From owner-freebsd-hackers@FreeBSD.ORG  Tue Aug  9 21:31:39 2005
Return-Path: <owner-freebsd-hackers@FreeBSD.ORG>
X-Original-To: hackers@freebsd.org
Delivered-To: freebsd-hackers@FreeBSD.ORG
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id B9D7416A41F
	for <hackers@freebsd.org>; Tue,  9 Aug 2005 21:31:39 +0000 (GMT)
	(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 4B5434448D
	for <hackers@freebsd.org>; Tue,  9 Aug 2005 21:31:39 +0000 (GMT)
	(envelope-from dan@dan.emsphone.com)
Received: (from dan@localhost)
	by dan.emsphone.com (8.13.1/8.13.3) id j79LVUYY022367;
	Tue, 9 Aug 2005 16:31:30 -0500 (CDT) (envelope-from dan)
Date: Tue, 9 Aug 2005 16:31:30 -0500
From: Dan Nelson <dnelson@allantgroup.com>
To: "M. Warner Losh" <imp@bsdimp.com>
Message-ID: <20050809213130.GB71687@dan.emsphone.com>
References: <20050809.133734.08360256.imp@bsdimp.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20050809.133734.08360256.imp@bsdimp.com>
X-OS: FreeBSD 5.4-STABLE
X-message-flag: Outlook Error
User-Agent: Mutt/1.5.9i
Cc: hackers@freebsd.org
Subject: Re: Converting libfoo.so for linux to freebsd
X-BeenThere: freebsd-hackers@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Technical Discussions relating to FreeBSD
	<freebsd-hackers.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>, 
	<mailto:freebsd-hackers-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-hackers>
List-Post: <mailto:freebsd-hackers@freebsd.org>
List-Help: <mailto:freebsd-hackers-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>,
	<mailto:freebsd-hackers-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Tue, 09 Aug 2005 21:31:39 -0000

In the last episode (Aug 09), M. Warner Losh said:
> I have recently purcahsed a device that comes with a .so for linux,
> but no sources.  Is there any way one can take an arbitrary linux .so
> which appears to have no dependencies to a FreeBSD .so?  The binary
> code is about 20k or so.

As long as any structs that are passed back and forth have the same
members and alignment, it should work.  This includes struct FILE,
which means if the app tries to use stdio it'll likely crash.

I just compiled a little "hello world" object file on SUSE and linked
it on FreeBSD and it ran (it just calls printf, which is safe since it
doesn't pass a FILE *).

-- 
	Dan Nelson
	dnelson@allantgroup.com