东北大学 bootblock
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boot list optionBoot List OptionIntroductionThe boot list option refers to a menu that allows users to choose the device or partition from which the computer will boot. It is an essential feature of the system's firmware or BIOS (Basic Input/Output System) and plays a vital role in determining the order and priority of boot devices. In this document, we will explore the concept of the boot list option along with its significance, advantages, and common use cases.Understanding the Boot List OptionWhen a computer is turned on or restarted, it goes through a process known as the boot sequence, during which the system's firmware or BIOS identifies and initiates the necessary components for the operating system to start. The boot list option comes into play during this process, enabling users to select the desired boot device or partition.The boot list option is typically accessible through the system's firmware or BIOS settings. Users can access these settings by pressing a specific key (such as F2, F10, or Delete) during the boot process depending on the manufacturer and model of the computer. Once in the firmware or BIOS settings, users can navigate to the boot section, where they will find the boot list option.Importance of the Boot List OptionThe boot list option allows users to determine the order in which the computer searches for and boots from various bootable devices or partitions. This feature is particularly useful in scenarios where multiple storage devices are connected to the computer, such as hard drives, SSDs (Solid State Drives), USB drives, or CD/DVD-ROMs. By specifying the boot device priority, users can ensure that the system boots from the desired device or partition.Advantages of Using the Boot List Option1. Flexibility: The boot list option provides users with the flexibility to choose the boot device or partition according to their needs. For example, if a user wants to install a new operating system from a USB drive, they can set the USBdrive as the primary boot option without disconnecting or rearranging other storage devices.2. Troubleshooting: The boot list option proves to be invaluable when troubleshooting boot-related issues. If the computer fails to boot from the default device, users can quickly access the boot list option and select an alternative boot device to determine if the problem lies with the default device or the computer's configuration.3. Multiboot Systems: For users running multiple operating systems on their computers, such as Windows and Linux, the boot list option allows them to switch between different operating systems during startup. By specifying the boot order for each operating system, users can seamlessly choose the desired operating system without manual intervention.Common Use Cases of the Boot List Option1. Installation of Operating System: During the installation of an operating system, the boot list option is highly beneficial. Users can set the bootable installation media (such as a USB drive or DVD-ROM) as the primary boot option, ensuring that the computer boots from the installation media rather than the existing operating system.2. Data Recovery: In cases where the operating system fails to boot or data becomes inaccessible, the boot list option can be used to boot the computer from a recovery disk or drive. This allows users to access and recover their important files and data.3. Booting from External Devices: The boot list option is essential for scenarios where users want to boot their computer from external devices. For example, users can boot from a USB drive to run a portable operating system or use diagnostic software.ConclusionIn conclusion, the boot list option is a crucial feature of a computer's firmware or BIOS, offering users the ability to choose the boot device or partition. By defining the boot device priority, users can control the startup process and ensure that the computer boots from the desired device. Whether it is for flexibility, troubleshooting, or managing multiboot systems, the boot list option proves to be a valuable tool. Understanding its significance and knowing how to access and utilize this feature empowers users to optimize their computer's startup experience.。
BootBlock恢复主板BIOS有什么技巧Boot Block恢复主板BIOS有什么技巧升级主板BIOS一向被朋友们认为是高难度的DIY操作,所以许多新手也不敢随便升级BIOS。
其实,只要按照正确的步骤进行操作,BIOS的升级并不可怕。
但是一旦升级失败后怎么办?Boot Block恢复主板BIOS有什么技巧呢?下面店铺带着大家一起来了解一下吧!有一些主板(主要是使用AwardBIOS的主板),BIOS中有一个引导块(BootBlock),在升级BIOS时一般是不会被覆盖的,也有的主板在写入新的BIOS文件之前会询问是否覆盖引导区(UpdateBIOSIncludingBootBlockandESCD)(为保险起见,最好选N)。
假如BootBlock未被破坏,就可以利用它来恢复原来的BIOS。
不过,BIOS中的.BootBlock只支持软驱和ISA显卡等最基本的硬件,假如显卡是AGP或PCI接口的话,操作时就只能盲操作了(现在一些主板的BIOS的BootBlock也支持PCI显卡),但此时软驱仍可以正常读盘。
