From patchwork Sat Sep 28 16:23:18 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roy Franz X-Patchwork-Id: 2957961 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id DD76ABFF0B for ; Sat, 28 Sep 2013 16:24:14 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id EAC522035F for ; Sat, 28 Sep 2013 16:24:13 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E9066202D1 for ; Sat, 28 Sep 2013 16:24:12 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VPxJ6-00071o-NN; Sat, 28 Sep 2013 16:23:48 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VPxJ2-0005M0-FQ; Sat, 28 Sep 2013 16:23:44 +0000 Received: from mail-qc0-f177.google.com ([209.85.216.177]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VPxIo-0005JD-T4 for linux-arm-kernel@lists.infradead.org; Sat, 28 Sep 2013 16:23:31 +0000 Received: by mail-qc0-f177.google.com with SMTP id x12so2547568qcv.36 for ; Sat, 28 Sep 2013 09:23:08 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=Jj7621GbU59of15G+Rj4OLBfWuG5jJg2JJruDllLvEU=; b=YqiOTwHHpjgZrRkbUwQd6fDq7/ZlKrAx28gdnXU6exx5Oo+F2ncBSr58YOn5U+M1M7 tbrvCua95tbC5CLVtWIJ3wxV+uD6Tr+rTuEp/hdOGdwPDbgZHlGwc6BaizszMI7Zpn2g tZ/ZaUyXvrmfkARvosIXDYDN+d9v8oLH7KcLa2Amb3p/binHHepLJmfgegpuzSEZ2Omg prsgjElsUGDsRbjOFR6JAAO9IZBDoypeUZdSvkohs1F6LSo5t5sbVQ3rh4WS80xcOgF2 eFV1WdUVEk0o2kTnHQegewyN5BgNedMg8ysD46QwAqlDGZKeUJFwH4B5+BBuHT6aRg4c fUTA== X-Gm-Message-State: ALoCoQmIyLuyy/3QSVd1wk1y/45a0SFJXXWT2WJNmqei2yO8GqYq+NHwcSAagyuFGmPS9u+G/Z+F X-Received: by 10.224.165.20 with SMTP id g20mr21185302qay.17.1380385386658; Sat, 28 Sep 2013 09:23:06 -0700 (PDT) Received: from rfranz-t520.caveonetworks.com (static-108-20-23-67.bstnma.fios.verizon.net. [108.20.23.67]) by mx.google.com with ESMTPSA id l2sm31145506qad.10.1969.12.31.16.00.00 (version=TLSv1.2 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Sat, 28 Sep 2013 09:23:06 -0700 (PDT) From: Roy Franz To: linux-kernel@vger.kernel.org, linux-efi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, matt.fleming@intel.com, linux@arm.linux.org.uk Subject: [PATCH 1/6] efi-stub.txt updates for ARM Date: Sat, 28 Sep 2013 09:23:18 -0700 Message-Id: <1380385403-31904-2-git-send-email-roy.franz@linaro.org> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1380385403-31904-1-git-send-email-roy.franz@linaro.org> References: <1380385403-31904-1-git-send-email-roy.franz@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130928_122330_984354_E590BF5C X-CRM114-Status: GOOD ( 15.47 ) X-Spam-Score: -2.6 (--) Cc: grant.likely@linaro.org, Roy Franz , dave.martin@arm.com, leif.lindholm@linaro.org, msalter@redhat.com X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-6.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Update efi-stub.txt documentation to be more general and not x86 specific. Add ARM only "dtb=" command line option description. Signed-off-by: Roy Franz --- Documentation/efi-stub.txt | 27 ++++++++++++++++++++------- 1 file changed, 20 insertions(+), 7 deletions(-) diff --git a/Documentation/efi-stub.txt b/Documentation/efi-stub.txt index 44e6bb6..19e897c 100644 --- a/Documentation/efi-stub.txt +++ b/Documentation/efi-stub.txt @@ -1,13 +1,16 @@ The EFI Boot Stub --------------------------- -On the x86 platform, a bzImage can masquerade as a PE/COFF image, -thereby convincing EFI firmware loaders to load it as an EFI -executable. The code that modifies the bzImage header, along with the -EFI-specific entry point that the firmware loader jumps to are -collectively known as the "EFI boot stub", and live in +On the x86 and ARM platforms, a kernel zImage/bzImage can masquerade +as a PE/COFF image, thereby convincing EFI firmware loaders to load +it as an EFI executable. The code that modifies the bzImage header, +along with the EFI-specific entry point that the firmware loader +jumps to are collectively known as the "EFI boot stub", and live in arch/x86/boot/header.S and arch/x86/boot/compressed/eboot.c, -respectively. +respectively. For ARM the EFI stub is implemented in +arch/arm/boot/compressed/efi-header.S and +arch/arm/boot/compressed/efi-stub.c. EFI stub code that is shared +between architectures is in drivers/firmware/efi/efi-stub-helper.c. By using the EFI boot stub it's possible to boot a Linux kernel without the use of a conventional EFI boot loader, such as grub or @@ -23,7 +26,9 @@ The bzImage located in arch/x86/boot/bzImage must be copied to the EFI System Partiion (ESP) and renamed with the extension ".efi". Without the extension the EFI firmware loader will refuse to execute it. It's not possible to execute bzImage.efi from the usual Linux file systems -because EFI firmware doesn't have support for them. +because EFI firmware doesn't have support for them. For ARM the +arch/arm/boot/zImage should be copied to the system partition, and it +may not need to be renamed. **** Passing kernel parameters from the EFI shell @@ -63,3 +68,11 @@ Notice how bzImage.efi can be specified with a relative path. That's because the image we're executing is interpreted by the EFI shell, which understands relative paths, whereas the rest of the command line is passed to bzImage.efi. + + +**** The "dtb=" option + +For the ARM architecture, 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 process in the same manner as the "initrd=" option that is described +above.