From owner-freebsd-hackers@freebsd.org Fri Nov 6 19:47:21 2020 Return-Path: Delivered-To: freebsd-hackers@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id E1E41447DE4 for ; Fri, 6 Nov 2020 19:47:21 +0000 (UTC) (envelope-from rpokala@freebsd.org) Received: from smtp.freebsd.org (smtp.freebsd.org [IPv6:2610:1c1:1:606c::24b:4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "smtp.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4CSWBK655Bz4gHL for ; Fri, 6 Nov 2020 19:47:21 +0000 (UTC) (envelope-from rpokala@freebsd.org) Received: from [192.168.1.10] (c-98-207-126-143.hsd1.ca.comcast.net [98.207.126.143]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) (Authenticated sender: rpokala) by smtp.freebsd.org (Postfix) with ESMTPSA id 8198D2EC73 for ; Fri, 6 Nov 2020 19:47:21 +0000 (UTC) (envelope-from rpokala@freebsd.org) User-Agent: Microsoft-MacOutlook/16.42.20101102 Date: Fri, 06 Nov 2020 11:47:16 -0800 Subject: Re: Have trick, not sure where to document... From: Ravi Pokala To: "freebsd-hackers@freebsd.org" Message-ID: <9498D30F-4FDE-40BE-9941-B7C2DBD6E9DA@panasas.com> Thread-Topic: Have trick, not sure where to document... Mime-version: 1.0 Content-type: text/plain; charset="UTF-8" Content-transfer-encoding: 7bit X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 06 Nov 2020 19:47:21 -0000 -----Original Message----- Date: Fri, 6 Nov 2020 12:02:56 +0100 From: Mateusz Piotrowski <0mp@FreeBSD.org> To: Poul-Henning Kamp , hackers@freebsd.org Subject: Re: Have trick, not sure where to document... Message-ID: <6225bae3-0bb4-bd14-51f3-de72eaa4dc98@FreeBSD.org> Content-Type: text/plain; charset=utf-8; format=flowed On 11/6/20 11:23 AM, Poul-Henning Kamp wrote: > This seems like a genuinely useful trick to have in the tool-box > and now I'm trying to find out where in our documentation something > like this belongs ? > > It seems too specialized and with too many sharp edges for the handbook ? > > Wiki/UEFI seems rather historical... > > Suggestions ? > If you can think of a manual page that would be appropriate then it might be nice to but it there. Otherwise, perhaphs the FAQ book (https://www.freebsd.org/doc/en_US.ISO8859-1/books/faq/book.html)? If the system has IPMI, there are ways to configure it such that it will enable the watchdog during POST, then disable it when it hands off to the OS. At which time, of course, the OS can re-enable it. Interestingly, it looks like `ipmitool' does not offer a way to set the BMC watchdog configuration, just report, reset, and disable it. But ipmi(4) can configure things, in concert with `watchdogd'. More importantly, the IPMI specs describe how to set different configurations for different stages of operation: - POST - POST, after timing out the previous POST - OS loading (meaning after POST, before watchdog driver takes over) - OS normal operation (after the watchdog driver is running) It should be possible to teach ipmi(4) how to configure the timer for POST and OS-load, then have `watchdogd' issue those commands as part of shutdown. https://www.intel.com/content/www/us/en/products/docs/servers/ipmi/ipmi-second-gen-interface-spec-v2-rev1-1.html ; section 27. -Ravi (rpokala@)