From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 41C4EC4361B for ; Tue, 15 Dec 2020 21:23:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 14C4D22CBB for ; Tue, 15 Dec 2020 21:23:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727966AbgLOVWs (ORCPT ); Tue, 15 Dec 2020 16:22:48 -0500 Received: from mx2.suse.de ([195.135.220.15]:57114 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727896AbgLOVWl (ORCPT ); Tue, 15 Dec 2020 16:22:41 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 695CEAC93; Tue, 15 Dec 2020 21:22:00 +0000 (UTC) Message-ID: <0c29dbdb8c6b042dd1c2dd6f4ed3b113aba19d97.camel@suse.de> Subject: Re: [PATCH 0/6] Expose RPi4'd bootloader configuration From: Nicolas Saenz Julienne To: Rob Herring Cc: Catalin Marinas , Srinivas Kandagatla , devicetree@vger.kernel.org, "maintainer:BROADCOM BCM7XXX ARM ARCHITECTURE" , "moderated list:BROADCOM BCM2835 ARM ARCHITECTURE" , linux-arm-kernel , "linux-kernel@vger.kernel.org" , Russell King , Will Deacon , Tim Gover , Phil Elwell Date: Tue, 15 Dec 2020 22:21:59 +0100 In-Reply-To: References: <20201215155627.2513-1-nsaenzjulienne@suse.de> <20201215184407.GA44849@C02TF0J2HF1T.local> <1e0ad098ca7b1c13dbc6602285b77790b9cd54a1.camel@suse.de> Content-Type: multipart/signed; micalg="pgp-sha256"; protocol="application/pgp-signature"; boundary="=-p4v4j9FxejBEde40K8yJ" User-Agent: Evolution 3.38.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org --=-p4v4j9FxejBEde40K8yJ Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Hi Rob, thanks for having a look at this. On Tue, 2020-12-15 at 13:54 -0600, Rob Herring wrote: > On Tue, Dec 15, 2020 at 1:01 PM Nicolas Saenz Julienne > wrote: > >=20 > > Hi Catalin, > >=20 > > On Tue, 2020-12-15 at 18:44 +0000, Catalin Marinas wrote: > > > On Tue, Dec 15, 2020 at 04:56:20PM +0100, Nicolas Saenz Julienne wrot= e: > > > > Soon to be released versions of RPi4's firmware will take of care > > > > passing their bootloader's configuration to the OS by copying it in= to > > > > memory and creating a reserved memory node in the board's DT. In or= der > > > > to make use of this information, this series introduces a new gener= ic > > > > nvmem driver that maps reserved-memory nodes into nvmem devices. > > > >=20 > > > > An alternative approach, less nice IMO, would be to create a > > > > platform-specific 'soc' driver. > > >=20 > > > What kind of information is this and how would the kernel use it? > >=20 > > Sorry, I wasn't clear enough, the ultimate goal is to use this informat= ion from > > user-space, through nvmem's sysfs interface. The kernel itself has no u= se for > > it. >=20 > That still leaves the first question. It's the bootloader configuration, stuff like boot order, TFTP IP, etc... S= ee more here: https://www.raspberrypi.org/documentation/hardware/raspberrypi/bcm2711_boot= loader_config.md I'll add a new paragraph explaining all this on next version's cover letter= . Regards, Nicolas --=-p4v4j9FxejBEde40K8yJ Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- iQEzBAABCAAdFiEErOkkGDHCg2EbPcGjlfZmHno8x/4FAl/ZKPcACgkQlfZmHno8 x/6MKgf7BO8gBlEQPizFY2pVw0UcI+ewT5fdSAO2v/tenS5h7UoAVU+hB/BzsI6E 0W0X9jBkKxTmL7ZYH6qE2A6E/7JJQ4VaGwxAjq8mmmqYuWq0qjZ/VeDiCOVz3pP/ ukelSJJWGKTex3/ylirX8QoKS31kgZkLstMjSZnDk8fG4y35QhpBgnlqACcPNGim D91ybwJkGN75bVKRxysWsMMwkclek4ey6ILvrpVshpRyT3LJJKKoQGIeN1rHtbyi 7bncoTJB/eRIVelZZru5CSyZnWX905nils6TS6pb1RUGzp52x0R2V/eEFd5CaoZj 0liDYByLl+H8g9XHmhkttDu7A/zz+g== =S4P/ -----END PGP SIGNATURE----- --=-p4v4j9FxejBEde40K8yJ--