I have a plaque attached with GPIOs J990 connector using pins 3 through 22.
I'm using 8 input pins and 12 output pins, where I have connected some LEDs and some relays.
The fact is that during the process launched, I see some LEDs light up, and gpio137 gpio157 specifically, and I hear a relay switch.
When he finishes the boot process, all ports are initialized GPIO, and everything works, but I need to avoid problems during the boot process.
How I can get during the boot process I leave all connector pins to 0?
Do I need an MLO file modified to keep all pins to 0?
Yes, at least you should create a custom MLO. You should download the source code and add mux configurations to the code.
You can download the source code from out git repositories:
http://git.isee.biz/?p=pub/scm/igep-x-l ... ;a=summary
Hope it helps you.