Can a normal external hard drive work with battlefield 3 for xbox 360 slim?

I keep reading yes but only for ones made for xbox, and i read that you can format any hard drive to make it work for battlefield 3. So now that the game has been out for a while can a normal 120G external hard drive with usb connection work with xbox360 to save the battlefield 3 HD updates? Or am i stuck buying the microsoft made xbox 360 hard drive?Can a normal external hard drive work with battlefield 3 for xbox 360 slim?
i am pretty sure if has to be an xbox hard drive to work but im sure if you google it enough you should be able to find a jailbreak way for it to work. good luck hunting