System Management Mode (SMI# & SMIACT#)
System Management Mode (SMM) is a special mode of operation supported by x86 microprocessors in addition to their real and protected modes of operation. SMM was introduced originally to support power management in mobile PCs. Today power management is largely handled by the operating system (O.S.), but SMM is still used in a variety of other applications.
System management mode (SMM) allows the processor to execute code from system management memory that is separate from the regular memory used by the operating system and applications. This permits the system designer to implement features that are transparent to the operating system, making SMM extremely valuable for applications not supported ...