Re: AT Keyboard (was: Helge Hafting vs. make menuconfig help)

[Helge Hafting <helgehaf@aitel.hist.no>]

On Tue, Jun 15, 2004 at 05:46:51PM +0000, Karel Kulhavý wrote:
> > In 2.4.x, the transition from "old-style" input drivers to new-style
> > (Input API) was never finished. Instead, Input API was introduced, and
> > HID devices reported their input to Input API, while old drivers still
> > used all their old ways to deliver their input.
> 
> I (hopefully correctly) assume that one of the old ones is AT keyboard.
> 
> What happens when I press a key on keyboard and the application that
> has the keyboard somehow on it's stdin reads a key? What happens between
> the two events and how does it travel inside the kernel?
> 
> I know how the keys can be read from port 0x60 or whichever.
> 
1. You press the key (on an AT keyboard)
2. The keyboard hardware makes an interrupt
3. The interrupt acitvates the i8042 driver (in 2.6)
   which does the port 0x60 stuff.  
4. From there, the key is propagated through tty and
   console and ends up in your application.  This application
   might be X, which passes the key onto some program using X.

Helge Hafting