I am interested in hearing about your experiences with this project.
According to the information I have on the G400S that I’ve used before, the JTAG Lines are connected to the SOM pins.
I guess what you mean is that you didn’t expose them on your carrier board?
You are correct. Our “carrier board” is actually a pretty complex motherboard with slots for 6 daughter cards that interface to a variety of peripherals so we really don’t want to have to re-spin it just to add a JTAG connector.