I always find it funny when people do that with Windows, Mac, and Linux. It completely misses the fact that Linux can be all of these things.
OS for kids: https://www.sugarlabs.org/
Just works: https://www.linuxmint.com/
Fuck around and find out: https://www.linuxfromscratch.org/
More likely running Wind River’s VxWorks. Which, as far as I know is the big dog in the RTOS space. The OS being deterministic is super important in safety critical applications like flight computers and cars. Wind River does have a linux distro, but I don’t think VxWorks is. Although, they’ve kind of got caught being complacent and others are moving into the space like Red Hat In Vehicle Operating System.
For a few brief beautiful moments, I assumed you were talking about the firmware running on the Fisher Price toy.
As your answer included more details, my understanding became a delightful confusion and then realization.