Example of Hard Real Time Operating System
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Wind River Vxworks Platforms 3.8
Wind River VxWorks Platforms 3.8 The market for secure, intelligent, Table of Contents Build System ................................ 24 connected devices is constantly expand- Command-Line Project Platforms Available in ing. Embedded devices are becoming and Build System .......................... 24 VxWorks Edition .................................2 more complex to meet market demands. Workbench Debugger .................. 24 New in VxWorks Platforms 3.8 ............2 Internet connectivity allows new levels of VxWorks Simulator ....................... 24 remote management but also calls for VxWorks Platforms Features ...............3 Workbench VxWorks Source increased levels of security. VxWorks Real-Time Operating Build Configuration ...................... 25 System ...........................................3 More powerful processors are being VxWorks 6.x Kernel Compatibility .............................3 considered to drive intelligence and Configurator ................................. 25 higher functionality into devices. Because State-of-the-Art Memory Host Shell ..................................... 25 Protection ..................................3 real-time and performance requirements Kernel Shell .................................. 25 are nonnegotiable, manufacturers are VxBus Framework ......................4 Run-Time Analysis Tools ............... 26 cautious about incorporating new Core Dump File Generation technologies into proven systems. To and Analysis ...............................4 System Viewer ........................ -
Comparison of Contemporary Real Time Operating Systems
ISSN (Online) 2278-1021 IJARCCE ISSN (Print) 2319 5940 International Journal of Advanced Research in Computer and Communication Engineering Vol. 4, Issue 11, November 2015 Comparison of Contemporary Real Time Operating Systems Mr. Sagar Jape1, Mr. Mihir Kulkarni2, Prof.Dipti Pawade3 Student, Bachelors of Engineering, Department of Information Technology, K J Somaiya College of Engineering, Mumbai1,2 Assistant Professor, Department of Information Technology, K J Somaiya College of Engineering, Mumbai3 Abstract: With the advancement in embedded area, importance of real time operating system (RTOS) has been increased to greater extent. Now days for every embedded application low latency, efficient memory utilization and effective scheduling techniques are the basic requirements. Thus in this paper we have attempted to compare some of the real time operating systems. The systems (viz. VxWorks, QNX, Ecos, RTLinux, Windows CE and FreeRTOS) have been selected according to the highest user base criterion. We enlist the peculiar features of the systems with respect to the parameters like scheduling policies, licensing, memory management techniques, etc. and further, compare the selected systems over these parameters. Our effort to formulate the often confused, complex and contradictory pieces of information on contemporary RTOSs into simple, analytical organized structure will provide decisive insights to the reader on the selection process of an RTOS as per his requirements. Keywords:RTOS, VxWorks, QNX, eCOS, RTLinux,Windows CE, FreeRTOS I. INTRODUCTION An operating system (OS) is a set of software that handles designed known as Real Time Operating System (RTOS). computer hardware. Basically it acts as an interface The motive behind RTOS development is to process data between user program and computer hardware. -
Evidence Company Description …And Future Challenges
1 Evidence Company description …and future challenges Paolo Gai, [email protected] IWES Workshop Pisa, 21 September 2016 2 The company Founded in 2002 as spin-off company of the Real-Time Systems Lab at Scuola Superiore S.Anna ~20 qualified people with an average age of 34 years 10+ years of experience in academic and industrial projects One third of the company has a PhD degree Our Mission : design and development software for small electronic devices 3 The company Partner in several European and Italian research projects (FP6, FP7, Ind.2015, Reg. Tuscany, H2020) Founded SSG Srl in November 2011 http://www.ssginnovation.com/ - (link to SSG slides) Evidence won the first prize at Start Cup Pisa 2005 March 12, 2007 - selected by ”Corriere della Sera ” as one of the most innovative Italian young entrepreneurs 4 (some) customers OSEK, microcontrollers, schedulability analysis, code generation Linux, SW devel. Listed as 3 rd party 5 products and services RTOS , Firmware, Embedded Linux Model-based design • OSEK/VDX, • Matlab/Simulink/Stateflow AUTOSAR, device drivers • Embedded Linux: 8 Yrs experience • National Instruments custom BSPs, GCC, U-Boot, LabView Kernel drivers • Initial developers of the • E4Coder toolset for code SCHED_DEADLINE patch generation • QEMU and emulators • UML/SYSML/Ecore/ Application Development Eclipse/Acceleo 6 Something about ERIKA Enterprise http://erika.tuxfamily.org • ERIKA Enterprise is an RTOS OSEK/VDX certified • ERIKA Enterprise implements an API inspired to a subset of the AUTOSAR API • open-source license -
