Subject: Re: question about mmap
To: Chan-youn Park <phygeeks@gmail.com>
From: Eduardo Horvath <eeh@NetBSD.org>
List: tech-kern
Date: 03/10/2005 16:57:44
On Wed, Mar 09, 2005 at 05:12:30PM +0900, Chan-youn Park wrote:
> Hi. I'm developing a device driver on PowerPC/Sandpoint platform. 
> 
> What I want to do is to implement an mmap interface in the device
> driver. The device driver is for a DSP, and the DSP had its own
> internal RAM which can be seen through PCI bus.
> 
> I've succeeded in seeing the memory space in the kernel, but when I
> tried to see it using the mmap I've implemented, it does not work.

How is it not working?  What do you see in that memory?  Could it
be that the cache is enabled and you are not seeing changes?  
Or could it be an endianness issue since the PowerPC is big-endian
and the PCI bus is little endian?

Eduardo