Efi_pci_root_bridge_io_protocol.pollmem(), Pollmem() – Intel Extensible Firmware Interface User Manual
Page 434

Extensible Firmware Interface Specification
12-16
12/01/02
Version 1.10
EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.PollMem()
Summary
Reads from the memory 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 memory operations. Type
EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH
is defined
in Section 12.2.
Address
The base address of the memory 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 memory 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.