Embedded Systems

Definition

Embeddedsystemsareapplication-centric,basedonmoderncomputertechnology,andcanbebasedonuserneeds(Function,reliability,cost,volume,powerconsumption,environment,etc.)Adedicatedcomputersystemthatflexiblytailorssoftwareandhardwaremodules.

Summaryofmainpoints:

Application-centric:Emphasizethatthegoalofembeddedsystemsistomeetthespecificneedsofusers.Formostcompleteembeddedsystems,userscandirectlyenjoytheirfunctionswhenturningonthepower,withoutsecondarydevelopmentoronlyasmallamountofconfigurationoperations.

Specificity:Mostoftheapplicationsofembeddedsystemshavehigherrequirementsforreliabilityandreal-timeperformance,whichdeterminesthatdedicatedsystemsservingspecificapplicationsarethemainstreammodeofembeddedsystems.Emphasizetheversatilityandscalabilityofthesystem.Thiskindofspecializationusuallyalsoleadstotheembeddedsystembeingafinalsystemwithtightlyintegratedsoftwareandhardware,becausethiscanmoreeffectivelyimprovethereliabilityoftheentiresystemandreducecosts,andmakeithaveabetteruserexperience.

Withmoderncomputertechnologyasthecore:themostbasicsupporttechnologyforembeddedsystems,roughlyincludingintegratedcircuitdesigntechnology,systemstructuretechnology,sensingandtestingtechnology,embeddedoperatingsystemandreal-timeoperatingsystemtechnology,High-reliabilitysoftwaredevelopmenttechnologyforresource-constrainedsystems,systemformalspecificationandverificationtechnology,communicationtechnology,lowpowerconsumptiontechnology,dataanalysisforspecificapplicationfields,signalprocessingandcontroloptimizationtechnology,etc.,theyareintegratedaroundthebasicprinciplesofcomputerEnteraspecificdedicateddevicetoformanembeddedsystem.

Softwareandhardwarecanbetailored:Embeddedsystemsareaimedatsomanyapplicationscenarios,andbringextremelydifferentdesignindexrequirements(functionalperformance,reliability,cost,powerconsumption),sothattherealityItisdifficulttohaveasetofsolutionstomeetallsystemrequirements.Therefore,accordingtodifferentrequirements,flexibletailoringofsoftwareandhardwareandbuildingafinalsystemthatmeetstherequirementsisaninevitabletechnicalrouteforthedevelopmentofembeddedtechnology.

Developmentprocess

Therealdevelopmentofembeddedcomputerswasaftertheadventofmicroprocessors.InNovember1971,thearithmeticunitandthecontrollercircuitweresuccessfullyintegrated,andthefirstmicroprocessorwaslaunched.Afterthat,variousmanufacturerssuccessivelyintroduced8-bitand16-bitmicroprocessors.Systemsbasedonthesemicroprocessorsarewidelyusedinthefieldsofinstrumentation,medicalequipment,robots,andhouseholdappliances.Theextensiveapplicationofmicroprocessorshasformedabroadembeddedapplicationmarket.ComputermanufacturershavebeguntoprovideuserswithOEMproductsinalargenumberofplug-ins,andthenuserscanchooseasetofsuitableCPUboards,memoryboardsandvarioustypesaccordingtotheirneeds.TheI/Oplug-inboardconstitutesadedicatedembeddedcomputersystemandembedsitinitsownsystemequipment.

Inthe1980s,withtheimprovementofmicroelectronicstechnology,integratedcircuitmanufacturersbegantointegratethemicroprocessors,I/Ointerfaces,A/Dconverters,D/Aconverter,serialinterface,andRAM,ROMandothercomponentsareallintegratedintoaVLSI,therebymanufacturingamicrocontrollerforI/Odesign,whichiscommonlyknownasasingle-chipmicrocomputer.Thesingle-chipmicrocomputerhasbecomearookieemergingintheembeddedcomputer.Inthe1990s,drivenbyhugedemandsfordistributedcontrol,flexiblemanufacturing,digitalcommunications,andinformationappliances,embeddedsystemsdevelopedrapidly.DSPproductsforreal-timesignalprocessingalgorithmsaredevelopinginthedirectionofhighspeed,highprecision,andlowpowerconsumption.The21stcenturyisanerainwhichnetworksareprevalent,andtheapplicationofembeddedsystemstovariousnetworksisanimportantdirectionforitsdevelopment.