如果对盲操作没有把握,也可以事先做好一张紧急恢复盘,除拷贝入awdflash.exe和*.bin两个文件外,再建立一个Autoexec.bat文件,内容如下:awdflash.exe*.bin/sn/py sn代表不备份旧的BIOS文件,这样可免去一次按N键的操作;py 代表自动完成BIOS的刷新任务。
这样就可以利用这张启动盘来自动恢复受损的BIOS了。
不过,笔者有一点要特别提醒各位:现在7.0版本后的Awdflash.exe程序会默认刷新主板上的BootBlock,因此假如想保存BootBlock的话,必须在升级BIOS时使用/sb参数,这样就会强行跳过这一模块,这可要记住。
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马虎不得的PCI设备BlOS学堂(三)
姜一
【期刊名称】《网友世界》
【年(卷),期】2007()22
【摘要】PCI设备在电脑各个配件中应该属于最不打眼的,而且目前主板一般都集成了声卡、网卡这两个重要的PCI设备,因此,BIOS中有关PCI设备的选项更加简单。
然而,一旦引澈置出了问题,就将严重影响电脑的使用。
【总页数】1页(P71-71)
【关键词】PCI设备;BlOS;BIOS;虎;电脑;声卡;主板;网卡
【作者】姜一
【作者单位】
【正文语种】中文
【中图分类】TP311
【相关文献】
1.“马虎”毛病马虎不得 [J],
2.马虎不得的PCI设备 BIOS学堂(三) [J],
3.“马虎不得”马虎了 [J], 戴俊
4.春播玉米看过来,播前、播期马虎不得 [J], 李佚明;杨光
5.脑供血不足,
万万马虎不得 [J], 轩辕
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Bootblock.s 流程:1.ds寄存器清0;2.设置堆栈于0:0x7c00处3.压栈6个字节的0, 以便存储分区表中的驱动器号和分区的起始位置4.BP指向该处: ss:bp =5.分区表中引导分区的入口地址入栈6.di 获得存放一个磁盘每道的扇区数的内存的始址7.如果是软盘(dl为整数),转 flppy, 否则从wincheser开始执行8.从分区表中得到引导分区的起始扇区号; 并将他们存储在堆栈中由BP指向的位置加2开始的地方; lowsec+0(bp); 即将分区的扇区数9.利用ah=8的int 13h 获得dl指定的驱动器几何参数: cl=每磁道最大扇区数, dh=最大磁头数(从1开始)10.将每磁道扇区数存于secter标号处的每磁道扇区数11.转loadboot: 从引导设备上加载次级引导代码12. 计算每柱面的扇区数,并存于堆栈的bp(spcpcyl)处13. 给出加载的起始地址: es:bx = BOOTSEG:000014. 读取装有次级引导程序的分片的地址: 连续扇区数和起始扇区号(dx15.:ax) (这里的扇区号是一个相对扇区号,即一个分区内部的扇区号)16. 将相对扇区号转换成绝对扇区号,即加上分区的起始扇区号:ds:ax = ds:ax + lowsec+bp(2):lowsec+bp(0)17. 在将上面的绝对扇区号转换成磁盘物理地址形式(柱面号:磁头号:扇区号)18. 并按照int 13h调用的要求重新组织参数,并且不能跨越磁道一次读多个扇区19. 读所有的分片中存放的次级引导程序;20. 跳转到 done21. 恢复es:si从堆栈;22. 跳转到 BOOTSEG:BOOTOFF23.说明: 次级引导程序在磁盘中的位置的存放格式(允许不连续存放), 但是将一个连续的扇区块称为一个partition, 每个partition需要记录连续扇区数count, 和连续扇区的起始扇区号。
嵌入式操作系统中硬件抽象层的描述
张益农;黄文玲
【期刊名称】《内蒙古工业大学学报(自然科学版)》
【年(卷),期】2002(021)004
【摘要】本文结合一个具体的嵌入式系统的实现,探讨了硬件抽象层
HAL(Hardware Abstraction Layer) 的作用、主要内容以及具体实现方式等,并提出了实现硬件抽象层的基本原则和方法.
【总页数】5页(P293-297)
【作者】张益农;黄文玲
【作者单位】清华大学自动化系,北京,100084;内蒙古工业大学信息工程学院,内蒙古,呼和浩特,010062
【正文语种】中文
【中图分类】TP3
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5.STM32硬件抽象层中DCMI驱动的研究 [J], 郭朕
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Installation Instructions ArmorBlock MaXum 8 Output Module Series B(Cat. No. 1792D-0B8D) Array42335This ArmorBlock MaXum™ I/O module (Cat. No. 1792D-0B8D) is a stand-alone 24V dc I/O product which communicates via a DeviceNet™ network. The sealed housing of this module requires no enclosure.This module has 8 outputs. Outputs are self-protected 24V dc andprovide up to 1A each. Diagnostic features included are short circuitand no load detection reported to the point level. Local logic control has been added to the Series B version of this product.Publication 1792D-IN003B-EN-P - September 20002 ArmorBlock MaXum 8 Output Module Series BPublication 1792D-IN003B-EN-P - September 2000Check Package ContentsYour package contains:•1 ArmorBlock MaXum Module •Installation Instructions European Communities (EC) Directive ComplianceIf this product has the CE mark it is approved for installation within the European Union and EEA regions. It has been designed and tested to meet the following directives.EMC DirectiveThis product is tested to meet the Council Directive 89/336/EC Electromagnetic Compatibility (EMC) by applying the following standards, in whole or in part, documented in a technical construction file:•EN 50081-2 EMC — Generic Emission Standard, Part 2 — Industrial Environment•EN 50082-2 EMC — Generic Immunity Standard, Part 2 — Industrial Environment This product is intended for use in an industrial environment.Low Voltage DirectiveThis product is tested to meet Council Directive 73/23/EEC Low Voltage, by applying the safety requirements of EN 61131-2Programmable Controllers, Part 2 - Equipment Requirements and Tests.For specific information required by EN 61131-2, see the appropriate sections in this publication, as well as the Allen-Bradley publication Industrial Automation Wiring and Grounding Guidelines For Noise Immunity, publication 1770-4.1.Cable bases are ordered and shipped separately.ArmorBlock MaXum 8 Output Module Series B 3Publication 1792D-IN003B-EN-P - September 2000Install Your ArmorBlock MaXum I/O ModuleTo install the module you must:•Set the node address•Mount the module to the cable base•Connect the output cord sets to the MaXum module•Communicate with your ArmorBlock MaXum I/O moduleMore detailed information about each of these steps is in the following procedures.Set the Node AddressValid node addresses are 00 to 63.Set the node address using the rotary switches, RSNetWorx forDeviceNet ™ software, or another software configuration tool. Setting the switches between 64 to 99 lets the software have address control.Each module is shipped with the node address set to 63. The switches are located on the underside of the module. The two switches are:•MSD (most significant digit)•LSD (least significant digit)To reset the node address, use a small blade screwdriver