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SubjectRe: [newb] mmap pci
Date
Arjan van de Ven wrote:

> On Wed, 16 Apr 2008 07:23:29 -0400
> Neal Becker <ndbecker2@gmail.com> wrote:
>
>> We have a device - an FPGA board on PCI bus. It has a range of
>> internal memory mapped to PCI. I want to expose this to user via
>> mmap. Is there some example code someone could point me to?
>>
>> If this is not the best forum for such questions, what would be a
>> better choice?
>
> Hi,
>
> if it's just a PCI bar, you can already memory map it without even writing
> a driver! You can just use the sysfs files for this, for example
> /sys/devices/pci0000:00/0000:00:02.0/resource1
>
> There's also a way to do this via the /proc representation of the PCI
> device..
>
> Greetings,
> Arjan van de Ven
>
>

Thanks! Only problem: seems the mapping is read-only?
This python test code works if prot=mmap.PROT_READ, but I get
permission denied if PROT_READ|PROT_WRITE.

import mmap
import struct

f = open ('/sys/bus/pci/devices/0000:05:0f.0/resource0','rw')
m = mmap.mmap(f.fileno(), 1000000, prot=mmap.PROT_READ)




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