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RP + PYNQ MAC address changes on power recycle

Posted: Sat Jan 15, 2022 7:46 am
by rvinayak
Hi,

I'm using a pynq image for Redpitaya-125-14 provided by pau_gk.
https://github.com/dspsandbox/Pynq-Redpitaya-125

I'm trying to sign a unique hostname to the board based on the MAC address.
The problem is the MAC address changes every time I recycle power to the RP board and hence the hostname changes as well.

It there a way to read the permanent MAC address from EEPROM and keep it constant for the board?

As there are multiple RP + PYNQ boards in the network I would like to assign a unique yet constant hostname to the PYNQ RP board.

Many thanks,

Rohit

Re: RP + PYNQ MAC address changes on power recycle

Posted: Sat Jan 15, 2022 8:16 am
by pavel
It is u-boot that reads the MAC address from the EEPROM and sets it for the network interface. If it does not in your SD card image, then it probably means that u-boot is not configured correctly.

Here are the links to the u-boot configuration file and the patches that work for me:
https://github.com/pavel-demin/red-pita ... _defconfig
https://github.com/pavel-demin/red-pita ... 1.04.patch

Re: RP + PYNQ MAC address changes on power recycle

Posted: Sat Jan 15, 2022 1:50 pm
by rvinayak
Many thanks Pavel.

I know its a different question but could you point me on how to use these files.

I'm more familiar with the s/w side of things. Could I use these files in the build process as per https://github.com/dspsandbox/Pynq-Redpitaya-125 ?

Many thanks,

Rohit

Re: RP + PYNQ MAC address changes on power recycle

Posted: Sun Jan 16, 2022 10:34 am
by pavel
I checked the Pynq-Redpitaya-125 instructions but did not understand how to properly configure u-boot by following these instructions.

I would try to build u-boot and boot.bin separately using my configuration file and patches, then I would try to replace boot.bin on the Pynq-Redpitaya-125 SD card.

Another approach would be to open a new issue in the Pynq-Redpitaya-125 repository stating that u-boot does not configure the MAC address of the network interface. Maybe the author of the Pynq-Redpitaya-125 project would have an idea how to fix it.

Yet another approach would be to manually assign a static IP address to each of the Red Pitaya boards as the author of the Pynq-Redpitaya-125 project recommends in his notes:
https://github.com/dspsandbox/FPGA-Note ... ip-address

Re: RP + PYNQ MAC address changes on power recycle

Posted: Tue May 24, 2022 6:29 am
by rvinayak
Hi Pavel,

Many thanks for the explanation and advice.

I have posted on the pynq-RP repo in GitHub as well.

Pau Gomez, who made the build, has come back and mentioned this is know issue with the image and he will fix it in the next release.

Until then he has suggested a solution here:
https://github.com/dspsandbox/Pynq-Redp ... 1134774153


Incase anyone else has the same problem.

Thanks again.

Rohit