A Reverse Design Framework for Modifiable-off-the-Shelf Embedded Systems: Application to Open-Source Autopilots

The development of real-time embedded systems is usually preceded by an important design phase to ensure that functional and behavioural constraints are met. However, the modification of some systems, especially Unmanned Air Vehicles that need to be frequently customised, is typically done in an ad-hoc way. Indeed, the design information may not be available, which may affect the proper functioning of the system. This paper aims to propose a framework helping reverse-engineering a Modifiable Off-The-Shelf (MOTS) embedded system in order to be able to ease its modification. In other words, our objective is to point out where modifications have to happen, and allow smooth use of third-party analysis and/or architecture exploration tools to re-analyse non-functional properties (safety, performances, etc.) regarding the customisation. This framework extracts functional-chains from the source code and represents them visually as a model-based design by using model-driven engineering settings.