Re: Introducing the LCD-Linux project

[James Simmons <jsimmons@infradead.org>]

> > 3) Invert the VT layer. Currently the console/printk driver is on top of
> >    the tty layer. It would be nice to be able to only use a very light 
> >    weight vt printk without the VT tty on top for embedded platforms.
> 
> No. printk hits console drivers why may or may not be frame buffer
> interfaces. Has done for a very long time. Keith Packard has also been
> doing stuff with crash time oops displays etc over an X display.

Correct. What I mean is have the ability to just register the console 
driver but not the tty driver.
  
> > 4) Seperate out the VT emulation layer. Related to 3.
> 
> Separate from what ?

We can still have a basic tty layer without the control characters, think 
do_con_trol in vt.c, junk compiled into the kernel. Make it a options for 
userland to do the vt100 emulation.

> > 5) Multiple independent VT support. Which brings up the question what 
> >    should the mapping of VCs to a VT look like. 
> 
> I would suggest we borrow the X idea and each VC is
> 
> 	int display;	/* Display it is on (for console flipping) */
> 	struct something *vt;	/* VT which it is displaying */
> 	int x,y,w,h;	/* Window onto vt */

/dev/tty[0-16]  -> VT display 0
/dev/tty[17-31] -> VT display 1

etc.

At least that is how I handled it  several years ago.