1. A computer system, comprising: a processor; system memory coupled to the processor; a Basic Input/Output System (BIOS) executed by the processor; and an input/output (I/O) bridge coupled to the processor, wherein the I/O bridge traps a shutdown request and causes the system to enter a System Management Mode (SMM) so that the BIOS scrubs the system memory during the shutdown process; wherein the BIOS selectively scrubs the system memory during a shutdown process of the computer system.