.…”

System architecture and software design for electric vehicles

“…First of all, gaining higher computational performance without increasing the power consumption and heat dissipation can only be achieved by adding new cores rather than increasing clock frequencies of single-core processors [19]. Moreover, the enhanced performance per watt ratio supports the strict energy requirements in EVs and the higher level of parallelism provided by multicore systems allows for the compliance with automotive safety standards like ISO 26262 [20]. Finally, a major advantage is that software from single-core ECUs can be ported to multi-core ECUs more easily than to architectural different computational platforms, like FPGAs.…”

Embedded systems and software challenges in electric vehicles

“…Car manufacturers and suppliers currently favor multi-core ECUs as the computing devices for next-generation vehicles, see [6]. One advantage of multi-core systems is that existing software of multiple conventional single-core ECUs can be executed in parallel without any software changes using an appropriate operating system.…”