Thedevelopmentofembeddedsystemshasroughlygonethroughthefollowingthreestages:

Thefirststage:theearlystageofembeddedtechnology.Theembeddedsystemexistsintheformofaprogrammablecontrollerwithasimplefunctionspecialcomputerorasingle-chipmicrocomputerasthecore,andhasthefunctionsofmonitoring,servo,andequipmentindication.Thissystemismostlyusedinvariousindustrialcontrolsandweaponsandequipmentsuchasaircraftandmissiles.

Thesecondstage:markedbyhigh-endembeddedCPUandembeddedoperatingsystem.Themainfeatureofthis-stagesystemistheemergenceofhighlyreliable,low-powerembeddedCPUsincomputerhardware,suchasARM,PowerPC,etc.,andsupportstheoperatingsystem,andsupportsthedevelopmentandoperationofcomplexapplications.

Thethirdstage:MarkedbychiptechnologyandInternettechnology.Therapiddevelopmentofmicroelectronicstechnology,SOC(SystemonChip)makesembeddedsystemssmallerandsmaller,buttheirfunctionsaregettingstronger.Atpresent,mostembeddedsystemsarestillisolatedfromtheInternet,butwiththedevelopmentoftheInternetandtheincreasinglycloseintegrationofInternettechnologywithinformationappliances,industrialcontroltechnology,etc.,embeddedtechnologyisenteringaperiodofrapiddevelopmentandwidespreadapplication.

Features

Thehardwareandsoftwareoftheembeddedsystemmustbeselectedaccordingtospecificapplicationtasks,withpowerconsumption,cost,volume,reliability,andprocessingcapabilitiesasindicators.Thecoreofanembeddedsystemissystemsoftwareandapplicationsoftware.Duetothelimitedstoragespace,thesoftwarecodeisrequiredtobecompact,reliable,andhavestrictrequirementsforreal-timeperformance.

Fromtheperspectiveofcomposition,theembeddedsystemisacomputersystemthatintegratessoftwareandhardwareandcanworkindependently;fromtheappearance,theembeddedsystemislikea"programmable"electronic"device";Fromafunctionalpointofview,itisacontrollerthatcontrolsthetargetsystem(hostobject)andmakesitintelligent.Fromthedifferentperspectivesofusersanddevelopers,comparedwithordinarycomputers,embeddedsystemshavethefollowingcharacteristics.

(1)Strongspecificity.Sincetheembeddedsystemisusuallyorientedtoaspecificapplication,thehardwareandsoftwareoftheembeddedsystem,especiallythesoftware,aredesignedforaspecificusergroup,andusuallyhaveacertainspecificity.

(2)Miniaturization.Theembeddedcomputerintegratesmanytaskscompletedbytheboardinageneral-purposecomputersystemintothechip,therebyfacilitatingminiaturizationandembeddingtheembeddedsystemintothetargetsystem.

(3)Goodreal-timeperformance.Embeddedsystemsarewidelyusedinproductionprocesscontrol,dataacquisition,transmissionandcommunicationandotheroccasions.Theyaremainlyusedtocontrolhostobjects,sotherearemoreorlessreal-timerequirementsforembeddedsystems.Forexample,thereal-timerequirementsforembeddedsystemsinweaponsandcontrolsystemsincertainindustrialcontroldevicesareextremelyhigh.Somesystemsdonothaveveryhighreal-timerequirements,suchashandheldcomputersthathavedevelopedrelativelyfastinrecentyears.Butingeneral,real-timeisauniversalrequirementforembeddedsystems,andanimportantindicatorthatdesignersandusersshouldfocuson.

(4)Goodtailorability.Fromtheperspectiveofthespecificcharacteristicsoftheembeddedsystem,thesupplieroftheembeddedsystemshouldprovideavarietyofhardwareandsoftwareasalternatives,andstrivetoachievehigherperformanceonthesamesiliconchiparea,sothatitcanbeusedinspecificareas.Morecompetitiveintheapplication.

(5)Highreliability.Becausethecomputingtasksundertakenbysomeembeddedsystemsinvolveimportantmatterssuchasthecriticalqualityoftheaccusedproduct,personalequipmentsafety,andevennationalsecrets,andthehostobjectsofsomeembeddedsystemsworkinunattendedsituations,suchasinhigh-risksituations.Themonitoringdeviceintheharshindustrialenvironmentandharshoutdoorenvironment.Therefore,comparedwithordinarysystems,embeddedsystemshaveextremelyhighrequirementsforreliability.

