Enabling RAS drivers on NX dev kit (Reliability, Accessibility and Serviceability)

Hi Nvidia community, I’m interested in using the Xavier NX’s built-in Reliability, Accessibility and Serviceability (RAS) drivers to understand ECC performance of the Carmel CPUs in an extreme environment.

2 goals :
(1) Report any RAS errors (both correctable & uncorrectable) to the serial UART2 debug interface. Also report the origin of the error i.e. CPU unit

(2) “Spoof” or trigger a RAS error to mimic the conditions the Jetson will live in, and validate that software recovery from the error happens correctly.

I’ve seen the following 3 threads:

However I’m unable to find any of the drivers or functions mentioned such as :


In fact, those directory locations don’t even exist on my machine.

After lots of grep, the only reference I see to anything ras-related is .h header files:




Also dmesg log says “CPU features: detected: RAS Extension Support”. I guess that means something?

How can I get the .c drivers installed + fully functional to do the 2 actions I want above?

I’m using the Jetson Xavier NX dev kit running Jetpack 5.0.2, 5.10.104-tegra.

RAS driver has been moved from Kernel to ATF (ARM Trusted Firmware) in the new releases with Kernel-5.10.

Thank you @sumitg ! I see. Will use these docs for ATF then.

And please correct me if i’m wrong, but from the older posts on this topic + a paper I read, it seemed that the carmel_ras.c and arm64_ras.c were out-of-the-box implementations provided in Jetpack 4.x to capture RAS errors in UART debug logs (same as any other errors thrown). Injecting errors via the RAS_MCA_ERR-trip node could also be done out-of-the-box.

I’m not seeing any analogous code examples though in the ATF docs. I’m more interested in seeing the errors as debug logs post-runtime rather than polling RAS registers real-time as errors happen.

  • Would I write my own C driver to capture & inject errors to replicate the functionality that was provided in Jetpack 4.x?
  • If so, is there a way to port the old drivers over to Jetpack 5.x to avoid re-doing this from scratch?

Please check about the ‘tf-a-tests’ project and how to deploy it on their device.
The RAS tests are already part of tftf/tests/tests-tegra194.mk - TF-A/tf-a-tests - Gitiles
So, If you can run the framework then the test will be executed automatically on boot.

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