A little journey inside Windows memory

In 2005 and 2006, two security researchers, Maximilian Dornseif and Adam Boileau, showed an offensive use of the FireWire bus. They demonstrated how to take control of a computer equipped with a FireWire port. This work has been continued. After a brief summary of how memory works on modern OS, we will explain how the FireWire bus works, and it can be used to access physical memory. Since modern operating system and processors use virtual addresses (and not physical ones), we rebuild the virtual space of each process in order to retrieve and understand kernel structures. Thus, we now have an instant view of the operating system without being submitted to the security protections provided by the processor or the kernel. We will demonstrate several uses for this. First we will show what can be done only with an interpretation of kernel structures (read access). For example, we can have the list of all processes, access to the registry with no control even for protected keys like the SAM ones. This is used to dump credentials. Then, we see what can be done when one modifies the memory (write access). As an example, we show a 2 byte patch to unlock a workstation without knowing the password. Last but not least, code execution is not supposed to happen through FireWire since it is only a bus providing read/write access to the memory. However, slightly modifying the running kernel lets us do whatever we want. We will explain how to have a shell with SYSTEM privileges before any authentication.     

Testing Gbps interfaces without a gigahertz tester

As device manufacturers scale their silicon technology, and processor speeds rise above 1 GHz, it's becoming common for every processor company to tout gigahertz processors. To continually improve system-level performance, system designers have begun increasing I/O performance. Some of these changes are evolutionary; some are revolutionary. The latter necessitate a change in test methodology and in the subsequent DFT. Intel's changing its processors' front-side bus from common-clock to source-synchronous (SS) signaling and increasing their bus transfer rate from less than 100 MHz to 800 megatransfers/second (1 MT/s= 1 Mbyte/s/pin). On the chipset side, Intel has upgraded its universal serial bus from 48 Mbps to 400 Mbps and has transitioned to the serial advanced technology attachment (SATA) standard at a 1.25-Gbps data rate. we show how we've solved the testing problem of the SS interface and how this self-test scheme is extendable to other high-speed I/O circuits, including high-speed serial (HSS) signaling.     

SPI总线接口扩展与应用

在众多型号的单片机中,有许多不带SPI串行总线接口,从而限制了其对SPI总线接口器件的使用.本文介绍了SPI串行总线的特征和时序,对无SPI总线接口的单片机采用其I/O端口,通过程序控制的方法,模拟SPI串行总线接口,使其能与SPI总线接口的器件之间进行数据传送,并以串行E2PROM应用为例,介绍了模拟SPI串行总线接口的使用方法.     

SPI串行总线在单片机8031应用系统中的设计与实现

ＭＣＳ５１系列,ＡＴＭＥＬ８９系列等单片机应用很广,但他们没有ＳＰＩ串行总线接口品,限制了在这些系统中使用具有ＳＰＩ总线接口器件的应用,本文将介绍ＳＰＩ串行总线的性能,并以串行Ｅ＾２ＰＲＯＭ为例,给出了在８０３１上利用Ｉ／Ｏ线实现ＳＰＩ串行总线的方法和软件设计。     

基于ATmega88的USART多处理机通信

单片机接口技术发展的一个趋势是：由并行外围总线接口向串行外围总线接口转变。USART全称是通用同步异步收发器,它是一种单片机外设模块,该资源常用于CPU与较远距离的设备进行通讯。USART接口可以用作同步传送或异步传送,是工业通信中的一种标准接口,而且USART串行接口外围扩展技术具有方便灵活、电路系统简单、占用I/O口资源少等特点。文章所实现的USART多处理机通信,通过地址和数据两种命令格式进行交互,此通信系统可以用作设备控制总线,方便灵活地控制外围设备。     

Using SPIN to Analyse the Tree Identification Phase of the IEEE 1394 High-Performance Serial Bus (FireWire) Protocol

We describe how the tree identification phase of the IEEE 1394 high-performance serial bus (FireWire) protocol is modelled in Promela and verified using SPIN. The verification of arbitrary system configurations is discussed. Received July 2001/Accepted in revised form November 2002 Correspondence and offprint requests to: Alice Miller, Department of Computing Science, University of Glasgow, 17 Lilybank Gardens, Glasgow G12 8QQ, UK. Email: alice@dcs.gla.ac.uk     

The development of an enterprise resources planning system using a hierarchical design pyramid

