Example watchdog
This is a guide to the watchdog C example project included in the EMAC OE SDK.
A Watchdog Timer (WDT) is a hardware circuit that can reset the computer system in case of a software fault. This is an example test for the Linux watchdog API.
The watchdog project builds one executable: watchdog-test.
Contents
Opening, Building and Uploading the Project Files
stubbooo
Usage and Behavior
watchdog
Hardware Requirements
fof ofoo
watchdog Usage
./watchdog-test [-det]
- d Disable the watchdog card.
- -e" to enable the watchdog card
- -s set the watchdog timeout
Usage Example
root@som9g20:/tmp# ./watchdog-test
Watchdog Ticking Away!
We have activated the watchdog and it's counting down to computer reset - or rather it would be if we didn't keep resetting it's timer. That's the LED on the SoM blinking at about 1 Hz. Every second watchdog-test is sending an IOCTL to the watchdog driver, which in turn ticks the watchdog to reset its internal timer so it doesn't time-out and trigger a system reset.
Now we will stop interrupting the watchdog and let it trigger a computer reset. Hit CTRL-C.
...and the system resets.
