Intel Extensible Firmware Interface - Manual (Page 139)

Services — Boot Services
Version 1.10 12/01/02 5-41
components that use the OpenProtocol() and CloseProtocol() boot services, a safe
version of this function can be implemented.
When this function is called, a call is first made to the boot service
UninstallProtocolInterface() . This will guarantee that all of the agents are currently
consuming the protocol interface OldInterface will stop using OldInterface . If
UninstallProtocolInterface() returns EFI_ACCESS_DENIED , then this function
returns EFI_ACCESS_DENIED , OldInterface remains on Handle , and the protocol notifies
are not processed because NewInterface was never installed.
If UninstallProtocolInterface() succeeds, then a call is made to the boot service
InstallProtocolInterface() to put the NewInterface onto Handle .
Finally, the boot service ConnectController() is called so all agents that were forced to
release OldInterface with UninstallProtocolInterface() can now consume the
protocol interface NewInterface that was installed with InstallProtocolInterface() .
After OldInterface has been replaced with NewInterface , any process that has registered
to wait for the installation of the interface is notified.
Status Codes Returned
EFI_SUCCESS The protocol interface was reinstalled.
EFI_NOT_FOUND The OldInterface on the handle was not found.
EFI_ACCESS_DENIED The protocol interface could not be reinstalled,
because
OldInterface is still being used by a
driver that will not release it.
EFI_INVALID_PARAMETER One of the parameters has an invalid value.