ASR-A501 Watchdog
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A Watchdog Timer (WDT) is a hardware circuit that can reset the computer system in case of a software fault.
ASR-A501 supports one external watchdog. The default value of timeout is 60 seconds, and it can be set from 1 second to 6527 seconds.
Check Watchdog Device
List watchdog device.
# ls /dev/watchdog /dev/watchdog
Usage
Here are two ways to use watchdog:
1. Use “echo” command Writing any character except the specific magic character 'V' will open the watchdog, and write once before the timeout (60 seconds by default) passes, otherwise the system will reboot.
# echo A > /dev/watchdog
Writing the specific magic character 'V' to stop the watchdog.
# echo V > /dev/watchdog
2. Write a program using “ioctl”See more details in [BSP]/kernel/Documentation/watchdog/watchdog-api.rst