Today, manufacturers are measured by their ability to respond quickly to sudden, often unpredictable changes in customer needs and wants. Competition beyond the twenty-first century places an increased emphasis upon receiving business information that is accurate and up to date. In order to achieve this, a business planning and closed-loop manufacturing execution system must reflect how work is done, in order to support the overall business objectives without being limited by any hardware, software and human resource constraints. Enterprise resources planning (ERP) is considered to be the most effective computer application in the modern manufacturing industry which meets these requirements. However, only a few manufacturers can design and implement the system successfully. They encounter various problems during the design and implementation cycle. One of the major reasons why they cannot implement the system successfully is the inappropriate use of design and implementation methodology. A systematic design and implementation methodology is therefore proposed for ERP. Called the hierarchical design pyramid (HDP), it encompasses recent research on the ICAM definition method (IDEF) and the object-oriented methodology (OOM) as well as an architecture for any manufacturers who seriously consider ERP implementation.     

Windows CE设备驱动程序开发

Windows CE操作系统标准设计的一个重要方面,就是原始设备制造商(OEMs)和独立硬件开发商(IHVs)可以自主开发设备驱动程序来支持他们的硬件,而不需要微软公司去另外开发设备驱动程序。该文介绍了Windows CE体系结构和开发wince设备驱动程序的过程,阐述了设备驱动程序模型、设备驱动结构和中断处理。Windows CE操作系统支持4种设备驱动模型：本机设备驱动,流接口设备驱动,USB设备驱动,NDIS网络驱动。     

FireWire总线及其在测试仪器中的应用

ＦｉｒｅＷｉｒｅ决线或称ＩＥＥＥ－１３９４总线是一种新型的数字接口,它具有高速度、高性能、低价格等优点,将成为未来计算机、消费类电子产品及测试仪器的总线标准。本文介绍了ＦｉｒｅＷｉｒｅ总线及其特点,论述了其在测试仪器中的应用和前景。     

串行E~2PROM存贮器的应用

比较了串行总线与并行总线非易失性存贮器件的优势和特点 ,并以 ATMEL 公司的 AT2 4 C2 5 6为例 ,详细介绍了该器件的电气特性和软件编程说明及流程图。软件稍加修改 ,也适用于其他公司生产的串行存贮器件     

EEPROM与DSP的接口技术

I2C总线是一种用于IC器件之间连接的二线制总线。I2C增加了高速模式,其速度可达3.4Mbits/s。它使得I2C总线能够支持现有以及将来的高速串行传输应用,例如EEPROM和Flash存储器。而AT24C02是美国爱特梅尔(ATMEL)公司生产的最新串行CMOS EEPROM芯片,支持I2C总线协议。数字信号处理器(DSP)具有丰富的接口,将DSP的多通道缓冲串行接口(简称MCBSP)配置成GPIO(一般通用输入输出口),能够按照I2C协议进行工作。     

FireWire finally comes home

The article discusses the IEEE 1394 networking standard, otherwise known as FireWire. FireWire was designed to link personal computers, digital cameras, televisions, DVD players, printers, and other home electronics equipment. At the time FireWire seemed like a perfect idea whose time had come, but there was one small problem: a competing technology, called Universal Serial Bus (USB), promised to do nearly the same thing. Like FireWire, USB can connect multiple peripherals to a single port on the back of our computers. But USB is designed to be a simpler, slower interface that is less expensive to manufacture. Because both technologies arrived at about the same time, hardware and software vendors had to make a choice as to which technology to develop and support. USB got the nod in the Wintel world-with Windows driver support for USB peripherals as early as October 1996-but it wasn't until Windows 98 that consumers got full OS support for USB. Early support on the Wintel platform, however, could account for the large number of USB components that have been popping up over the past two years, such as speakers, joysticks, printers, video cameras, and the like, all of which have made it to market much more quickly than FireWire based technologies. The prospect of the increasing use of FireWire is discussed     

对RS232转USB接口的通信方法研究设计

USB通用串行总线是计算机外设接口的发展趋势,已经取代PC机上的RS232协议串口,因此很多传统的RS232接口设备都将面临一个向USB接口转换的问题。本文以IC卡门禁考勤系统为例,提出一种方案,使传统的RS232接口转化为USB接口后直接通过USB总线接入PC,同时使IC卡门禁考勤设备增加了USB总线具有的热插拔、自动配置和智能电源管理等功能;着重剖析USB通信内核,探讨系统软硬件设计方案。     

