My Xbox360 can update its firmware over the internet, my computer can update itself over the internet. Why cant my cellphone? Why must i take it in?
'Cause it’d be really bad if you lost connection or power halfway through the install process- as in, “you now have a completely useless brick-shaped object” bad.
Which is a total non-answer, since increasing numbers of cell phones CAN have their firmware updated OTA.
I think it’s a matter of scale, though. Updating a normal phone is probably not much of a problem- the file is small, probably small enough to be loaded into system memory before the update process. A PDA, though, is a bit more problematical- my HTC 8525 is getting a whole new operating system later this month, and that’s a huge file to download to the machine, store in memory, and then install. Data connections are getting better, and storage is getting cheaper, so I wouldn’t be surprised if we see more OTA updating as time goes by.
Yeah, memory is likely the major bottleneck here. Phones don’t need lots of fast DRAM, they store most of the information they hold in slow, but nonvolatile, flash RAM. As you note, the firmware upgrade has to be downloaded, stored in memory, verified for accuracy and then flashed to the firmware ROM. On modern phones, that can amount to upwards of several megabytes of data. If you want to flash your firmware quickly before something bad happens, you want fast RAM, not flash memory.