Hello everybody,
my question is about how (peripheral) device drivers fit the OSI model. In particular:
I understand the meaning of all OSI layers when it comes to peer to peer communication (ler's say, PC to PC communication). However I get confused when it comes to communication between PC and generic peripheral device (say, the keyboard). In my understanding, here is what happens in this case (much simplified):
Let's say that one process on my PC wants to receive data form the keyboard. The process calls some Operating System routine, which invoke the keyboard function driver and any Bus driver related to the keyboard (for example, if it is a USB keyboard, the USB Host driver is invoked).
At this point, the drivers-stack manages the reading operations from the the keyboard controller (writing to its registers); then this logical chain is reversed (with interrupt or polling techniques) in order to deliver the keyboard data to the process which requested them.
This said (please correct me if I said something wrong), it is not clear to me what follows:
1) Is OSI model applicable also to (PC to peripherals) communication?
2) If yes, where are the seven OSI layers hidden within the logical process I just described?
3) Which protocols rule the OSI layers in this case?
4) Which role plays the device function driver in this scenario? Which role plays the Bus driver? Which layers do they fit?
Thank you
Federico
