On the Functional Qualification of a Platform Model

This work focuses on the use of functional qualification for measuring the quality of co-verification environments for hardware/software (HW/SW) platform models. Modeling and verifying complex embedded platforms requires co-simulating one or more CPUs running embedded applications on top of an operating system, and connected to some hardware devices. The paper describes first a HW/SW co-simulation framework which supports all mechanisms used by software, in particular by device drivers, to access hardware devices so that the target CPU´s machine code can be simulated. In particular, synchronization between hardware and software is performed by the co-simulation framework and, therefore, no adaptation is required in device drivers and hardware models to handle synchronization messages. Then, Certitude¿, a flexible functional qualification tool, is introduced. Functional qualification is based on the theory of mutation analysis, but it is extended by considering a mutation to be killed only if a testcase fails. Certitude¿ automatically inserts mutants into the HW/SW models and determines if the verification environment can detect these mutations. A known mutant that cannot be detected points to a verification weakness. If a mutant cannot be detected, there is evidence that actual design errors would also not be detected by the co-verification environment. This is an iterative process and functional qualification solution provides the verifier with information to improve the co-verification environment quality. The proposed approach has been successfully applied on an industrial platform as shown in the experimental result section.