Patent ID: 6658548
Filing Date: 2003-12-02
Classification: G06F

Abstract:
A method, within a data processing system having a physical memory and a virtual memory for accessing data from a protected region of the physical memory, said method comprising:loading an executable first code into a physical memory; activating a memory mapping facility to prevent software from accessing a protected memory region of said physical memory; mapping a virtual memory onto said physical memory, said virtual memory including a range of addresses associated with a second executable code stored in said physical memory, said second executable code having common code with said first executable code, said range of addresses including at least one same address in said virtual memory as said first code in said physical memory such that an interruption of an execution of said second executable code due to a deactivation of said memory mapping facility results in execution of said first executable code; executing said second executable code to deactivate said memory mapping facility; while said memory mapping facility is inactive, executing said first executable code to copy data from said protected memory region to a second physical memory region; and reactivating said memory mapping facility to map said data from said second physical memory region into said virtual memory.