信息安全风险管理系统的设计与实现

嵌入式设备随着应用领域的扩展呈现出多样性以及复杂性,而嵌入式实时系统普遍不具有良好的设备驱动体系结构,造成驱动开发困难、可移植性差.该文给出了一种嵌入式实时操作系统下的驱动框架,支持各种设备及总线接口,设计了一种快速的设备中断机制,符合嵌入式实时系统的强实时、高可靠的特点,能够满足开发各种嵌入式系统.     

嵌入式实时系统的快速开发框架研究

嵌入式实时开发是当今计算机应用研究的热点,该文结合模型驱动架构的系统无关模型和系统相关模型思想,提出了一种基于平台设计的快速开发嵌入式实时系统的方法:首先采用实时应用接口RTAI将嵌入式Linux改造成具有硬实时性能的实时操作系统平台;然后利用Matlab/Simulink/RTW和RTAI-Lab工具对实际系统进行快速化建模、仿真和驱动开发,并自动生成实时的可执行代码;最后将代码加载到嵌入式实时系统.通过倒立摆嵌入式实时控制器系统设计实例说明了这种方法可以有效降低系统设计复杂度,提高嵌入式软件的开发效率.     

Windows CE.NET中断架构分析和高速AD驱动程序的开发

分析了Windows CE.NET嵌入式实时系统的中断架构和流式驱动架构,及其设备驱动程序的开发方法.实现了该系统下的高速AD驱动程序的开发,并进行了实际测试.     

嵌入式实时系统及其在烟机中的应用

近年来，嵌入式实时系统已经在工业等各个领域得到广泛关注与应用，本文介绍嵌入式实时系统的特点，关键技术，优势，以及嵌入式实时系统在高档卷接设备和包装设备中的应用情况；展望嵌入式实时系统的发展趋势及在烟机上的应用前景。     

一种飞艇半物理仿真系统ARINC429驱动的设计与实现

为了满足飞艇实际飞行过程对通信可靠性和实时性的需求,半物理仿真系统的飞艇模型计算机采用以PC为平台的Xpc嵌入式实时系统,飞控计算机采用以PowerPC为平台的VxWork嵌入式实时系统,通过ARINC429协议完成数据通讯;硬件上,PowerPC通过桥接芯片访问并控制PCI设备;软件上,按照Xpc系统和vxWork系统PCI设备驱动程序的编写流程,分析了xPC内存驱动框架和vxBus驱动框架关键技术点,设计了飞艇模型计算机Xpc和飞控计算机Vxwork的ARINC429通讯卡驱动程序;通过实际的应用,证实所开发的ARINC429驱动程序满足飞艇半物理仿真平台数据通讯的可靠性和实时性。     

嵌入式实时系统及其在烟机中的应用

近年来,嵌入式实时系统已经在工业等各个领域得到广泛关注与应用.本文介绍嵌入式实时系统的特点、关键技术、优势,以及嵌入式实时系统在高档卷接设备和包装设备中的应用情况;展望嵌入式实时系统的发展趋势及在烟机上的应用前景.     

基于VxWorks的PXI板卡驱动程序开发

对嵌入式实时系统VxWorks中的设备驱动程序开发进行了简要的介绍,讨论了VxWorks操作系统下的I/O系统和设备驱动程序、应用程序之间的关系,说明了VxWorks下与一般操作系统下驱动程序设计的不同;另外根据作者开发PCI9054数据通信卡驱动程序的实践,讨论了VxWorks下PXI设备驱动程序的框架;根据设备驱动程序的功能,将其分为初始化、中断挂接、中断处理、DMA块读写等几大模块,并详细说明了这些模块的具体实现.     

