REAL-TIME SYSTEMS: an INTRODUCTION Keep up with the Data Stream from the Landing Radar
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A Programmable Microkernel for Real-Time Systems∗
A Programmable Microkernel for Real-Time Systems∗ Christoph M. Kirsch Marco A.A. Sanvido Thomas A. Henzinger University of Salzburg VMWare Inc. EPFL and UC Berkeley [email protected] tah@epfl.ch ABSTRACT Categories and Subject Descriptors We present a new software system architecture for the im- D.4.7 [Operating Systems]: Organization and Design— plementation of hard real-time applications. The core of the Real-time systems and embedded systems system is a microkernel whose reactivity (interrupt handling as in synchronous reactive programs) and proactivity (task General Terms scheduling as in traditional RTOSs) are fully programma- Languages ble. The microkernel, which we implemented on a Strong- ARM processor, consists of two interacting domain-specific Keywords virtual machines, a reactive E (Embedded) machine and a proactive S (Scheduling) machine. The microkernel code (or Real Time, Operating System, Virtual Machine microcode) that runs on the microkernel is partitioned into E and S code. E code manages the interaction of the system 1. INTRODUCTION with the physical environment: the execution of E code is In [9], we advocated the E (Embedded) machine as a triggered by environment interrupts, which signal external portable target for compiling hard real-time code, and in- events such as the arrival of a message or sensor value, and it troduced, in [11], the S (Scheduling) machine as a universal releases application tasks to the S machine. S code manages target for generating schedules according to arbitrary and the interaction of the system with the processor: the exe- possibly non-trivial strategies such as nonpreemptive and cution of S code is triggered by hardware interrupts, which multiprocessor scheduling. -
The Design of the EMPS Multiprocessor Executive for Distributed Computing
The design of the EMPS multiprocessor executive for distributed computing Citation for published version (APA): van Dijk, G. J. W. (1993). The design of the EMPS multiprocessor executive for distributed computing. Technische Universiteit Eindhoven. https://doi.org/10.6100/IR393185 DOI: 10.6100/IR393185 Document status and date: Published: 01/01/1993 Document Version: Publisher’s PDF, also known as Version of Record (includes final page, issue and volume numbers) Please check the document version of this publication: • A submitted manuscript is the version of the article upon submission and before peer-review. There can be important differences between the submitted version and the official published version of record. People interested in the research are advised to contact the author for the final version of the publication, or visit the DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. -
UG1046 Ultrafast Embedded Design Methodology Guide
UltraFast Embedded Design Methodology Guide UG1046 (v2.3) April 20, 2018 Revision History The following table shows the revision history for this document. Date Version Revision 04/20/2018 2.3 • Added a note in the Overview section of Chapter 5. • Replaced BFM terminology with VIP across the user guide. 07/27/2017 2.2 • Vivado IDE updates and minor editorial changes. 04/22/2015 2.1 • Added Embedded Design Methodology Checklist. • Added Accessing Documentation and Training. 03/26/2015 2.0 • Added SDSoC Environment. • Added Related Design Hubs. 10/20/2014 1.1 • Removed outdated information. •In System Level Considerations, added information to the following sections: ° Performance ° Clocking and Reset 10/08/2014 1.0 Initial Release of document. UltraFast Embedded Design Methodology Guide Send Feedback 2 UG1046 (v2.3) April 20, 2018 www.xilinx.com Table of Contents Chapter 1: Introduction Embedded Design Methodology Checklist. 9 Accessing Documentation and Training . 10 Chapter 2: System Level Considerations Performance. 13 Power Consumption . 18 Clocking and Reset. 36 Interrupts . 41 Embedded Device Security . 45 Profiling and Partitioning . 51 Chapter 3: Hardware Design Considerations Configuration and Boot Devices . 63 Memory Interfaces . 69 Peripherals . 76 Designing IP Blocks . 94 Hardware Performance Considerations . 102 Dataflow . 108 PL Clocking Methodology . 112 ACP and Cache Coherency. 116 PL High-Performance Port Access. 120 System Management Hardware Assistance. 124 Managing Hardware Reconfiguration . 127 GPs and Direct PL Access from APU . 133 Chapter 4: Software Design Considerations Processor Configuration . 137 OS and RTOS Choices . 142 Libraries and Middleware . 152 Boot Loaders . 156 Software Development Tools . 162 UltraFast Embedded Design Methodology GuideSend Feedback 3 UG1046 (v2.3) April 20, 2018 www.xilinx.com Chapter 5: Hardware Design Flow Overview . -
Chapter 1. Origins of Mac OS X
