Intel Extensible Firmware Interface User Manual

Page 430

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Extensible Firmware Interface Specification

12-12

12/01/02

Version 1.10

EFI_PCI_ATTRIBUTE_VGA_IO

If this bit is set, then the PCI I/O cycles in the ranges 0x3B0-0x3BB and 0x3C0-0x3DF
are forwarded onto a PCI root bridge using a 10-bit address decoder on address bits 0..9.
Address bits 10..15 are not decoded, and the address bits 16..31 must be zero. This bit is
used to forward I/O cycles for a VGA controller onto a PCI root bridge. Since

EFI_PCI_ATTRIBUTE_ENABLE_VGA_IO

also includes the I/O range described by

EFI_PCI_ATTRIBUTE_ENABLE_VGA_PALETTE_IO

, the

EFI_PCI_ATTRIBUTE_ENABLE_VGA_PALETTE_IO

bit is ignored if

EFI_PCI_ATTRIBUTE_ENABLE_VGA_IO

is set.

EFI_PCI_ATTRIBUTE_IDE_PRIMARY_IO

If this bit is set, then the PCI I/O cycles in the ranges 0x1F0-0x1F7 and 0x3F6-0x3F7 are
forwarded onto a PCI root bridge using a 10-bit address decoder on address bits 0..9.
Address bits 10..15 are not decoded, and address bits 16..31 must be zero. This bit is
used to forward I/O cycles for a Primary IDE controller onto a PCI root bridge.

EFI_PCI_ATTRIBUTE_IDE_SECONDARY_IO

If this bit is set, then the PCI I/O cycles in the ranges 0x170-0x177 and 0x376-0x377 are
forwarded onto a PCI root bridge using a 10-bit address decoder on address bits 0..9.
Address bits 10..15 are not decoded, and address bits 16..31 must be zero. This bit is
used to forward I/O cycles for a Secondary IDE controller onto a PCI root bridge.

EFI_PCI_ATTRIBUTE_MEMORY_WRITE_COMBINE

If this bit is set, then this platform supports changing the attributes of a PCI memory
range so that the memory range is accessed in a write combining mode. By default, PCI
memory ranges are not accessed in a write combining mode.

EFI_PCI_ATTRIBUTE_MEMORY_CACHED

If this bit is set, then this platform supports changing the attributes of a PCI memory
range so that the memory range is accessed in a cached mode. By default, PCI memory
ranges are accessed noncached.

EFI_PCI_ATTRIBUTE_MEMORY_DISABLE

If this bit is set, then this platform supports changing the attributes of a PCI memory
range so that the memory range is disabled, and can no longer be accessed. By default,
all PCI memory ranges are enabled.

EFI_PCI_ATTRIBUTE_DUAL_ADDRESS_CYCLE

This bit may only be used in the

Attributes

parameter to

AllocateBuffer()

. If

this bit is set, then the PCI controller that is requesting a buffer through

AllocateBuffer()

is capable of producing PCI Dual Address Cycles, so it is able to

access a 64-bit address space. If this bit is not set, then the PCI controller that is
requesting a buffer through

AllocateBuffer()

is not capable of producing PCI Dual

Address Cycles, so it is only able to access a 32-bit address space.

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