Patent ID: 7058768
Filing Date: 2006-06-06
Classification: G06F

Abstract:
1. A method of controlling memory usage in a system that comprises a plurality of memory locations, some of the memory locations being designated to be accessible only by a trusted source, each of the memory locations having a physical address, the system supporting the use of virtual addresses to address the memory locations, the memory location that corresponds at a given point in time to a given virtual address being at least partly determined by a selectable group of address translation data that is storable in the memory locations, the system further comprising a writeable storage location that contains, at any given point in time, a pointer to the particular group of address translation data that has been selected to partly determine which of the memory locations corresponds to a given virtual address, the method comprising: receiving a request to write a new pointer into the storage location; determining that loading the new pointer into the storage location will not cause any of the memory locations that are designated to be accessible only by the trusted source to correspond to any virtual address; and allowing the request to proceed.