1 Chapter 1. Origins of Mac OS X "Most ideas come from previous ideas." Alan Curtis Kay The Mac OS X operating system represents a rather successful coming together of paradigms, ideologies, and technologies that have often resisted each other in the past. A good example is the cordial relationship that exists between the command-line and graphical interfaces in Mac OS X. The system is a result of the trials and tribulations of Apple and NeXT, as well as their user and developer communities. Mac OS X exemplifies how a capable system can result from the direct or indirect efforts of corporations, academic and research communities, the Open Source and Free Software movements, and, of course, individuals. Apple has been around since 1976, and many accounts of its history have been told. If the story of Apple as a company is fascinating, so is the technical history of Apple's operating systems. In this chapter,[1] we will trace the history of Mac OS X, discussing several technologies whose confluence eventually led to the modern-day Apple operating system. [1] This book's accompanying web site (www.osxbook.com) provides a more detailed technical history of all of Apple's operating systems. 1 2 2 1 1.1. Apple's Quest for the[2] Operating System [2] Whereas the word "the" is used here to designate prominence and desirability, it is an interesting coincidence that "THE" was the name of a multiprogramming system described by Edsger W. Dijkstra in a 1968 paper. It was March 1988. The Macintosh had been around for four years. -
Research Purpose Operating Systems – a Wide Survey
GESJ: Computer Science and Telecommunications 2010|No.3(26) ISSN 1512-1232 RESEARCH PURPOSE OPERATING SYSTEMS – A WIDE SURVEY Pinaki Chakraborty School of Computer and Systems Sciences, Jawaharlal Nehru University, New Delhi – 110067, India. E-mail: [email protected] Abstract Operating systems constitute a class of vital software. A plethora of operating systems, of different types and developed by different manufacturers over the years, are available now. This paper concentrates on research purpose operating systems because many of them have high technological significance and they have been vividly documented in the research literature. Thirty-four academic and research purpose operating systems have been briefly reviewed in this paper. It was observed that the microkernel based architecture is being used widely to design research purpose operating systems. It was also noticed that object oriented operating systems are emerging as a promising option. Hence, the paper concludes by suggesting a study of the scope of microkernel based object oriented operating systems. Keywords: Operating system, research purpose operating system, object oriented operating system, microkernel 1. Introduction An operating system is a software that manages all the resources of a computer, both hardware and software, and provides an environment in which a user can execute programs in a convenient and efficient manner [1]. However, the principles and concepts used in the operating systems were not standardized in a day. In fact, operating systems have been evolving through the years [2]. There were no operating systems in the early computers. In those systems, every program required full hardware specification to execute correctly and perform each trivial task, and its own drivers for peripheral devices like card readers and line printers. -
OPERATING SYSTEMS.Ai
Introduction Aeroflex Gaisler provides LEON and ERC32 users with a wide range of popular embedded operating systems. Ranging from very small footprint task handlers to full featured Real-Time Operating System (RTOS). A summary of available operating systems and their characteristics is outlined below. VxWorks The VxWorks SPARC port supports LEON3/4 and LEON2. Drivers for standard on-chip peripherals are included. The port supports both non-MMU and MMU systems allowing users to program fast and secure applications. Along with the graphical Eclipse based workbench comes the extensive VxWorks documentation. • MMU and non-MMU system support • SMP support (in 6.7 and later) • Networking support (Ethernet 10/100/1000) • UART, Timer, and interrupt controller support • PCI, SpaceWire, CAN, MIL-STD-1553B, I2C and USB host controller support • Eclipse based Workbench • Commercial license ThreadX The ThreadX SPARC port supports LEON3/4 and its standard on-chip peripherals. ThreadX is an easy to learn and understand advanced pico-kernel real-time operating system designed specifically for deeply embedded applications. ThreadX has a rich set of system services for memory allocation and threading. • Non-MMU system support • Bundled with newlib C library • Support for NetX, and USBX ® • Very small footprint • Commercial license Nucleus Nucleus is a real time operating system which offers a rich set of features in a scalable and configurable manner. • UART, Timer, Interrupt controller, Ethernet (10/100/1000) • TCP offloading and zero copy TCP/IP stack (using GRETH GBIT MAC) • USB 2.0 host controller and function controller driver • Small footprint • Commercial license LynxOS LynxOS is an advanced RTOS suitable for high reliability environments. -
Microkernel Construction Introduction