to rotate the switches. Line up the small black dot on the switch with the number setting you wish to use.The rotary switches are read at module power up only. Settings between 64 and 99 cause the module to use the last valid node address stored internally. Example: The last setting was 40. If a change is made to 68, and then you power up, the address will default to 40.4 ArmorBlock MaXum 8 Output Module Series B Publication 1792D-IN003B-EN-P - September 2000Refer to the illustration of the node address below.The module is equipped with AutoBaud detect. AutoBaud lets the module read the settings already in use on your DeviceNet network and automatically adjusts to follow those settings.Mount the Module to the Cable BaseThis module mounts to the following cable bases:•1792D-CBFM for KwikLink ™ flat media installation •1792D-CB12 for 12mm drop cable installation•1792D-CB18P for round media DeviceNet connection •or other optional cable base assemblyIMPORTANTThe cable base should already be mounted. See publications 1792D-IN009B-EN-P (CBFM & CB12) or 1792D-IN036B-EN-P (CB18, CB18P) for moreinformation on installing the cable base.ArmorBlock MaXum 8 Output Module Series B 5 To install the module:Proper alignment of the screws is necessary tocomplete the connections between the modulecontacts and cable contacts.1.Position the module over the mounted cable base. Align thethree captive screws in the module with the acceptingreceptacles in the base.2.Tighten the screws with a torque of 8 inch-pounds to securethe module to the base.Dimensions change according to the cable baseand module combination used.Publication 1792D-IN003B-EN-P - September 20006 ArmorBlock MaXum 8 Output Module Series BPublication 1792D-IN003B-EN-P - September 2000Connect the Output Cord Sets to the MaXum ModuleThis module uses 5 pin micro (12mm) style PCB mounted connectors.Eight micro caps cover the connectors on your module. Remove the caps and connect your cables to the appropriate ports.Use the micro caps to cover and seal unused ports. A pinout diagram for the connectors is shown below.Please refer to publication 889-5.0 for Rockwell Automation cables and cord sets offerings.ATTENTION!ATTENTION:•Make sure all connectors and caps are securely tightened to properly seal the connections against leaks and maintain IP67 requirements.•For maximum noise immunity, input and output cable return wires must be properly terminated. When inputs and outputs are connected in loopback, return wires should be connected together.•I/O cable length should be less than 30meters.41452Output Micro-Connector (View into Sockets)Pin 1 Not Used Pin 2 Not UsedPin 3 Auxiliary Power Ground Pin 4 Output A Pin 5 Not UsedArmorBlock MaXum 8 Output Module Series B 7Publication 1792D-IN003B-EN-P - September 2000I/O connectors for this module are shown below.DeviceNet CableDeviceNet cables are described in the installation publications for the cable base assembly of your choice. Refer to the following publications:•1792D-IN009B-EN-P ArmorBlock MaXum Cable Base Installation Guide•DN-6.7.2 DeviceNet Cable Planning and Installation ManualConnector B Output 1Connector A Output 0Connector C Output 2Connector D Output 38 ArmorBlock MaXum 8 Output Module Series B Communicate with Your ArmorBlock MaXumI/O ModuleThis ArmorBlock module’s I/O is exchanged with the master through a poll, change-of-state, or cyclic connection.The module consumes and produces output data as follows:Type of I/O Connections Consumes ProducesCyclic 1 Bytes 2 BytesPolled 1 Bytes 2 BytesChange-of-State 1 Bytes 2 BytesCyclic - allows configuration of the block as an I/O client. The block will produce and consume its I/O cyclically at the rate configured. Polled - a master initiates communication by sending its polled I/O message to the module. This 8 output module consumes the message, updates outputs and produces a response. The response has output faults and the status of the Auxiliary power.Change-of-state - productions occur when an input changes or a fault condition occurs. If no input or fault condition change occurs within the expected packet rate, a heartbeat production occurs. This heartbeat production tells the scanner module that the I/O module is alive and ready to communicate.Refer to the table below for the word/bit definitions.Bit0706050403020100 Produces 0OFLT7OFLT6OFLT5OFLT4OFLT3OFLT2OFLT1OFLT0 Produces 1RSVP OPWR RSVP RSVP RSVP RSVP RSVP RSVP Consumes 0O7O6O5O4O3O2O1O0 Where: OFLT = Output Fault OPWR = Output Power O = Output RSVP = ReservedPublication 1792D-IN003B-EN-P - September 2000ArmorBlock MaXum 8 Output Module Series B 9Publication 1792D-IN003B-EN-P - September 2000The DeviceNet Network uses advanced network technology, producer/consumer communication, to increase network functionality