/proc/bus/pci Question

[Martin Mares]

Hi,

> On my system, in /proc/bus/pci, there are two directories, "00" and "01",
> I assume these represent the first and second PCI busses on my system.  
> My question is, what do the files in these directories do?

   These files contain full configuration space of the corresponding
devices.

> Also, a possibly related question:  Is there any way to get the
> pci_devices dev->class field from userspace?  I notice that the new
> /proc/bus/pci/devices file has a lot of information, but doesn't include
> the class type (e.g. Storage, Video).  I see that this information is
> present in /proc/pci, but my understanding is that /proc/pci is
> obsolete.  Any easy way to get this information?

   Yes, you can read it from the configuration registers mapped as files.
Anyway, it's much better to use the libpci library from the pciutils
package (ftp://atrey.karlin.mff.cuni.cz/pub/linux/pci/pciutils-2.1.4.tar.gz)
for this purpose -- it provides a clean interface for accessing of PCI
registers and uses the appropriate low-level functions according to the
OS, libraries and CPU you have.

				Have a nice fortnight
-- 
Martin `MJ' Mares <mj en ucw.cz> <mj en suse.cz> http://atrey.karlin.mff.cuni.cz/~mj/
"REALITY.SYS corrupted - reboot Universe (Y/N)?"

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo en vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/