Intel Extensible Firmware Interface - Manual (Page 141)

Services — Boot Services
Version 1.10 12/01/02 5-43
LocateHandle()
Summary
Returns an array of handles that support a specified protocol.
Prototype
EFI_STATUS
LocateHandle (
IN EFI_LOCATE_SEARCH_TYPE SearchType,
IN EFI_GUID *Protocol OPTIONAL,
IN VOID *SearchKey OPTIONAL,
IN OUT UINTN *BufferSize,
OUT EFI_HANDLE *Buffer
);
Parameters
SearchType Specifies which handle(s) are to be returned. Type
EFI_LOCATE_SEARCH_TYPE is defined in “Related Definitions.”
Protocol Specifies the protocol to search by. This parameter is only valid if
SearchType is ByProtocol . Type EFI_GUID is defined in the
InstallProtocolInterface() function description.
SearchKey Specifies the search key. This parameter is ignored if SearchType is
AllHandles or ByProtocol . If SearchType is
ByRegisterNotify , the parameter must be the Registration
value returned by function RegisterProtocolNotify() .
BufferSize On input, the size in bytes of Buffer . On output, the size in bytes of
the array returned in Buffer (if the buffer was large enough) or the
size, in bytes, of the buffer needed to obtain the array (if the buffer was
not large enough).
Buffer The buffer in which the array is returned. Type EFI_HANDLE is
defined in the InstallProtocolInterface() function
description.