It a dam phone.. in on a network.. the phone has a bootstrap loader that tells it when its first turned on .. connect to network and download the new OS!!!
Or a checksum?
FedEx ships Apple handsets to the U.S. mainly using Boeing 777s, according to Satish Jindel, a logistics-industry consultant and president of SJ Consulting Group. Those planes can make the 15-hour flight from China to the main U.S. hub for freight shipments in Memphis, Tennessee, without refueling, Jindel said. The 777s can carry about 450,000 iPhones and cost about $242,000 to charter, with fuel accounting for more than half the expense.
Apple has used less conventional aircrafts to transport its gadgets in the past. Before the debut of new iPods last decade, Apple packed an old Russian transporter plane with the media players to get them to stores on time, said a person familiar with the flight.
The iPhone’s high price and light weight mean Apple can still reap big margins while packing many devices into air shipments, instead of using sea cargo as was historically the case with consumer electronics, said Mike Fawkes, a former supply-chain executive at Hewlett-Packard. “If you have a product like a printer that costs $100 and is pretty big, you can’t air ship that because it destroys the economics,” he said.
According to the same article, the OS is loaded onto the phones in China before they are shipped.