Debugging and dynamic modification of embedded systems

The paper describes the debugging and dynamic modification facilities provided for real time distributed systems within the Testbed embedded systems environment. We exploit natural break-points present in a state machine programming model to perform monitoring and debugging actions. This technique can avoid the probe effect which is a major problem in debugging concurrent and real-time systems. We describe the background debugging technique in which debugging is partially automated to further reduce interference. Testbed also supports a dynamic modification technique that avoids re-starting the application, which may be inappropriate for embedded systems that run continuously without a notion of stopping time. Background debugging and dynamic modification complement each other in Testbed to provide a powerful alternative to traditional debugging methods