I'm seeing more and more often our custom board entering BOOTLOADER SHELL MODE

[unphased]

When this starts to happen, the device is effectively bricked.

How to exit Bootloader Shell Mode?

This may not be a hardware problem. You can try to flash your board with sdkmanager and it shall work.

There is not enough information in this related topic to explain what this mode is, how to prevent it (or trigger it), and what the causes might be for entering the mode.

What I have observed:

I have a board that it began to happen on, and I thought it was “broken” in this way. Reflashing the SoM does not seem to change its behavior.

Then a few weeks later I tried the board again and it worked like normal for a few boots, and went back to going into this mode again.

On another device which was working fine, it did this once, and the next boot attempt, it booted fine.

There seems to be some sort of maybe power-related behavior that triggers entering this mode.

[WayneWWW]

Just want to clarify, are these on devkit or custom board?

[unphased]

custom carrier board with the optional reboot timing circuit as detailed by my colleague in:

Reboot stops working on Jetpack 4.6.2 after update from Jetpack 4.6.1

Hello, This alteration to the device tree allowed us to produce a working reboot on a custom carrier board with the optional reboot timing circuit. After doing an apt update and apt upgrade, the reboot no longer functions. We can go back to 4.6.1 but we want to make sure we’re keeping up with updates. Is there something we need to change to get it to work again? Do we need to revert to the original device tree?

[WayneWWW]

Hello,

Just want to clarify this again. Could you share the boot log when you enter the bootloader shell ?

[unphased]

Thanks for the suggestion and request. I know about the boot log, this is a serial log that I will need to connect somehow to read its output, right? I have never obtained this. I will look into how to do it.