(6)Lowpowerconsumption.Manyembeddedsystemshostsmallapplicationsystems,suchasmobilephones,MP3s,digitalcameras,etc.ItisimpossibleforthesedevicestobeequippedwithACpowersuppliesorlarge-capacitypowersupplies,solowpowerconsumptionhasalwaysbeenthegoalpursuedbyembeddedsystems.

(7)Theembeddedsystemitselfdoesnothavetheabilitytodevelopitself,andmustbedevelopedwiththehelpofageneral-purposecomputerplatform.Afterthedesignofanembeddedsystemiscompleted,ordinaryusersusuallyhavenowaytomodifytheprogramorhardwarestructure,andtheymusthaveasetofdevelopmenttoolsandenvironmenttoproceed.

(8)Embeddedsystemsareusuallyimplementedbymeansof"softwareandhardwareco-design".Earlyembeddedsystemdesignmethodsoftenadoptedthe"hardwarefirst"principle,thatis,undertheconditionofonlyroughlyestimatingtherequirementsofthesoftwaretask,thehardwaredesignandimplementationarecarriedoutfirst,andthenthesoftwaredesigniscarriedoutonthishardwareplatform.Ifthetraditionaldesignmethodisadopted,onceaproblemisfoundinthetestandthedesignneedstobemodified,theentiredesignprocesswillberepeated,whichwillhaveagreatimpactonthecostanddesigncycle.Thedesignofthesystemdependstoalargeextentontheexperienceofthedesigner.Sincethe1990s,withthedevelopmentofrelatedtechnologiessuchaselectronicsandchips,asoftwareandhardwareco-designmethodhasemergedinthedesignandimplementationofembeddedsystems,thatis,theuseofunifiedmethodsandtoolstodescribe,synthesizeandverifysoftwareandhardware.Undertheguidanceofsystemgoalsandrequirements,throughthecomprehensiveanalysisofsystemsoftwareandhardwarefunctionsandexistingresources,thesoftwareandhardwarearchitectureiscollaborativelydesignedtomaximizethesystem'ssoftwareandhardwarecapabilitiesandavoidallkindsofproblemscausedbyindependentdesignofthesoftwareandhardwarearchitecture.Disadvantages,gethigh-performance,low-costoptimizeddesign.

Systemcomposition

Fromtheperspectiveofexternalcharacteristics,anembeddedsystemisusuallyafullyfunctionalsoftwareandhardwareintegratedsystemthatcanrunindependentlywithoutrelyingonotherexternaldevices.Ifyoudividesuchasystem,youcanfindthatitmayroughlyincludesuchseverallevels,asshowninFigure1.

Thecoreleveloftheembeddedsystemisthecentralprocessingunit,whichcontainsarithmeticunitsandcontrollermodules.Onthebasisofthecpu,itisfurtherequippedwithmemorymodules,powermodules,resetmodules,etc.toformtheusualThesmallestsystem.Duetotechnologicaladvancement,integratedcircuitmanufacturersusuallyintegratemanyperipheralsintothesameintegratedcircuit,whichismoreconvenienttouse.Suchachipisusuallycalledamicrocontroller.Onthebasisofthemicrocontroller,furtherexpandthepowersupplysensinganddetection,actuatormodulesandsupportingsoftwaretoformacompleteunitwithspecificfunctions,whichiscalledanembeddedsystemorembeddedapplication.

Hardwarestructure

Althoughthefunctions,appearanceinterfaces,operations,etc.ofvariousspecificembeddedsystemsaredifferentorevendifferent,thebasichardwarestructureissimilar,andIthasahighdegreeofsimilaritywiththehardwaresystemofgeneral-purposecomputers.Thehardwarepartoftheembeddedsystemlooksnodifferentfromthatofageneral-purposecomputersystem,anditisalsocomposedofprocessors,memories,peripheraldevices,I/Ointerfaces,andgraphicscontrollers.However,theapplicationcharacteristicsofembeddedsystemsmakethecompositionandrealizationofsoftwareandhardwaredifferentfromgeneralcomputersystems.Inordertomeettherequirementsofembeddedsystemsintermsofspeed,sizeandpowerconsumption,operatingsystems,applicationsoftware,specialdata,andotherdatathatneedtobestoredforalongtime,usuallydonotusediskssuchaslarge-capacityandslowerstoragemedia,butmostUseEPROM,E2PROMorflashmemory(FlashMemory).Inembeddedsystems,A/DorD/Amodulesaremainlyusedformeasurementandcontrol,whicharerarelyusedingeneral-purposecomputers.Dependingontheactualapplicationandscale,someembeddedsystemsneedtouseanexternalbus.Withtherapidexpansionofembeddedsystemapplications,embeddedsystemsarebecomingmoreandmorepersonalized,andmoreandmoretypesofbusesareusedaccordingtotheirowncharacteristics.Inaddition,inordertotesttheinternalcircuitsoftheembeddedprocessor,theprocessorchipgenerallyusestheboundaryscantesttechnology(JTAG).

