Unified Extensible Firmware Interface Specification
xx June, 2013 Version 2.4
2.3.2 IA-32 Platforms ................................................................................................... 24
2.3.3 Intel
®
Itanium
®
-Based Platforms......................................................................... 27
2.3.4 x64 Platforms ...................................................................................................... 30
2.3.5 AArch32 Platforms .............................................................................................. 33
2.3.6 AArch64 Platforms .............................................................................................. 36
2.4 Protocols ......................................................................................................................... 40
2.5 UEFI Driver Model .......................................................................................................... 45
2.5.1 Legacy Option ROM Issues ................................................................................ 47
2.5.2 Driver Initialization............................................................................................... 49
2.5.3 Host Bus Controllers ........................................................................................... 50
2.5.4 Device Drivers..................................................................................................... 52
2.5.5 Bus Drivers.......................................................................................................... 53
2.5.6 Platform Components ......................................................................................... 55
2.5.7 Hot-Plug Events .................................................................................................. 56
2.5.8 EFI Services Binding........................................................................................... 56
2.6 Requirements.................................................................................................................. 58
2.6.1 Required Elements.............................................................................................. 58
2.6.2 Platform-Specific Elements ................................................................................ 59
2.6.3 Driver-Specific Elements..................................................................................... 61
2.6.4 Extensions to this Specification published elsewhere........................................ 63
3
Boot Manager................................................................................................ 65
3.1 Firmware Boot Manager ................................................................................................. 65
3.1.1 Boot Manager Programming ............................................................................... 66
3.1.2 Load Option Processing...................................................................................... 66
3.1.3 Load Options....................................................................................................... 67
3.1.4 Boot Manager Capabilities .................................................................................. 69
3.1.5 Launching Boot#### Applications....................................................................... 69
3.1.6 Launching Boot#### Load Options Using Hot Keys ........................................... 70
3.2 Globally Defined Variables.............................................................................................. 72
3.3 Boot Option Variables Default Boot Behavior ................................................................. 76
3.4 Boot Mechanisms ........................................................................................................... 77
3.4.1 Boot via the Simple File Protocol ........................................................................ 77
3.4.2 Boot via LOAD_FILE PROTOCOL...................................................................... 78
4
EFI System Table.......................................................................................... 81
4.1 UEFI Image Entry Point .................................................................................................. 81
EFI_IMAGE_ENTRY_POINT .............................................................................. 81
4.2 EFI Table Header............................................................................................................82
EFI_TABLE_HEADER ........................................................................................ 83
4.3 EFI System Table ........................................................................................................... 84
EFI_SYSTEM_TABLE......................................................................................... 84
4.4 EFI Boot Services Table ................................................................................................. 85
EFI_BOOT_SERVICES ...................................................................................... 86
4.5 EFI Runtime Services Table ........................................................................................... 90