Advantech ARK-3531 Series User Manual page 71

3.2.3.8 Security Configuration
RTC Memory Lock

Enable will lock bytes 38h-3Fh in the lower/upper 128-byte bank of RTC RAM.
BIOS Lock

"Enable or Disable" the PCH BIOS Lock Enable feature. Required to be enabled
to ensure SMM protection of flash.
59 ARK-3531 User Manual