We present the first end-to-end modeling and compilation flow to parallelize hard real-time control applications while fully guaranteeing the respect of real-time requirements on off-the-shelf hardware. It scales to thousands of dataflow nodes and has been validated on two production avionics applications. Unlike classical optimizing compilation, it takes as input non-functional requirements (real time, resource limits). To enforce these requirements, the compiler follows a static resource allocation strategy, from coarse-grain tasks communicating over an interconnection network all the way to individual variables and memory accesses. It controls timing interferences resulting from mapping decisions in a precise, safe, and scalable way.

Hard real-time avionics systems like flight control software are expected to always react in time. Consequently, it is essential for the timing validation of the software that the worst-case execution time (WCET) of all tasks on a given hardware configuration be known. Modern processor components like caches, pipelines, and branch prediction complicate the determination of the WCET considerably since the execution time of a single instruction may depend on the execution history. The safe, yet overly pessimistic assumption of no cache hits, no overlapping executions in the processor pipeline, and constantly mispredicted branches results in a serious overestimation of the WCET. Our approach to WCET prediction was implemented for the Motorola ColdFire 5307. It includes a static prediction of ∗ This work was partly supported by the RTD project IST-1999-20527 “DAEDALUS” of the European FP5 program. cache and pipeline behavior, producing much tighter upper bounds for the execution times. The WCET analysis tool works on real applications. It is safe in the sense that the computed WCET is always an upper bound of the real WCET. It requires much less effort, while producing more precise results than conventional measurement-based methods.