A timeliness-guaranteed kernel model-DREAM kernel-and implementation techniques

An essential building-block for construction of future real-time computer systems (RTCS's) is a timeliness-guaranteed operating system. The first co-author recently formulated a model of an operating system kernel which can support both real-time processes and new-style real-time objects with guaranteed timely services. The model has been named the DREAM kernel. The key emphasis in formulating the DREAM kernel was in realization of guaranteed timely service capabilities with minimal loss of hardware utilization. This paper presents a summary of the main structuring principles that were exploited to realize guaranteed timely service capabilities together with modularity and expandability in the DREAM kernel. A prototype implementation of the DREAM kernel, v.D2, has been produced by the authors to run on a network of PC's connected by an Ethernet. Several implementation techniques that were adopted during the course of this prototype implementation and may be applicable to other real-time kernel development environments, are briefly discussed in this paper. The prototype kernel (v.D2) has been used to run a real-time object structured non-trivial defense C3 application together with a real-time simulator of the application environment.