Microkernel Construction Introduction Nils Asmussen 04/09/2020 1 / 32 Normal Organization Thursday, 4th DS, 2 SWS Slides: www.tudos.org ! Studies ! Lectures ! MKC Subscribe to our mailing list: www.tudos.org/mailman/listinfo/mkc2020 In winter term: Microkernel-based operating systems (MOS) Various labs 2 / 32 Organization due to COVID-19 Slides and video recordings of lectures will be published Questions can be asked on the mailing list Subscribe to the mailing list! Practical exercises are planed for the end of the semester Depending on how COVID-19 continues, exercises are in person or we use some video-conferencing tool 3 / 32 Goals 1 Provide deeper understanding of OS mechanisms 2 Look at the implementation details of microkernels 3 Make you become enthusiastic microkernel hackers 4 Propaganda for OS research done at TU Dresden and Barkhausen Institut 4 / 32 Outline Organization Monolithic vs. Microkernel Kernel design comparison Examples for microkernel-based systems Vision vs. Reality Challenges Overview About L4/NOVA 5 / 32 Monolithic Kernel System Design u s Application Application Application e r k Kernel e r File Network n e Systems Stacks l m Memory Process o Drivers Management Management d e Hardware 6 / 32 Monolithic Kernel OS (Propaganda) System components run in privileged mode No protection between system components Faulty driver can crash the whole system Malicious app could exploit bug in faulty driver More than 2=3 of today's OS code are drivers No need for good system design Direct access to data structures Undocumented -
Real-Time Operating System Modelling and Simulation Using Systemc
Real-Time Operating System Modelling and Simulation Using SystemC Ke Yu Submitted for the degree of Doctor of Philosophy Department of Computer Science June 2010 Abstract Increasing system complexity and stringent time-to-market pressure bring chal- lenges to the design productivity of real-time embedded systems. Various System- Level Design (SLD), System-Level Design Languages (SLDL) and Transaction- Level Modelling (TLM) approaches have been proposed as enabling tools for real-time embedded system specification, simulation, implementation and verifi- cation. SLDL-based Real-Time Operating System (RTOS) modelling and simula- tion are key methods to understand dynamic scheduling and timing issues in real- time software behavioural simulation during SLD. However, current SLDL-based RTOS simulation approaches do not support real-time software simulation ade- quately in terms of both functionality and accuracy, e.g., simplistic RTOS func- tionality or annotation-dependent software time advance. This thesis is concerned with SystemC-based behavioural modelling and simu- lation of real-time embedded software, focusing upon RTOSs. The RTOS-centric simulation approach can support flexible, fast and accurate real-time software tim- ing and functional simulation. They can help software designers to undertake real- time software prototyping at early design phases. The contributions in this thesis are fourfold. Firstly, we propose a mixed timing real-time software modelling and simula- tion approach with various timing related techniques, which are suitable for early software modelling and simulation. We show that this approach not only avoids the accuracy drawback in some existing methods but also maintains a high simu- lation performance. Secondly, we propose a Live CPU Model to assist software behavioural timing modelling and simulation. -
Debugging Threadx RTOS Applications Using Tracex Contents
Application Note Renesas Synergy™ Platform R20AN0404EJ0112 Debugging ThreadX RTOS Applications Rev.1.12 Using TraceX Sep 10, 2018 ThreadX® is an RTOS from Express Logic which is based on a high-performance embedded kernel. This application note provides procedures to check ThreadX thread and object states (referred to as resources) during the development of applications in e2 studio for Renesas Synergy™. The procedure for starting TraceX® is also explained. For the ThreadX specifications and functions, visit the Express Logic (http://rtos.com/) website. For TraceX specifications and functions, visit the Synergy Software (https://www.renesas.com/us/en/products/synergy.html) page. Under the Development Tools tab, select TraceX. This application note explains examples using a project called Blinky with ThreadX that is available after installing the Renesas Synergy™ Software Package (SSP). For procedures covering operations with Blinky with ThreadX, see the Renesas Synergy™ e2 studio v6.2 or Greater Getting Started Guide available on the Synergy Solutions Gallery (https://www.renesas.com/us/en/products/synergy/gallery.html). This document describes general usage of e2 studio. This application note supports SSP version 1.4.0 and later and e2 studio version 6.2.0 and later. Target Environment The operations covered in this document were confirmed in the following environment. • Renesas SynergyTM Software Package (SSP) v1.4.0 or later • e2 studio for Renesas Synergy™ v6.2.0 or later • ThreadX (requires development/production license, see section 5.1, Licenses for ThreadX) • Development Kit for DK-S7G2 Synergy MCU Group R20AN0404EJ0112 Rev.1.12 Page 1 of 23 Sep 10, 2018 Renesas Synergy™ Platform Debugging ThreadX RTOS Applications Using TraceX Contents 1. -
Linux on the OSF Mach3 Microkernel
