udev for multi board setup

Questions and discussions about the Xillybus IP core and drivers

udev for multi board setup

Postby Guest »

I was wondering if you had any pointers on the best way to setup udev for a multi-board configuration in order to force consistent naming of the PCIe devices running Xillybus.

Thanks!

Vitaliy
Guest
 

Re: udev for multi board setup

Postby support »

Hello,

I don't have a reference, but I'm quite sure it's impossible nowadays to rename character devices with udev. if you want to run multiple PCIe endpoints on a computer, there's a special driver for that, which you can obtain from Xillybus' support. That driver adds a number to the device file names, so at least they don't clash. But these numbers are not guaranteed to be consistent.

You may then write udev rules for creating symlinks, based upon the PCIe bus address. That is as consistent as your bus enumeration -- that is, not necessarily consistent. In particular, if any PCIe device is added to the computer, the enumeration may change, not always as one would expect. Enumeration is done by the BIOS, after all.

So the only way to be really sure about consistency is allocating a Xillybus stream from the FPGA to the host, which contains some identification info. What this information is, and how each FPGA has this info is application dependent.

I hope this helped, even though it's not exactly the solution you asked for.

Regards,
Eli
support
 
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Re: udev for multi board setup

Postby Guest »

That makes sense. Appreciate the quick feedback!

Vitaliy
Guest
 


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