Intel Extensible Firmware Interface - Manual (Page 438)

Extensible Firmware Interface Specification
12-20 12/01/02 Version 1.10
EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.Mem.Read()
EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.Mem.Write()
Summary
Enables a PCI driver to access PCI controller registers in the PCI root bridge memory space.
Prototype
typedef
EFI_STATUS
(EFIAPI *EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_IO_MEM) (
IN EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL
*This,
IN EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH Width,
IN UINT64 Address,
IN UINTN Count,
IN OUT VOID *Buffer
);
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.
Width Signifies the width of the memory operation. Type
EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH is defined
in Section 12.2.
Address The base address of the memory operation. The caller is
responsible for aligning the
Address if required.
Count The number of memory operations to perform. Bytes moved is
Width size * Count , starting at Address .
Buffer For read operations, the destination buffer to store the results. For
write operations, the source buffer to write data from.