U25 PetaLinux

[WafaaFadlelmula]

Hi Matthew,

Thank you for all you efforts. Your notes are really helpful.

I built and deployed PetaLinux on Alveo U25 using Vivado 2023.1 and PetaLinux 2023.1. The system boots properly via JTAG and Linux runs correctly. However, when trying to read UART output, all text is grabled. I tried different baud rates (9600 - 230400) but nothing works.

I have read that this could be voltage mismatch. Could this be the issue? if not, have you encountered something similar and how can we interact with PetaLinux otherwise?

Thank you in advance.

[mwrnd]

Yes, it could be a voltage issue. I run the UART connection through a 3.3V<->1.8V adapter. The Alveo U25 requires 1.8V UART signals. Take a look at the following project:
https://github.com/mwrnd/AlveoU25_JTAG_Adapter

Confirm the UART's GND connection is solid. Check for any dirt or debris on UART-related connectors and traces. Try a different UART adapter.
If you have the ability, scope the UART signals and confirm the signals look good.

I have no notes on the UART beyond the following:
https://github.com/mwrnd/alveo_u25_notes/blob/main/debug_log.md#alveo-u25-debug-log
https://github.com/mwrnd/alveo_u25_notes/blob/main/debug_log.md#tracing-a8-a9-debug-connector-uart-signals

When setting up the Processing System (PS), try setting the UART pin's drive strength to higher and lower values.
https://github.com/mwrnd/alveo_u25_notes/blob/main/debug_log_vitis.md#zynq-mpsoc-hardware-setup-in-vivado