From owner-freebsd-current@FreeBSD.ORG  Fri Feb 23 06:20:41 2007
Return-Path: <owner-freebsd-current@FreeBSD.ORG>
X-Original-To: freebsd-current@freebsd.org
Delivered-To: freebsd-current@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52])
	by hub.freebsd.org (Postfix) with ESMTP id 03A1E16A401
	for <freebsd-current@freebsd.org>; Fri, 23 Feb 2007 06:20:41 +0000 (UTC)
	(envelope-from dan@dan.emsphone.com)
Received: from dan.emsphone.com (dan.emsphone.com [199.67.51.101])
	by mx1.freebsd.org (Postfix) with ESMTP id B7F8713C461
	for <freebsd-current@freebsd.org>; Fri, 23 Feb 2007 06:20:40 +0000 (UTC)
	(envelope-from dan@dan.emsphone.com)
Received: from dan.emsphone.com (dan@localhost [127.0.0.1])
	by dan.emsphone.com (8.14.0/8.13.8) with ESMTP id l1N5hLgE046464
	(version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO)
	for <freebsd-current@freebsd.org>; Thu, 22 Feb 2007 23:43:22 -0600 (CST)
	(envelope-from dan@dan.emsphone.com)
Received: (from dan@localhost)
	by dan.emsphone.com (8.14.0/8.14.0/Submit) id l1N5hLUI046459;
	Thu, 22 Feb 2007 23:43:21 -0600 (CST) (envelope-from dan)
Date: Thu, 22 Feb 2007 23:43:21 -0600
From: Dan Nelson <dnelson@allantgroup.com>
To: Giorgos Keramidas <keramida@ceid.upatras.gr>
Message-ID: <20070223054321.GB43770@dan.emsphone.com>
References: <76EBE649FB0E0E4DA883B5840459059F143A182705@AA-EXMSG-C412.southpacific.corp.microsoft.com>
	<20070223010358.GA4946@kobe.laptop>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20070223010358.GA4946@kobe.laptop>
X-OS: FreeBSD 6.2-STABLE
User-Agent: Mutt/1.5.13 (2006-08-11)
Cc: Mayank Kumar <mayank@microsoft.com>, freebsd-current@freebsd.org
Subject: Re: what does _eprol mean and how is it compututed
X-BeenThere: freebsd-current@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Discussions about the use of FreeBSD-current
	<freebsd-current.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>, 
	<mailto:freebsd-current-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-current>
List-Post: <mailto:freebsd-current@freebsd.org>
List-Help: <mailto:freebsd-current-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>,
	<mailto:freebsd-current-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Fri, 23 Feb 2007 06:20:41 -0000

In the last episode (Feb 23), Giorgos Keramidas said:
> On 2007-02-22 04:20, Mayank Kumar <mayank@microsoft.com> wrote:
> > While calling monstartup in crt0.c, _eprol and _etext are passed to
> > monstartup.  _etext means end of segment, what does _eprol mean and
> > how is it computed
> 
> Are you sure you are talking about FreeBSD?
> 
>   build@kobe:/home/build/src$ egrep -r -e '_eprol|_etext' *
>   build@kobe:/home/build/src$
> 
> I don't see any reference to '_eprol' or '_etext' in our source tree,
> and 'monstartup' doesn't really ring any bells.

It's actually "eprol" and "etext", and the source file is crt1.c,
located at /usr/src/lib/csu/<arch>/crt1.c .  The monstartup function
has a manpage that describes its arguments.  eprol is declared via some
__asm__() code in crt1.c to ensure that it's the first symbol in
gcrt1.o's text segment, which ensures that it's the first symbol in a
program's text segment (since gcrt1.o is the first thing linked into a
profiled binary).

-- 
	Dan Nelson
	dnelson@allantgroup.com