SoftwareSystem

Thesoftwaresystemoftheembeddedsystemisdesignedforthespecifichardwaresystemanduserrequirementsoftheembeddedsystem.Itisanimportantpartoftheembeddedsystemandrealizestheembeddedsystem.Thekeytothefunctionofthesystem.Theembeddedsystemsoftwaresystemissimilartothegeneralcomputersoftwaresystem,dividedintofourlayers:driverlayer,operatingsystemlayer,middlewarelayerandapplicationlayer,eachwithitsowncharacteristics.

Driverlayer

Thedriverlayeristhelayerthatdirectlyinteractswiththehardware.Itprovideshardwaredriversorunderlyingcoresupportfortheoperatingsystemandapplications.Inembeddedsystems,thedriverissometimescalledaboardsupportpackage(BSP).BSPhasthefunctionofinitializingthebasichardwareenvironmentoftheembeddedsystemafterpoweron.Thebasichardwareincludesmicroprocessor,memory,interruptcontroller,DMA,timerandsoon.Driverlayer-Generallytherecanbethreetypesofprograms,namelyboard-levelinitializationprogram,standarddriverandapplicationdriver.

Operatingsystemlayer

Theoperatingsystemintheembeddedsystemhasthecorefunctionsofageneraloperatingsystemandisresponsiblefortheallocationofallsoftwareandhardwareresourcesoftheembeddedsystem,Schedulingworkcontrol,coordinationofconcurrentactivities.ItstillhasembeddedcharacteristicsandbelongstoEmbeddedOperatingSystem(EOS).ThemainstreamembeddedoperatingsystemsincludeWindowsCE,Palm:OS,Linux,VxWorks.pSOS.QNX.LynxOS,etc.Withanembeddedoperatingsystem,writingapplicationsisfaster,moreefficient,andmorestable.

Middlewarelayer

Middlewareissoftwareusedtohelpandsupportapplicationsoftwaredevelopment,usuallyincludingdatabase,networkprotocol,graphicssupportandcorrespondingdevelopmentTools,suchasMySQL,TCP/IP,GU1,etc.belongtothiscategoryofsoftware.

Applicationlayer

Embeddedapplicationsoftwareissoftwarethatisaimedataspecificapplicationfieldandisusedtoachievetheexpectedgoalsofusers.Thereisacertaindifferencebetweenembeddedapplicationsoftwareandordinaryapplicationsoftware.Itnotonlyrequiresaccuracy,safetyandstabilitytomeettheneedsofactualapplications,butalsooptimizesasmuchaspossibletoreducetheconsumptionofsystemresources.,Reducehardwarecosts.Theapplicationsoftwareintheembeddedsystemisthemostactiveforce,andeachapplicationsoftwarehasaspecificapplicationbackground.Althoughitissmallinscale,itishighlyspecialized.Therefore,embeddedapplicationsoftwareisnotrestrictedbyforeignproductslikeoperatingsystemsandsupportingsoftware.Itisthedominantfieldofembeddedsoftwareinmycountry.

Embeddingmethod

TheembeddedsystemworksbyembeddingtheCPUinthetargetsystemorcontrolledsystem.Butindifferentembeddedsystems,theformanddegreeofembeddingaredifferent.Accordingtotheclosenessoftheconnectionbetweentheembeddedsystemandthegeneral-purposecomputer,theembeddedformcanbedividedintoafullyembeddedmodeandasemi-embeddedmode.

