ESP32 Forum

Here's only a process diagram,
https://docs.espressif.com/projects/esp ... grade.html
I cannot find the contents of the packets (maybe http or tcp or any other).

Howerer, I plan to upgrade/ota the mesh device through raspberry pi (python)，so is there a document explain how to build the mupgrade packtes?

You don't need to care about the packet format of the communication during mupgrade. You only need to send the firmware to the root node. The subsequent process will be maintained by mupgrade. You can refer to https://github.com/espressif/esp-mdf/tree /master/examples/function_demo/mupgrade