Page3
WhatUEFIhastoOffer
TheprimarygoalofUEFIistodefineanarchitecturethatcanscalewithtimeandtoofferstructuredcoding
environmentallowingeasyenablementofnewtechnology.ThemaincharacteristicsofUEFIare:
AbstractionfortheOperation System.TheUEFIspecificationprovidesaninterfacebetweentheplatform
firmwareandthe
operatingsystem.Theinterfaces/API/protocolsmarkaclearboundarybetweenthe
firmwareandtheoperatingsystemandtheoperatingsystemloader.
Abstractionfordevicesandrelatedcode.UEFIabstractsinterfacesthatmakeitpossibletobuildcode
whichworksonarangeofunderlyinghardwaredeviceswithouthavingexplicitknowledge
ofthespecifics
foreachdevice.Thespecificationdefinesinterfacestoplatformcapabilitiessuchasstandardbustypes
(PCI,USB,andSCSI).Thelistofsupportedbustypesmaygrowovertime.Thesedefinedinterfacesandthe
abilitytoextendtofuturebustypesarecomponentsoftheUEFIDriver
Model.
Scalableplatformenvironment.Thespecificationdefinesacompletesolutionforthefirmwareto
describeallplatformfeaturesandcapabilitiestotheoperatingsystemduringthebootprocess.These
definitionscoverarangeofthecontemporaryplatformdesignsbutaresimpleenoughtobeableto
extendinthe
future.
OperatingSystemAgnosticRichPre‐Bootenvironment.TheUEFIspecificationdefinesextensible
interfacesthatenablecreationofplatformdrivers.Thedrivers,analogoustooperatingsystemdrivers,
providesupportfornewdevicesandmayprovideenhancedplatformcapabilities,suchasfirmware
update,platformconfiguration,diagnosticsanddeployment services.The
existenceofnetworking,USB,
andfilesystemcapabilitiesaddstotherichnessofthepre‐bootenvironment.
GUIDPartitionTable.TheUEFIdefinesanewstandardlayoutforthepartitiontable,knownasGUID
PartitionTable(GPT).GPTprovidesamoreflexiblemechanismforpartitioningdisksthanthe
Master
BootRecord(MBR)partitioningschemethathasbeencommontocomputers.MBRdiskssupportonly
fourpartitiontableentriesandthepartitionsizeislimitedto2TB.GPTschemeallowsupto128primary
partitionsandcansupportlargerthan2‐terabytepartitions.Somenear‐termlimitationsto2terabyte
supportexistduetodevicesupport,butoncedevicesfullysupportGPT/UEFI,thiswillnolongerbean
issue.Seethe“Limitations”section.
HowisDell’sUEFIimplemented?
TosupportbootingtobothUEFIandnon‐UEFIawareoperatingsystems,theDellBIOSsupportsaBootMode
optionintheBIOSSetupUtility.TheBootModecanbesettoBIOSorUEFI.
SettingtheBootModetoUEFIallowsbootingtoaUEFI‐awareoperatingsystemandprovides
theUEFIBoot
Manager.ThisistheonlychangerequiredtoenableUEFIonthesystem.SettingtheBootModetoBIOSprovides
supportforallcurrentandlegacyoperationsystems.
Comments to this Manuals