BIOSOverview同济大学BIOS和UEFI课程

Tel：69589584Email:wang.box@163.com同济大学软件学院UEFI与固件程序设计

What’stheUEFI?继续返回UEFI(UnifiedExtensibleFirmwareInterface)是由英特尔公司联合业界共同提出的一种欲在未来电脑系统中替代传统BIOS(LegacyBIOS)的升级解决方案。Anotherquestion,What’stheBIOS?What’stheBIOS?继续返回BIOS(BasicInputandOutputSystem)基本输入输出系统，它是一组固化到计算机内主板上一个ROM芯片上的程序，它保存着计算机最重要的开机上电自检、硬件初始化程序和系统底层的服务程序等。硬件逻辑PushPowerButtonCPUResetRTCBIOSOSFoundMBR继续返回AgendaBIOSbackgroundHistoryFunctionsLegacyBIOS’sFlawsChange继续返回BIOSbackground--HistoryBeforefirmware—SwitchsonapieceofplywoodBIOS--fororiginalIBMPC/XTandPC/ATin1980sEFI--Spring2000IDF(IntelDeveloper’sForum)

--EFI1.10specification

UEFI–

OriginatedfromtheEFI1.10specification

--UpdatedandmanagedbytheUnifiedEFIForum继续返回BIOSbackground--FunctionsBasedon8086architecturePOST—PowerOnSelfTestAgroupofclearlydefinedOS-independentinterfaceforhardwareInt10forVideoserviceInt13diskserviceInt16keyboardserviceInt18BIOSROMloaderInt19bootstraploaderAvailabilityofMS-DOSoutsideofIBMallowedapplicationstorunequallywellacrossdifferentbrandsofbox"PCclones".继续返回BIOSbackground--Legacy

BIOS’sFlawsItisnotplatformindependent,ithighlydependsonIntel8086SoftwareInterruptmodelRealmode16-bitsregisteraccessNomemoryaddressbeyond1MBOptionROMspacelimitedtobelow1MBModernIntelCPUarchitecturehascometo32bits,64bitsprotectionmode,withHTandMulti-core,butforcompatibility,itshouldstillbootupin16bitrealmode继续返回BIOSbackground–Flaws(cont.)Itisinaccessibletoboot64bitssystemwhichstillcallinto16bitlegacyfirmwarewhenItaniumprocessorfamilycomeintolife.Moreandmorenewtechnologycomeout,likeVT,LTetc.Itisveryhardtoenablethosetechnologyinthewholeeco-systemquicklyinlegacyBIOSArchitectureindependentisthekeyforthenextgenerationBIOS,thatiswheretheEFIcomefrom,singledrivercanworkinx86,ItaniumandXScaleetc.继续返回BIOSbackground–Flaws(cont.)CodeRealModeAssemblerSpaghettiScalabilityComplexityMaintenanceIssueSpecNone!CompatibilityOSLoaderTiedtoHWandBIOSSlowsinnovationCarrieslegacy继续返回BIOSbackground–ChangeUnifiedExtensibleFirmwareInterfaceUEFIisaninterfacespecification--downloadfromAbstractstheplatformfromOSIncludesamodulardrivermodelandCPU-independentoptionROMsCompatiblebydesignModularandextensibleComplementsexistinginterfacesFlexibletomeetexistingandfutureneedsOSLoaderHardwareFirmwareUEFICompatibility继续返回BIOSbackground–ChangeCodeRealModeAssemblerSpaghettiScaleabilityComplexityMaintenanceIssueSpecNone!CompatibilityOSLoaderTiedtoHWandBIOSSlowsinnovationCarrieslegacyHighl