5. Model-Based Debugging of Embedded Software Systems

Model-Driven Development (MDD) is slowly superseding traditional ways of developing embedded software. In line with the MDD, debugging real-time embedded software systems (RTESS) and visualizing their behavior using models, such as UML diagrams, is becoming a reality. However, the additional overhead, introduced by the existing techniques, presents a hurdle in applying model-based debugging for resource constrained, deeply embedded systems. To address this gap, we discuss a model-based debugging methodology for RTESS, which employs a target debugger on the host and runtime monitoring mechanisms on the target. Two variants of a time and memory-aware runtime monitoring methodology, namely, (a) software and (b) on-chip monitoring, are discussed. Using the proposed approach, the target behavior can be visualized in real time using UML sequence and timing diagrams with minimal, generic overhead in the target. An empirical evaluation, based on a prototype implementation of the proposed runtime monitoring mechanisms, is presented. Performance metrics, such as the instrumentation overhead and time spent in the monitoring routine, are discussed.