Available GPIO Pins

I am trying to figure out which GPIO pins I am able and not able to use. I have referenced:

https://www.jetsonhacks.com/2015/12/29/gpio-interfacing-nvidia-jetson-tx1/
https://www.jetsonhacks.com/nvidia-jetson-tx2-j21-header-pinout/

The first article indicates that only 8 GPIO pins are available to use. Why is this the case? I cannot find a distinguishing feature among the ones listed. How can I tell which ones I am able to use for the Jetson TX2?

hello pgpetrak,

please also check the Jetson TX2 Module Pinmux, there are several pin that were able to configure as GPIOs.
thanks