The easiest way to perform the flash is by booting into Raspbian and performing the process interactively. Without this one-time process, you can't netboot, as

The easiest way to perform the flash is by booting into Raspbian and performing the process interactively. Without this one-time process, you can't netboot, as the default setting is the SD card, then USB: https://www.raspberrypi.org/documentation/computers/raspberry-pi.html#boot_order-fields https://www.raspberrypi.org/documentation/computers/raspberr...