From owner-freebsd-questions@FreeBSD.ORG  Mon Sep  6 10:56:26 2010
Return-Path: <owner-freebsd-questions@FreeBSD.ORG>
Delivered-To: freebsd-questions@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id 3CDBE10656DF
	for <freebsd-questions@freebsd.org>;
	Mon,  6 Sep 2010 10:56:26 +0000 (UTC)
	(envelope-from bruce@cran.org.uk)
Received: from woodbine.london.02.net (woodbine.london.02.net [87.194.255.145])
	by mx1.freebsd.org (Postfix) with ESMTP id CF6338FC13
	for <freebsd-questions@freebsd.org>;
	Mon,  6 Sep 2010 10:56:25 +0000 (UTC)
Received: from unknown (94.193.93.212) by woodbine.london.02.net (8.5.124.10)
	id 4C6543E700AA5463; Mon, 6 Sep 2010 11:56:04 +0100
Date: Mon, 6 Sep 2010 11:55:56 +0100
From: Bruce Cran <bruce@cran.org.uk>
To: vyaaghrah-nix@yahoo.com
Message-ID: <20100906115556.00004758@unknown>
In-Reply-To: <383147.13442.qm@web113909.mail.gq1.yahoo.com>
References: <291410.40127.qm@web113906.mail.gq1.yahoo.com>
	<20100906084913.0000120f@unknown>
	<383147.13442.qm@web113909.mail.gq1.yahoo.com>
X-Mailer: Claws Mail 3.7.4cvs1 (GTK+ 2.16.0; i586-pc-mingw32msvc)
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Cc: freebsd-questions@freebsd.org
Subject: Re: FreeBSD
X-BeenThere: freebsd-questions@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: User questions <freebsd-questions.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-questions>, 
	<mailto:freebsd-questions-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-questions>
List-Post: <mailto:freebsd-questions@freebsd.org>
List-Help: <mailto:freebsd-questions-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-questions>, 
	<mailto:freebsd-questions-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Mon, 06 Sep 2010 10:56:26 -0000

On Mon, 6 Sep 2010 01:50:37 -0700 (PDT)
vyaaghrah-nix@yahoo.com wrote:

> So is it that doadump is the only function which is responsible for
> writing dump in BSD? Or thier are other fucntion which can also do
> this.

doadump() is the main entry-point which triggers dumping. There's also
a textdump system.

> [...] 
> I need docs or links which could help me in understanding the role of
> the doadump, panic and boot.

There's information about how to do kernel debugging at
http://www.freebsd.org/doc/en/books/developers-handbook/kerneldebug.html

But essentially panic() is called in kernel code when something wrong
is detected so the system can stop whatever it's doing. doadump() just
dumps the contents of memory to disk.

-- 
Bruce Cran