From owner-svn-src-head@FreeBSD.ORG  Sat Mar 13 19:25:00 2010
Return-Path: <owner-svn-src-head@FreeBSD.ORG>
Delivered-To: svn-src-head@FreeBSD.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id AFE4C106564A;
	Sat, 13 Mar 2010 19:25:00 +0000 (UTC) (envelope-from imp@bsdimp.com)
Received: from harmony.bsdimp.com (bsdimp.com [199.45.160.85])
	by mx1.freebsd.org (Postfix) with ESMTP id 6B1068FC18;
	Sat, 13 Mar 2010 19:25:00 +0000 (UTC)
Received: from localhost (localhost [127.0.0.1])
	by harmony.bsdimp.com (8.14.3/8.14.1) with ESMTP id o2DJJOW5085827;
	Sat, 13 Mar 2010 12:19:24 -0700 (MST) (envelope-from imp@bsdimp.com)
Date: Sat, 13 Mar 2010 12:19:32 -0700 (MST)
Message-Id: <20100313.121932.997044077387131740.imp@bsdimp.com>
To: ed@80386.nl
From: "M. Warner Losh" <imp@bsdimp.com>
In-Reply-To: <20100313170725.GW8200@hoeg.nl>
References: <20100313090844.GV8200@hoeg.nl>
	<20100313.090709.407454645627448944.imp@bsdimp.com>
	<20100313170725.GW8200@hoeg.nl>
X-Mailer: Mew version 6.3 on Emacs 22.3 / Mule 5.0 (SAKAKI)
Mime-Version: 1.0
Content-Type: Text/Plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Cc: unixmania@gmail.com, svn-src-head@FreeBSD.org, svn-src-all@FreeBSD.org,
	src-committers@FreeBSD.org, nwhitehorn@FreeBSD.org
Subject: Re: svn commit: r205014 - in head: . sys/amd64/amd64
 sys/amd64/conf sys/amd64/include sys/amd64/linux32 sys/compat/freebsd32
 sys/compat/ia32 sys/conf sys/fs/procfs sys/ia64/conf sys/ia64/ia64
 sys/ia64/...
X-BeenThere: svn-src-head@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: SVN commit messages for the src tree for head/-current
	<svn-src-head.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/svn-src-head>,
	<mailto:svn-src-head-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/svn-src-head>
List-Post: <mailto:svn-src-head@freebsd.org>
List-Help: <mailto:svn-src-head-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/svn-src-head>,
	<mailto:svn-src-head-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sat, 13 Mar 2010 19:25:00 -0000

In message: <20100313170725.GW8200@hoeg.nl>
            Ed Schouten <ed@80386.nl> writes:
: * M. Warner Losh <imp@bsdimp.com> wrote:
: > that sounds like a good idea.  But it isn't as simple as changing all
: > the COMPAT_FREEBSDX in the .c code.  There's also hooks in the syscall
: > glue generation that would be affected.
: 
: Hmmm... Indeed.
: 
: I thought a bit more about this and I realized it would be better if we
: wouldn't use a FreeBSD major number for this, but the actual
: __FreeBSD_version.

Hmmm, that might be harder.  The problem is that when I want to run a
program from FreeBSD 3.0, I may need an interface that was in 3.0, but
was removed prior to 5.0 shipping.  This means the kernel needs the
COMPAT_FREEBSD4 option right now to work.  So things are kind of
confusing.

Under your plan, which __FreeBSD_version would we use here?

The COMPAT_FREEBSD_BACK_TO=3 would be the right setting here.  This
may pick up a little extra junk, but would be clear to the user what
they are configuring.

Comments?

Warner