linux-kernel - Re: Questions about Watch Dog Timer under Linux.

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Sat, 12 Dec 2009 11:46:04 +0800
From:	Cypher Wu <cypher.w@...il.com>
To:	Mark Brown <broonie@...nsource.wolfsonmicro.com>
Cc:	linux-kernel@...r.kernel.org
Subject: Re: Questions about Watch Dog Timer under Linux.

On Fri, Dec 11, 2009 at 6:21 PM, Mark Brown
<broonie@...nsource.wolfsonmicro.com> wrote:
> On Fri, Dec 11, 2009 at 04:27:55PM +0800, Cypher Wu wrote:
>
> Please reply in-line to e-mails, it makes the conversation much easier
> to follow.
>
>> It seems WATCHDOG_NOWAYOUT is a software mechanism? If it is defined
>> as 1 then the WDT can't be stopped if it has been started whether bye
>> closing the device file or writing the magic character 'V'.
>
> Yes, it's a kernel build time configurable option to select this
> behaviour.  In effect all you'd be doing is making a driver which turns
> it on all the time.
>

My point is not making a driver which turns WDT on all the time, but
how to work with a WDT hardware which will startup to working just
after power on and the only interface it provides is clearing the
timer. This type of WDT is widely used in our embedded systems and we
usually install a callback in timer interrupt to clearing WD before
BSP starting the RTOS kernel, and then starting a task to clear WD and
uninstall the callback.
I'm wonder when cope with that type of WD, is there any framework
already in the Linux kernel and booter, or I've to modify them by
myself?
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/