From owner-freebsd-hackers@FreeBSD.ORG Wed Jul 10 21:50:52 2013 Return-Path: Delivered-To: hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by hub.freebsd.org (Postfix) with ESMTP id C8469F96 for ; Wed, 10 Jul 2013 21:50:52 +0000 (UTC) (envelope-from jkh@mail.turbofuzz.com) Received: from mail.crittercasa.com (mail.turbofuzz.com [208.87.221.144]) by mx1.freebsd.org (Postfix) with ESMTP id B6C981D9B for ; Wed, 10 Jul 2013 21:50:52 +0000 (UTC) Received: from [10.20.30.11] (75-101-82-48.static.sonic.net [75.101.82.48]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (No client certificate requested) by mail.crittercasa.com (Postfix) with ESMTPS id D8B88164893; Wed, 10 Jul 2013 14:47:58 -0700 (PDT) Content-Type: text/plain; charset=iso-8859-1 Mime-Version: 1.0 (Mac OS X Mail 7.0 \(1784.1\)) Subject: Re: Kernel dumps [was Re: possible changes from Panzura] From: Jordan Hubbard In-Reply-To: Date: Wed, 10 Jul 2013 14:50:19 -0700 Content-Transfer-Encoding: quoted-printable Message-Id: <3592BFB7-0663-4381-AFF5-C7DE0AE16858@mail.turbofuzz.com> References: <9890DFF1-892A-4DCA-9E33-B70681154F43@mail.turbofuzz.com> To: asomers@gmail.com X-Mailer: Apple Mail (2.1784.1) Cc: hackers@freebsd.org, Julian Elischer X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 10 Jul 2013 21:50:52 -0000 On Jul 10, 2013, at 1:04 PM, asomers@gmail.com wrote: > I don't doubt that it would be useful to have an emergency network > stack. But have you ever looked into debugging over firewire? Absolutely. In fact, before the advent of remote network debugging, FW = was totally the debugging method of choice since firewire target DMA = lets you do all kinds of useful things (as well as a few things that = simply scare the security guys to death ;-) ). My point was more that actually being able to debug a machine over the = network is such a step up in terms of convenience/awesomeness that if = anyone is thinking of putting any time and attention into this area at = all, that's definitely the target to go for. Looking at = http://www.opensource.apple.com/tarballs/xnu/xnu-2050.22.13.tar.gz = there's even reasonable "documentation" on the kernel debugging protocol = in xnu/osfmk/kdp. Folks could do worse than try to clone it. The gdb = debugger macros in support of it are also in xnu/kgmacros. None of it = is going to be 'drop in' for FreeBSD by any stretch of the imagination, = but it's always easier to get to a destination when you have a map. :-) = Anyone with a Mac can also ""nvram boot-args=3D"debug=3D0x144"" and = test-drive it around, just to see how it works in actual practice. See = also: = https://developer.apple.com/library/mac/#documentation/Darwin/Conceptual/K= EXTConcept/KEXTConceptDebugger/debug_tutorial.html - Jordan