Intel Extensible Firmware Interface - Manual (Page 222)

Extensible Firmware Interface Specification
8-2 12/01/02 Version 1.10
8.2 EFI_DEVICE_PATH Protocol
This section provides a detailed description of the EFI_DEVICE_PATH protocol.
EFI_DEVICE_PATH Protocol
Summary
Can be used on any device handle to obtain generic path/location information concerning the
physical device or logical device. If the handle does not logically map to a physical device, the
handle may not necessarily support the device path protocol.
GUID
#define DEVICE_PATH_PROTOCOL \
{ 09576e91-6d3f-11d2-8e39-00a0c969723b }
Protocol Interface Structure
EFI_DEVICE_PATH *DevicePath ;
Parameters
DevicePath A pointer to device path data. The device path describes the location of
the device the handle is for. The size of the Device Path can be
determined from the structures that make up the Device Path. Type
EFI_DEVICE_PATH is defined in the LocateDevicePath()
function description.
Description
The executing EFI Image may use the device path to match its own device drivers to the particular
device. Note that the executing EFI OS loader and EFI application images must access all physical
devices via Boot Services device handles until
ExitBootServices() is successfully called.
An EFI driver may access only a physical device for which it provides functionality.