A non-volatile random access memory (NVRAM) is used in a computer system to perform multiple roles in a platform storage hierarchy, specifically, to replace traditional mass storage that is accessible by an I/O. The computer system includes a processor to execute software and a memory coupled to the processor. At least a portion of the memory comprises a non-volatile random access memory (NVRAM) that is byte -rewritable and byte-erasable by the processor. The system further comprises a memory controller coupled to the NVRAM to perform a memory access operation to access the NVRAM in response to a request from the software for access to a mass storage.