1. An apparatus providing for a secure execution mode of operation, comprising: a microprocessor, comprising a single integrated circuit disposed on a single die, configured to execute non-secure application programs and a secure application program, wherein said secure application program is executed exclusively within the secure execution mode within said microprocessor, and wherein said non-secure application programs are accessed from a system memory via a system bus, said microprocessor comprising: a non-volatile enabled indicator register, configured indicate whether said microprocessor is within the secure execution mode or a non-secure execution mode, wherein contents of said non-volatile enabled indicator register persist through power removal and reapplication to said microprocessor; and a secure non-volatile memory, coupled to said microprocessor via a private bus, configured to store said secure application program, wherein transactions over said private bus between said microprocessor and said secure non-volatile memory are isolated from said system bus and corresponding system bus resources within said microprocessor, and wherein, upon enablement of said secure execution mode, said microprocessor encrypts said secure application program and transfers said secure application program to said secure non-volatile memory over said bus.