and throughput. Visit our web site at/networks for producer/consumer technology information and updates.Troubleshoot with the IndicatorsThis module has the following indicators:•Network/Module status indicator •Logic status indicators •Auxiliary status indicator•Individual point status indicatorsByte Bit DescriptionProduces 000-07Output no load or overload fault (OFLT): When the bit is set (1), an output fault has occurred. OFTO corresponds to output 0, OFT1 corresponds to output 1, OFT2 corresponds to output 2, OFT3 corresponds to output 3, OFT4corresponds to output 4, OFT5 corresponds to output 5, OFT6 corresponds to output 6, and OFT7 corresponds to output 7.Produces 100-05, 0706ReservedOutput Power Fault (OPWR): When the bit is set (1), Auxiliary Power is not present.Consumes 000-07Output bits: When the bit is set (1), the output will be turned on. Bit 00 corresponds to output 0, bit 01 corresponds to output 1, bit 02 corresponds to output 2, bit 03corresponds to output 3, bit 04 corresponds to output 4, bit 05 corresponds to output 5, bit 06 corresponds to output 6, bit 07 corresponds to output 7.10 ArmorBlock MaXum 8 Output Module Series BPublication 1792D-IN003B-EN-P - September 2000The following illustration describes module status indicators.The following table describes the network and module status indicator.Net/Mod Status Indicator Indication Status:OffNo power or auto baudingFlashing Green/Off On line but not connected Solid Green On line, link OK, connectedFlashing RedRecoverable fault - module configuration errorI/O connection fault - one or more I/O connections in the timed-out stateSolid RedUnrecoverable faultCommunication failure - duplicate node address present or incorrect baud rateGreen to Red to Off At powerup only - LED testoutput 1output 0output 2Connector C output 3ArmorBlock MaXum 8 Output Module Series B 11Publication 1792D-IN003B-EN-P - September 2000The following table describes logic status indicators.The following table describes auxiliary status indicators.The following table describes I/O status indicators.For more information on indications, see the Technical Data, publication 1792-TD001B-EN-P.Logic Status IndicatorsState Status OffLogic is disabled Solid Green Logic is enabled Flashing Green Local forces are applied and local logic is enabledAuxiliary Status Indicators IndicationStatus None No Auxiliary power Solid Green Auxiliary power presentI/O Status IndicatorsFunction Module Status Indicator Point Indicator ConditionOutputs Green Green Module Status blink red Module Status blink red Module Status blink red Module Status blink red None Yellow Orange Red Orange Red Output not energized Output energized Output shorted-auto restart Output shorted-latching output no load-auto restart Output no load-latching12 ArmorBlock MaXum 8 Output Module Series BPublication 1792D-IN003B-EN-P - September 2000Specifications8 Output Module - Cat. No. 1792D-0B8D Output SpecificationsMax.Min.Outputs per block8 sourcing outputs labeled O0 through O7Output Auxiliary Voltage30V 10V On-state Voltage Drop1V -On-state Current1A -Off-state Leakage1.5mA -Module Current (all outputs)4.0A -Surge Current - for 10 ms, repeatable every 2s2.4A -No Load Sense Current (On-state)0.18A -Indicators Net/Mod Status - red/green Logic Status - red/green Auxiliary Power - green Point LED - yellow/orange/red Communication Rate •125Kbps @ 500 meters (1600 feet)for thick cable, flat media length 375meters (1230 feet)•250Kbps @ 200 meters (600 feet) forthick cable, flat media length 150meters (492 feet)•500Kbps @ 100 meters (330 feet) forthick cable, flat media length 75meters (246 feet)DeviceNet Power Voltage Current25V dc max 75mA 11V dc min 150mA Auxiliary Power Voltage Current 30V dc 4A10V dc 4A Dimensions (assembled to base)inches - (millimeters)1.9H x2.7W x 6.85D (48.26)H x (68.6)W x (174)DArmorBlock MaXum 8 Output Module Series B 13Publication 1792D-IN003B-EN-P - September 20008 Output Module - Cat. No. 1792D-0B8D Environmental Conditions Operational TemperatureStorage Temperature Relative Humidity Shock Operating Non-operating Vibration-25 to 60o C (-13 to 140o F)-25 to 80o C (-13 to 176o F)Up to 100%30g peak acceleration, 11 (+1) ms pulse width 50g peak acceleration, 11 (+1) ms pulse width Tested 10g @ 10-500 Hz per IEC 68-2-6ConductorsPublication DN-6.7.2EnclosureMeets or exceeds IP67General SpecificationsAgency Certification (when product is marked)•CSA certified •CSA Class 1, Division 2, Groups A, B,C, D certified•UL listed •CE marked for all applicable directivesTechnical Data (user information)Publication 1792-TD001B-EN-P14 ArmorBlock MaXum 8 Output Module Series BHazardous Location ApprovalThe following information applies only to products marked with Hazardous Location Approval, when operating in hazardous locations:Products marked “CL I, DIV 2, GP A, B, C, D” are suitable for use in Class I Division 2 Groups A, B, C, D, Hazardous Locations and nonhazardous locations only. Each product is supplied with markings on the rating nameplate indicating the hazardous location temperature code. When combining products within a system, the most adverse temperature code (lowest “T” number) may be used to help determine the overall temperature code of the system. Combinations of equipment in your system are subject to investigation by the local Authority Having Jurisdiction at the time of installation.EXPLOSION HAZARD-•Do not disconnect equipment unless powerhas been removed or the area is known to benonhazardous.