Fullyembeddedmethod

Ifthefullyembeddedmethodisadopted,theembeddedsystem(oritscorefunction)canworkindependentlywithoutrelyingonthegeneralcomputersystem.Atypicalexampleisamobilephone,MP4,carGPSnavigationsystem,etc.Theembeddedsystemadoptingthefullyembeddedmodehasthefollowingcharacteristics.

(1)Ithasanindependentprocessorsystemandacompleteinput/outputsystem,whichcanindependentlycompletethefunctionsofthesystem.

(2)High-endCPUssupportembeddedoperatingsystemsandcandevelopcomplexapplications.

(3)Generally,itisaportablehandhelddevice,anditsworkingenvironmentisgenerallyunattended,mobilespace,highaltitudeorotherenvironmentswithharshconditions.

(4)Thepowersupplymethodisgenerallybattery-powered.Insomecases,itcanalsobedirectlypoweredbythemains220V,andtheconversionandvoltagestabilizingcircuitisdesignedbythesystem.Higher-enddevicesoftencombinethetwopowersupplymodes,allowinguserstousethemmoreflexibly.

(5)Thefullyembeddedmethodissuitableforanyoccasionwheregeneral-purposecomputersarenotsuitable,suchasconsumerelectronics,householdappliances,communicationnetworkequipment,industrialcontrol,intelligentinstruments,battlefieldelectroniccountermeasures,aerospaceweapons,etc.,anditsapplicationsThescopeisverywide.

Semi-embeddedmethod

Ifthesemi-embeddedmethodisadopted,theembeddedsystem(oritscorefunction)needstobecombinedwithageneralcomputersystemtoworknormally.AtypicalexampleisamedicalB-modeultrasound.System,dataacquisitionsystembasedonPCIcard,etc.Theembeddedsystemadoptingthesemi-embeddedmodehasthefollowingcharacteristics.

(1)Generally,thereisnoindependentprocessor,buttheCPUofageneral-purposecomputersystemisusedtocompletecalculationand/orcontrolfunctions;sometimesevenwithitsownindependentprocessor,theprocessoronlyperformssomelimitedfunctions.Itdoesnothavethefunctionofcontrollingtheentiresystem.

(2)Theembeddedsystemisonlyapartofthewholesystem,andcanonlycompletepartofthefunctionsofthewholesystem,whileotherfunctionsneedtobecompletedonageneral-purposecomputer.General-purposecomputersusetheirrichsoftwareandhardwareresourcestoprovideafriendlyman-machineinterfaceandpowerfuldataprocessingcapabilities.

(3)Thefunctionoftheembeddedsystemisembodiedinthecollectionandexecutionoffront-enddatatocontrolthecontrolledobject,andthefunctionsofdataanalysis,processingandstoragearecompletedbythegeneral-purposecomputersystem.

(4)Embeddedsystemsgenerallyusevariousstandardizedbusformstoconnectwithgeneral-purposecomputers.TypicalexamplesarePCIbus,USBbus,etc.Simpleembeddedsystemscanalsobeconnectedthroughserialports.

(5)Embeddedsystemsareconnectedtogeneral-purposecomputersasperipherals,sogeneral-purposecomputersgenerallyneedtoprovidestandarddriversforembeddedsystems.

Relatedintroduction

Embeddedmicroprocessor

Themicroprocessoristhecoreoftheentiresystem,usuallycomposedofthreemajorparts:controlunit,arithmeticlogicunitandregister.

EmbeddedOperatingSystem

EmbeddedOperatingSystemEOS(EmbeddedOperatingSystem)isakindofsystemsoftwarewithawiderangeofuses.Inthepast,itwasmainlyusedinthefieldsofindustrialcontrolanddefensesystems.EOSisresponsiblefortheallocation,scheduling,controlandcoordinationofconcurrentactivitiesofallsoftwareandhardwareresourcesoftheembeddedsystem;itmustreflectthecharacteristicsofthesystemwhereitislocated,andcanachievetherequiredfunctionsofthesystembyloadingandunloadingcertainmodules.Atpresent,someEOSproductserieswithrelativelysuccessfulapplicationshavebeenlaunched.WiththedevelopmentofInternettechnology,thepopularizationandapplicationofinformationappliances,andtheminiaturizationandspecializationofEOS,EOShasbeguntodevelopfromasingleweakfunctiontoahighlyspecializedandstrongfunction.Theembeddedoperatingsystemhasmoreprominentfeaturesinthereal-timeefficiencyofthesystem,thedependencyofthehardware,thesolidificationofthesoftware,andthespecificityoftheapplication.

