From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gdb-return-22613-listarch-gdb=sources.redhat.com@sources.redhat.com>
Received: (qmail 1872 invoked by alias); 22 Sep 2005 04:10:13 -0000
Mailing-List: contact gdb-help@sources.redhat.com; run by ezmlm
Precedence: bulk
List-Subscribe: <mailto:gdb-subscribe@sources.redhat.com>
List-Archive: <http://sources.redhat.com/ml/gdb/>
List-Post: <mailto:gdb@sources.redhat.com>
List-Help: <mailto:gdb-help@sources.redhat.com>, <http://sources.redhat.com/ml/#faqs>
Sender: gdb-owner@sources.redhat.com
Received: (qmail 1809 invoked by uid 22791); 22 Sep 2005 04:10:03 -0000
Received: from sa8169016.temp.wsu.edu (HELO tara.shadowpimps.net) (134.121.169.16)
    by sourceware.org (qpsmtpd/0.30-dev) with ESMTP; Thu, 22 Sep 2005 04:10:03 +0000
Received: from tara (localhost.localdomain [127.0.0.1])
	by tara.shadowpimps.net (Postfix) with ESMTP id C87A61C3AC6
	for <gdb@sources.redhat.com>; Wed, 21 Sep 2005 21:10:01 -0700 (PDT)
Date: Thu, 22 Sep 2005 04:10:00 -0000
From: Scott Robinson <scott_gdb@scott.tranzoa.net>
To: gdb@sources.redhat.com
Subject: i8086 debugging issues.
Message-ID: <20050922041001.GA11595@localhost.localdomain>
Mime-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha1;
	protocol="application/pgp-signature"; boundary="liOOAslEiF7prFVr"
Content-Disposition: inline
User-Agent: Mutt/1.5.6+20040907i
X-SW-Source: 2005-09/txt/msg00168.txt.bz2


--liOOAslEiF7prFVr
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable
Content-length: 587

I am attempting to debug i8086 (16-bit) code with gdb, but am running
into a problem. This problem occurs with the gdb remotes in both bochs
and qemu.

My issue is the program counter. Specifically, $pc is mapped to $eip -
which isn't strictly valid in 16-bit mode. To obtain information about
the actual current $pc, I need to perform the calculation manually.
(($cs << 4) + $eip)

Manually setting $pc causes the system to panic, obviously. :-(

In short, is there a way to make gdb cognizent of the segment registers?

Scott.

--=20
http://quadhome.com/            - Personal webpage

--liOOAslEiF7prFVr
Content-Type: application/pgp-signature; name="signature.asc"
Content-Description: Digital signature
Content-Disposition: inline
Content-length: 197

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.5 (GNU/Linux)

iEYEARECAAYFAkMyLpkACgkQ2wcaZqTSGsTewgCgqiycsoElensGogvTwMITabSM
JnAAn1QsEEtH87PCYGYgG2+JO0CI1xoe
=ZviT
-----END PGP SIGNATURE-----

--liOOAslEiF7prFVr--