my macbook kept bothering me to do updates, i rarely do them, but i figured i should never had to do one of these EFI firmware updates before. it's kinda scary actually. you have to have the power cord plugged in (macbook). then shutdown. then hold the power button till the sleep light flashes rapidly, you will hear a loud beep noise, followed by the apple startup noise. it boots to an apple and a progress bar. that completes in about 2 mins and it reboots. done what does it do?