Component-Based Design of Safe Real-Time Kernels for Embedded Systems

The paper presents a component-based framework for safe real-time kernels for embedded applications. In this framework, a component is defined as a self- contained unit encapsulating a specific kernel subsystem. Complex components are decomposed into sub-components that implement an atomic functionality within the subsystem under consideration. Each component is specified in terms of public functions (primitives) and protected functions that are used by other components. Accordingly, kernel configurations are modeled by component call graphs that take into account components and their interactions. Such configurations are actually developed by deriving a conformance class specification from the requirements specification of a real-time application, and then mapping it onto an appropriate subset of kernel components, augmented with relevant component dependencies. Kernel safety is enhanced by the rigorous design of kernel functions, using advanced algorithms that provide for very small overhead and constant execution time of kernel primitives, independent of the number of tasks involved.