Porting Embedded Systems to Uclinux
Porting Embedded Systems to uClinux António José da Silva Instituto Superior Técnico Av. Rovisco Pais 1049-001 Lisboa, Portugal [email protected] ABSTRACT Concerning response times, computer systems can be di- The emergence of embedded computing in our daily lives vided in soft and hard real time[26]. In soft real time sys- has made the design and development of embedded applica- tems, missing a deadline only degrades performance, unlike tions into one of the crucial factors for embedded systems. in hard real time systems. In hard real time systems, miss- Given the diversity of currently available applications, not ing a time constraint before giving an answer may be worse only for embedded, but also for general purpose systems, it than having no answer at all. An example of a soft real time will be important to easily reuse part, if not all, of these ap- system is a common DVD player. While good performance plications in future and current products. The widespread is desirable, missing time constraints in this type of system interest and enthusiasm generated by Linux's successful use only results in some frame loss, or some quirks in the user in a number of embedded systems has made it into a strong interface, but the system can continue to operate. This is candidate for defining a common development basis for em- not the case for hard real time systems. Missing a deadline bedded applications. In this paper, a detailed porting guide in a pace maker or in a nuclear plant's cooling system, for to uClinux using the XTran-3[20] board, an embedded sys- example, can lead to catastrophic scenarios! tem designed by Tecmic, is presented. -
RT-ROS: a Real-Time ROS Architecture on Multi-Core Processors
Future Generation Computer Systems 56 (2016) 171–178 Contents lists available at ScienceDirect Future Generation Computer Systems journal homepage: www.elsevier.com/locate/fgcs RT-ROS: A real-time ROS architecture on multi-core processors Hongxing Wei a,1, Zhenzhou Shao b, Zhen Huang a, Renhai Chen d, Yong Guan b, Jindong Tan c,1, Zili Shao d,∗,1 a School of Mechanical Engineering and Automation, Beihang University, Beijing, 100191, PR China b College of Information Engineering, Capital Normal University, Beijing, 100048, PR China c Department of Mechanical, Aerospace, and Biomedical Engineering, The University of Tennessee, Knoxville, TN, 37996-2110, USA d Department of Computing, The Hong Kong Polytechnic University, Hong Kong, China article info a b s t r a c t Article history: ROS, an open-source robot operating system, is widely used and rapidly developed in the robotics Received 6 February 2015 community. However, running on Linux, ROS does not provide real-time guarantees, while real-time tasks Received in revised form are required in many robot applications such as robot motion control. This paper for the first time presents 20 April 2015 a real-time ROS architecture called RT-RTOS on multi-core processors. RT-ROS provides an integrated Accepted 12 May 2015 real-time/non-real-time task execution environment so real-time and non-real-time ROS nodes can be Available online 9 June 2015 separately run on a real-time OS and Linux, respectively, with different processor cores. In such a way, real-time tasks can be supported by real-time ROS nodes on a real-time OS, while non-real-time ROS nodes Keywords: Real-time operating systems on Linux can provide other functions of ROS. -
Rtlinux and Embedded Programming
RTLinux and embedded programming Victor Yodaiken Finite State Machine Labs (FSM) RTLinux – p.1/33 Who needs realtime? How RTLinux works. Why RTLinux works that way. Free software and embedded. Outline. The usual: definitions of realtime. RTLinux – p.2/33 How RTLinux works. Why RTLinux works that way. Free software and embedded. Outline. The usual: definitions of realtime. Who needs realtime? RTLinux – p.2/33 Why RTLinux works that way. Free software and embedded. Outline. The usual: definitions of realtime. Who needs realtime? How RTLinux works. RTLinux – p.2/33 Free software and embedded. Outline. The usual: definitions of realtime. Who needs realtime? How RTLinux works. Why RTLinux works that way. RTLinux – p.2/33 Realtime software: switch between different tasks in time to meet deadlines. Realtime versus Time Shared Time sharing software: switch between different tasks fast enough to create the illusion that all are going forward at once. RTLinux – p.3/33 Realtime versus Time Shared Time sharing software: switch between different tasks fast enough to create the illusion that all are going forward at once. Realtime software: switch between different tasks in time to meet deadlines. RTLinux – p.3/33 Hard realtime 1. Predictable performance at each moment in time: not as an average. 