[SOLVED] what kind of Linux does the NES classic use?

I am reading in https://www.theverge.com/circuitbrea...m-raspberry-pi that the Nintendo Nes Classic console runs some form of Linux. I immediately wondered what kind of Linux. It's not necessarily any distro I've ever heard of--perhaps Nintendo made it themselves from scratch, for all I know--but does anyone know more about it?

Never mind, I just saw the LXer posts listed. Hmm...Unity for Linux. Looking it up.