•Do not disconnect connections to thisequipment unless power has been removedor the area is known to be nonhazardous.Secure any external connections that mate tothis equipment by using screws, slidinglatches, threaded connectors, or other meansprovided with this product.•Substitution of components may impairsuitability for Class I, Division 2.•If this product contains batteries, they mustonly be changed in an area known to benonhazardous.Use supply wires suitable for 30°C abovesurrounding ambient.Publication 1792D-IN003B-EN-P - September 2000ArmorBlock MaXum 8 Output Module Series B 15When used in a Class I, Division 2, hazardouslocation, this equipment must be mounted in asuitable enclosure with proper wiring method thatcomplies with the governing electrical codes.Les informations suivantes ne concernent que les produits marqués pour une utilisation en environnements dangereux : Les produits marqués « CL I, DIV 2, GP A, B, C, D » ne conviennent qu’à une utilisation en environnements de Classe I Division 2 Groupes A, B, C, D dangereux et non dangereux. Chaque produit est livré avec des marquages sur sa plaque d’identification qui indiquent le code de température pour les environnements dangereux. Lorsque plusieurs produits sont combinés dans un système, le code detempérature le plus défavorable (code de température le plus faible) peut être utilisé pour déterminer le code de température global du système. Les combinaisons d’équipements dans le système sont sujettes à inspection par les autorités locales qualifiées au moment de l’installation.RISQUE D’EXPLOSION -•Couper le courant ou s’assurer quel’environnement est classé non dangereuxavant de débrancher l’équipement.•Couper le courant ou s’assurer quel’environnement est classé non dangereuxavant de débrancher les connecteurs. Fixertous les connecteurs externes reliés à cetéquipement à l’aide de vis, loquetscoulissants, connecteurs filetés ou autresmoyens fournis avec ce produit.•La substitution de composants peut rendre cetéquipement inadapté à une utilisation enenvironnement de Classe I, Division 2.•S’assurer que l’environnement est classé nondangereux avant de changer les piles.Publication 1792D-IN003B-EN-P - September 2000Utiliser des fils d’alimentation qui conviennent àune température de 30°C au-dessus de latempérature ambiante.Pour une utilisation en environnement de classe i,division 2 dangereux, cet equipement doit etremonte dans un boitier a vec un cablage approprieconforme aux normes electriques en vigueur. This product has been tested at an Open DeviceNet Vendor Association, Inc. (ODVA) authorized independent test laboratory and found to comply with ODV A Conformance Test. Please contact the ODV A website () for listing of products tested by ODV A independent test labs for further details.ArmorBlock and ArmorBlock MaXum, and KwikLink are trademarks of Rockwell Automation. RSNetWorx for DeviceNet is a trademark of Rockwell Software, Inc.DeviceNet is a trademark of Open DeviceNet Vendor Association (ODVA).Publication 1792D-IN003B-EN-P - September 2000PN 957400-09 Supersedes Publication 1792D-IN003A-US-P - May 2000© 2000 Rockwell International Corporation. Printed in USA。
基于ARM9-LINUX掌上电脑样机系统中Bootloader的设
计与实现
王敬晓;陈良益
【期刊名称】《科学技术与工程》
【年(卷),期】2007(007)004
【摘要】目前,嵌入式技术在日常生活中得到越来越广泛地运用,越来越多的开发者也投入到嵌入式技术领域当中.在嵌入式系统设计中,相应的Bootloader代码的设计是一个重点.文中用三星公司一款基于ARM9架构的微处理器S3C2410A作为主控芯片,使用源码公开的LINUX操作系统,外扩了大量的功能模块,开发一掌上电脑样机.文中仅对开发过程中Bootloader的设计流程以及关键技术做了详细说明.【总页数】5页(P497-500,506)
【作者】王敬晓;陈良益
【作者单位】中国科学院西安光学精密机械研究所,西安710068;中国科学院研究生院,北京100039
【正文语种】中文
【中图分类】TP368.33
【相关文献】
1.基于ARM嵌入式系统的Bootloader的设计与实现 [J], 朱华宽;朱维杰
2.基于ARM7TDMI的嵌入式系统BootLoader的设计与实现 [J], 汪金宝;陶玉贵;陈付龙
3.基于嵌入式ARM9-Linux网络视频监控系统的设计与实现 [J], 陈平;程亚维
4.基于ARM的嵌入式系统Bootloader的设计与实现 [J], 潘孝帮;刘连浩
5.基于嵌入式S3C2440系统Bootloader设计与实现 [J], 范蟠果;邢保毫;米晓亮;余书宝;王婷
因版权原因,仅展示原文概要,查看原文内容请购买。
基于IC卡技术的高安全性门禁系统
胡伟;杜谦
【期刊名称】《武汉理工大学学报(信息与管理工程版)》
【年(卷),期】2007(029)012
【摘要】研究并设计了一种可联机使用也可单独使用的高安全性的无线IC卡读写模块,它以AT89C51单片机为微控制器,以MF RC500芯片为IC卡读写器,构建了一个使用简单的IC卡读写系统.该系统基于MFRC500芯片构成读写模块,并对微控制器与读写芯片的通信方式作了详细介绍.该系统的最大特点在于其通信过程中使用高安全性的数据加密算法.
