Model Checking Memory-Related Properties of Hardware/Software Co-designs

Abstract

Hardware/software codesign enables the integrated development of hardware and software in a single design language. In combination with transaction level modeling, it can be used to efficiently model complex systems on different levels of abstraction. As such systems are often used in safety-critical applications, the correctness is crucial to prevent high financial losses or casualties. Especially memory-related errors can cause severe problems as they either result in deadlocks, runtime-errors or undefined system behavior. Although HW/SW codesign usually provides means for testing and simulation during the whole development process, these techniques are incomplete and can never ensure the absence of errors. In contrast, formal verification techniques like model checking can be used to guarantee the correctness of a design. Although there exist several approaches for the formal verification of HW/SW codesigns, memory-related constructs and operations are only insufficiently considered.In this thesis, we present an approach for model checking of memoryrelated properties on digital HW/SW systems. To this end, we focus on the system level description language SystemC, the de facto standard for HW/SW codesign. To support transaction level modeling, we additionally take the widely used SystemC transaction level modeling standard (TLM) into account. The main idea of our approach is to provide a formal semantics for the most relevant parts of the TLM standard and a formal memory model, which captures all relevant memory-related constructs and operations. We combine these with an already existing formalization of the basic SystemC constructs and provide transformation rules to enable the fully automatic transformation of SystemC/TLM designs into semantically equivalent Uppaal timed automata models. On the resulting model, we use the Uppaal model checker to verify important properties, including memory-related properties, timing, liveness and safety properties. To ease this verification, we automatically generate a set of verification properties, which can be used to ensure the absence of many common errors in a given design. This includes memory-related errors like null pointer accesses and array out of bounds accesses on a given design as well as the absence of assertion violations.If a property is violated, the Uppaal model checker generates a counterexample. As our formal semantics for SystemC/TLM is structure-preserving, this counterexample can easily be transferred back to the SystemC/TLM code manually and thereby allows for the localization of detected errors. To enhance the applicability of our approach for complex designs, we provide a set of optimization techniques. These are used to reduce the semantic state space and, thus, yield a better verification performance.We have implemented our transformation and our optimization techniques in a toolchain, which can be applied to SystemC/TLM designs fully automatically. We demonstrate both, the verification performance and the errordetection capabilities of ...

Bit-Precise Formal Verification for SystemC Using Satisfiability Modulo Theories Solving

“…To evaluate our approach, we use two case studies and compare the verification times with those achieved with UPPAAL [10,14]. In the first case study, two producers and one consumer communicate over a FIFO buffer (3 processes, 1 channel).…”

“…Bit-precise hardware data types are not explicitly considered. In [10,14], an approach for the formal verification of SystemC designs using the model checker UPPAAL is presented. A large subset of SystemC is supported.…”

Modular Design and Verification of Distributed Adaptive Real-Time Systems Based on Refinements and Abstractions

“…The work of [12] supports a large subset of SystemC including the SystemC transaction level modelling standard TLM [22] and the most important memory related operations [23] and enables model checking with the UPPAAL model checker. Therefore, it is well suited for the formal verification of SystemC designs.…”