Index: [thread] [date] [subject] [author]
  From: Andreas Beck <becka@rz.uni-duesseldorf.de>
  To  : ggi-develop@eskimo.com
  Date: Fri, 21 May 1999 21:25:01 +0200

Re: Independent Multihead

> I'm trying to chase the independent multi-head thing and although I do not
> have it set up yet, I have 2 matrox millenium cards. 

Multihead is pretty tricky with fbdev. Marcus is trying to fix that, but it
seems it isn't quite easy.

> So far I have tried to run XGGI unsuccessfully with matroxfb on kernel
> v2.2.2.  All that I get is either a blank screen, or a screen that only
> has the blue colour, and lots of other weirdness.  

Other demos work ?

> So, my first real question is this:  Where do I need to do to create an
> input driver and make it compile, etc?  I presume that the easiest
> approach would be to take something like the file input driver and modify
> it to read from the serial port instead? 

Yes. This or the linux_keyboard driver or similar. You'll probably need some
keymapping stuff as well, but for a start, it is a good idea to just copy an
existing driver.

> What background info do I need to know to make a successful keyboard 
> driver?  

You should know about the concept of the button, label and symbol entries in
the gii_key events. Ask, if this isn't documented enough.

That should be the main obstacle.

> I guess I just need to fill out the inp-> structure as in the 
> initialization routines?  

Yes. You should parse your parameters, and then set up the pointers to the
driver functions and your private data. Prepare eventual devinfo structs
you will return on queries and set up maxfd, the fdset, the curreventmask 
and the targetcan mask, plus eventual flags like GII_FLAGS_HASPOLLED, if
there is no FD to watch, but this is rather a polled source.

> Next, what about the GGI part?  I have been looking through the GGI
> source for the fbdev and it seems to want to open the tty that is
> associated with the frame buffer, as well as do a bunch of VT switching
> stuffs.  I don't think that all this would  be wanted if all that I want
> is to run X on a second display.

Depends. The Linux kernel isn't really up to multihead, but we try our best
to get it done. I suppose the other answers to that part of the questions
should help.

CU, ANdy

-- 
= Andreas Beck                    |  Email :  <andreas.beck@ggi-project.org> =

Index: [thread] [date] [subject] [author]