【总页数】4页(P77-80)
【作者】胡伟;杜谦
【作者单位】武汉理工大学,信息工程学院,湖北,武汉,430070;武汉理工大学,信息工程学院,湖北,武汉,430070
【正文语种】中文
【中图分类】TP31
【相关文献】
1.非接触IC卡技术在门禁系统中的应用 [J], 吴国英
2.基于SIMPASS技术的高安全性门禁系统设计 [J], 周杰;王凯
3.基于IC卡技术的个人研修室门禁系统设计与实现 [J], 苏宁
4.基于IC卡技术的高安全性门禁系统 [J], 胡伟;杜谦
5.基于IC卡技术的个人研修室门禁系统设计与实现 [J], 苏宁
因版权原因,仅展示原文概要,查看原文内容请购买。
boot分区刷写指令-回复关于boot分区刷写指令的操作步骤和注意事项引言:在计算机系统中,分区是将硬盘划分为多个逻辑部分的过程。
而boot 分区则是其中一个重要的分区,用于存储引导引导程序。
为了改变或修复引导程序,我们可能需要对boot分区进行刷写。
本文将介绍boot分区刷写的指令及相关操作步骤,并提供一些注意事项。
第一部分:了解boot分区在开始操作之前,我们需要对boot分区有一定的了解。
boot分区是一个特殊的分区,通常位于硬盘的第一个扇区,并包含引导加载程序(bootloader)。
当计算机启动时,BIOS将读取boot分区的内容并加载引导加载程序,然后引导加载程序将负责加载操作系统。
第二部分:选择合适的刷写指令在进行boot分区刷写之前,我们需要选择合适的刷写指令。
这些指令通常由操作系统或相关软件提供。
下面列举一些常见的刷写指令:1. dd命令dd命令是一种在UNIX系统上常用的刷写指令,用于将数据从一个地方复制到另一个地方。
在刷写boot分区时,我们可以使用类似以下命令:dd if=/path/to/bootloader.img of=/dev/sdX bs=512 count=1 其中,if参数指定了引导加载程序的来源,可以是一个文件路径或设备文件。
of参数指定了要刷写的目标设备文件,通常是硬盘或分区设备。
bs参数指定了每次复制的字节数,count参数指定了复制的次数。
2. bootsect命令bootsect命令是一个Windows上常用的刷写指令,用于修改引导扇区。
在刷写boot分区时,我们可以使用类似以下命令:C:\> bootsect /nt60 C:其中,/nt60参数表示将引导加载程序刷写到指定的分区(C盘)上。
第三部分:boot分区刷写操作步骤在选择合适的刷写指令之后,我们可以按照以下步骤刷写boot分区:1. 备份重要数据在进行任何磁盘操作之前,务必先备份重要数据。
如何快速启动嵌入式系统开发
赛灵思公司
【期刊名称】《世界电子元器件》
【年(卷),期】2010(000)012
【摘要】@@ 为了削减成本,提升性能和保持灵活性,在工业、医疗、汽车、航天和军用产品等广泛的应用领域,包括处理器和外设在内的完整的嵌入式系统被整合到了FPGA上.
【总页数】5页(P49-53)
【作者】赛灵思公司
【作者单位】
【正文语种】中文
【相关文献】
1.赛灵思推出新型MICROBLAZE嵌入式套件可使嵌入式系统设计快速启动 [J],
2.嵌入式Linux快速启动技术综述 [J], 张全胜;陈鹏;王树志
3.基于状态保持恢复的嵌入式Linux快速启动方法的研究 [J], 陈鹏;王树志;张全胜;董孝峰
4.嵌入式Linux系统的快速启动 [J], 王亚军
5.一种基于休眠的嵌入式Linux快速启动的方法 [J], 张释文;陈莉君
因版权原因,仅展示原文概要,查看原文内容请购买。
boot0和boot1的用法-回复Boot0和Boot1是两个引导位,通常用于开发者定制自己的操作系统或固件。
引导位是硬件芯片中的一小段代码,负责在系统启动时加载操作系统或固件。
在开发过程中,开发者可以通过定制Boot0和Boot1来实现自己的需求,如引导多个操作系统、自定义引导过程等。
首先,让我们了解一下引导位的作用。
在计算机硬件中,引导位位于硬盘或其他存储介质的引导扇区中,这是系统启动的第一个扇区。
当计算机开机时,BIOS会读取硬盘的引导扇区,并将控制权交给引导位所在的代码。
这段代码将负责加载操作系统或固件,并完成系统的初始化和启动。
在通常情况下,Boot0和Boot1都是由芯片厂商提供的默认引导代码。
它们具有通用性,可以加载大多数操作系统或固件。
然而,在特殊应用或需要定制化的场景中,开发者可能需要对Boot0和Boot1进行修改或重新编写。
为了定制Boot0和Boot1,开发者需要了解相关的底层知识和编程技术。
首先,开发者需要熟悉引导过程中的各个阶段。
引导过程一般可以分为硬件初始化、引导加载和启动执行三个阶段。
在不同的阶段,开发者可以插入自己的代码以实现自定义的功能或逻辑。
接着,开发者需要理解具体的硬件架构和引导代码的实现细节。
不同的硬件平台可能有不同的引导方式和代码结构。
例如,某些平台可能使用汇编语言编写引导代码,而另一些平台可能使用C语言。
开发者需要熟悉这些语言和相关的开发工具。
在开始定制之前,开发者可以先阅读和理解由芯片厂商提供的默认引导代码。
这些代码通常会包含详细的注释和说明,帮助开发者理解引导过程和关键代码段。
通过仔细研究默认代码,开发者可以了解硬件平台的特点和限制,为后续的定制工作打下基础。
接下来,开发者可以根据自己的需求修改或添加代码。
例如,如果开发者希望引导多个操作系统,可以在Boot0代码中添加选择操作系统的逻辑。
如果开发者需要在引导过程中执行一些自定义的初始化操作,可以在Boot1代码中插入相应的代码段。
B级安全的轻量级内核BSK的设计与实现
冷健;谢冬青
【期刊名称】《计算机工程》
【年(卷),期】2006(032)005
【摘要】提出的BSK安全模型是一种达到B级安全的轻量级安全内核模型.BSK 对监控器和BLP模型进行扩充,借鉴Mach消息传递机制,采用面向对象机制,提出了基于安全对象的安全对象模型和消息调度模型,并且给出了BSK消息调度算法.消息调度中主体对客体的访问是有状态的,通过安全检测的访问路由信息存放于缓冲器中,避免过多的安全判定对性能的损失.
