Beaglebone black watchdog...is it hardware? Because it doesn't work when I use halt -f.

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1

Currently trying to get the watchdog on the BBB working.

It works fine when the code stops running, but from what I gather, it is an embedded circuit, so it should work if the processor freezes up.

Am I wrong here? Do I need to buy an external watchdog for when the BBB completely locks up?

I run the watchdog, and then run a halt -f command. The BBB freezes up, doesn’t perform a shutdown though.

The watchdog never reboots the BBB.

I’ve tried playing with the NOWAYOUT setting in the /etc/watchdog.conf file but that didn’t seem to work.

Thanks for any help,

Daniel

2

See if this helps. Gives a bit of an explanation, and example code in what seems like maybe python ?

http://inspire.logicsupply.com/2014/08/beaglebone-using-watchdog-timer.html

3

By the way, the command example he gives requires the user to be root. SO I’m assuming the code, or other code that uses the watchdog requires root user privileges too. By default. Perhaps another user could be part of the required group for /dev/watchdog, but not sure how that works . . .

4

Were you able to get any clarification here? I’m running into the same issue but it seems this is still an open question.

5

if the processor locks up the only to do a full reset is to pull
PMIC_PGOOD low which pulls PORZ low which will cold reset the IC.
the internal WDT only does warm resets which will do no good unless
something in the processor is paying
attention to it.

so for full bullet proof operation yes you need an external WDT.