USB serial adapter without drivers

Does an USB to serial RS232 adapter which does not require drivers exist?
An adapter which can be connected to a USB device which does not have an operating system at the USB end and then convert the USB data to serial RS232.

Never heard of one yet.

Might be able to use a Raspberry Pie to build something…

How about an adapter with the drivers built-in into the adapter itself. Anybody heard of that?

To answer my own question: It would be major challenge to make a USB Serial adapter that does not use drivers, or has built-in drivers since the since the drivers is what ties the converted data to wherever they need to go at the computer end. It would also be difficult for a user to use the adapter.