Intel Extensible Firmware Interface - Manual (Page 436)

Extensible Firmware Interface Specification
12-18 12/01/02 Version 1.10
EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.PollIo()
Summary
Reads from the I/O space of a PCI Root Bridge. Returns when either the polling exit criteria is
satisfied or after a defined duration.
Prototype
typedef
EFI_STATUS
(EFIAPI *EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_POLL_IO_MEM) (
IN struct EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL
*This,
IN EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH Width,
IN UINT64 Address,
IN UINT64 Mask,
IN UINT64 Value,
IN UINT64 Delay,
OUT UINT64 *Result
);
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 I/O operations. Type
EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH is defined
in Section 12.2.
Address The base address of the I/O operations. The caller is responsible
for aligning
Address if required.
Mask Mask used for the polling criteria. Bytes above Width in Mask
are ignored. The bits in the bytes below Width which are zero in
Mask are ignored when polling the I/O address.
Value The comparison value used for the polling exit criteria.
Delay The number of 100 ns units to poll. Note that timer available may
be of poorer granularity.
Result Pointer to the last value read from the memory location.