From patchwork Thu Sep 6 18:29:27 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Grant Likely X-Patchwork-Id: 10590933 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 97D2B921 for ; Thu, 6 Sep 2018 18:30:34 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 872682AE86 for ; Thu, 6 Sep 2018 18:30:34 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 851112B03C; Thu, 6 Sep 2018 18:30:34 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAD_ENC_HEADER,BAYES_00, DKIM_SIGNED,DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id DBEBF2AE86 for ; Thu, 6 Sep 2018 18:30:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:To :From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=N+8L7frDIPIoDJhtd52ymB5FZ9iSbYDiqj3ep1pzEMM=; b=KLMU30w5ZtKA8l HjOfnhiITeCa15XdCEp1XuC+7HWwdyvpNe0p0od/SIe8EtfA/KzR4LUL62Qh4vepm7yQWXkvwmYpL qcZ+elOQcvNllQJN5OxJRauDwMnnG0mPGgCNkHKJhKpFd4WnzGP3jo0HxhXNFkvS/xaNK8FObDkWL 2AjzFhEkP2UH+Oejn+kwu4PzGDsbl03RMovDfX32n14f6Jpp3QsTwfyFIwex7Ybm4L3ZReK73EZV/ Q0c0hnpugBR5hiRlqbFa0lQEwgpmh3mng76wYINpUo3D8JWZIFuDpBSF9TYWa/fynBu+Qs1sfNG/p GEvlFUXh7G7P4RunpaNw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1fxz2x-00076W-PH; Thu, 06 Sep 2018 18:30:27 +0000 Received: from mail-db5eur01on0053.outbound.protection.outlook.com ([104.47.2.53] helo=EUR01-DB5-obe.outbound.protection.outlook.com) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1fxz2t-0006N1-Ne for linux-arm-kernel@lists.infradead.org; Thu, 06 Sep 2018 18:30:25 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=armh.onmicrosoft.com; s=selector1-arm-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=WeIf5Y6HVLIVw1Bgw07hUUgHgfUUF6dCW8c8SaOc5Wc=; b=FH1QGklEVggRXu4194UioogC3cAkNJdOiuJlhHkSDjAM7mpRUXDEYkDxAcCV0JqV4jXWhPiXn8anw33moxYb1BBC1/O08RSYHw3i8FIOD97PG6I3yX+Cn2f+JeaVF1Coi3j0HaF6ltO9Gh38rUwFgafiia7X05YRhcpiKM8hriw= Authentication-Results: spf=none (sender IP is ) smtp.mailfrom=Grant.Likely@arm.com; Received: from tiffany.emea.arm.com (217.43.126.139) by VI1PR0801MB1759.eurprd08.prod.outlook.com (2603:10a6:800:5b::8) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.1101.17; Thu, 6 Sep 2018 18:30:08 +0000 From: Grant Likely To: linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH RESEND] efi_stub: update documentation on dtb= parameter Date: Thu, 6 Sep 2018 19:29:27 +0100 Message-Id: <20180906182927.22318-1-grant.likely@arm.com> X-Mailer: git-send-email 2.11.0 MIME-Version: 1.0 X-Originating-IP: [217.43.126.139] X-ClientProxiedBy: DB7PR04CA0010.eurprd04.prod.outlook.com (2603:10a6:10:12::23) To VI1PR0801MB1759.eurprd08.prod.outlook.com (2603:10a6:800:5b::8) X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: 0a391ed3-409f-4012-9f1b-08d61426c6a1 X-MS-Office365-Filtering-HT: Tenant X-Microsoft-Antispam: BCL:0; PCL:0; RULEID:(7020095)(4652040)(8989137)(4534165)(4627221)(201703031133081)(201702281549075)(8990107)(5600074)(711020)(4618075)(2017052603328)(7153060)(7193020); SRVR:VI1PR0801MB1759; X-Microsoft-Exchange-Diagnostics: 1; VI1PR0801MB1759; 3:FvbQo0GMwmYT2hPjQFPIABsnrTCdiV/hgQmiA231rUzljIt+X6oA65C/9GuWMmm4pGDOVp1lneSkPUsIBaeJMq6/AMJHIWiJ0UYNt/DUWL6p4adejkYJrwlMHbnWubY125jjXcgf8GmTwr7Vu0Z3cdAdG2sczun/wHptjMNjZditmMBLln2iU4grxmkLDNjbKec8zzN8QVY1zTVYw9Ik7vGxD0ALlbqfFsNssTrGMOGZZ/5vhppVztSsXfvanegv; 25:COfJtd1cpnQugIK94ItJnRvvuRsVVpC2ojG0jjCWg1TzSeySDEyR1GtQEuP+pnAVvV7+O15p3Ox/slr8TSTZx2dDtG7u8V1SICUB8ipwFRXa375HN3AvNwGXWJPxzpf6CtrCLcEQEoStTidJsI8ZH/FEt3c/Z6jkUuPuuYGq0uUk9MIe4xgJxgSHBr/633AHhmQVbMNKGlIgj8F7VVY1AMPrCYPq1hnFWJm/j788atNm1RDQ237IOvUFjcntiBUF9lIJJ5kGZupz+3mj3sDrq2h2rQqNUTylpZ+kCmHoHyycOP+4TtuKy1Y5BFNncxbGy/AiMb/hMCCkSdfGVo5/3A==; 31:kNcTfXqJefm54OC5vhHxuvpM1tc0bIfJHX9FERqGeR4eLQvE7W6HDn4i7g4aC15Zr9wAu5Q71H2GjPjd1uk3g5zH0wtapIgnlmhorJWSbAf0ScxiDyT8Yup53AgE69vgoDPZ3OpNL2rOxFolaJgjn0Jsp586hh7bjrHQUH1uzYhj4XFnBfUTGMEnRfd9ZmBUT4olueDniPxd2szw7QLLvQCP5+H2TWR2WOeYLJqMZ7E= X-MS-TrafficTypeDiagnostic: VI1PR0801MB1759: NoDisclaimer: True X-Microsoft-Exchange-Diagnostics: 1; VI1PR0801MB1759; 20:El8/uezQGu4YHyX7S3i9w4M/qcQPW0neLVnxsnJl/3HWzaSWldjgOYM4z0JMJs7WJ7iU319yrUhIP7aFLJ5KFA/lRaboDUS+Zi1fLV0oEjNXyTnaC3pBJdO7r3OuWyXR44MhQjN0neU83+56l+h8nCTBJ71oWqZVrmlqo/MSBsdbstqWU1MY/jp2j4NieB0rnRqUVb+HgSqeWzJYTjZ+WKKm4iyiBPoxoitHtMYrOtm3Z7vzkzxjqjClv6wMI2JnoU0VMjNByxmafyhZhlsdBZgfIDk6l7Gw9okNC8TvfV65IuNbDGmldLcWahwEDLOKJZTZC8Nhgirik1/kDn7UiGHYPcx/aFZLQOLUwnnPwfcPDHAC6J3Y+7ueMZ47Z+HhonI0ZqKmIbARctpqxknmn67DDUBBicYvH0dyGPIBFq8=; 4:Ml5R7zW0ohyAnEm/A+pfY48ap2/bUWFKIqVFCLUXhTjgDBMWXN4yhl8xL+EP9+b8w3agQOBQzmsgWe4T1396DsRVzZ0Ul6KXGmspjIxvvw1FJFV/sTX1Yt/eYgXM2qZxpDTOOfMj4++OtmDuyauHY0P+rMkHFKlLk42zgsmu0YrTY+7grSOji6FeYyAiJXp3q9zZ+bnwrus7exQGivfi7vQSHqsQf8mvR77dA3lQqR7k/VmKk3rN8oPW6rxwZiPMBysk3KLp5jf9TmmpjKGnDfYdJ5VUs+V4V8zyLiKBfPeCQK5XHWuK8Ycf0gAPvhDw X-Microsoft-Antispam-PRVS: X-Exchange-Antispam-Report-Test: UriScan:(180628864354917); X-MS-Exchange-SenderADCheck: 1 X-Exchange-Antispam-Report-CFA-Test: BCL:0; PCL:0; RULEID:(8211001083)(6040522)(2401047)(8121501046)(5005006)(823301075)(10201501046)(3002001)(3231311)(944501410)(52105095)(93006095)(93001095)(6055026)(149027)(150027)(6041310)(20161123564045)(20161123558120)(20161123562045)(20161123560045)(201703131423095)(201702281528075)(20161123555045)(201703061421075)(201703061406153)(201708071742011)(7699016); SRVR:VI1PR0801MB1759; BCL:0; PCL:0; RULEID:; SRVR:VI1PR0801MB1759; X-Forefront-PRVS: 