Application

Theapplicationofembeddedsystemisveryextensive,involvingindustrialproduction,dailylife,industrialcontrol,aerospaceandotherfields,andwiththedevelopmentofelectronictechnologyandcomputersoftwaretechnologyDevelopmenthasnotonlybecomemoreandmorein-depthapplicationsinthesefields,butalsograduallyrevealeditsusefulnessinothertraditionalnon-informationequipment.

Industrialcontrol

Industrialautomationequipmentbasedonembeddedchipswillmakegreatprogress.Therearealreadyalargenumberof8-bit,16-bit,and32-bitembeddedmicrocontrollersinapplications..Networkingisthemainwaytoimproveproductionefficiency,productquality,andreducehumanresources,suchasindustrialprocesscontrol,digitalmachinetools,powersystems,powergridsecurity,powergridequipmentmonitoring,andpetrochemicalsystems.Asfarastraditionalindustrialcontrolproductsareconcerned,low-endproductsoftenuse8-bitmicrocontrollers.Withthedevelopmentofcomputertechnology,32-bitand64-bitprocessorshavegraduallybecomethecoreofindustrialcontrolequipment.

Trafficmanagement

Invehiclenavigation,flowcontrol,informationmonitoringandcarservices,embeddedtechnologyhasbeenwidelyused,andembeddedGPSmodule,GSMmodulemobilepositioningTheterminalhasbeensuccessfulinvarioustransportationindustries.Atpresent,GPSequipmenthasenteredthehomesofordinarypeoplefromcutting-edgetechnologyproducts.

Informationappliances

Homeapplianceswillbecomethelargestapplicationfieldofembeddedsystems.Thenetworkingandintelligenceofrefrigeratorsandairconditionerswillleadpeople'slivesintoabrandnewspace.Evenifyouarenotathome,youcanremotelycontrolyourhomeappliancesthroughthephoneortheInternet.Inthesedevices,embeddedsystemswillbeveryuseful.

Homeintelligentmanagementsystem

Remoteautomaticmeterreadingsystemforwatermeters,electricitymeters,andgasmeters,safetyfireprotection,anti-theftsystem,embeddedwithspecialcontrolchip,thisspecialcontrolchipwillreplaceTraditionalmanualoperationcompletestheinspectionfunctionandachieveshigher,moreaccurateandsaferperformance.Atpresent,theadvantagesofembeddedsystemshavebeenembodiedintheservicefield,suchasremoteorderingdevices.

POSnetworkande-commerce

SmartATMterminalssuchasthepublictransportationcontactlesssmartcard(ContactlessSmartCard,CSC)issuancesystem,publictelephonecardissuancesystem,andautomaticvendingmachineshavebeenfullyimplementedPeople’slivescantravelallovertheworldwithacardinhandinthenot-too-distantfuture.

Environmentalengineeringandnature

Inmanyareaswithharshenvironmentsandcomplexterrain,real-timehydrologicaldatamonitoring,floodcontrolsystemandwaterandsoilqualitymonitoringarerequiredfordykesafetyandearthquakemonitoring,andreal-timemeteorologicalinformationAndwhenitcomestoairpollutionmonitoring,theembeddedsystemwillrealizeunmannedmonitoring.

Robots

Thedevelopmentofembeddedchipswillmakerobotsmoreobviousintermsofminiaturizationandhighintelligence.Atthesametime,theywillgreatlyreducethepriceofrobotsandmakethemintheindustrialfield.Andtheservicefieldhasbeenwidelyused.

Developmentprocess

TaketheLinuxoperatingsystemasanexampletodiscussthedevelopmentprocessofembeddedsystems.

Establishadevelopmentenvironment

Installtheoperatingsystemandcross-compiler.TheoperatingsystemgenerallyusesRedhatLinux.Choosecustominstallationorfullinstallation,anddownloadthecorrespondingInstalltheGCCcrosscompiler(forexample,armn-1inux-gcc,arm-uclibc-gcc),orinstalltherelevantcrosscompilerprovidedbytheproductmanufacturer.

