How to interact with AON SPE?

The example code and documentation for the SPE is not very clear.

  • How do you run the applications after flashing?
  • How do you interact with the processor and for example read the printf statements in the examples or send the processor data from the main Linux system? Is it a serial port something else? Some device?
  • Is there some kind of debugger support?

Hello, bastibr8yu:

  1. SPE firmware will run automatically after device up.
  2. For communication between SPE firmware and CCPLEX (Linux), please refer to doc/devicetree-ivc.md. SPE firmware can print message through TCU. Refer to https://elinux.org/Jetson/AGX_Xavier_Tegra_Combined_UART for details.
  3. You can add some print code in SPE firmware for debug.

Let me know if you have further questions.

br
Chenjian

Thank you. Could you elaborate on the devicetree IVC part. It is very brief in terms of explanation. What is IVC?

If I understood it correctly the other communication essentially requires an external micro usb connection to read. However, we would like to talk directly between the main and SPE processor.

Hello, bastibr8yu:
IVC provides an example data channel between CCPLEX (Linux) and SPE firmware.
You can read/write the sysfs node described in devicetree-ivc.md to exchange data.
e.g. echo xxx > …/data_channel. (send message to SPE FW)
cat …/data_channel (get the data from SPE FW)

For details, check the code listed in that doc.

If I understood it correctly the other communication essentially requires an external micro usb connection to read. However, we would like to talk directly between the main and SPE processor.
SPE does not support USB.

br
ChenJian