Real-time dynamic relinking

In this paper we present a method for automatically, on demand, linking entire functions into statically linked running embedded multi-tasking real-time applications. The purpose is to facilitate dynamic instrumentation of deployed systems. The method makes it possible to dynamically instrument the target in run-time, without preparing the source code. Code segments that are modified are substituted on the function level by the introduction of a dynamic relink method. The actual modification of the execution binary is performed in a safe and controlled manner by a low interference task. An algorithm is introduced for reusing memory from obsolete functions.