There are no x-rated games on the PS2. Most eroge end up having the sex scenes removed when they are ported. (That's called ALL AGE version)
They, however, have some ecchi scenes in them. (Pantyshot, suggestive scenes, ...)
But it's as far as you'll get.
However, if you have a Sega Saturn or a PC Engine, you can get some old hardcore eroge.
The Nec PC-FX is also full of those.
The best console you can get for hentai games is a FM Towns Marty.
As far as "drivers for consoles" goes, there are none. You can't run a PC game on a console and it's not a PC.
The developpers have "Dev Kits" which are consoles that can run burned CD/DVD games and perform debugging.
Consoles don't need to have a driver as there is only one kind of hardware to work with. (The point of drivers on PC was to make life easier for devs by giving them a standard set of function calls for a lot of different hardware.)
They recieve a bunch of stuff with the devkits. It usually all they need to work with that specific platform (Compiler, docs, etc.)