0787459938 X-Forefront-Antispam-Report: SFV:NSPM; SFS:(10009020)(346002)(396003)(376002)(366004)(39860400002)(136003)(199004)(189003)(2906002)(8936002)(106356001)(54906003)(1076002)(6116002)(3846002)(476003)(6666003)(50226002)(316002)(52116002)(44832011)(7696005)(68736007)(105586002)(16586007)(51416003)(14444005)(2616005)(305945005)(7416002)(16526019)(575784001)(8676002)(86362001)(5660300001)(81156014)(81166006)(15650500001)(36756003)(7736002)(478600001)(956004)(186003)(486006)(48376002)(58726001)(25786009)(97736004)(6486002)(386003)(47776003)(26005)(50466002)(53936002)(66066001)(4326008)(72206003)(58736002); DIR:OUT; SFP:1101; SCL:1; SRVR:VI1PR0801MB1759; H:tiffany.emea.arm.com; FPR:; SPF:None; LANG:en; PTR:InfoNoRecords; A:1; MX:1; Received-SPF: None (protection.outlook.com: arm.com does not designate permitted sender hosts) X-Microsoft-Exchange-Diagnostics: =?us-ascii?Q?1; VI1PR0801MB1759; 23:KZLRqkgrwuVAuCTO3ui0Fund5cm06wr9dKWeGEn?= 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 X-Microsoft-Antispam-Message-Info: CiP9sSa9/v+kI6M6pXlUV2DUpoD42KlPEf/2751Mt//bSzg1zE2P64DEdKAHSAPzjlalF0lk8SXMhw2OE0pPMD3fTyyvKDacm8Ra7QGVAmojgTS51TLWYf4haWggqG5F/cOUHQlocUrlzAs7WX8hSgt3TeGfnZdIrPm98Ho71wiVhAcg1ZCd2aBsixCo8yCmPAT2U8kXdItBWOVQLnGS1LislesYtgTA5yZulfq5qdR1xPgrvaU8T9Y8lZj0ZNIgSEwnoo7f6Gmjs8VxplCd140HXbOHb6lGCBBdKfV8CiI2um4FyOtGW+cTKxbJx3nGkguUdvt5jxGTcLDZlcbBQte1TX09ivzaXJfpwFsuD3g= X-Microsoft-Exchange-Diagnostics: 1; VI1PR0801MB1759; 6:skLM2OrdlT2xUINEsG7plNgFFcgUWoDMAt/1wggxGVZnzkMng4KaN+VghweVOIoHIONOmzg+o3jz/fCydvAZSHUE3hMxwMu+EH8MYCd8IZFuctOnMW03V6Gzy+IpG/V8h+Loi7kDdJAwkjvCXSVZJ+PJPQaU8gQpuKh8cscRAaDpKkwuEsQNZeNVpeb8xEgvBVYfdHrpmPM5xX0wMDMfw8KfN7PT9M34eifW1KnOTmj/1TXStBLr2UuE3DC1pmH9wVY/rrPl5Pk0XmC7KY57AGyaP9If8w5Shvc1A2bZGHsTfFBfMV+T0Cw288A1XapNNT9hRUhnnNMAxpL8Y0CyRoeqRHbzZ3/Z/rDCHmBCvsG+sHOOVQeWYcpBEaKeEgdfQwVxW0/Y7KpJf1Uj3+XzSJ9CdskTmeRoIncCPdNf+q5xem8V4CUIToVt4Gadpk+HntHgb2ocWAc1OzAGNFjd9Q==; 5:KmymMcvn8KSXbRRFoQinuEdWpR2PKc8CpIDennzWUau8Fi2TIAKzanhNcYl01xgyZVmc78nbN+1RtZOIIJ9U6CCgx9E2p360jhWpLyek8TBSvb0LhPH9dPcxj/j4r+xv0Dn8/iHwyuwZZ9lHgzVM1m8jRv/pMrYjPsvO7uPom4Y=; 7:DprwknPWJmqIHZj+5UeaB54Iz8i7ot1vjNtpFZOuK1o0jSbWCbyHszBSBoKurMovRbTvhrv0mo+P6K7e19HqzeYQhBsUAZGDbm34wkKwUg6dmSkzbPXvc0Zr4S3kBpQxaBEYCus1RZHXEdECI7wKxTAFe9umhxBq4qxUHzap0GwoFGU8Sc0psLPHBUQgqs9qc44gF1A23jW2gs6Ta7iVMglixVxDJX7SJkbNy3rXIJU8j3QX2smdBcva5ZvoFmzq SpamDiagnosticOutput: 1:99 SpamDiagnosticMetadata: NSPM X-OriginatorOrg: arm.