Application Tracing

[中文]

This feature allows transferring arbitrary data between the host and ESP32 via the JTAG interface with small overhead on program execution.

Developers can use this library to send application-specific state of execution to the host and receive commands or other types of information in the opposite direction at runtime.

Let’s open an ESP-IDF project. For this tutorial, we will use the system/app_trace_to_host example.

  1. Navigate to View > Command Palette.

  2. Type ESP-IDF: New Project, select the command, and choose the ESP-IDF version to use.

    Note

    If you don’t see the option, please review the setup in Install ESP-IDF and Tools.

  3. A window will open with settings to configure the project. You can later choose from a list of ESP-IDF examples. Go to the system section and choose app_trace_to_host. You will see a Create Project Using Example app_trace_to_host button at the top and a description of the project below. Click the button, and the project will open in a new window.

    ../_images/app_tracing.png

    For this example, the project is already configured for application tracing purposes. In other projects, you need to enable CONFIG_APPTRACE_DEST_TRAX and CONFIG_APPTRACE_ENABLE with the ESP-IDF: SDK Configuration Editor command.

  4. Configure, build, and flash your project as explained in the Build the project.

  5. First, click ESP-IDF Explorer in the Visual Studio Code Activity bar. Second, in the IDF APP TRACER section, click Start App Trace. This will execute the extension’s OpenOCD server and send the corresponding tracing commands to generate a tracing log. Third, you can see the generated tracing log in the APP TRACE ARCHIVES named Trace Log #1.

    Each time you execute Start App Trace, a new tracing is generated and shown in the archives list. You can also start tracing by running the ESP-IDF: App Trace command.

    Note

    • The OpenOCD server output is shown in menu View > Output > ESP-IDF.

    • Ensure that OpenOCD configuration files are properly configured with the ESP-IDF: Select OpenOCD Board Configuration command.

    ../_images/start_tracing.png

  6. Click Trace Log #1 to open a window with the trace report. Click the Show Report button to see the trace output.

    ../_images/trace_report.png

For more information, please refer to Application Level Tracing Library.