An ACPI (Non-Volatile Sleeping) NVS memory region is allocated and defined
so that a system BIOS can allocate a placeholder for the different
parameters that are passed from the ACPI ASL code to the system
management mode (SMM) handler for execution of real mode calls. The
different parameters will be updated by runtime ACPI ASL code depending
on what needs to be passed to the SMM handler. The SMM handler invokes
appropriate calls based on retrieving of different parameters in the ACPI
NVS memory region that have been passed from the ACPI ASL code.