ESP32C3 forever loop at boot

[chegewara]

I think its the problem with "limbo state".
viewtopic.php?t=27736
https://github.com/esp8266/Arduino/issu ... -873684757
https://www.youtube.com/watch?v=cKDv0aN67BY

[starostarf]

I have the same situation, the chip esp32-c3 freeze at unnown state, when power is stabilizing after some glitches:

Code: Select all

rst:0x3 (RTC_SW_SYS_RST),boot:0x0 (USB_BOOT)
Saved PC:0x40048b82
Invalid mode for secure boot download
ESP-ROM:esp32c3-api1-20210207
Build:Feb  7 2021
rst:0x3 (RTC_SW_SYS_RST),boot:0x0 (USB_BOOT)
Saved PC:0x40048b82
Invalid mode for secure boot download
ESP-ROM:esp32c3-api1-20210207
Build:Feb  7 2021
rst:0x3 (RTC_SW_SYS_RST),boot:0x0 (USB_BOOT)
Saved PC:0x40048b82
Invalid mode for secure boot download
ESP-ROM:esp32c3-api1-20210207

And exit from this state only by hardware reset or power restart.

Dear Espressif engineer, if the problem really exists and the chip doesn't work at good power after some issues, maybe you can correct it in your bootloader firmware level? 
It is not normal that some condition exists, when the chip stops working at all, even when power is excellent. The chip must work well when power is good and doesn't work when power is bad.

In my opinion the simplest solution for such situation is to make a software watchdog in esp32 bootloader. It should reset the chip after some times of repeating the

Code: Select all

 rst:0x3 (RTC_SW_SYS_RST),boot:0x0 (USB_BOOT)

or another repeating message.

For you this is a simple task, which can noticeably improve stability and significantly reduce the number of failures of your chips. 
Maybe you can give the source code of this bootloader and describe the way to download it?
I am sure the community will be very appreciative of such possibility.

[softwaretom]

Hi everyone,
Is there any software solution for this type of infinite loop?
We have 360 devices manufactured, and some of them are starting to get stuck in an infinite loop with the following log:
rst:0x3 (RTC_SW_SYS_RST),boot:0xc (SPI_FAST_FLASH_BOOT)
Saved PC:0x40048b82
Only a complete battery disconnection from the board and reconnection helps to resolve the issue temporarily.

We have both the watchdog and brownout detection enabled.

Thank you in advance for any advice or guidance!

Tomas