Intel Extensible Firmware Interface - Manual (Page 152)

Extensible Firmware Interface Specification
5-54 12/01/02 Version 1.10
Examples
EFI_BOOT_SERVICES_TABLE *gBS;
EFI_HANDLE ImageHandle;
EFI_DRIVER_BINDING_PROTOCOL *This;
IN EFI_HANDLE ControllerHandle,
extern EFI_GUID gEfiXyzIoProtocol;
EFI_XYZ_IO_PROTOCOL *XyzIo;
EFI_STATUS Status;
//
// EFI_OPEN_PROTOCOL_BY_HANDLE_PROTOCOL example
//
Retrieves the XYZ I/O Protocol instance from ControllerHandle
// The application that is opening the protocol is identified by ImageHandle
// Possible return status codes:
// EFI_SUCCESS : The protocol was opened and returned in XyzIo
// EFI_UNSUPPORTED : The protocol is not present on ControllerHandle
//
Status = gBS->OpenProtocol (
ControllerHandle,
&gEfiXyzIoProtocol,
&XyzIo,
ImageHandle,
NULL,
EFI_OPEN_PROTOCOL_BY_HANDLE_PROTOCOL
);
//
// EFI_OPEN_PROTOCOL_GET_PROTOCOL example
//
Retrieves the XYZ I/O Protocol instance from ControllerHandle
// The driver that is opening the protocol is identified by the
// Driver Binding Protocol instance This. This->DriverBindingHandle
// identifies the agent that is opening the protocol interface, and it
// is opening this protocol on behalf of ControllerHandle.
// Possible return status codes:
// EFI_SUCCESS : The protocol was opened and returned in XyzIo
// EFI_UNSUPPORTED : The protocol is not present on ControllerHandle
//
Status = gBS->OpenProtocol (
ControllerHandle,
&gEfiXyzIoProtocol,
&XyzIo,
This->DriverBindingHandle,
ControllerHandle,
EFI_OPEN_PROTOCOL_GET_PROTOCOL
);
//
// EFI_OPEN_PROTOCOL_TEST_PROTOCOL example
//
Tests to see if the XYZ I/O Protocol is present on ControllerHandle
// The driver that is opening the protocol is identified by the
// Driver Binding Protocol instance This. This->DriverBindingHandle
// identifies the agent that is opening the protocol interface, and it
// is opening this protocol on behalf of ControllerHandle.
// EFI_SUCCESS : The protocol was opened and returned in XyzIo
// EFI_UNSUPPORTED : The protocol is not present on ControllerHandle
//
Status = gBS->OpenProtocol (
ControllerHandle,
&gEfiXyzIoProtocol,