10.2 Service Driver

If the UEFI Driver is a Service Driver, the Service Binding Protocol is installed in the driver entry point. The following example shows an implementation of a Service Binding Protocol that is installed into the Handle Database in the driver entry point. A Service Binding Protocol is always paired with another protocol so, for this example, the paired protocol is the ABC_PROTOCOL.

Global variables are declared for the handle on which the Service Binding Protocol is installed, the instance of the Service Binding Protocol, and an instance of the ABC_PROTOCOL. The ABC_PROTOCOL instance is installed onto a new handle every time the Service Binding Protocol service CreateChild() is called. The ABC_PROTOCOL is uninstalled from a child handle every time the Service Binding Protocol service DestroyChild() is called.

Example 125-Service Binding Protocol for Service Driver

#include <Uefi.h>
#include <Protocol/ServiceBinding.h>
#include <Library/UefiBootServicesTableLib.h>

typedef struct {
  UINT32 AbcField;
} ABC_PROTOCOL;

EFI_HANDLE gAbcServiceBindingHandle = NULL;

EFI_SERVICE_BINDING_PROTOCOL gAbcServiceBinding = {
  AbcCreateChild,
  AbcDestroyChild
};

ABC_PROTOCOL gAbc = {
  0
};

EFI_STATUS
EFIAPI
AbcCreateChild (
  IN     EFI_SERVICE_BINDING_PROTOCOL  *This,
  IN OUT EFI_HANDLE                    *ChildHandle
  )
{
  EFI_HANDLE  NewHandle;
  NewHandle = NULL;
  return gBS->InstallMultipleProtocolInterfaces (
                &NewHandle,
                &gAbcProtocolGuid,
                &gAbc,
                NULL
                );
}

EFI_STATUS
EFIAPI
AbcDestroyChild (
  IN EFI_SERVICE_BINDING_PROTOCOL  *This,
  IN EFI_HANDLE                    ChildHandle
  )
{
  return gBS->UninstallMultipleProtocolInterfaces (
                ChildHandle,
                &gAbcProtocolGuid,
                &gAbc,
                NULL
                );
}

EFI_STATUS
EFIAPI
AbcDriverEntryPoint (
  IN EFI_HANDLE        ImageHandle,
  IN EFI_SYSTEM_TABLE  *SystemTable
  )
{
  //
  // Install Service Binding Protocol for ABC onto a new handle
  //
  return gBS->InstallMultipleProtocolInterfaces (
                &gAbcServiceBindingHandle,
                &gAbcServiceBindingProtocolGuid,
                &gAbcServiceBinding,
                NULL
                );
}