Intel Extensible Firmware Interface, Specification

Page: 82 / 494

Extensible Firmware Interface Specification
64 12/12/00 Version 1.02
3.3.6 HandleProtocol()
Summary
Queries a handle to determine if it supports a specified protocol.
Prototype
EFI_STATUS
HandleProtocol (
IN EFI_HANDLE Handle,
IN EFI_GUID *Protocol,
OUT VOID **Interface
);
Parameters
Handle
The handle being queried. Type
EFI_HANDLE
is defined in
Section 3.3.1. If
Handle
is not a valid
EFI_HANDLE
, then
EFI_INVALID_PARAMETER
is returned.
Protocol
The published unique identifier of the protocol. Type
EFI_GUID
is
defined in Section 3.3.1. It is the callers responsibility to pass in a valid
GUID. See “Wired For Management Baseline” for a description of valid
GUID values.
Interface
Supplies the address where a pointer to the corresponding Protocol
Interface is returned.
NULL
will be returned in
*Interface
if a
structure is not associated with
Protocol
.
Description
The
HandleProtocol()
function queries
Handle
to determine if it supports
Protocol
. If it
does, then on return
Interface
points to a pointer to the corresponding Protocol Interface.
Interface
can then be passed to any Protocol Service to identify the context of the request.
Status Codes Returned
EFI_SUCCESS The interface information for the specified protocol was returned.
EFI_UNSUPPORTED The device does not support the specified protocol.
EFI_INVALID_PARAMETER One of the parameters has an invalid value.