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VAR-SOM-MX6 watchdog

1 Kernel configuration

The internal watchdog is enabled by default in the kernel configuration.

To verify that the i.MX watchdog driver (CONFIG_IMX2_WDT) is enabled in your kernel configuration:

  • In menuconfig: Device Drivers -> Watchdog Timer Support -> <*> IMX2+ Watchdog

2 Using a command line

Watchdog will be activated as soon as /dev/watchdog is opened and will reboot unless the watchdog is pinged within timeout (128 is the preconfigured value).

# echo "1" > /dev/watchdog0

Within 128 seconds the board will reset.

3 Compile a watchdog test application

There's a watchdog testing utility C code example in the kernel source tree: tools/testing/selftests/watchdog-test.c (in older kernels: Documentation/watchdog/src/watchdog-test.c).

To cross compile it:
Install the toolchain and source the environment setup script, by following the Yocto Toolchain installation guide, then run:

$ $CC ./tools/testing/selftests/watchdog-test.c -o ./watchdog-test