Most systems can support a different operating system after a period of time and the know how to do it.
Some systems even supported it day one. The Sony Linux lawsuit aside, Sega had full blown windows available on the Dreamcast in some countries.
The Saturn had a computer platform in Japan. Sega released a Genesis based computer and I believe it was JVC that actually released a Basic package for the genewis in cart format. Nintendo had programming platforms since the famicom through the 64.
Xbox modding started day one.
The thing is, even if the company actually supports it (Sony PlayStation, Xbox, Dreamcast) it can cut off the ability. You can dodge online firmware updates as many people did, but the firmware was added to actual game discs. To play the game, you got the update anyway. Now they load the payload into the game title rather than a system update.
