Intel Extensible Firmware Interface - Manual (Page 245)

Protocols — EFI Driver Model
Version 1.10 12/01/02 9-3
ImageHandle The image handle of the EFI Driver that produced this instance
of the
EFI_DRIVER_BINDING_PROTOCOL .
DriverBindingHandle The handle on which this instance of the
EFI_DRIVER_BINDING_PROTOCOL is installed. In most
cases, this is the same handle as ImageHandle . However, for
EFI Drivers that produce more than one instance of the
EFI_DRIVER_BINDING_PROTOCOL , this value may not be
the same as ImageHandle .
Description
The EFI_DRIVER_BINDING_PROTOCOL provides a service to determine if a driver supports a
given controller. If a controller is supported, then it also provides services to start and stop the
controller. All EFI drivers are required to be reentrant so they can manage one or more controllers.
This requires that drivers not use global variables to store device context. Instead, they must
allocate a separate context structure per controller that the driver is managing. Bus drivers must
support starting and stopping the same bus multiple times, and they must also support starting and
stopping all of their children, or just a subset of their children.