Software synthesis is a new approach which focuses on the support of embedded systems without the use of operating-systems. Compared to traditional design practices, a better utilization of the available time and hardware resources can be achieved with software synthesis, because the static information provided by the system specification is fully exploited and a application specific solution is automatically generated. In this paper on-going research on a software synthesis approach for real-time information processing systems is presented which starts from a concurrent process system specification and tries to automate the mapping of this description to a single processor. An internal representation model which is well suited for the support of concurrency and timing constraints is proposed, together with flexible execution models for multi-tasking with real-time constraints. The method is illustrated on a personal terminal receiver demodulator for mobile satellite communication.

Multiprocessors have been accepted as vehicles for improved computing speeds, cost/performance, and enhanced reliability or availability. However, the added performance requirements of user programs and functional capabilities of parallel hardware introduce new challenges to operating system design and implementation. This paper reviews research and commercial developments in multiprocessor operating system kernels from the late 1970's to the early 1990's. The paper first discusses some common operating system structuring techniques and examines the advantages and disadvantages of using each technique. It then identifies some of the major design goals and key issues in multiprocessor operating systems. Issues and solution approaches are illustrated by review of a variety of research or commercial multiprocessor operating system kernels. College of Computing Georgia Institute of Technology Atlanta, Georgia 30332--0280 Contents 1 Introduction 1 2 Structuring an Operating System 4 2....

This paper presents the design of a new version of the Arena operating system targeted at real-time applications. Arena is a run-time operating system for parallel applications. The main principle of Arena is to provide predictable and controllable resource management. This is achieved by placing resource management at the user level of the system, thereby allowing any degree of application influence. Extensions to the system for improved real-time performance are discussed in detail. This version of Arena is to provide a research platform into co-operative robotics, and so the interface between the target robot hardware (built especially for this project) and Arena is also examined in detail. 1. Introduction and Background The Arena operating system has been developed by previous research to investigate how the efficiency of parallel systems may be improved by through operating system provision for predictable and controllable resource management by the application (Mayes [8]). Commo...

This article describes a graduate course on the subject of "Reactive and Real-Time Systems", which serves as the basis for courses taught by the authors at Bar-Ilan University and at Tel-Aviv University, and undergraduate course at the Netania Academic College and The Academic College of Tel-Aviv-Yaffo. The course focuses on the development of provably correct reactive or real-time systems. It is mainly a theoretical course, hence the students do not build (even the simplest) systems. Still, we try to make things as tangible as possible. This means that all the mathematical and logical frameworks introduced are followed by presentation of software tools that implement them. This course is planned so that no purchasing of special hardware and/or software is needed. All the software tools used are freely available from various Internet sites and can be installed quite easily. This should make our course attractive to institutions and instructors for which purchasing and maintaining a spe...

lications," by Ahmed Gheith and Karsten Schwan, which appeared in ACM Transactions on Computer Systems, vol. 11, no. 1, pp. 33--72, February 1993, c fl1993, Association for Computing Machinery, Inc. 2 A Concurrent, Hierarchical, Adaptable Operating System supporting atomic, real- time computations. Sec. 3.1 Reliability in Real-Time Systems 39 and (2) by provision of constructs with which programmers may guarantee desired performance and functionality levels of selected computations in real-time applications. CHAOS arc deals with uncertainty by permitting programs to adapt [1] (i.e., change at run time) in performance and functionality to varying operating conditions. Our past research has addressed adaptations that anticipat

Discrete Event System Specification (DEVS) is a formal modeling and simulation (M&S) framework that supports hierarchical, modular models. DEVS-based M&S environments have been used successfully to understand, analyze, and develop a variety of systems. Some of the environments and systems modeled with DEVS are difficult to replicate and analyze; on the other hand, some others are populated with small, embedded devices that perform critical operations with dedicated hardware and software. In both cases the design, simulation and test of these models tend to grow in size and complexity. In each of the development stages, different methods of modeling, implementation and testing are used without any relation among them. CD++ is a modeling and simulation toolkit based on the DEVS formalism. This thesis proposes a modeling, simulation and benchmarking environment based on the CD++ toolkit. Two different tools are presented to the user of the CD++ toolkit: a Benchmarking tool for comparison of the modelling and simulation CD++ tool with other simulators including a benchmarking methodology, and an Integrated Development Environment (IDE) for the conception and construction of models of Real-Time embedded systems, as well as the final implementation and deployment on an