From owner-freebsd-arch@FreeBSD.ORG  Wed Jan  4 01:32:43 2012
Return-Path: <owner-freebsd-arch@FreeBSD.ORG>
Delivered-To: freebsd-arch@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id C3208106566B;
	Wed,  4 Jan 2012 01:32:43 +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 616798FC0A;
	Wed,  4 Jan 2012 01:32:43 +0000 (UTC)
Received: from 63.imp.bsdimp.com (63.imp.bsdimp.com [10.0.0.63])
	(authenticated bits=0)
	by harmony.bsdimp.com (8.14.4/8.14.3) with ESMTP id q041VBGr013707
	(version=TLSv1/SSLv3 cipher=DHE-DSS-AES128-SHA bits=128 verify=NO);
	Tue, 3 Jan 2012 18:31:12 -0700 (MST) (envelope-from imp@bsdimp.com)
Mime-Version: 1.0 (Apple Message framework v1084)
Content-Type: text/plain; charset=us-ascii
From: Warner Losh <imp@bsdimp.com>
In-Reply-To: <CAJ-Vmo=quF5oDs7WFx01BDXy2nUHhEWvsWncLxYyzKxq36K5JQ@mail.gmail.com>
Date: Tue, 3 Jan 2012 18:31:11 -0700
Content-Transfer-Encoding: quoted-printable
Message-Id: <5B845928-5DDC-4DB8-BFD5-1A0599D261EC@bsdimp.com>
References: <CAJ-Vmomk4JTnZ0avRqdte9Th5F7G7x9eWTcwcd+T4HrcE0Mgxw@mail.gmail.com>
	<15285562-E9BA-431B-A2C1-D0547DFB2663@bsdimp.com>
	<201201030924.44493.jhb@freebsd.org>
	<CAJ-VmondtfzqRhD5nFZuHYJOc91sKM4BKhkVZsq0w4bgtDTFvw@mail.gmail.com>
	<B25F6CF4-6FBF-4E47-8832-AD4830E61728@bsdimp.com>
	<CAJ-VmonfMnMMmK=zzmaE=u8uRT_yxK06WP4+cVzGfBdSaXAtqQ@mail.gmail.com>
	<EBBFC2E5-034E-42EA-9D95-69454832470D@bsdimp.com>
	<CAJ-Vmo=quF5oDs7WFx01BDXy2nUHhEWvsWncLxYyzKxq36K5JQ@mail.gmail.com>
To: Adrian Chadd <adrian@freebsd.org>
X-Mailer: Apple Mail (2.1084)
X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.0.1
	(harmony.bsdimp.com [10.0.0.6]);
	Tue, 03 Jan 2012 18:31:12 -0700 (MST)
Cc: freebsd-arch@freebsd.org
Subject: Re: Request for help: how do teach module building about kernel
	options?
X-BeenThere: freebsd-arch@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Discussion related to FreeBSD architecture <freebsd-arch.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-arch>,
	<mailto:freebsd-arch-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-arch>
List-Post: <mailto:freebsd-arch@freebsd.org>
List-Help: <mailto:freebsd-arch-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-arch>,
	<mailto:freebsd-arch-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Wed, 04 Jan 2012 01:32:43 -0000


On Jan 3, 2012, at 5:12 PM, Adrian Chadd wrote:

> On 3 January 2012 15:31, Warner Losh <imp@bsdimp.com> wrote:
>=20
>> Please find enclosed a proposed patch.  This will not build, of =
course, since there's no file in the tree mesh_baby.c, so if you have =
IEEE80211_SUPPORT_MESH defined, it won't work.  It keys off the actual =
define.
>>=20
>> It even works with devices (which define DEV_xxx), but only if you =
have it in the options file like isa (eg, you need to tell config to =
generate it).
>>=20
>> Comments?
>=20
> I don't strictly need the SRCS line just yet - I can wrap it up in an
> if: (not correct make fu, but you get the idea):
>=20
> .if (KERNOPT_IEEE80211_SUPPORT_MESH =3D=3D 1)
> SRCS+=3D ieee80211_mesh.c
> .endif
>=20
> .if (KERNOPT_IEEE80211_SUPPORT_TDMA =3D=3D 1)
> SRCS+=3D ieee80211_tdma.c
> .endif

The problem with this method is the chicken/egg problem.  These defines =
aren't defined until after kmod.mk has been included.  But the kmod.mk =
files depend, in some places, on having a full list.  The =
SRCS_IEE80211_SUPPORT_MESH solves this problem nicely.

> What do you mean about DEV_xxx? Can you give me an example to look at
> in the sys directory?

isa.  Look at sys/conf/options* to see what I'm talking about.

Warner=