设计外文翻译

-嵌入式技术的发展需要网络/服务器技术在嵌入式领域的应用，并提供基TCPIP协议栈、协议模型的低效率，在嵌入式系统接入到因特网时实现完整的TCPIPTCPIP协议，并给出协议每一LwIPLwIP设计的，并且能分析通信时客户端和服务器状态的转换。最后，EWS被用于对蓄电关键词-LwIP;嵌入式技术;网页服务器;uC/OS-II;Web服务，从而实现通过浏览器灵活地进行远程监控和管理，这已经成为嵌TCPIP子网到嵌入式系统中。为了保证实1时性和可靠性，我们还需要移植μC/OS-II。考虑到时间和性能的限制，最好是使用裁剪的TCP/IP。LWIP[2]（Light-WeightInternetProtocol）TCPIP协议套件，由AdamDunkels在瑞典计算机科学院（SICS）的计算机和网络架构（CNA）实验室开发。lwIP协议栈实现的重点是在减少内存使用量和代码尺寸的情况下，使LWIP适用于资源非常有限的小型客户端。ICMP（InternetControlMessageProtocol）1WEICHEN,SHU-BOQIU,YING-CHUNZHANG.IEEEXploreDigitalDHCP（DynamicHostConfigurationPPP（Point-to-PointARP（AddressResolutionProtocol）IPLwIPIP最基本的功能。它可以发送，接收和转发数据包，但不能IP版本字段和报头长度的初始检查，并对包头校验和进行IP地址，来确定数据验和计算。IP数据包的源地址和目的地址被作为一个参数传递给函数ICMPip_input()ICMPicmp_input()进行解码，并进行适当处理。ICMP目的地址不可达消息可以通过传输层协议发送，特别是通过UDP，函数icmp_dest_unreach()ICMP1所示。UDPrecvrecv_arg将被使用。当数据包被接收时，recv所指向的函数UDP的简单性，输入和输出的处理也同样简单，并遵循一个相当直的IPIPip_route（）在某些情况下被调用，以便址。最后，该包被移交给ip_output_if（）进行传输。TCPTCPTCPtcp_output（）将检（）TCP段所属的TCP连接。TCPtcp_process（）TCP状态机，ACK，该数据将从缓冲区移除并回收其内存。此外，LwIP已经把有关硬件，操作系统，编译器的部分包含在/src/arch下。我们这个操作系统模拟层为底层操作系统和LwIP提供一个接口，因此当我们移植LwIP到新的目标时，我们只需要在这一层设计一些函数。这些函数有关段，消UC/OS-II并不对其进行管理。我们必须根据UC/OS-II来实现它们。以下结构用来管理信息。struct{OS_EVENT*void*pvQEntries[MAX_QUEUE_使用和删除的消息。整合上述两成员就形成了lwIP的消息队列功能。UC/OS-IIOSTaskCreate（）创建一个新的线程，但我们必须提前分配优先级给在lwIP中的新线程。PS的关键[7]P的服务器我们称为瘦服务器[8]eb服务器将数据上传至网络上，并在网页上显PLPDPS是非常有利的。这是种典型的网络/。S4。在被添加到服务器中的“RET”状态下，不需要接收任何消息就可以直接跳转到“IN”状态。这个服务器的端口始终是敞开的。当连接建立后，一旦服务80”pingEWS，我们可以得到四个响应数据包，并且司的蓄电池生产控制系统上进行测试过。当我们输入蓄电池生产控制系统的IPEWS的优点是成本低，可视化，独立的平台，灵活的部署，优良的远程Web服务器，可以在网页上对设备进行监测和灵活地Web服务器BilekJ,RuzickaIP.Evolutionarytrendsofembeddedsystems.IEEEInternationalConferenceonIndustrialTechnology,vol2,no3,2003,pp.901-905.AdamD.DesignandImplementationoftheLwIPTCP/IPStack[Z].SwedishInstituteofComputerScience,2001.TianZe.TheDevelopmentandImplementationofEmbeddedSystem[M].Beijing:BeiHangUniversityPress,2005.JeanJ.Labrosse.TheEmbeddedReal-timeμC/OS-II[M].Beijing:BeiHangUniversityPress,2003.J.Benthem.TCP/IPLean:EmbeddedWEBServer[M].Beijing:ChinaMachinePress,2003.YangYe.TheImplementationofTCP/IPunderμC/OS-II[J].Microcontrollers&EmbeddedSystems,vol7,no3,2003,pp.80-83JuHT,ChoiMJ,HongJW."Ews-basedmanagementapplicationinterfaceandintegrationmechanismsforweb-basedelementmanagement,"JournalofNetworkandSystemsManagement,vol.9,no.1,pp.31-50.,Jan,2001.XuFeng,ChenYan,ZhaoHai,HanGuang-jie.StudyonArchitectureofInternetAccessServerforNon-PCDevices[J].JournalofNortheasternUniversity(NaturalScience),vol26,no1,2005,pp.236-239.GaoPo-po,ShaoShi.ResearchandImplementationofEmbeddedWebServeronLow-endDevice[J].ComputerEngineering,vol31,no5,2005,pp.219-221.ThePortingandImplementationofLight-WeightTCP/IPforEmbeddedWebServerWEICHEN, SHU-BOQIU, YING-CHUNZHANG,DepartmentofAutomationofShandongInstituteofLightIndustryˈJinan,Abstract--Thedevelopmenttrendofembeddedtechnologyneedtheweb/servertechnologyappliesintoembeddedfieldsandprovidesaflexibleremotedevicemonitoringandmanagementfunctionbasedonInternetbrowser.But,duetothelimitationofhardwareresourceandthelow-efficiencyofgeneralpurposeTCP/IPprotocolstacksandprotocolmodels,itisquitedifficulttoimplementfullTCP/IPprotocolintoembeddedsystemwhenaccessingtoInternet.ThepaperanalysestheLight-WeightTCP/IPandgivesthedetailedprocessingofeverylayerfirst,thenesignedthehardwareplatformwiththePHILIPSLPC2200andRTL8019AScoreandthesoftwareplatformwithUC/OS-II,portingtheLwIPbasedonthem.AthinserverisdesignedbasedonLwIP,andthestatetransformofclientandserverwhentheywerecommunicatingwasanalyzed.Atlast,theEWSwastestedontheProductionofStorageBatteryControlSystem,theresultindicatedtheEWScanlong-distancemonitorthedevicesreal-timelyandperfectly.Keywords--LwIP;embeddedtechnology;web/server;UC/OS-II; ThetraditionalInternetweb/serveristhefatserver/thinclient,thismodeisperfectwhentranslateandstoreabundanceofdata,butdoesn'tbehaveexcellentinembeddedfield.AndtheInternethasbecomeoneofthemostimportantbasicinformationfacilitiesintheworld,theWWWserviceitoffershasbecomeoneofthefastestgrowingandwidestappliedservice,whichhaveagreatdealofadvantagessuchasvisualization,easyremoteaccessing,multidataformatsupporting,platformindependentandthinclient,etc.ConnectingtheembeddeddevicetotheInternet,implementingperfectWebserviceonit,andthusrealizingaflexibleremotemonitoringandmanagementthroughInternetbrowserhasalreadybecomeaninevitabledevelopmenttrendofembeddedTechnology[1].But,duetothelimitationofhardwareresourceandthelow-efficiencyofpurposeTCP/IPprotocolstacksandprotocolmodels,itisquitedifficulttoimplementfullTCP/IPprotocolintoembeddedsystemwhenaccessingtoInternet.Therefore,weneedtoportasubnetofTCP/IPintotheembeddedsystem.Inordertoensurethereal-timecharacterandthereliability,wealsoneedtoporttheµC/OS-II.Consideringthelimitationoftimeandperformance,itisbettertousetheexitedreducedTCP/IP.lwIP[2](Light-WeightInternetProtocol)isasmallindependentimplementationoftheTCP/IPprotocolsuitethathasbeendevelopedbyAdamDunkelsattheComputerandNetworksArchitectures(CNA)labattheSwedishInstituteofComputerScience(SICS).ThefocusofthelwIPstackistoreducememoryusageandcodesize,makinglwIPsuitableforuseinsmallclientswithverylimitedresources.lwIPfeatures:IP(InternetProtocol)includingpacketforwardingovermultiplenetworkICMP(InternetControlMessageProtocol)fornetworkmaintenanceandUDP(UserDatagramProtocol)includingexperimentalUDP-liteTCP(TransmissionControlProtocol)withcongestioncontrol,RTTestimationandfastrecovery/fastretransmitSpecializedrawAPIforenhancedOptionalBerkeley-alikesocketDHCP(DynamicHostConfigurationPPP(Point-to-PointARP(AddressResolutionProtocol)for IPlwIPimplementsonlythemostbasicfunctionalityofIP.Itcansend,receiveandforwardpackets,butcannotsendorreceivefragmentedIPpacketsnorhandlepacketswithIPoptions.Formostapplicationsthisdoesnotposeanyproblems.ReceivingForincomingIPpackets,processingbeginswhentheip_input()functioniscaiiedbyanetworkdevicedriver.Here,theinitialsanitycheckingoftheIPversionfieldandtheheaderlengthisdone,aswellascomputingandcheckingtheheaderchecksum.Next,thefunctionchecksthedestinationaddresswiththeIPaddressesofthenetworkinterfacestodetermineifthepacketwasdestinedforthehost.SendingAnoutgoingpacketishandledbythefunctionip_output(),whichusesthefunctionip_route()tofindtheappropriatenetworkinterfacetotransmitthepacketon.Whentheoutgoingnetworkinterfaceisdetermined,thepacketispassedtoip_output_if()whichtakestheoutgoingnetworkinterfaceasanargument.Here,allIPheaderfieldsarefilledinandtheIPheaderchecksumiscomputed.ThesourceanddestinationaddressesoftheIPpacketispassedasanargumenttoip_output_if().ICMPICMPpacketsreceivedbyip_input()arehandedovertoicmp_input(),whichdecodestheICMPheaderandtakestheappropriateaction.ICMPdestinationunreachablemessagescanbesentbytransportlayerprotocols,inparticularbyUDP,andthefunctionicmp_dest_unreach()isusedforthis.TheICMPprocessingisshowninFig.1.UDPUDPisasimpleprotocolusedfordemultiplexingpacketsbetweendifferentprocesses.ThestateforeachUDPsessioniskeptinaPCBstructure.Thelasttwoargumentsrecvandrecv_argareusedwhenadatagramisreceivedinthesessionspecifiedbythePCB.ThefunctionpointedtobyrecviscalledwhenadatagramisDuetothesimplicityofUDP,theinputandoutputprocessingisequallysimpleandfollowsafairlystraightline(Fig.2).Tosenddata,theapplicationprogramcallsudp_send()whichcallsuponudp_output().Herethenecessarycheck-summingisdoneandUDPheaderfieldsarefilled.SincethechecksumincludestheIPsourceaddressoftheIPpacket,thefunctionip_route()isinsomecasescalledtofindthenetworkinterfacetowhichthepacketistobetransmitted.TheIPaddressofthisnetworkinterfaceisusedasthesourceIPaddressofthepacket.Finally,thepacketisturnedovertoip_output_if()fortransmission.TCPTCPisatransportlayerprotocolthatprovidesareliablebytestreamservicetotheapplicationlayer.ThebasicTCPprocessing(Fig.3)isdividedintosixfunctions;whenanapplicationwantstosendTCPdata,tcp_write()iscalled.Thefunctiontcp_write()passescontroltotcp_enqueue()whichwillbreakthedataintoappropriatesizedTCPsegmentsifnecessaryandputthesegmentsonthetransmissionqueuefortheconnection.Thefunctiontcp_output()willthencheckifitispossibletosendthedata,Inputprocessingbeginswhenip_input()afterverifyingtheIPheaderhandsoveraTCPsegmenttotcpinput().InthisfunctiontheinitialsanitychecksaredoneaswellasdecidingtowhichTCPconnectionthesegmentbelongs.Thesegmentisthenprocessedbytcp_process(),whichimplementstheTCPstatemachine,andanynecessarystatetransitionsaremade.Thefunctiontcp_receive()willbecallediftheconnectionisinastatetoacceptdatafromthenetwork.Ifso,tcp_receive()willpassthesegmentuptoanapplicationprogram.IfthesegmentconstitutesanACKforunacknowledgeddata,thedataisremovedfromthebuffersanditsmemoryisreclaimed.Also,ifanACKfordatawasreceivedthereceivermightbewillingtoacceptmoredataandthereforetcp_output()iscalled. PORTINGOFLWIPBASEDONTheportingofFormula[4]isveryeasynow,soItalkabouttheportingoflwIPonitdirectly.lwIPhadputtheportionabouthardware,OS,compilerunder/src/arch.Ourmaintaskistoperfectthefilesunderthatdirectoryandseldommodifytheotherfilesintheporting.Inthisporting,therealizationoftheoperatingsystememulationlayerisveryimportant.InordertomakelwIPportable,operatingsystemspecificfunctioncallsanddatastructuresarenotuseddirectlyinthecode.Instead,whensuchfunctionsareneededtheoperatingsystememulationlayerisused.Theoperatingsystememulationlayerprovidesauniforminterfacetooperatingsystemservicessuchastimers,processsynchronization,andmessagepassingmechanisms.Inprinciple,whenportinglwIPtootheroperatingsystemsonlyanimplementationoftheoperatingsystememulationlayerforthatparticularoperatingsystemisneeded.TheoperatingsystememulationlayerprovideaninterfacebetweenthebottomoperationsystemandthelwIP,thusweonlyneedtodesignsomefunctionsinthislayerwhenweportlwIPtoanewtargetoperation.Somefunctionaboutsegment,message,timeout,newthreadandsoon.Besides,wehavetoputattentionontwoquestionsaboutFormuladuringtheimplementationoflwIP[6].Wecan'tusethemessageswhichinthemessagequeuedirectly,becauseFormuladoesn'tmanagethem.WemustimplementthembasedontheFormula.Thestructuredefinedtomanagethemessages.typedefOS_EVENT*void*pvQEntries[MAX_QUEUE_TothequeueitselfmanagedbyFormulaandusethemoduleofEMSmemorymanagetorealizetheset,useanddeleteofmessage.TheintegrationoftheabovetwocanformthemessagequeuefunctionoflwIPCreateNewThereisnothreadbuttaskinFormulaWecancreatethenewthreadthroughcallingOSTaskCreate(),butwemustassignedthePRIforthenewthreadinlwIPinIVREALIZATIONOFTheportingoflwIPisthekeytorealizetheEWS[7].TheserverbasedonlwIPwenamedthinserver[8],itsatisfiestheembeddeddevices'request.Thedeviceinformationcanbeuploadedonthewebpageandappearasdata,tableandcartoonetc.EmbeddedwebserverissuethedatatotheInternetasthewebpagesothattheremoteusercanbrowsetheinformation.Fromthewebpagewecanknowthedetailedstatusofdevicesandmaketherelevantcontrolimmediately.Inapplicationlayer,HTTPistheprimaryprotocol,wecanmonitorthedevicesonthespotordownloadthenewestdriver.Inaddition,theDHCPinlwIPisverybeneficialforourEWS.It'smodeofserviceisthetypicalweb/server,themasterServercanreceivetherequestdatapackagefromclients,readtherequestmessage,parseitandsendtheresponsetotheclients[9].ThestatetransformofEWSasshowninFig.4.Thestate“RESET”beingaddedintotheserver,thereneedn'treceiveanymessagetojumptothestateof“LISTEN”directlyinthisstate.Theportoftheserverisalwaysopen.Oncetheserverfindsthe“ACK”packageiswrongortheserverportisnot80whentheconnectionhasbeenestablished,thestatewilljumpto“RESET”andsendaof“RST”toreestablishconnection.Inordertoavoidcongestion,oncetheconnectionisovertime,itwillbeclosed. UsingPINGcommandtolinkEWSinlocalareanetwork,wecangetfourresponsedatapackagesandthetimeitusedislessthan20msandthereisnodatapackagelost.ThisEWSwastestedontheProductionofStorageBatteryControlSystemwhichbelongstoTuo-ChiElectricApplianceCompanyinZi-Bo.WhenweinputtheIPaddressofProductionofStorageBatteryControlSystem,wecanopenthewebpagethroughthebrowserquicklyandcorrectly.ThuswecanbelievetheEWScanlong-distancemonitorthedevicesreal-timelyandperfectly.functionistoassignIPaddress.UsingtheHTTPtheWeb TheadvantagesofthisEWSarelowcost,visualization,platformindependent,flexibledeployment,excellentremoteaccessing,etc.Theequipmentscanbemonitoredandcontrolledflexiblyinwebpagesthroughembeddedwebserver.Inindustrycontrolfield,theusingofembeddedwebserveronintelligencedevice,instrumentandsensortorealizeflexibleremotecontrolhasveryhightheoreticalandapplicationvalue.BilekJ,RuzickaIP.Evolutionarytrendsofembeddedsystems.IEEEInternationalConferenceonIndustrialTechnology,vol2,no3,2003,pp.901-905.AdamD.DesignandImplementationoftheLwIPTCP/IPStack[Z].SwedishInstituteofComputerScience,2001.TianZe.TheDevelopmentandImplementationofEmbeddedSystem[M].Beijing:BeiHangUniversityPress,2005.JeanJ.Labrosse.TheEmbeddedReal-timeμC/OS-II[M].Beijing:BeiHangUniversityPress,