The watchdog is a timer mechanism that starts counting after it is started.
The system or software must communicate with the watchdog periodically, commonly known as "feeding the dog", to reset the timer.
This process is carried out in a loop to confirm the normal operation of the system and software.
If the "feeding the dog" operation is not completed within the specified time, the watchdog will time out and trigger a reset signal, causing the main controller to restart, thereby helping the system to get out of the stuck state.
Watchdog is enabled by default.
For more information, please go to Programming Guide
# View node
ls -l /dev/watchdog
# Write anything (except capital letter ‘V’),
# turn on watchdog --- the dog needs to be fed every 44 seconds
echo A > /dev/watchdog
# Turn on watchdog --- the kernel feeds the dog every 21 seconds
echo V > /dev/watchdog