Notice of upcoming change: ESP-IDF will disable ROM BASIC console

[ESP_igrr]

We are planning to roll out a change which automatically disables ROM BASIC console by burning respective Efuse, when the application starts up. Newly produced ESP32 chips will also come with ROM BASIC console disabled.

If you wish to preserve this function for your chips/modules, please use `espefuse.py` tool to write-protect respective Efuse.

[cmorgan]

Could you share why this ROM BASIC console is being disabled?

Chris

[ESP_igrr]

This is related to the issue that upon exit from deep sleep, ESP32 may try to read code from flash before flash has powered on. When this happens, it will consider going into built-in BASIC console. If nothing is received from UART before watchdog timer expires, the chip is reset by the watchdog, and boot process is restarted. If any character is received from UART, ROM code disables the watchdog and enters the console.

The issue which some of our customers have encountered is that there is a chance that UART may receive stray characters when there is another MCU connected to the UART. Once ESP32 enters ROM console, it can no longer be restarted by the watchdog, and requires an external reset to be applied.

Given that ROM console is very rarely used, we decided that it is safer to disable ROM console.

[rudi ;-)]

Given that ROM console is very rarely used, we decided that it is safer to disable ROM console.

Can we enable it again?

[ESP_igrr]

Efuses are single use, so once they are burned, they can not be reversed. If you want to keep ROM console working, use espefuse.py tool to write-protect the efuse.

[rudi ;-)]

Efuses are single use, so once they are burned, they can not be reversed. If you want to keep ROM console working, use espefuse.py tool to write-protect the efuse.

ah - perhabs i missunderstood your first post,
the SoC itself ( on sales ) is not burn efuse to disable the ROM console by manufacturer right?
only the next ESP-IDF then the first "flash" will disable this by efuse?

and if i want not this - i must write-protect before the first flash the efuse.

can you point perhabs please to this step ivan, i think there are more people not informed about the steps to do this,
perhabs a note in the datasheet? esp32 technical docu?

thank you!
best wishes
rudi