By providing a secure EEPROM (Electrically Erasable Programmable Read Only
Memory) device or other non-volatile memory (NVM) as a system operation
key (SOK) to control the configurable machine option attributes, various
problems associated with machine option configuration and updates may be
accommodated. At initial SOK install the identity of the machine is
written to the NVM, i.e. the machine serial number. This is performed
during the initial machine power up or reboot sequence. As part of the
power on or reboot routine the machine will check to ensure no tampering
has taken place and that the machine identity and the NVM serial number
location data match. A new swapped in SOK can be installed so long as the
NVM serial number location has not been previously written to with a
conflicting identification number. The machine will then write the serial
number to the new SOK thereby protecting it.