【总页数】3页(P125-127)
【作者】冷健;谢冬青
【作者单位】湖南大学计算机与通信学院,长沙,410012;湖南大学计算机与通信学院,长沙,410012;中国科学院软件所计算机科学重点实验室,北京,100081
【正文语种】中文
【中图分类】TP309
【相关文献】
1.SKEE——针对ARM架构的轻量级Linux内核安全执行环境 [J], 申文博
2.安全Linux内核安全功能的设计与实现 [J], 石文昌;孙玉芳;梁洪亮;张相锋;赵庆松;单智勇
3.基于轻量级目录服务的安全控制系统的设计与实现 [J], 王宇杰;高勃;杨文宾
4.基于Skyeye和μClinux的轻量级安全Web服务器的设计与实现 [J], 陆萍
5.轻量级安全的RFID电能计量封印的设计与实现 [J], 周振柳;李丰鹏;郑安刚因版权原因,仅展示原文概要,查看原文内容请购买。
利用根区作用修复主板BIOS来源:中国电脑救援中心作者:阅读: 8032 发布时间:2008-01-15很多朋友都知道刷新主板BIOS失败后可以利用根区(Boot Block)作用来修复(条件是根区程序未受损坏),这可以说是最简单的自救方法,那么其工作原理是什么呢?什么是根区我们知道,主板厂商为避免用户刷新BIOS时出现差错,特意将BIOS 分成了两个区域:一个存放着BIOS的程序代码,就是我们可以用CBROM 软件查看和修改的模块部分;另一个存放的是不能被我们修改的用来急救的一小段程序代码,也就是我们在刷新BIOS时,进度条上最后面一小块颜色不同的部分。
所以当我们用CBROM软件查看BIOS文件时往往会发现文件的实际容量会小于是128KB或256KB(1Mbit或2Mbit),这个我们看不到也不能修改的部分就是BIOS的根区。
根区的作用当我们开机时,计算机会首先执行根区程序,由它检测BIOS文件的完整性。
如BIOS完好无损时,就会正常引导自检;如发现BIOS程序受到破坏就会启用根区程序,但这时程序能够驱动的只有软驱、ISA显卡、键盘等最“原始”的设备,连硬盘都不能识别。
假如这时主板插有ISA显卡和DOS启动盘的话一样可以引导系统进入DOS模式。
修复主板BIOS如何判断BIOS根区是否损坏?最简单的办法就是观察软驱指示灯,如有闪动的现象基本上就有救了。
当然现在找ISA显卡可能较难了,但既然软驱能被识别,我们就可以利用软驱启动计算机在摸黑之下重新刷回备份的源文件(如没备份就只好上网下载了),而更好的方法就是编辑一条批处理命令让计算机自动执行。
下面以Award BIOS为例,讲一下具体的操作方法:首先利用一台正常运行的计算机制作一张DOS启动盘,把刷新程序Awdflash和备份文件(Back.bin)都复制到启动盘里,打开记事簿,键入如下命令:Awdflash back.bin /py/sn/sb/rpy:自动执行刷新程序sn:不备份旧的BIOS文件sb:刷新时强行跳过BIOS根区r:刷新BIOS结束后自动重启然后把它命名为AutoBIOS.bat并保存在启动盘里,再用它来启动主板BIOS出问题的计算机(如以前没有设置软驱优先启动,可以利用跳线清空CMOS,一般清空CMOS后默认的优先启动项是A盘),很快就会听到“哒”的一声,这表明软驱已经开始工作,等待一段时间,如无意外,计算机自动重启,修复成功。
Minix代码分析之一:引导扇区代码作者:聪聪()本文本可以任意发布,在发布时注意请保持原作者的姓名。
email: luocong@1.1 计算机加电当我们打开计算机电源时,计算机叽叽嘎嘎进行设备和内存检测过后就读取硬盘或者软盘的引导扇区,这个扇区只有512字节(每个扇区都一样大),显然这512字节不能够有多大作用,操作系统需要通过这个引导扇区代码再装载操作系统的其他部分。
这512字节的代码被BIOS放在地址从0x0000:0x7c00开始处。
然后直接跳转到0x0000:0x7c00处去执行。
以上工作是BIOS干的,你什么也不用作在还没有跳转到这段代码之前,也就是BIOS把磁盘的引导扇区读入到内存之后,其DL和ES、SI寄存器的内容如下:DL:表示启动设备,例如,如果计算机是从软盘启动的则DL=0,若是从IDE的C、D盘启动的则DL分别为0x80和0x81。
如果是从硬盘启动的话,ES:SI是指向BIOS中的硬盘分区表存放的地址。
1.2 执行引导扇区代码好了,我们现在已经知道,计算机的BIOS已经把引导扇区的512字节的内容读入到了0:0x7c00处,然后就跳转到0:0x7C00处去执行,也就是执行引导扇区代码,其引导扇区代码见后面。
下面对引导扇区代码进行解释。
引导扇区代码的执行过程如下:1.2.1 BIOS在把引导扇区装载到地址0:0x7C00处后,引导扇区代码首先设置正确的堆栈。
其堆栈内容如下图所示:1.2.2 调用BIOS中断:ah=0x08,int 0x13得到磁盘驱动器参数。
其BIOS中断调用ah=0x08,int 0x13说明如下:中断调用ah=0x08,int 0x13返回后,在以下寄存器返回以下信息:DL:本机软盘驱动器的数目DH:最大磁头号(或说磁面数目)。
0表示有1个磁面,1表示有2个磁面CH:存放10位磁道柱面数的低8位(高2位在CL的D7、D6中)。
1表示有1个柱面,2表示有2个柱面,依次类推。
2000 ! Bootblock 1.4 - Minix boot block. Author: Kees J. Bot2001 ! 21 Dec 19912002 !2003 ! When the PC is powered on, it will try to read the first sector of floppy2004 ! disk 0 at address 0x7C00. If this fails due to the absence of flexible2005 ! magnetic media, it will read the master boot record from the first sector2006 ! of the hard disk. This sector not only contains executable code, but also2007 ! the partition table of the hard disk. When executed, it will select the2008 ! active partition and load the first sector of that at address 0x7C00.2009 ! This file contains the code that is eventually read from either the floppy2010 ! disk, or the hard disk partition. It is just smart enough to load the2011 ! secondary boot code from the boot device into memory at address 0x10000 and2012 ! execute that. The disk addresses for this secondary boot code are patched2013 ! into this code by installboot as 24-bit sector numbers and 8-bit sector2014 ! counts above enddata upwards. The secondary boot code is in turn smart2015 ! enough to load the different parts of the Minix kernel into memory and2016 ! execute them to finally get Minix started.当PC加电后,PC试图读软盘0的第一扇区到0x7C00。
如果因为没有可用的磁介子而失败,则它试图读从硬盘的第一个扇区读主引导记录(master boot record),该扇区不仅包含可执行代码,也包含硬盘的分区表(DPT,partition table)。
当他执行时,他将选择活动分区并他的第一个扇区到0x7C00。
本文件包含最终从软盘或从硬盘分区读出的代码,它将从引导设备上加载次级引导代码到内存地址0x10000处,并执行他。
次级引导代码在磁盘上的地址是由installboot将24位的扇区号和8位的扇区数(above enddata upwards)。
次级引导代码也足够聪明,能够将MINIX内核的不同部分加载到内存,并执行他们直到最后使Minix启动。
