Difference between revisions of "Watchdog"

Revision as of 16:40, 28 September 2010

On this page, you will find usefull informations to configure and use the Watchdog of your APF boards.

Configuration

First be sure to have the Watchdog Linux driver activated:

 $ make linux26-menuconfig

[*] Watchdog Timer Support  --->
    <M>   IMX Watchdog

 $ make

Installation

If you choose to include driver in Linux kernel then reflash your kernel image.
Else either copy the generated module through NFS to your board or reflash your rootfs.

Usage

Load the module (here with a 5 secs timeout):

 # modprobe imx-wdt timeout=5

You can now access the watchdog through /dev/watchdog device file:

• to activate it, just open the file, then you will have to write to this file regularly or your system will be reseted.

Note: On APF27 watchdog is then unstoppable and will reset your board if you don't service it

• there is a small daemon useful to periodically trig the watchdog (here every 3 seconds):

 # watchdog -t 3 /dev/watchdog

if your system hangs, the daemon can't trig the watchdog and your system is reseted. To quickly check that you can do a:

 # killall watchdog

Links