Hey is there any onboard firmware that gets loaded without an SD card? Trying to figure out if I should be seeing any debug output on the serial port without an SD card...currently nothing is coming out of it. I hope the serial port only gets enabled once the linux kernel is loaded otherwise it seems like I have a dead board.
As I know before the kernel also the u-boot gets loaded from the SDcard and will produce the first serial output.
without a u-boot from the card there shouldnt be a output.
Did you test another card? Has another OS bootet successfully on that board?
Or is it a n"new" board for you and it us the first boot?