Message-ID: <4B1FDDE2.1090507@draigBrady.com>
Date: Wed, 09 Dec 2009 17:26:58 +0000
From: =?ISO-8859-1?Q?P=E1draig_Brady?= <P@draigBrady.com>
User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1.5) Gecko/20091204 Thunderbird/3.0
MIME-Version: 1.0
To: Cypher Wu <cypher.w@gmail.com>
CC: linux-kernel@vger.kernel.org
Subject: Re: Questions about Watch Dog Timer under Linux.
References: <f9f38a550912090647q5af6cb14w84ea8d9223d82bd9@mail.gmail.com>
In-Reply-To: <f9f38a550912090647q5af6cb14w84ea8d9223d82bd9@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 999
Lines: 26

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,
P?draig.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/