Dependable Software Generation and Execution on Embedded Systems

For generating and executing dependable software, the effects of hardware layer faults at the software layer have to be accurately analyzed and modeled. This requires relevant information from the hardware and software layers, as well as an in-depth analysis of how an application’s outputs are affected by errors, and quantifying the error masking and error propagation on the software layer. Based on this analysis, techniques for generating dependable software can be proposed, e.g., by different dependability-aware compiler-based software transformations or selective instruction protection. Beside functional aspects, timing also plays an important role, as oftentimes tasks have to be finished before a certain deadline to provide useful information, especially in real-time systems. Both aspects are jointly taken into account by the run-time system software which decides—with the help of offline and online-generated data—for multiple concurrently executing applications how to protect and when to execute which application task to optimize for dependability and timing correctness. This is achieved for example by selecting appropriate application versions and protection levels for single and multi-core systems—for example using redundant multithreading (RMT) in different modes—under tolerable performance overhead constraints.