Watchdog

The phyCORE-i.MX7 SOM comes equipped with a hardware Watchdog that is accessible through /dev/watchdog. The Watchdog feature is intended to automatically restart the system should it face a critical software or hardware hang up. This guide will walk through the basic setup and verification of the watchdog by manually triggering a Kernel panic to initiate an automatic reboot. 

Step-by-Step Guide

• Ensure that your phyCORE-i.MX7 Development Kit is booted into Linux and that you are logged in as the root user.

• Set the Watchdog's timeout to 10 seconds using the following command:  

  Target (Linux)

  wdctl -s 10

  CODE

• Now manually trigger a Kernel failure: 

  Target (Linux)

  echo c > /proc/sysrq-trigger

  CODE
• You should see the phyCORE-i.MX7 begin to reboot approximately 10 seconds after the end of the Kernel panic.

For a more useful guide on how to enable the WatchDog automatically upon boot, check out Write a Script That Runs Automatically During Boot.