ESP32 Forum

We're working on an OTA component via a potentially very slow connection (GPRS or IoT-NP). We're using esp_ota_begin(), esp_ota_write_with_offset() and esp_ota_end(). The arduino-esp32 version is 4.2. The build environment is Visual Micro.

Everything works as expected. However as the last piece we would like to enable automatic rollback if the upgrade crashes. For this we need to set the CONFIG_BOOTLOADER_APP_ROLLBACK_ENABLE option. Is there an easy way to set this option? It doesn't seems like the sdkconfig.defaults route works in the Arduino setup but not sure...

Any help is appreciated...

The CONFIG_ features are compiled into the libraries included in arduino-esp32. You would need to compile you own libraries with the lib-builder if you want to enable this. I don't know your exact method of update, but it seems like what you want is already there. That CONFIG option is used if you want to fully control the update process, and decide for yourself if the image is valid. If turned off, however, it will automatically mark the OTA invalid and rollback if the new image is invalid. You can test this by adding corruption into a .bin file and uploading manually with esptool.

Hi, nice to see you here. Thanks for the quick response!

The issue we're trying to address is not a potentially bad image. We were planning to account for that via a SHA signature but from what you say, we might actually be able to save ourselves the trouble.

What we are trying to implement is the rare case when a legitimate image crashes on a particular machine be it due to a bug, a weird configuration or any number of other combinations. The application is a rural well monitoring system and any failure in the field could be rather expensive.

From what we understand is that this is how the workflow is supposed to work when the CONFIG_BOOTLOADER_APP_ROLLBACK_ENABLE flag is set:

• Down load the image and save it with esp_ota_begin() and esp_ota_write()/esp_ota_write_with_offset()
• Finalize the upgrade with esp_ota_end() and esp_ota_set_boot_partition()
• Reboot the system
• If the system crashes during reboot and testing, the bootloader will automaticially roll back to the previous image. (There is also a manual option to roll back)

However It seems pretty involved to build a custom boot loader just to set a single flag.
Best,
Gregor

I post docker containers for release versions on dockerhub. While large (~500MB), they make it simple to build libraries for a quick change like this.
https://hub.docker.com/r/lbernstone/esp ... b-builder/

Thanks, that really appreciate and should close the last big gap in functionality between ESP32 Arduino and ESP-IDF. I wasn't too fa,iliar with Docker but it seems a great solution for this.

Unfortunately the Docker command line doesn't work. You're sure you made the packet public? Also, the URL is referencing esp32s2. I thought that was the single core MCU. Are the bootloaders identical for both?
Thanks again for all the hard work!
Best...

NM, ignore the last message. However the correct docker tag is (not esp32s2).

This was really a great help and again, very much appreciated.
Gregor