2. Low latency response to events. 3. Precise scheduling of periodic tasks. RTLinux – p.4/33 Soft realtime Good average case performance Low deviation from average case performance RTLinux – p.5/33 The machine tool generally stops the cut as specified. The power almost always shuts off before the turbine explodes. Traditional problems with soft realtime The chips are usually placed on the solder dots. -
Vxworks - Real Time Operating System
VxWorks - Real Time Operating System General Purpose Platform, VxWorks Edition, is a complete, flexible, optimized COTS development and run-time platform that works out of the box and across the enterprise. The platform provides a powerful, scalable development environment built on open standards and industry-leading tools; the industry’s most trusted commercial-grade RTOS; and tightly integrated run-time technologies. This proven technology package comes wrapped in a 20+-year track record, an exceptional ecosystem of hardware and software partners, and the industry’s most comprehensive support organization. General Purpose Platform is an optimized develop and run solution for a range of devices, from A&D applications to networking and consumer electronics, robotics and industrial applications, precision medical instruments, and car navigation and telematics systems. The platform provides a robust foundation for companies that need to leverage their investment in proprietary intellectual property. It has been deployed successfully in millions of devices worldwide. General Purpose Platform is based on the world’s most widely adopted RTOS. Built on a highly scalable, deterministic, hard real-time kernel, VxWorks enables companies to scale and optimize their run-time environment using only the specific technologies required by their device. From the smallest footprint requirement to the highest performance level, VxWorks gives developers the flexibility to build their optimal solution quickly and easily while meeting cost, quality, and functionality requirements. VxWorks supports POSIX and industry-standard protocols such as TIPC and IPv6, ensuring maximum code portability and interoperability. VxWorks 6.x is backward compatible with previous releases, so developers can leverage and reuse existing projects, intellectual property, BSPs, and drivers, as well as open-source applications. -
Embedded GNU/Linux and Real-Time an Executive Summary
Embedded GNU/Linux and Real-Time an executive summary Robert Berger Embedded Software Specialist Stratigou Rogakou 24, GR-15125 Polydrosso/Maroussi, Athens, Greece Phone : (+ 30) 697 593 3428, Fax: (+ 30) 210 684 7881 email: [email protected] Abstract What is real-time and how can it be added to a plain vanilla Linux kernel[1]? Two fundamentally different approaches are described here. One approach attempts to patch the vanilla Linux kernel (PREEMPT_RT[2]) to achieve real-time functionality, while the other one utilizes a dual kernel architecture (RTAI[3], RTLinux/GPL[4], Xenomai[5], XM/eRTL[6], Real-Time Core[7], XtratuM[8], seL4[9], PaRTiKle[10],...), where Linux runs as the idle process on top of the real- time kernel. How do those approaches compare? At the time I started my quest for the holy grail of real-time Linux I hoped that it would be a clear decision wether to use p-rt or dk, but things seem to be less black and white than I initially thought. Bear with me to find out what changed my initial believes. 1 Introduction I would like to thank Nicholas Mc Guire, Paulo Montegazza, Philippe Gerum1 and Jan Kiszka from the dual kernel (dk) camp and Thomas Gleixner from the preempt-rt (p-rt) side as well as Paul E. McKenney and Carsten Emde for sharing their precious time with me to provide valu- able input and to review this paper. 2 Real-Time Real-Time has to do with time (timeliness), but most of all with determinism (predictability, time and event determinism). -
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. -
The Challenges of Hardware Synthesis from C-Like Languages
