Openprotocol(), Stop(), Functions of th – Intel Extensible Firmware Interface User Manual
Page 147
Services — Boot Services
Version 1.10
12/01/02
5-49
OpenProtocol()
Summary
Queries a handle to determine if it supports a specified protocol. If the protocol is supported by the
handle, it opens the protocol on behalf of the calling agent. This is an extended version of the EFI
boot service
Prototype
typedef
EFI_STATUS
(EFIAPI *EFI_OPEN_PROTOCOL) (
IN
EFI_HANDLE
Handle,
IN
EFI_GUID
*Protocol,
OUT VOID
**Interface
OPTIONAL,
IN
EFI_HANDLE
AgentHandle,
IN
EFI_HANDLE
ControllerHandle,
IN
UINT32
Attributes
);
Parameters
Handle
The handle for the protocol interface that is being opened.
Protocol
The published unique identifier of the protocol. 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
.
This parameter is optional, and will be ignored if
Attributes
is
EFI_OPEN_PROTOCOL_TEST_PROTOCOL
.
AgentHandle
The handle of the agent that is opening the protocol interface
specified by
Protocol
and
Interface
. For agents that
follow the EFI Driver Model, this parameter is the handle that
contains the
EFI_DRIVER_BINDING_PROTOCOL
instance
that is produced by the EFI Driver that is opening the protocol
interface. For EFI Applications, this is the image handle of the
EFI Application that is opening the protocol interface. For EFI
Applications that use
HandleProtocol()
to open a protocol
interface, this parameter is the image handle of the EFI firmware.