Subject: Re: bus_spacing a FreeBSD driver
To: Matthias Scheler <tron@lyssa.owl.de>
From: Jason Thorpe <thorpej@nas.nasa.gov>
List: tech-kern
Date: 09/11/1998 15:06:06
On 11 Sep 1998 22:21:22 GMT 
 tron@lyssa.owl.de (Matthias Scheler) wrote:

 > So how do I change this? Can I modify this structure, map it properly
 > and still peek into it? Or will I have to use bus_map_*_read() with
 > a base address and some kind of offset?
 > 
 > [Sorry, if these question are stupid but this is my first encounter
 >  with kernel hardware handling.]

Base and offset; you cannot use structs:

	(1) different arch's will have different struct padding!

	(2) the device may be mapped sparse by the hardware.

Jason R. Thorpe                                       thorpej@nas.nasa.gov
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