Embodiments of the present invention are directed to a method and system for allowing data structures to be moved between storage locations of varying performance and cost without changing the application firmware. In one embodiment, rather than application firmware directly accessing memory, the application firmware requests a data structure by parameters, to which the implementation returns a pointer. The parameters can be, for example, the logical block address of a data sector, and the data structure can be mapping and associated information of that logical block address (LBA) to a location in the flash device.