Maintenance of embedded systems: Supporting program comprehension using dynamic analysis

Maintenance of embedded software systems is faced with multiple challenges, including the exploration and analysis of the actual system's runtime behavior. As a fundamental technique, tracing can be used to capture data about runtime behavior as a whole, and represents one of the few methods to observe and record data about embedded systems within their production environments. In this paper we present a software-based, function-boundary tracing approach for embedded software systems. It uses static binary instrumentation, which implies only lightweight memory and performance overheads. To further reduce these overheads, instrumentation can be configured per trace, i.e., activated only for a specified group of functions without having to recompile the system. The technique can be characterized by its robust implementation and its versatile usage. It is complemented by a visualization framework that allows for analysis and exploration of a system's runtime behavior, e.g., to examine thread interaction. To show the technique's applicability, we conclude with a case study that has been applied to an industrial embedded software system.