A method and system for providing an external locking mechanism for memory
locations. The memory includes a first plurality of storage locations
configured with BIOS data and a second plurality of storage locations.
The second plurality of storage locations includes a first plurality of
blocks readable only in SMM and a second plurality of blocks readable in
SMM and at least one operating mode other than SMM. The computer system
includes a bus, a memory coupled to the bus, and a device coupled to
access the memory over the bus. The memory includes a plurality of
storage locations, divided into a plurality of memory units. The device
includes one or more locks configured to control access to one or more of
the plurality of memory units.