FAT32文件系统白皮书(E文原版)

HardwareWhitePaperHardwareWhitePaperHardwareWhitePaperHardwareWhitePaperDesigningHardwareforMicrosoft®OperatingSystemsMicrosoftExtensibleFirmwareInitiativeFAT32FileSystemSpecificationFAT:GeneralOverviewofOn-DiskFormatVersion1.03,December6,2000MicrosoftCorporationTheFAT(FileAllocationTable)filesystemhasitsoriginsinthelate1970sandearly1980sandwasthefilesystemsupportedbytheMicrosoft®MS-DOS®operatingsystem.Itwasoriginallydevelopedasasimplefilesystemsuitableforfloppydiskdriveslessthan500Kinsize.Overtimeithasbeenenhancedtosupportlargerandlargermedia.CurrentlytherearethreeFATfilesystemtypes:FAT12,FAT16andFAT32.ThebasicdifferenceintheseFATsubtypes,andthereasonforthenames,isthesize,inbits,oftheentriesintheactualFATstructureonthedisk.Thereare12bitsinaFAT12FATentry,16bitsinaFAT16FATentryand32bitsinaFAT32FATentry.ContentsNotationalConventionsinthisDocument..............................................................................................7GeneralComments(ApplicabletoFATFileSystemAllTypes)............................................................7BootSectorandBPB...............................................................................................................................7FATDataStructure...............................................................................................................................13FATTypeDetermination......................................................................................................................14FATVolumeInitialization....................................................................................................................19FAT32FSInfoSectorStructureandBackupBootSector.....................................................................21FATDirectoryStructure.......................................................................................................................22FATLongDirectoryEntries.................................................................................................................25NameLimitsandCharacterSets...........................................................................................................29NameMatchingInShort&LongNames..............................................................................................30NamingConventionsandLongNames.................................................................................................30EffectofLongDirectoryEntriesonDownLevelVersionsofFAT.....................................................32ValidatingTheContentsofaDirectory................................................................................................32OtherNotesRelatingtoFATDirectories..............................................................................................33Microsoft,MS_DOS,Windows,andWindowsNTaretrademarksorregisteredtrademarksofMicrosoftCorporationintheUnitedStatesand/orothercountries.Otherproductandcompanynamesmentionedhereinmaybethetrademarksoftheirrespectiveowners.©2000MicrosoftCorporation.Allrightsreserved.FAT:GeneralOverviewofOn-DiskFormat—Page2©2000MicrosoftCorporation.Allrightsreserved.2MicrosoftExtensibleFirmwareInitiativeFAT32FileSystemSpecificationIMPORTANT-READCAREFULLY:ThisMicrosoftAgreement(“Agreement”)isalegalagreementbetweenyou(eitheranindividualorasingleentity)andMicrosoftCorporation(“Microsoft”)fortheversionoftheMicrosoftspecificationidentifiedabovewhichyouareabouttodownload(“Specification”).BYDOWNLOADING,COPYINGOROTHERWISEUSINGTHESPECIFICATION,YOUAGREETOBEBOUNDBYTHETERMSOFTHISAGREEMENT.IFYOUDONOTAGREETOTHETERMSOFTHISAGREEMENT,DONOTDOWNLOAD,COPY,ORUSETHESPECIFICATION.TheSpecificationisownedbyMicrosoftoritssuppliersandisprotectedbycopyrightlawsandinternationalcopyrighttreaties,aswellasotherintellectualpropertylawsandtreaties.1.LIMITEDLICENSEANDCOVENANTNOTTOSUE.(a)ProvidedthatyoucomplywithalltermsandconditionsofthisAgreementandsubjecttothelimitationsinSections1(c)-(f)below,Microsoftgrantstoyouthefollowingnon-exclusive,worldwide,royalty-free,non-transferable,non-sublicenseablelicenseunderanycopyrightsownedorlicensablebyMicrosoftwithoutpaymentofconsiderationtounaffiliatedthirdparties,toreproducetheSpecificationsolelyforthepurposesofcreatingportionsofproductswhichcomplywiththeSpecificationinunmodifiedform.(b)ProvidedthatyoucomplywithalltermsandconditionsofthisAgreementandsubjecttothelimitationsinSections1(c)-(f)below,Microsoftgrantstoyouthefollowingnon-exclusive,worldwide,royalty-free,non-transferable,non-sublicenseable,reciprocallimitedcovenantnottosueunderitsNecessaryClaimssolelytomake,havemade,use,import,anddirectlyandindirectly,offertosell,sellandotherwisedistributeanddisposeofportionsofproductswhichcomplywiththeSpecificationinunmodifiedform.Forpurposesofsections(a)and(b)above,theSpecificationis“unmodified”iftherearenochanges,additionsorextensionstotheSpecification,and“NecessaryClaims”meansclaimsofapatentorpatentapplicationwhichare(1)ownedorlicenseablebyMicrosoftwithoutpaymentofconsiderationtoanunaffiliatedthirdp