A complete tool-chain for an interference-free deployment of avionic applications on multi-core systems

In the safety critical domain such as in avionics, existing embedded solutions based on single-core COTS processors are very unlikely to handle the new level of performance requirement of next generation safety-critical applications. One alternative would be to use multi-core COTS computers, but the predictability versus performance trade-off remains an obstacle for their use in a safety critical context: concurrent accesses to shared hardware resources are generating inter-task or inter-application interferences, breaking the isolation principles required by such critical software. To enable the usage of multi-core processors on safety critical systems, interferences need to be controlled and techniques need to be developed to exploit multi-core performance benefits.

In this paper, we have developed an approach and an associated tool suite able to enforce an interference-free system execution while emphasizing task parallelization to benefit from multi-core systems inherent performance. Providing strong certification guarantees of interference-free multi-core systems would require us to identify all potential sources of interference. This is beyond the scope of this paper. While restricting ourselves to the memory subsystems and the I/Os, our goal is to ensure an interference-free execution of a safety critical application deployed on a multi-core architecture, by proposing an approach avoiding interference scenarios. Our proposed approach couples hardware configurations minimizing interferences with a software execution model decoupling communication phases from execution phases. We are relying on a constraint problem solving (CPS) approach to build an interference-free multi-core deployment. This approach has been fully automated and is supported by a toolchain from the problem formulation to the code generation. It has been experimented on an avionic application, and both the absence of interference and the performance benefits have been evaluated. With this approach, large safety-critical applications can be ported to multi-core COTS processors while preserving single-core based analysis methodologies.