On Fri, Jul 20, 2001 at 05:13:17PM +1000, Andrew van der Stock wrote:

 > That's the function of the OS glue, deep down in bsd_video.c and friends
 > that Simon is working on.

Only the kernel can perform some of these functions, e.g. validate DMA
addresses, and arbitrate writes to control registers.  Hell, only the
kernel can enforce mmap'ing the allowed regions of the device!

 > 
 > Andrew
 > 
 > ----- Original Message -----
 > From: "Todd Vierling" <tv@wasabisystems.com>
 > To: "Simon Burge" <simonb@wasabisystems.com>
 > Cc: "NetBSD-current Discussion List" <current-users@netbsd.org>
 > Sent: Friday, July 20, 2001 12:53 PM
 > Subject: Re: Why not track our xsrc with X11R6.6 from X.org?
 > 
 > [snip]
 > > 1. determine the mmap-allowable data area of a card
 > > 2. arbitrate writes to control registers
 > > 3. validate DMA values used in control registers before an actual write to
 > >    those registers is performed
 > >
 > > This shouldn't be a difficult thing, but it would likely require that
 > XFree
 > > supply some level of abstraction to make (2) and (3) work -- because the
 > > hardware vendor needs to write the code for (2) which will call our
 > supplied
 > > hooks for (3).
 > 
 > 

-- 
        -- Jason R. Thorpe <thorpej@zembu.com>