anand lalgondar said;

> PCI Related Frame buffer implementation:
>               /usr/src/sys/arch/bebox/pci/pfb.c
>               /usr/src/sys/arch/macppc/dev/ofb.c

Yes, they should be examples, too.
I'm a writer of lunafb.c.  Along with NetBSD chorogical, I can tell some
history.  Years ago I wanted to have raster console for a certain 68030
UNIX box, and paid attention on sun3 code for prototype.  I found that
time Chris Demeritou has mostly finished WSCONS framework for
DEC3000 (the first alpha processor computer on world).  I switched
my attention to it as it was better engineered than old SunOS compatible
interface.  Since then, recognized the design virsatileness, Mattias Drochner
pumped enourmous efforts and completed archtecture independent
N(ew)WSCONS framework _with_ extention and adaption to PC
display/ PC kbd.  And Andrew Doran created a new set of raster character
rendering routines capable of various frame depths.  That was the beginning. 
Many NetBSD developers adapted it making foofb.c for their own purposes.

> I could get this point, do you mean you are going to change the WSCONS 
> framework.

No.  All I have to do is to prepare a new set of raster rendering routines
and complete them in a single driver, say, anothernewfb.c.  Please take a look
at dev/tc/sfb.c which is one of my favourite to show how hardware accelerating
circuit is used for WSCONS context.

> I have one more doubt, what is the term raster console, could you give me 
> some information.

Raster console is a beast appears on bitmapped display like Sun Workstation,
and hardly seen in PC world.   Character glyphs are rendered as horizontal series
of (mono-spacing) bitmap characters which is drowned by CPU itself, not a
attributed character generator circuit in video hardware.

>  (caddr_t)MIPS_PHYS_TO_KSEG1(addr);) Need to figure out what.

Yes, it's the hardest part.  It would be challenging to determine physical address
of your video card in PCI context if you want to avoid hardcoded magic number
scheme.

Toru Nishimura/ALKYL Technology