It's not really a good option, however SMM mode could be (you'd need to figure how to do network calls, though). The only thing changed by UEFI in this case is

It's not really a good option, however SMM mode could be (you'd need to figure how to do network calls, though). The only thing changed by UEFI in this case is unified interface to register SMM components (You can have UEFI system with no SMM).