Linux on top of the OSF Mach3 Microkernel Linux on top of the OSF Mach3 Microkernel Linux on top of OSF MK The Mach3.0 Microkernel: Design • microkernel abstractions François Barbou des Places ([email protected]) • task, thread, port, message, memory object Nick Stephen ([email protected]) • resources and services represented as ports OSF Research Institute - Grenoble • interfaces implemented via RPC to an object port Task Message • Objectives: • widen the audience for the free OSF micro-kernel Ports • provide a complete and free platform to develop new Threads servers, applications or kernel extensions • provide Apple with a freely redistributable microkernel-based operating system for the Memory Apple/PowerMac platform Object Freely Redistributable Software Conference - 5 Feb 1996 - Cambridge 1/17 Freely Redistributable Software Conference - 5 Feb 1996 - Cambridge 2/17 Linux on top of the OSF Mach3 Microkernel Linux on top of the OSF Mach3 Microkernel The Mach3.0 microkernel: Benefits OSF MK Improvements • portability (modular design) • performance • symmetric multi-processing support • kernel-loaded servers (collocation) • thread migration • scalability (from desktop PCs to high-end multi-computers) • short-circuited RPC • extensibility • real-time • OS-neutrality • preemptable kernel • support for OS personalities running as user tasks • real-time RPC, priority inheritance • pageable, preemptable • distributed system (clusters and multi-computers) • more portable: isolated from hardware • DIPC: transparent Distributed IPC • simpler: -
Xenomai - Implementing a RTOS Emulation Framework on GNU/Linux Philippe Gerum First Edition Copyright © 2004
Xenomai - Implementing a RTOS emulation framework on GNU/Linux Philippe Gerum First Edition Copyright © 2004 Copyright © 2002 Philippe Gerum Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front- Cover Texts, and no Back-Cover Texts. A copy of the license is published on gnu.org: "GNU Free Documentation License" [http://www.gnu.org/licenses/ fdl.html]. April 2004 Abstract Generally speaking, the Xenomai technology first aims at helping application designers relying on traditional RTOS to move as smoothly as possible to a GNU/ Linux-based execution environment, without having to rewrite their application entirely. This paper discusses the motivations for proposing this framework, the general observations concerning the traditional RTOS directing this technology, and some in-depth details about its implementation. The Xenomai project has been launched in August 2001. It has merged in 2003 with the RTAI project [http://www.gna.org/projects/rtai/] to produce an industrial- grade real-time Free Software platform for GNU/Linux called RTAI/fusion, on top of Xenomai's abstract RTOS core. Eventually, the RTAI/fusion effort became independent from RTAI in 2005 as the xenomai project [http://www.gna.org/ projects/xenomai/]. Linux is a registered trademark of Linus Torvalds. Other trademarks cited in this paper are the property of their respective owner. 1 Xenomai - Implementing a RTOS emulation framework on GNU/Linux Table of Contents 1. White paper ................................................................................................. 2 1.1. -
Scalability of Microkernel-Based Systems
Scalability of Microkernel-Based Systems Zur Erlangung des akademischen Grades eines DOKTORS DER INGENIERWISSENSCHAFTEN von der Fakultat¨ fur¨ Informatik der Universitat¨ Fridericiana zu Karlsruhe (TH) genehmigte DISSERTATION von Volkmar Uhlig aus Dresden Tag der mundlichen¨ Prufung:¨ 30.05.2005 Hauptreferent: Prof. Dr. rer. nat. Gerhard Goos Universitat¨ Fridericiana zu Karlsruhe (TH) Korreferent: Prof. Dr. sc. tech. (ETH) Gernot Heiser University of New South Wales, Sydney, Australia Karlsruhe: 15.06.2005 i Abstract Microkernel-based systems divide the operating system functionality into individ- ual and isolated components. The system components are subject to application- class protection and isolation. This structuring method has a number of benefits, such as fault isolation between system components, safe extensibility, co-existence of different policies, and isolation between mutually distrusting components. How- ever, such strict isolation limits the information flow between subsystems including information that is essential for performance and scalability in multiprocessor sys- tems. Semantically richer kernel abstractions scale at the cost of generality and mini- mality–two desired properties of a microkernel. I propose an architecture that al- lows for dynamic adjustment of scalability-relevant parameters in a general, flex- ible, and safe manner. I introduce isolation boundaries for microkernel resources and the system processors. The boundaries are controlled at user-level. Operating system components and applications can transform their semantic information into three basic parameters relevant for scalability: the involved processors (depending on their relation and interconnect), degree of concurrency, and groups of resources. I developed a set of mechanisms that allow a kernel to: 1. efficiently track processors on a per-resource basis with support for very large number of processors, 2.