From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from vs81.iboxed.net ([185.82.85.146]) by bombadil.infradead.org with esmtps (Exim 4.85_2 #1 (Red Hat Linux)) id 1cDqtI-0006uN-Te for barebox@lists.infradead.org; Mon, 05 Dec 2016 10:53:02 +0000 Date: Mon, 5 Dec 2016 11:49:24 +0100 (CET) From: Alexander Kurz In-Reply-To: <20161205082919.vbqtltxd43jw4qvj@pengutronix.de> Message-ID: References: <1480618503-11376-1-git-send-email-akurz@blala.de> <1480671998.17003.37.camel@pengutronix.de> <20161205082919.vbqtltxd43jw4qvj@pengutronix.de> MIME-Version: 1.0 Content-Type: MULTIPART/MIXED; BOUNDARY="-598520180-1263828847-1480934964=:13323" List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: Re: [PATCH] bootm: dont use internal oftree fallback by default To: =?ISO-8859-15?Q?Uwe_Kleine-K=F6nig?= Cc: barebox@lists.infradead.org This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. ---598520180-1263828847-1480934964=:13323 Content-Type: TEXT/PLAIN; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable On Mon, 5 Dec 2016, Uwe Kleine-K=F6nig wrote: > On Fri, Dec 02, 2016 at 10:46:38AM +0100, Lucas Stach wrote: > > Am Donnerstag, den 01.12.2016, 19:55 +0100 schrieb Alexander Kurz: > > > Booting via bootm offers several methods to load oftree data. When no > > > dedicated oftree image is provided, barebox checks for the presence of > > > its own internal oftree, assuming it as a good choice for boot. > > >=20 > > > This fallback method breaks the usecase when a modern OF-based barebox > > > is used to boot a legacy ATAG dependent non OF based vendor provided = kernel > > > (e.g. ATAGs will be switched off). > > > Unfortunately those kernels are being still actively shipped today. > > >=20 > > > Change barebox according to the principle of least surprise: when no > > > oftree data is proactively configured, then perform a non-oftree boot. > > > Make the fallback-use of the barebox internal oftree an opt-in featur= e. > > >=20 > > > Note: this will break boards where the boot process relied on this fe= ature, > > > e.g.: oftree based barebox plus oftree based kernel without an explic= it > > > given dts. For those boards global.bootm.internal_oftree_fallback=3D1= should > > > be set. > > >=20 > > The least surprise on a modern oftree based kernel is that the firmware > > (Barebox) provides the DT, if there isn't an explicit override. > >=20 > > So NACK on the patch in it's current form. If you have a board where you > > know that the kernel doesn't play along, you may reverse this patch so > > that you can set global.bootm.no_internal_oftree=3D1 in your board code. >=20 > Ack for the NAck. And AFAIK you can already today just do >=20 > oftree -f >=20 > before calling bootm to discard the internal dtb which should make > barebox fall back to ATAG. After flushing the DT, ATAGs get passed during boot, this makes my patch obsolete now. Thank you very much, Alexander >=20 > Best regards > Uwe >=20 > --=20 > Pengutronix e.K. | Uwe Kleine-K=F6nig = | > Industrial Linux Solutions | http://www.pengutronix.de/ | >=20 ---598520180-1263828847-1480934964=:13323 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox ---598520180-1263828847-1480934964=:13323--