From mboxrd@z Thu Jan 1 00:00:00 1970 From: ludo@gnu.org (Ludovic =?utf-8?Q?Court=C3=A8s?=) Subject: Re: Preliminary 'wip-armhf' branch pushed Date: Sat, 03 Jan 2015 20:07:32 +0100 Message-ID: <8761cnbs3v.fsf@gnu.org> References: <87lhln7mlk.fsf@netris.org> <20141231174719.GA8456@intra> <878uhn7he5.fsf@netris.org> <87sifsgb8h.fsf@gnu.org> <87vbkoygyp.fsf@yeeloong.lan> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Return-path: Received: from eggs.gnu.org ([2001:4830:134:3::10]:50563) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Y7U2x-0001xf-Eq for guix-devel@gnu.org; Sat, 03 Jan 2015 14:07:36 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Y7U2t-0002vN-Eh for guix-devel@gnu.org; Sat, 03 Jan 2015 14:07:35 -0500 Received: from hera.aquilenet.fr ([2a01:474::1]:53708) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Y7U2t-0002ug-7V for guix-devel@gnu.org; Sat, 03 Jan 2015 14:07:31 -0500 In-Reply-To: <87vbkoygyp.fsf@yeeloong.lan> (Mark H. Weaver's message of "Fri, 02 Jan 2015 17:07:26 -0500") List-Id: "Development of GNU Guix and the GNU System distribution." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: guix-devel-bounces+gcggd-guix-devel=m.gmane.org@gnu.org Sender: guix-devel-bounces+gcggd-guix-devel=m.gmane.org@gnu.org To: Mark H Weaver Cc: guix-devel@gnu.org Mark H Weaver skribis: > ludo@gnu.org (Ludovic Court=C3=A8s) writes: > >> Mark H Weaver skribis: >> >>> I don't think we need a 'system' for every combination of flags. We >>> should just find a small number of "sweet spots" in the tradeoff between >>> minimum requirements vs performance. IMO, for 32-bit ARM, two systems >>> should be enough: armhf, and maybe another one (armel?) that works on >>> lower-end processors. >> >> It=E2=80=99s not even clear that =E2=80=9Chf=E2=80=9D needs to be part o= f the system name. > > I think it needs to be part of the system name, because on ARM these are > two incompatible ABIs. Among other things, the hard-float ABI passes > floating point arguments in registers. > >> In theory, the bootstrap tarballs could be soft-float, which means they >> would run everywhere, and from there users could choose what >> --with-float and --with-fpu flags to use. > > A single GCC can generate code for both ABIs, but each ABI uses its own > dynamic linker. If we did as you suggest, we'd need two separate > bootstrap glibc's, and improve the dynamic-linker-name patching code in > our gcc package to rewrite the two dynamic linker names separately, etc. Very good points, I had overlooked this. Thanks, Ludo=E2=80=99.