Think: A Software Framework for Component-based Operating System Kernels

Building a flexible kernel from components is a promising solution for supporting various embedded systems. The use of components encourages code re-use and reduces development time. Flexibility permits the system to be configured at various stages of the design, up to run time. In this paper, we propose a software framework, called Think, for implementing operating system kernels from components of arbitrary sizes. A unique feature of Think is that it provides a uniform and highly flexible binding model to help OS architects assemble operating system components in varied ways. An OS architect can build an OS kernel from components using Think without being forced into a predefined kernel design (e.g. exo-kernel, micro-kernel or classical OS kernel). To evaluate the Think framework, we have implemented Kortex, a library of commonly used kernel components. We have used Kortex to implement several kernels, including an L4-like micro-kernel, and kernels for an active network router, for the Kaffe Java virtual machine, and for a Doom game. Performance measurements show no degradation due to componentization and the systematic use of the binding framework, and that application-specific kernels can achieve speed-ups over standard general-purpose operating systems such as Linux.