汽车总线数据采集模块设计

为了对汽车内部的总线数据传输进行有效的测试和监控,设计了基于微控制器PIC16F877和CAN控制器MCP2510的汽车CAN总线和LIN总线的数据采集模块,该模块接收CAN总线和LIN总线上的数据,经过缓冲后,转化为串口数据发送到计算机,通过计算机上的虚拟仪器软件接收并加以处理,讨论了数据采集模块在与PC的通讯过程中串口失效问题,分析了失效问题的原因,给出了具体传输方案,该方案成功解决了串口可靠性和通讯速率之间的矛盾,对其它串口设备与PC的通讯,也具有很好的借鉴作用.     

基于组态王软件的无纸记录仪与计算机的通讯研究

通过计算机上的RS232串行通讯接口与无纸记录仪上的RS485通讯接口及MAX202E线驱动/接收器、MAX3080串行通信转换成RS485总线芯片为硬件平台,利用MODBUS通讯协议和组态王软件为软件平台,根据设备串口通讯参数设置,设备生产厂家、名称、通讯方式配置,详细阐述了无纸记录仪的功能参数与组态王的变量名称、类型、寄存器、数据类型、读写属性的对应关系,实现无纸记录仪1375个参数集中管理,可视的操作界面。     

Micro standards: IEEE std P1394

Various standards organizations hope to provide a higher speed for the transmission of serial data. One attractive project, proposed IEEE Std P1394, particularly appeals to users because of its convenience and-since it requires fewer driven signals than parallel methods-its lower cost. This alternative transmits serial data with smaller cables and connectors and also applies to emerging plug-and-play standards. Since it assigns device addresses automatically and requires no bus termination, P1394 is much easier to use than several existing parallel data buses. P1394's serial bus supports low-cost desktop and mobile-computing applications. The inclusion of an isochronous data transfer mode makes P1394 especially attractive for use in consumer electronics as well as the more traditional computer environments. Isochronous means regular time measure. Thus, isochronous data transfers at regular time intervals, guaranteeing a latency period in the transfer     

Using RSS feeds for effective mobile web browsing

While mobile phones are becoming more popular, wireless communication vendors and device manufacturers are seeking new applications for their products. Access to the large corpus of Internet information is a very prominent field. However, the technical limitations of mobile devices pose many challenges. Browsing the Internet using a mobile phone is a large scientific and cultural challenge. Web content must be adapted before it can be accessed by a mobile browser. This work presents a new methodology that uses Really Simple Syndication (RSS) feeds for the adaptation of web content for use in mobile phones. This methodology is based on concrete design guidelines and supports different viewing modes. The mobile tool provided using the RSS feeds is evaluated based on user-centered evaluation and the results are presented.     

一种汽车行驶状态记录仪的研制

本文介绍了一种汽车行驶状态记录仪,可以记录汽车在行驶过程中的各种状态及数据,并可以把所记录的数据通过串口发送给计算机进行处理和存储以供用户查看,而且具备实时测试等功能.     

基于RS485和RS232的机车总线控制器设计

随着现代机车运行速度和运载能力的提高，为了保证机车的安全运行，需要准确采集机车运行的各种参数来进行数据的监控、管理和机车控制，此外也可以为故障诊断提供数据支持，因此需要开发一套可以准确、高速传输数据的大容量机车总线控制系统；设计了基于RS485和RS232的机车总线控制器，详细阐述了以STC8G2K64S4芯片为核心的主控模块、电平转换模块、时钟模块、电源模块和LED指示灯模块的硬件设计以及相互之间的软件逻辑控制和所用通信协议，通过4个串口实现程序的下载以及数据的交换；主要的交换参数包括电压、电流、总有功功率、频率等这些机车运行数据；测试结果表明该机车总线控制器可以高速、准确、及时的传输各个设备生成或采集到的数据，为后续的数据分析提供了支持。     

VxWorks中基于RS485总线的串口通信协议及实现

本文介绍了在嵌入式实时操作系统Vxworks下串行设备的驱动架构及实现,提出了一种基于RS-485总线的新型串口通信协议,重点讨论了基于这种协议的应用程序的设计方法,发送时主要采用了总线仲裁机制,接收时主要采用了字符合法性校验、长度校验、内容的CRC校验,提高了系统的通信效率和稳定性。