Re: Questions about Watch Dog Timer under Linux.

From: Pádraig Brady
Date: Wed Dec 09 2009 - 12:27:56 EST


On 09/12/09 14:47, Cypher Wu wrote:
I'm used to work on embedded systems, the Watch Dog Timer in our
products is usually a seperate chip on the board wich will start to
work after power reset and will time out in 2 seconds. The system has
to start dog clearing from the very beginning and there have no way to
disable WDT.

wow 2 seconds :(

It's easy to patch grub stage 1 to pat the watchdog.
I was even able to get support for the complicated iTCO intel
watchdogs in there, though your watchdog may be much simpler.

Then when the kernel started it patted the watchdog as normal.

Note I did this to support robust remote upgrade (as the boot
loader wasn't touched on upgrade), rather than to support a
very short timeout.

cheers,
Pádraig.
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