From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-qt1-x82e.google.com ([2607:f8b0:4864:20::82e]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1itVIy-0007Jh-Qx for barebox@lists.infradead.org; Mon, 20 Jan 2020 11:33:22 +0000 Received: by mail-qt1-x82e.google.com with SMTP id c24so16568375qtp.5 for ; Mon, 20 Jan 2020 03:33:16 -0800 (PST) MIME-Version: 1.0 From: Frederick Gotham Date: Mon, 20 Jan 2020 11:33:13 +0000 Message-ID: List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: cauldwell.thomas@gmail.com Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: Issue CPU instructions to start watchdog? To: barebox@lists.infradead.org I'm developing an embedded Linux device, and I'm using Barebox as a part of Buildroot. The CPU is x64 with 4 cores, and it has an Intel TCO watchdog timer. The exact processor I'm using is the Intel Silver N5000, and the datasheet for it says: "TCO_TMR is the watchdog timer provided by the ACPI block. It is used by an OS monitor for OS crashes." When I boot up Barebox, it does not have the file "/dev/watchdog". I've tried a few different things but I just simply can't get Barebox to recognise the Intel watchdog timer. Ideally I would like to have the watchdog timer start running at Power On, however my current BIOS hasn't got any watchdog settings, and so until I get a new BIOS (which might never happen), I have to start the watchdog timer from within Barebox in order to get the device to reboot if the Linux kernel freezes while it's loading. At this stage I think I might actually have to write assembler to issue instructions to the CPU to start the Watchdog timer. I have looked this up and it's definitely not straight-forward, e.g. interfacing with the ACPI block and its registers... I would be pretty much writing a device driver. Anyone got any ideas? I really need my device to reboot if the Linux kernel freezes while loading. Frederick _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox