Re: Mapping virtual addresses to physical

["Alan Casey" <alan.casey5@xxxxxxxxxxx>]

>On Wed, Jul 02, 2008 at 09:42:26PM +0100, Alan Casey wrote:
>>   I have used code similar to the devmem2.c example at
>>   www.simtec.co.uk/appnotes/AN0014/ to map physical
>>   addresses to virtual addresses (i.e. user space pointers) 
>>   but am just wondering how do you do the reverse - i.e.
>>   map virtual addresses to physical addresses in a user
>>   space program without writing a device driver??
>
>What kind of interface to this functionality are you expecting?  What
>use case would such an interface have?

  I need to get the virtual address of a file on a Linux filesystem
  or a memory buffer and convert it to a physical address for the 
  purposes of programming a custom DMA Controller (on an FPGA) with 
  source read (+destination write) addresses. I dont have any experience
  of writing Linux Device Drivers and am just wondering if it's possible
  to do this in a userspace program.

  Regards,
  Alan.



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