Architecting reconfigurable component-based operating systems

Dynamic reconfiguration allows modifying a system during its execution, and can be used to apply patches and updates, to implement adaptive systems, dynamic instrumentation, or to support third-party modules. Dynamic reconfiguration is important in embedded systems, where one does not necessarily have the luxury to stop a running system. While several proposals have been presented in the literature supporting dynamic reconfiguration in operating system kernels, these proposals in general hardwire a fixed reconfiguration mechanism, which may be far from optimal in certain configurations. In this paper, we present a software-architecture-based approach to the construction of reconfigurable operating systems, and we show that it allows us (i) to support different mechanisms for dynamic reconfiguration, and (ii) to select between them at build time, with little or no changes in operating system and application components. Our approach relies on the use of a reflective component model and of its associated architecture description language.