常用嵌入式实时操作系统比较分析

以与实时系统开发过程密切相关的实时性、故障容错和标准兼容性等关键特征为基础,提出一套对嵌入式实时操作系统性能衡量的标准,涵盖体系结构、硬件支持、调度管理、内存管理、进程间通讯、定时性能、网络支持、文件系统、驱动编程以及开发调试等关键特证。并利用该标准对常用嵌入式实时操作系统进行了详细地分析与对比,为系统研发过程中嵌入式实时操作系统的选择提供指南。     

基于Linux的字符设备驱动设计与实现

在基于Linux的嵌入式工业控制系统的开发过程中,针对最常见的字符设备,探索了一种设备驱动程序设计的一般方法.该方法为这一类设备驱动实现提供了整体框架.降低了驱动设计难度.实时时钟模块是典型的字符设备也是工业控制系统中的重要组成部分.作者以基于I2C总线的实时时钟在ARM9平台的驱动实现为例,详细介绍了这一方法在嵌入式系统开发中的具体应用.     

开发RTEMS实时系统的板级支持包

板级支持包BSP在嵌入式系统中处于关键的位置,有力地支持了嵌入式系统的移植,而BSP的结构与功能随不同的嵌入式系统的软件硬件环境呈现较大的差异。本文介绍板级支持包的功能和实时系统RTEMS的体系结构,分析RTEMS的启动过程。借鉴SPARC微处理器ERC32 BSP,提出一种RTEMS板级支持包的开发流程,主要说明模板BSP的选取、启动代码模块和设备驱动程序模块的实现,链接器命令脚本的修改等。最后把BSP与RTEMS系统的其他模块组合在一起,生成最终可执行映像的过程。     

基于任务间通信的嵌入式组件模型

通用组件技术如COM、CORBA等技术已较完善,但是它们应用于嵌入式系统却有很多局限,如需要庞大的底层基础支持、没有实时调度能力等。根据嵌入式系统以及应用的特点,分析了现有的通用组件模型和当前嵌入式组件技术的发展现状,提出了一种新的嵌入式组件模型——基于任务间通信的嵌入式组件模型。该模型具有资源消耗小、有实时调度能力、无须大量底层支持的优点,该文介绍了系统框架和实现方法以及组件开发方法。     

在构件化嵌入式操作系统中应用抢占阈值调度

现有基于构件的嵌入式实时软件开发过程着重于从结构的角度分解系统成若干构件,以及重用构件。实践证明,该开发过程还应从运行角度将构件映射成任务,并选择适当的实时调度算法。为此,根据目前的工程实践提出一种实时构件模型,包含将构件映射成任务的方式。描述了当前构件化嵌入式操作系统可以使用的4种调度算法,并比较这些算法的性能特点。提出抢占阈值(preemptionthreshold)调度模型更适合构件化嵌入式实时系统,仿真实验的结果证明了该结论。比较结果和结论对构件化嵌入式实时系统的设计和开发有一定的参考价值。     

User-level Real-Time Network System on Microkernel-based Operating Systems

This paper presents the design and implementation of a user-level real-time network system in Real-Time Mach. Traditional network systems for microkernel based operating systems, which tend to focus on high performance and flexibility, are not suitable for real-time communication. Our network system provides a framework for implementing real-time network protocols which require to bound protocol processing time, and it is suitable for implementing on microkernel based operating systems. In this paper, we especially focus on the aspects to avoid the priority inversion problem in order to make network systems more preemptable and predictable. We also describe the feasibility of our network system for building distributed multimedia systems.     

基于S3C2416的嵌入式USB2.0/以太网转换器设计

文章介绍了一个基于S3C2416的嵌入式USB2.0/以太网转换器设计方案,采用以太网控制器DM9000a成功实现USB2.0到以太网的高速、高效率的数据交换。论文阐述了USB接口和网络接口电路基础上,重点对嵌入式Linux系统下的USB Gadget驱动框架和DM9000a的驱动程序进行了具体分析。     

嵌入式Linux设备驱动程序开发

阐述在嵌入式Linux环境下设备驱动程序的开发,详细探讨了嵌入式Linux设备驱动程序的通用模块框架和具体开发流程,说明了驱动程序与内核的关系,归纳嵌入式Linux设备驱动程序的共性.解析Linux设备驱动程序模块的概念,进一步分析了驱动模块的初始化和卸载这两个关键函数.通过实例论述如何设计和编写模块化的嵌入式Linux设备驱动程序,以及解释驱动程序的关键代码.最后归纳了开发嵌入式Linux设备驱动程序的核心思想.     

