As part of a procedure I am writing for rooting and flashing roms, I wanted to include what the bootstrap ap is doing. My understaing is I can power up my phone and hold down the volume keys to get to the setup menu. Why couldn't I just do that and pick the sd card .zip file that way? Bootstrap ap has me click 2 buttons. I know the second brings me to the boot menu, what does the first one do and why do it this way versus manually as I describe?