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 06 Sep 2018 18:30:08.2778 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 0a391ed3-409f-4012-9f1b-08d61426c6a1 X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: f34e5979-57d9-4aaa-ad4d-b122a662184d X-MS-Exchange-Transport-CrossTenantHeadersStamped: VI1PR0801MB1759 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20180906_113023_910087_16D56558 X-CRM114-Status: GOOD ( 11.73 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jonathan Corbet , arnd@arndb.de, scott.branden@broadcom.com, catalin.marinas@arm.com, Ard Biesheuvel , will.deacon@arm.com, agraf@suse.de, leif.lindholm@linaro.org, Grant Likely , olof@lixom.net, nd@arm.com Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP The dtb= parameter is no longer the primary mechanism for providing a devicetree to the kernel. Now either firmware or the boot selector (ex. Grub) should provide the devicetree and dtb= should only be used for debug or when using firmware that doesn't understand DT. Update the EFI stub documentation to reflect the current usage. Signed-off-by: Grant Likely Reviewed-by: Alexander Graf Acked-by: Leif Lindholm Acked-by: Olof Johansson Cc: Ard Biesheuvel Cc: Jonathan Corbet Acked-by: Ard Biesheuvel --- Resending because original post included Arm corporate disclaimer. Documentation/efi-stub.txt | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/Documentation/efi-stub.txt b/Documentation/efi-stub.txt index 41df801f9a50..833edb0d0bc4 100644 --- a/Documentation/efi-stub.txt +++ b/Documentation/efi-stub.txt @@ -83,7 +83,18 @@ is passed to bzImage.efi. The "dtb=" option ----------------- -For the ARM and arm64 architectures, we also need to be able to provide a -device tree to the kernel. This is done with the "dtb=" command line option, -and is processed in the same manner as the "initrd=" option that is +For the ARM and arm64 architectures, a device tree must be provided to +the kernel. Normally firmware shall supply the device tree via the +EFI CONFIGURATION TABLE. However, the "dtb=" command line option can +be used to override the firmware supplied device tree, or to supply +one when firmware is unable to. + +Please note: Firmware adds runtime configuration information to the +device tree before booting the kernel. If dtb= is used to override +the device tree, then any runtime data provided by firmware will be +lost. The dtb= option should only be used either as a debug tool, or +as a last resort when a device tree is not provided in the EFI +CONFIGURATION TABLE. + +"dtb=" is processed in the same manner as the "initrd=" option that is described above.