Configuretheparametersofthedevelopmenthost

ConfiguretheMNICOMparameters.TheMNICOMsoftwarefunctionsasamonitorandkeyboardinputfordebuggingtheinformationoutputoftheembeddeddevelopmentboardToolof.Undernormalcircumstances,theparametersare115200Baud/s,thedatabitis8bits,thestopbitis1,noparity,andthesoftwareandhardwareflowcontrolissettonone.ThesameistruefortheconfigurationofHyperTerminalunderWindows.TheconfigurationofthenetworkismainlytoconfiguretheNFSnetworkfilesystem,andthefirewallneedstobeturnedofftosimplifytheprocessofsettinguptheembeddednetworkdebuggingenvironment.

CreatebootloaderBOOTLOADER

DownloadsomeopensourceBOOTL0ADERfromtheInternet,suchasU-BOOT,BLOB,VIVI,LILO,ARM-Boot,RED-Boot,etc.,aretransplantedandmodifiedaccordingtothespecificchip.Somechipsdonothaveabuilt-inbootloader,soyouneedtowriteaFLASHprogrammingprogramonthedevelopmentboard,oryoucandownloadthecorrespondingprogrammingprogramontheInternet.Ifyoucannotburnyourowndevelopmentboard,youneedtomodifythesourcecodeaccordingtoyourspecificcircuit.Thisisthefirststeptomakethesystemwork.

DownloadthetransplantedLinuxoperatingsystemkernel

SuchasMCLiunx,ARM_Linux,PPC-Linux,etc.,ifthereisatransplantspecificallyfortheCPUusedTheLinuxoperatingsystemisgreat.Afterdownloading,addspecifichardwaredrivers,andthendebugandmodify.ForCPUswithMMU,youcanusethemoduletodebugthedrivers,butforsystemssuchasMCLiunx,youcanonlycompilethekernelfordebugging.

Buildarootfilesystem

DownloadandusetheBUSYBOXsoftwareforfunctionreductiontogenerateabasicrootfilesystem,andthenaddothersaccordingtoyourapplicationneedsprogramof.Sincethedefaultstartupscriptgenerallydoesnotmeettheneedsoftheapplication,itisnecessarytomodifythestartupscriptintherootfilesystem.Itsstoragelocationislocatedinthe/etcdirectory,including:/etc/init.drc.S,/etc/Profile,/etc/.profile,andtheconfigurationfile/etc/fstabforautomaticallymountingthefilesystem,etc.,willvaryfromsystemtosystem.Therootfilesystemisgenerallysetasread-onlyintheembeddedsystem,andtoolssuchasmkcramfsgenromfsneedtobeusedtogeneratetheburnedimagefile.

CreateFLASHdiskpartitionsforapplications

Generally,JFFS2orYAFFSfilesystemsareused,whichrequiresdriversforthesefilesystemstobeprovidedinthekernel.SomesystemsusealinearFLASHNORtype(512KB~32MB),somesystemsuseanon-linearFLASHNANDtype(8MB~512MB),andsomesystemsusebothatthesametime,andtheFLASHpartitionschemeneedstobeplannedaccordingtotheapplication.

Developapplications

Developapplicationsasneeded.Successfullydevelopedapplicationscanbeplacedintherootfilesystem,orinYAFFS,IntheJFFS2filesystem,someapplicationsdonotusetherootfilesystemanddirectlydesigntheapplicationandthekerneltogether,whichissomewhatsimilartotheuC/OS-IIapproach.

Burnthekernel,rootfilesystemandapplications,andreleasetheproduct

Introductiontosoftwareandhardwareco-design

Systemdescriptionh3>

Thedescriptionofembeddedsystemsismainlybasedontwoaspects,oneisperformance,andtheotherisfunction.Intheprocessofsystemdescription,notonlyonelanguagecanbeused,butalsomultiplelanguages​​canbeused.Atthesametime,thisdescriptionprocessisalsotheprocessofestablishingthesoftwaremodelandthesystemhardwaremodel.Whendescribingtheembeddedsystem,inordertoreducetheemergenceofproblemsintheinitialstageofthesoftwareandhardwareco-design,itisnecessarytodoagoodjoboftestingthebehaviorinthesystem.Ontheonehand,theunreasonablepartofthedesigncanbepostedatthefirsttime;ontheotherhand,itprovidesaguaranteeforthesafeandreliableoperationofthesystem.Thesystemdescriptionneedstobesupportedbythesystemmodel.Inordertomakeacorrectdescription,itshouldbeensuredthatthemodelincludesfourelements.Thefirstisthefunctionalcharacteristics,whichreferstothevariousfunctionsoftheembeddedsystem.Atthesametime,theinputandoutputrelationshipbetweenthefunctionandthesystemshouldbeclarified.Thesecondisperformancedescription.Incorporatingthisfactorintothesystemmodelcanmorecomprehensivelyreflecttheoverallstructureofthesystem,anditisnecessarytoexplaintherelationshipbetweensysteminputandoutput.Thethirdistheconstraintcondition.Thiselementnotonlyexplainstheperformancedefectsoftheembeddedsystem,butalsoreasonablyregulatestherequirementsinthesystemworkingenvironment.Thefourthisthetechnicalindicators,whichcanexplaintheproblemsandthequalityofthesystem,andlayagoodfoundationforthedevelopmentofthedesignwork.

