Messages in this thread | | | From | Neal Becker <> | Subject | Re: [newb] mmap pci | Date | Thu, 17 Apr 2008 08:30:29 -0400 |
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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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