Intel Extensible Firmware Interface - Manual (Page 143)

Services — Boot Services
Version 1.10 12/01/02 5-45
HandleProtocol()
Summary
Queries a handle to determine if it supports a specified protocol.
Prototype
typedef
EFI_STATUS
HandleProtocol (
IN EFI_HANDLE Handle,
IN EFI_GUID *Protocol,
OUT VOID **Interface
);
Parameters
Handle The handle being queried. If Handle is not a valid EFI_HANDLE , then
EFI_INVALID_PARAMETER is returned. Type EFI_HANDLE is
defined in the InstallProtocolInterface() function
description.
Protocol The published unique identifier of the protocol. It is the caller’s
responsibility to pass in a valid GUID. See “Wired For Management
Baseline” for a description of valid GUID values. Type
EFI_GUID is
defined in the InstallProtocolInterface() function
description.
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.