Softwareandhardwaresynthesistechnology

Inthesoftwareandhardwareco-designoftheembeddedsystem,thesoftwareandhardwaresynthesistechnologyisoneoftheimportanttechnologies,whichplaysaroleinthegeneraldesignofthesoftwareandhardwaresystem.Importantrole.Onthebasisofsystematicinspectionandevaluationofitsdesignresults,itispossibletocarryoutdetailedsystemproductionworkaccordingtothedesignrequirements,andcarryoutthedesignofsoftwareandhardwaretoensuretheircoordinationandconsistency,therebyimprovingthescientificnatureofthedesign.Theimprovementoftheoperatingefficiencyoftheentiresystemisofgreatsignificance.

Divisionofsoftwareandhardwarefunctions

Inthedivisionofsoftwareandhardwarefunctions,themainpurposeistoscientificallyandrationallydividethefunctionsofsoftwareandhardwareandembeddedsystems,andclarifytherelationshipbetweenthetwo.Amongthem,thecostfunctionisoneofthemainbasisforthedivisionofsoftwareandhardwarefunctions.Whenusingthecostfunction,manyfactorsneedtobeconsidered.Forexample,concurrencybetweenmodules,softwareexecutiontime,etc.

Co-simulationandsystemtestverification

Intermsofcoordinatedsimulationandsystemtestverification,itisnecessarytousethehardwaredescriptionlanguagetodescribethehardwaresystemoftheembeddedsystem.Inordertoeffectivelycompletethedesignworkandmeetthedesignrequirements,itisnecessarytoreasonablyapplythesoftwareandhardwaremethodsinordertocreateagoodenvironmentforthesubsequentdesignwork,whichcannotonlyimprovetheoveralldesignefficiencyandquality,butalsoreducethedesignCosttoensuregoodeconomicbenefits.

Developmentprospects

Nowadays,thedevelopmentofembeddedsystemstendstoprovidemorevividhuman-computerinteractioninterfaces;moresmallelectronicproductshavebetterportability,soastorealizetheirAutomation,lowpowerconsumptionandintelligence.

ExamplesofembeddedsysteminWEBserver

Inindustrialdesign,softwareThesimplicityofhardwareplaceshigherrequirementsonservers,whiletraditionalnetworkserversdonothavesimplicityandsupportremotecontrolofcomputersinheterogeneousnetworks.However,embeddingnetworkdevicesintoembeddeddeviceswillgreatlyreducetheuser'saccesstimeandenableprecisecontrolofexternalI/O.TheembeddedWEBserverdoesnotusethetraditionalTCP/IPprotocoltoconnecttotheInternet,butchoosestheUIPprotocolstacksimplifiedbyTCP/IPtorealizetheembeddedWEBserver.SuchanembeddedWEBservernotonlyhassimplicity,butalsogivestheMCUmorespacetocontrolexternalI/O.

Sensingtechnologybasedonembeddedsystems

TheInternetofThingsfieldhasgraduallybecomenumerousscholarssincePremierWenJiabaoproposedtheestablishmentofChinaSensingInformationCenterin2009Thefocusofattentionofenterprises,andsensingtechnologyasanimportantpartoftheInternetofThingsisnaturallyindispensable.Asasensorthatassumestheroleofinformationcollection,itmustbeorganicallycombinedwithembeddedsystems.Smartsensortechnologyhasexcellentinformationtransmissioncapabilities.Smartsensorshavetheabilitytoexchangeinformationbetweenthingsandbetweenthingsandcomputers,andwillbewidelyusedininformationexchangeanddatatransmissionwithcomputersandcommunications.EmbeddedsmartsensorsplayanimportantroleinthefieldofInternetofThings.