Embedded operating system

About: Embedded operating system is a research topic. Over the lifetime, 3636 publications have been published within this topic receiving 59156 citations.

Monitors: an operating system structuring concept

Abstract: This paper develops Brinch-Hansen's concept of a monitor as a method of structuring an operating system. It introduces a form of synchronization, describes a possible method of implementation in terms of semaphores and gives a suitable proof rule. Illustrative examples include a single resource scheduler, a bounded buffer, an alarm clock, a buffer pool, a disk head optimizer, and a version of the problem of readers and writers.

Exokernel: an operating system architecture for application-level resource management

Abstract: Traditional operating systems limit the performance, flexibility, and functionality of applications by fixing the interface and implementation of operating system abstractions such as interprocess communication and virtual memory. The exokernel operating system architecture addresses this problem by providing application-level management of physical resources. In the exokernel architecture, a small kernel securely exports all hardware resources through a low-level interface to untrusted library operating systems. Library operating systems use this interface to implement system objects and policies. This separation of resource protection from management allows application-specific customization of traditional operating system abstractions by extending, specializing, or even replacing libraries. We have implemented a prototype exokemel operating system. Measurements show that most primitive kernel operations (such as exception handling and protected control transfer) are ten to 100 times faster than in Ultrix, a mature monolithic UNIX operating system. In addition, we demonstrate that an exokernel allows applications to control machine resources in ways not possible in traditional operating systems. For instance, virtual memory and interprocess communication abstractions are implemented entirely within an application-level library. Measurements show that application-level virtual memory and interprocess communication primitives are five to 40 times faster than Ultrix's kernel primitives. Compared to state-of-the-art implementations from the literature, the prototype exokernel system is at least five times faster on operations such as exception dispatching and interprocess communication.

Real-time dynamic voltage scaling for low-power embedded operating systems

Abstract: In recent years, there has been a rapid and wide spread of non-traditional computing platforms, especially mobile and portable computing devices. As applications become increasingly sophisticated and processing power increases, the most serious limitation on these devices is the available battery life. Dynamic Voltage Scaling (DVS) has been a key technique in exploiting the hardware characteristics of processors to reduce energy dissipation by lowering the supply voltage and operating frequency. The DVS algorithms are shown to be able to make dramatic energy savings while providing the necessary peak computation power in general-purpose systems. However, for a large class of applications in embedded real-time systems like cellular phones and camcorders, the variable operating frequency interferes with their deadline guarantee mechanisms, and DVS in this context, despite its growing importance, is largely overlooked/under-developed. To provide real-time guarantees, DVS must consider deadlines and periodicity of real-time tasks, requiring integration with the real-time scheduler. In this paper, we present a class of novel algorithms called real-time DVS (RT-DVS) that modify the OS's real-time scheduler and task management service to provide significant energy savings while maintaining real-time deadline guarantees. We show through simulations and a working prototype implementation that these RT-DVS algorithms closely approach the theoretical lower bound on energy consumption, and can easily reduce energy consumption 20% to 40% in an embedded real-time system.

Extensibility safety and performance in the SPIN operating system

Abstract: This paper describes the motivation, architecture and performance of SPIN, an extensible operating system. SPIN provides an extension infrastructure, together with a core set of extensible services, that allow applications to safely change the operating system's interface and implementation. Extensions allow an application to specialize the underlying operating system in order to achieve a particular level of performance and functionality. SPIN uses language and link-time mechanisms to inexpensively export fine-grained interfaces to operating system services. Extensions are written in a type safe language, and are dynamically linked into the operating system kernel. This approach offers extensions rapid access to system services, while protecting the operating system code executing within the kernel address space. SPIN and its extensions are written in Modula-3 and run on DEC Alpha workstations.

Introduction to Embedded Systems - A Cyber-Physical Systems Approach

Abstract: The most visible use of computers and software is processing information for human consumption. The vast majority of computers in use, however, are much less visible. They run the engine, brakes, seatbelts, airbag, and audio system in your car. They digitally encode your voice and construct a radio signal to send it from your cell phone to a base station. They command robots on a factory floor, power generation in a power plant, processes in a chemical plant, and traffic lights in a city. These less visible computers are called embedded systems, and the software they run is called embedded software. The principal challenges in designing and analyzing embedded systems stem from their interaction with physical processes. This book takes a cyber-physical approach to embedded systems, introducing the engineering concepts underlying embedded systems as a technology and as a subject of study. The focus is on modeling, design, and analysis of cyber-physical systems, which integrate computation, networking, and physical processes. The second edition offers two new chapters, several new exercises, and other improvements. The book can be used as a textbook at the advanced undergraduate or introductory graduate level and as a professional reference for practicing engineers and computer scientists. Readers should have some familiarity with machine structures, computer programming, basic discrete mathematics and algorithms, and signals and systems.