基于VxWorks的USB设备驱动的设计研究

VxWorks操作系统由于其高度的可靠性和优秀的实时性,而被广泛应用于嵌入式系统领域。本文在对VxWorks操作系统和USB2.0协议分析的基础上,对基于ZX2930 EVB2.0板的USB设备驱动进行了研究,并在此基础上对基于VxWorks的USB设备驱动进行了实现,成功建立了PC机与EVB2.0板之间的通信。实验结果表明,该驱动程序是稳健的、可靠的。     

A self-adaptive heterogeneous multi-core architecture for embedded real-time video object tracking

Sequential Monte Carlo (SMC) represents a principal statistical method for tracking objects in video sequences by on-line estimation of the state of a non-linear dynamic system. The performance of individual stages of the SMC algorithm is usually data-dependent, making the prediction of the performance of a real-time capable system difficult and often leading to grossly overestimated and inefficient system designs. Also, the considerable computational complexity is a major obstacle when implementing SMC methods on purely CPU-based resource constrained embedded systems. In contrast, heterogeneous multi-cores present a more suitable implementation platform. We use hybrid CPU/FPGA systems, as they can efficiently execute both the control-centric sequential as well as the data-parallel parts of an SMC application. However, even with hybrid CPU/FPGA platforms, determining the optimal HW/SW partitioning is challenging in general, and even impossible with a design time approach. Thus, we need self-adaptive architectures and system software layers that are able to react autonomously to varying workloads and changing input data while preserving real-time constraints and area efficiency. In this article, we present a video tracking application modeled on top of a framework for implementing SMC methods on CPU/FPGA-based systems such as modern platform FPGAs. Based on a multithreaded programming model, our framework allows for an easy design space exploration with respect to the HW/SW partitioning. Additionally, the application can adaptively switch between several partitionings during run-time to react to changing input data and performance requirements. Our system utilizes two variants of a add/remove self-adaptation technique for task partitioning inside this framework that achieve soft real-time behavior while trying to minimize the number of active cores. To evaluate its performance and area requirements, we demonstrate the application and the framework on a real-life video tracking case study and show that partial reconfiguration can be effectively and transparently used for realizing adaptive real-time HW/SW systems.     

Comparison of component frameworks for real-time embedded systems

The use of components significantly helps in development of real-time embedded systems. There have been a number of component frameworks developed for this purpose, and some of them have already became well established in this area. Even though these frameworks share the general idea of component-based development, they significantly differ in the range of supported features and maturity. This makes it relatively difficult to select the right component framework and thus poses a significant obstacle in adoption of the component-based development approach for developing real-time embedded systems. To provide guidance in choosing a component framework, or at least relevant concepts when building a custom framework, we present a survey, which illustrates distinguishing features and provides comparison of selected modern component-based frameworks for real-time embedded systems. Compared to other existing surveys, this survey focuses specifically on criteria connected with real-time and embedded systems. Further, to be practically relevant, we restrict the survey only to the frameworks that support the full development life cycle (i.e. from design till execution support). In this context, the survey illustrates the complexity of development in each framework by giving specification and code samples.     

实时操作系统mbedOS的移植方法

MbedOS是ARM公司于2014年开始推出的一款面向智能终端与物联网节点的实时操作系统,主要用于对响应时间有较高实时性要求的嵌入式系统.在深入分析mbedOS的基本功能、调度机制、延时函数机制、任务间通信机制等基础上,以可移植的mbedOS工程框架为基础,分析移植的共性问题,给出具体的移植方法.在此基础上,实现了mbedOS在ARM Cortex-M系列的不同内核及不同MCU上的移植,还给出了不同开发环境间移植共性问题分析,为mbedOS的应用研究提供了基础,有效地降低了mbedOS的移植难度,也可为其他RTOS的移植提供参考.