Intel Extensible Firmware Interface - Manual (Page 449)

Protocols — PCI Bus Support
Version 1.10 12/01/02 12-31
EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.AllocateBuffer()
Summary
Allocates pages that are suitable for an EfiPciOperationBusMasterCommonBuffer or
EfiPciOperationBusMasterCommonBuffer64 mapping.
Prototype
typedef
EFI_STATUS
(EFIAPI *EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_ALLOCATE_BUFFER) (
IN EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL
*This,
IN EFI_ALLOCATE_TYPE Type,
IN EFI_MEMORY_TYPE MemoryType,
IN UINTN Pages,
OUT VOID **HostAddress,
IN UINT64 Attributes
);
Parameters
This A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL .
Type EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL is defined in
Section 12.2.1.
Type This parameter is not used and must be ignored.
MemoryType The type of memory to allocate, EfiBootServicesData or
EfiRuntimeServicesData . Type EFI_MEMORY_TYPE is
defined in Chapter 5.
Pages The number of pages to allocate.
HostAddress A pointer to store the base system memory address of the
allocated range.