The Challenges of Hardware Synthesis from C-like Languages Stephen A. Edwards∗ Department of Computer Science Columbia University, New York Abstract most successful C-like languages, in fact, bear little syntactic or semantic resemblance to C, effectively forcing users to learn The relentless increase in the complexity of integrated circuits a new language anyway. As a result, techniques for synthesiz- we can fabricate imposes a continuing need for ways to de- ing hardware from C either generate inefficient hardware or scribe complex hardware succinctly. Because of their ubiquity propose a language that merely adopts part of C syntax. and flexibility, many have proposed to use the C and C++ lan- For space reasons, this paper is focused purely on the use of guages as specification languages for digital hardware. Yet, C-like languages for synthesis. I deliberately omit discussion tools based on this idea have seen little commercial interest. of other important uses of a design language, such as validation In this paper, I argue that C/C++ is a poor choice for specify- and algorithm exploration. C-like languages are much more ing hardware for synthesis and suggest a set of criteria that the compelling for these tasks, and one in particular (SystemC) is next successful hardware description language should have. now widely used, as are many ad hoc variants. 1 Introduction 2 A Short History of C Familiarity is the main reason C-like languages have been pro- Dennis Ritchie developed C in the early 1970 [18] based on posed for hardware synthesis. Synthesize hardware from C, experience with Ken Thompson’s B language, which had itself proponents claim, and we will effectively turn every C pro- evolved from Martin Richards’ BCPL [17]. -
L4-Linux Based System As a Platform for EPICS Ioccore
L4-Linux Based System As A Platform For EPICS iocCore J. Odagiri, N. Yamamoto and T. Katoh High Energy Research Accelerator Organization, KEK ICALEPCS 2001, Nov 28, San Jose Contents Backgrounds Causes of latency in Linux kernel Real-time Linux and EPICS iocCore L4-Linux as a real-time platform Conclusions Backgrounds iocCore portable to multi-platforms in EPICS 3.14 Linux promising candidate for running EPICS iocCore runs on Linux OS Interface libraries POSIX 1003.1c (Pthread) POSIX 1003.1b (real-time extension) However, … POSIX real-time extensions Unpredictable latency Not for hard real-time applications Possible rare misses to the deadline Causes Not in the libraries but in the Linux kernel Causes of Latency Non-preempt-able kernel Possibly up to 100 ms or more Disabling of interrupts Typically, several hundreds of µs Address Space Switching Tens of µs Non-preempt-able Kernel Interrupt Kernel Latency High Priority Process Low Priority Process Interrupt Disabling unsigned long flags; save_flags(flags); cli(); /* critical section */ restore_flags(flags); Address Space Switching Page Directory x86x86 Table User Page Space Table Physical Page Kernel Space Impacts on the Latency Non-preempt-able Kernel Interrupt Disabling Address Space Switching Two Different Approaches Kernel-level tasks / real-time scheduler RTLinux RTAI … User-level processes / low latency Linux Low latency patches Preempt-able kernel … RTLinux / RTAI Definitely shortest latency! Several tens of µs Free from all of the three obstacles -
Synchronously Waiting on Asynchronous Operations
Document No. P1171R0 Date 2018-10-07 Reply To Lewis Baker <[email protected]> Audience SG1, LEWG Synchronously waiting on asynchronous operations Overview The paper P1056R0 introduces a new std::experimental::task<T> type. This type represents an asynchronous operation that requires applying operator co_await to the task retrieve the result. The task<T> type is an instance of the more general concept of Awaitable types. The limitation of Awaitable types is that they can only be co_awaited from within a coroutine. For example, from the body of another task<T> coroutine. However, then you still end up with another Awaitable type that must be co_awaited within another coroutine. This presents a problem of how to start executing the first task and wait for it to complete. task<int> f(); task<int> g() { // Call to f() returns a not-yet-started task. // Applying operator co_await() to the task starts its execution // and suspends the current coroutine until it completes. int a = co_await f(); co_return a + 1; } int main() { task<int> t = g(); // But how do we start executing g() and waiting for it to complete // when outside of a coroutine context, such as in main()? int x = ???; return x; } This paper proposes a new function, sync_wait(), that will allow a caller to pass an arbitrary Awaitable type into the function. The function will co_await the passed Awaitable object on the current thread and then block waiting for that co_await operation to complete; either synchronously on the current thread, or asynchronously on another thread. When the operation completes, the result is captured on whichever thread the operation completed on.