Section: New Results
Virtual prototyping of avionic architecture descriptions
Participants : Yue Ma, Thierry Gautier, Paul Le Guernic, Jean-Pierre Talpin.
In the context of the TopCased project, we are designing and developing a tool for the virtual prototyping of avionic architecture specifications. It aims to interpret specifications expressed in AADL to the synchronous model of computation of Polychrony in order to provide a framework for the simulation, test and verification of integrated modular avionics. In particular, we worked on a translation from AADL programs to SIGNAL programs with tools for simulation and verification.
The SAE AADL is a standard for high level designing and evaluation of the architecture of real-time and embedded systems. The implementation of embedded systems is often distributed across asynchronous communication infrastructures. Such a distributed system is usually composed of locally synchronous processes communicating in a globally asynchronous manner, a GALS system. Yet, in a step-wise refinement based approach, one would prefer to model, simulate and validate such a system in a synchronous programming framework, and then automatically generate its GALS implementation. Our main objective is to perform simulation and validation that take into account both the system architecture and functional aspects. We consider the case where software components are implemented in the synchronous programming language SIGNAL.
First, we use the existing techniques and library of the Polychrony environment, which consist of a model of the APEX-ARINC-653 real-time operating system sevices. A set of rules are defined for these components translations, for example, an AADL processor is translated using the APEX partition-level-OS, and an AADL thread is using the APEX process.
Second, we are experimenting on automatic code distribution starting from system-level AADL specifications using SIGNAL distribution pragmas  . we present a methodology to implement such an approach using the polychronous model of computation how to generate distributed simulation code starting from system-level AADL specifications.
Third, we also work on the AADL behavior annex translations. Behavior annex is an extension for the specifications of the actual behaviors. This translation relies on the use of SSA (Static Single Assignment) as intermediate representation of programs. We also define a new library for the non-deterministic behaviors, such as timing actions delay()/computation().
We are currently working on producing a prototype ATL translator from a subset of the AADL metamodel into Signal metamodel, under Eclipse, and some real test cases (such as avionics application examples) will be used for testing. Our goal is to producing an automatic translatior from an AADL model to a SIGNAL model. Future work will focus on the verification and model-checking with some real test cases.