2017 !It's also important to know that dl contains the drive that was booted (in other words, the drive from which this code originated). This is 0x00 or 0x01 for the first or second floppy drives or 0x80, 0x81, 0x82, or 0x83 for the first through fourth hard drives.If this code originated from a hard drive and the master boot code loaded this code, then the partition table entry that corresponds to the booted partition is passed in es:si.0x80, 0x81, 0x82, or 0x83。
如果本代码来自于硬盘,并是主引导记录装载该代码,则对应于引导分区的分区表入口是由es:si传递。
20182019 LOADOFF=0x7C00 ! 0x0000:LOADOFF is where this code is loaded2020 BOOTSEG=0x1000 ! Secondary boot code segment.2021 BOOTOFF=0x0030 ! Offset into secondary boot above header2022BUFFER =0x0600 ! First free memory2023LOWSEC = 8 ! Offset of logical first sector in partition2024 ! table20252026 ! Variables addressed using bp register2027device = 0 ! The boot device2028lowsec = 2 ! Offset of boot partition within drive2029secpcyl= 6 ! Sectors per cylinder = heads * sectorsThis is fairly common practice in assembler. Several values are pushed on the stack (lines 2043, 2044, and 2046) and then the stack pointer, sp , is saved in bp (mov bp, sp - line 2047). If 2 byte values are pushed on the stack, then the last 2 bytes are accessed by 0(bp) , the next-to-last 2 bytes are accessed by 2(bp) , and so on (see line 2095).While these 3 variables take up 8 bytes, only 6 bytes are pushed onto the stack. lowsec (lines 2043 and 2044) and device (line 2046) are pushed, but what about secpcyl ? When a value is finally stored in secpcyl (line 2110), the first 2 bytes of the bootblock code are overwritten - the first xor ax, ax instruction (line 2036) is overwritten. This doesn't matter since the code never jumps back to the beginning. This saves not only the 2 bytes needed for the variable but also the memory required for a push instruction.这在汇编中是相当普遍的事。
将几个值压入堆栈(lines 2043, 2044, and 2046),并且堆栈指针sp保存在bp中(mov bp, sp - line 2047)。
如果2字节值压入堆栈,那么最后的两字节通过0(bp)存取,之后的两字节使用2(bp)存取,等等(见line 2095)。
这里有3个变量占用8字节,仅有6字节压入堆栈。
lowsec (lines 2043 and 2044) and device (line 2046) 被压入堆栈,但是secpcyl变量如何?当最后一个值存储到secpcyl变量中(line 2110),bootblock 代码的头两个字节被覆盖――即第一条指令xor ax, ax instruction (line 2036)被覆盖。
这没有关系因为代码在不会跳到开头执行。
这个存储不仅是变量需要的2字节,还有push指令需要的存储器。
20302031 .text20322033 ! Start boot procedure.20342035 boot:2036xor ax, ax ! ax = 0x0000, the vector segment2037mov ds, axThe first instruction zeroes the ax register (any number xor'ed with itself is zero). This is a pretty common practice. The instruction mov ax, #0is slower and is 3 bytes compared with xor's 2 bytes.One thing that initially confuses people with assembler is the order of the operands. The syntax of the mov instruction is: mov destination, sourceThis seems a little strange to me but most assemblers use this syntax.第一条指令(xor ax, ax)使AX清0。
它比mov ax, #0快。
指令中操作符的顺序:mov destination, sourceLOADOFF处2038cli ! Ignore interrupts while setting stack2039mov ss, ax ! ss = ds = vector segment2040mov sp, #LOADOFF! Usual place for a bootstrap stack2041stiWhenever a value is mov ed to the stack register (ss) or the stack pointer (sp), the interrupts must be disabled first. The stack holds the address to which an interrupt returns after its completion. If the ss and sp registers are in flux and an interrupt occurs, it's impossible to predict where the code will return.The interrupts are disabled with the cli (clear interrupts) instruction and reenabled with the sti (set interrupts) instruction.What's the pound (#) sign all about? The pound sign indicates that the value of LOADOFF(0x7C00 - see line 2019) is mov ed to the register rather than the contents of the memory location LOADOFF.当修改ss和sp的值时,必须首先屏蔽中断。