1. An apparatus for providing programmable minimum memory page sizes, the apparatus comprising: a pagegrain register, configured to prescribe a minimum page size, in default, according to a legacy memory management protocol, and in alternative, as one of the programmable minimum memory page sizes according to an extended memory management protocol; and a memory management unit (MMU), coupled to said pagegrain register, configured to store a plurality of page table entries (PTEs), each of said plurality of PTEs specifying a page granularity for a corresponding physical memory page, wherein said page granularity is bounded by said minimum page size, said MMU comprising: page granularity logic, configured to determine a page size for said corresponding physical memory page, wherein said page size is determined based on said minimum page size and said page granularity.