From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161357AbcFBPX3 (ORCPT ); Thu, 2 Jun 2016 11:23:29 -0400 Received: from mout.kundenserver.de ([217.72.192.74]:58155 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161276AbcFBPXZ (ORCPT ); Thu, 2 Jun 2016 11:23:25 -0400 From: Arnd Bergmann To: Gerd Hoffmann Cc: linux-arm-kernel@lists.infradead.org, Mark Rutland , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , Pawel Moll , Ian Campbell , Russell King , open list , Eric Anholt , Rob Herring , linux-rpi-kernel@lists.infradead.org, Kumar Gala Subject: Re: [PATCH 09/32] bcm2837-rpi-3-b.dts for 32bit arm Date: Thu, 02 Jun 2016 17:23:22 +0200 Message-ID: <71381147.fkGgHS4v7X@wuerfel> User-Agent: KMail/5.1.3 (Linux/4.4.0-22-generic; KDE/5.18.0; x86_64; ; ) In-Reply-To: <1464880291.24775.111.camel@redhat.com> References: <1464817421-8519-1-git-send-email-kraxel@redhat.com> <4795604.XAe8xnhung@wuerfel> <1464880291.24775.111.camel@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-Provags-ID: V03:K0:CWI7raCvIXg0pqYhb1zk4T2Q68Dm0PchB9meKwLrn60JZ/OSbaP KTjp6uS3VUacHtkUUSII0/vrN0dsW9POe+gR3pPWMUBLWXrnQvwgltxCrI4RmhVck99p9OQ 0eIzWADiHU/E67VO/tQtP0x7PtCjiJAlK53r1MG4Xe03gQR5oHFE4YyXFU0df/yusDLcYeJ tfEZ6s5UvOyy3mxIVEyfg== X-UI-Out-Filterresults: notjunk:1;V01:K0:mL/uvJFaHcQ=:fl3aiclRmb1hTa0b9Ulhqn TvpxMOntQ4e5YSxxr5AAwMIGv3aAW5k6SIEvWCB1Z8ttxS6U1y5xHnD0Rhnh5n9p3SgbBQxME vzciO2MFyuIEIfZ4DG3/TRIg4pfOkRdRCAxTYEqLJFqi6sx7WZlR9bkge3WzbsloVT1Zb3gTm 6CG5Yo5qZnzUTN1+2JZ3n1c1sI2vpPmB0wASRPW8g3VQDi5Io9byie8bwxhn+5JYUUxs4LAyT m918X1lmq4Jkxzun7n6ol38Ph5eG/buTI4RIp/QiDNuAe/GST/h3Nw4y1YO8GCorU6dP+aLV1 Qub6pabRUzKwd2e5J2VvnAeRiE2vyhWpl5CvFds8szy/tq2ZGYcQr1AXiOXmaB9AzONsnUfQS JxyFYHPVg90QQaMX5Do0D9fXyenWttrAyV9IS++1P5OnxxwvuNjQUOKbSrkOYU828zluIxA+Z 5c8MjyNWoYj9babIAk+d2Sp1Ubt/BQYL4wXfgXRD5gdvHHd7mly2I7v2ejqoPOx66BRtFxiOt NkEntf8DOD1+vOJBtkLKCPzJDV+gXssZsl0yF67jHp72H8wHwKfFsA436oxiwuXX+AFFtzl3r BoJGsTl6yAL1MhDc9YMFJPNz+BsZrhPRqPebM8Q0EfA/X53Q7ep5D7GrvhFCEyif/P2knQBUE ovG+1OsFoYSDwoChvSbAc9xzGMlamNHhaWfHQ3A7W8nX/idvzLBNwGS0kqtnJRuQRFTG5BqpK NIIIsPW/l+t2GmJk Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thursday, June 2, 2016 5:11:31 PM CEST Gerd Hoffmann wrote: > > > > > > Reference to ../../../arm64/boot/dts/broadcom/bcm2837-rpi-3-b.dts > > > > > directly in the Makefile? > > Actually tried that, and to my surprise this worked fine for both "make > dtbs" and "make dtbs_install". > > So we should just do that I guess ... Right. > > > Yes, in theory. No, in practice. As far I know the rpi3 is the only > > > 64bit soc where a almost identical 32bit version exists, so running > > > 32bit kernels on a 64bit processor actually happens in practice and I > > > expect this to continue. If you want create sdcard images which run on > > > any rpi variant this is pretty much the only reasonable way to do it. > > > > I think the Allwinner A64 and the Samsung s5p6818 are other examples > > for this, where the initial run of boards all run 32-bit kernels > > for much of the same reasons. If users want to run a 32-bit distro > > on rpi-3 and on e.g. orange-pi, I don't see why they wouldn't also run > > the same binary on A64. > > ... and others can join the party on a case-by-case basis. > > I still expect for the majority of arm64 boards it is not very useful, > so I don't think we should build all of them unconditionally. Well, they are still controlled by Kconfig symbols. Some of them are shared between arm and arm64 and you would just get all dtbs in that case, while other symbols are specific to one of the two. Just for fun, which machines do we actually get if we decide to just enter the arch/arm64/boot/dts/ directory in an allmodconfig build? Arnd