TLM.open: a SystemC/TLM Front-end for the CADP Verification Toolbox

Extended abstract for SBDCES workshop (http://unit.aist.go.jp/cvs/workshop/SBDCES.html)SystemC/TLM models allow the simulation of the embedded software before the hardware RTL descriptions are available, and are used as golden models for hardware verification. The verifi- cation of the SystemC/TLM models is an important issue, since a error in the model can mislead the system designers, or reveal an error in the specification. The OSCI provides an open-source simulator for SystemC/TLM but no tools for formal verification. In order to apply model checking to a SystemC/TLM program, the usual approach relies on the translation of the SystemC/TLM code to a formal language for which a model checker is available. We propose another approach that suppress the error-prone translation effort. Given a SystemC/TLM program, we execute the transitions using g++ and the OSCI library, and we ask the user to provide additional functions to store the current program state. These additional functions represent generally less than 20% of the size of the origianl model, and allows to apply all CADP tools to the SystemC/TLM program itself

Modélisation à haut niveau d'abstraction pour les systèmes embarqués

Modern embedded systems have reached a level of complexity such that it is no longer possible to wait for the first physical prototypes to validate choices on the integration of hardware and software components. It is necessary to use models, early in the design flow. The work presented in this document contribute to the state of the art in several domains. First, we present some verification techniques based on abstract interpretation and SMT-solving for programs written in general-purpose languages like C, C++ or Java. Then, we use verification tools on models written in SystemC at the transaction level (TLM). Several approaches are presented, most of them using compilation techniques specific to SystemC to turn the models into a format usable by existing tools. The second part of the document deal with non-functional properties of models: timing performances, power consumption and temperature. In the context of TLM, we show how functional models can be enriched with non-functional information. Finally, we present contributions to the modular performance analysis (MPA) with real-time calculus (RTC) framework. We describe several ways to connect RTC to more expressive formalisms like timed automata and the synchronous language Lustre. These connections raise the problem of causality, which is defined formally and solved with the new causality closure algorithm.Les systèmes embarqués modernes ont atteint un niveau de complexité qui fait qu'il n'est plus possible d'attendre les premiers prototypes physiques pour valider les décisions sur l'intégration des composants matériels et logiciels. Il est donc nécessaire d'utiliser des modèles, tôt dans le flot de conception. Les travaux présentés dans ce document contribuent à l'état de l'art dans plusieurs domaines. Nous présentons dans un premier temps de nouvelles techniques de vérification de programmes écrits dans des langages généralistes comme C, C++ ou Java. Dans un second temps, nous utilisons des outils de vérification formelle sur des modèles écrits en SystemC au niveau transaction (TLM). Plusieurs approches sont présentées, la plupart d'entre elles utilisent des techniques de compilations spécifiques à SystemC pour transformer le programme SystemC en un format utilisable par les outils. La seconde partie du document s'intéresse aux propriétés non-fonctionnelles des modèles~: performances temporelles, consommation électrique et température. Dans le contexte de la modélisation TLM, nous proposons plusieurs techniques pour enrichir des modèles fonctionnels avec des informations non-fonctionnelles. Enfin, nous présentons les contributions faites à l'analyse de performance modulaire (MPA) avec le calcul temps-réel (RTC). Nous proposons plusieurs connections entre ces modèles analytiques et des formalismes plus expressifs comme les automates temporisés et le langage de programmation Lustre. Ces connexion posent le problème théorique de la causalité, qui est formellement défini et résolu avec un algorithme nouveau dit de " fermeture causale "

A Schedulerless Semantics of TLM Models Written in SystemC via Translation into LOTOS

International audienceTLM (Transaction-Level Modeling) was introduced to cope with the increasing complexity of Systems-on-Chip designs by raising the modeling level. Currently, TLM is primarily used for system-level functional testing and simulation using the SystemC C++ API widely accepted in industry. Nevertheless, TLM requires a careful handling of asynchronous concurrency. In this paper, we give a semantics to TLM models written in SystemC via a translation into the process algebra LOTOS, enabling the verification of the models with the CADP toolbox dedicated to asynchronous systems. Contrary to other works on formal verification of TLM models written in SystemC, our approach targets fully asynchronous TLM without the restrictions imposed by the SystemC simulation semantics. We argue that this approach leads to more dependable models