From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:48040) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Uhcjv-0003L9-4a for qemu-devel@nongnu.org; Wed, 29 May 2013 05:32:22 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Uhcjl-0002c7-95 for qemu-devel@nongnu.org; Wed, 29 May 2013 05:32:15 -0400 Received: from ozlabs.org ([2402:b800:7003:1:1::1]:48291) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Uhcjk-0002au-T7 for qemu-devel@nongnu.org; Wed, 29 May 2013 05:32:05 -0400 Date: Wed, 29 May 2013 19:31:57 +1000 From: David Gibson Message-ID: <20130529093157.GF5489@boomeroo.fritz.box> References: <9b6a3a52e3f46cfbc1ded9ab56385ec045e46705.1369628289.git.peter.crosthwaite@xilinx.com> <20130529081853.GC5489@boomeroo.fritz.box> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="8JPrznbw0YAQ/KXy" Content-Disposition: inline In-Reply-To: Subject: Re: [Qemu-devel] [PATCH v2 1/1] configure: dtc: Probe for libfdt_env.h List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Maydell Cc: pbonzini@redhat.com, peter.crosthwaite@xilinx.com, qemu-devel@nongnu.org, edgar.iglesias@gmail.com --8JPrznbw0YAQ/KXy Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, May 29, 2013 at 10:14:19AM +0100, Peter Maydell wrote: > On 29 May 2013 09:18, David Gibson wrote: > > On Mon, May 27, 2013 at 02:20:57PM +1000, peter.crosthwaite@xilinx.com = wrote: > >> From: Peter Crosthwaite > >> Currently QEMU provides a local clone of the file libfdt_env.h in > >> /include. This file is supposed to come with the libfdt package and is > > > > So, this patch might be the right thing anyway, but the statement > > above is entirely false. libfdt_env.h is explicitly intended to be > > supplied by the build environment embedding libfdt. The version > > provided in the libfdt package is a example version which will do > > (although it might not be ideal) for userspace builds with a > > sufficiently normal C library. >=20 > (You're upstream for libfdt, yes?) More or less, yes. > If you're expecting that build environments provide a libfdt_env.h > then shouldn't you be avoiding making breaking changes to libfdt > that require build environments to fix their libfdt_env.h? > This came up in the first place because we no longer build with > new libfdt... I missed that discussion, what exactly was the problem? It's possible we did something silly in libfdt. Then again, although we certainly want to keep changes which require updates to libfdt_env.h rare, I'm not going to rule out extensions to libfdt which add new (minor) external dependencies, and therefore changes to libfdt_env.h. That said, I did put my correction a bit too strongly. While libfdt_env.h is notionally always provided by the surrounding environment, if the packaged one works for your environment, it's probably a good idea to use it. That should be the case for almost all userspace builds - providing a custom libfdt_env.h is more intended for kernels, bootloaders and other build environments with peculiar constraints. > (conversely, if we're supposed to update our libfdt_env.h as we > go along, is there a changelog that documents needed changes > and what needs to be present for compatibility with older versions > of libfdt?) Heh. There definitely should be a document covering what needs to be provided by libfdt_env.h, but alas there is not. --=20 David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson --8JPrznbw0YAQ/KXy Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iEYEARECAAYFAlGlyw0ACgkQaILKxv3ab8a8OACgkPC5Ikiz4kl9H/QWjZy52wUm EyAAn0LLAg9+1F+MnRpMne8L+n7HTpKC =oxsV -----END PGP SIGNATURE----- --8JPrznbw0YAQ/KXy--