Indicates whether a newly upgraded firmware version
should write to flash. When this object is temporary(2),
following a successful upgrade the system will switch to
run the new firmware but will not upgrade the new
firmware to flash. That means after a power cycle,
system will run the firmware residing the flash.
When this object is permanent(1), following a successful
firmware upgrade, the flash will be upgraded and the
system will automatically switch to run the new firmware.