Architecture of cars multimedia systems

Question

I wonder what is the software (OS, graphics libraries, etc.) and hardware architecture that cars use for their multimedia systems for controlling radio, cds, navigator or telephony.

I also noticed that the BMW's iDrive startup is immediate, no bootup process. I suppose that other systems work like that as well. How do they achieve this?

Thanks!

Answer 1

It is embedded systems, very often custom technology.