From patchwork Wed Feb 5 17:04:03 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Leif Lindholm X-Patchwork-Id: 24201 Return-Path: X-Original-To: linaro@patches.linaro.org Delivered-To: linaro@patches.linaro.org Received: from mail-yk0-f197.google.com (mail-yk0-f197.google.com [209.85.160.197]) by ip-10-151-82-157.ec2.internal (Postfix) with ESMTPS id 47D4220675 for ; Wed, 5 Feb 2014 17:05:52 +0000 (UTC) Received: by mail-yk0-f197.google.com with SMTP id 20sf3022377yks.0 for ; Wed, 05 Feb 2014 09:05:51 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:delivered-to:from:to:cc:subject :date:message-id:in-reply-to:references:x-original-sender :x-original-authentication-results:precedence:mailing-list:list-id :list-post:list-help:list-archive:list-unsubscribe; bh=I4oovykwZYJWTtdjjKT7+UcUTFncHq0MJSPLsMno41M=; b=H4DhHi9d/bgktT//2fXCeRSgbcX9ACFVaBF/zoEru6brCMs28EwhLnSkoLLzj/lSUU 6OqRVMhrtzq1Z0APBuas6w5hyxXl2tG7TpXmyWp3cmI2kDCijbqaEm8DGoJ4uT2xU+sX y/zWESDJmHrpLvmyzvB8zUcVejeUmc9FnVGaalE/jmoN72FqPn6kf6Mfj5vOW/mJvjvU AasoEtPfiMxz0Jg9pnZkM3Y3oPj7VOHBTCo1Q5tJ09iTociw4lBgQHUh8e+EKdgGyqHw QygQQ1PIv3/FiBT8fOmoozJjfJx4rHCEIIP8/h6wN+bEELsbvLw98j3alkFYUZuOqRj3 6baQ== X-Gm-Message-State: ALoCoQlMvqEXkVVULLq/5tmz9jnuDTLNZdEoKjjaUd765akMm0LZEW+2CHoJU8/OH640aJdnjS95 X-Received: by 10.236.121.195 with SMTP id r43mr840925yhh.44.1391619951408; Wed, 05 Feb 2014 09:05:51 -0800 (PST) MIME-Version: 1.0 X-BeenThere: patchwork-forward@linaro.org Received: by 10.140.89.145 with SMTP id v17ls206298qgd.82.gmail; Wed, 05 Feb 2014 09:05:51 -0800 (PST) X-Received: by 10.58.86.230 with SMTP id s6mr1747695vez.16.1391619951253; Wed, 05 Feb 2014 09:05:51 -0800 (PST) Received: from mail-vb0-f42.google.com (mail-vb0-f42.google.com [209.85.212.42]) by mx.google.com with ESMTPS id n8si9844627vdv.68.2014.02.05.09.05.51 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Wed, 05 Feb 2014 09:05:51 -0800 (PST) Received-SPF: neutral (google.com: 209.85.212.42 is neither permitted nor denied by best guess record for domain of patch+caf_=patchwork-forward=linaro.org@linaro.org) client-ip=209.85.212.42; Received: by mail-vb0-f42.google.com with SMTP id i3so507177vbh.15 for ; Wed, 05 Feb 2014 09:05:51 -0800 (PST) X-Received: by 10.59.5.102 with SMTP id cl6mr738908ved.41.1391619951142; Wed, 05 Feb 2014 09:05:51 -0800 (PST) X-Forwarded-To: patchwork-forward@linaro.org X-Forwarded-For: patch@linaro.org patchwork-forward@linaro.org Delivered-To: patches@linaro.org Received: by 10.220.174.196 with SMTP id u4csp64635vcz; Wed, 5 Feb 2014 09:05:50 -0800 (PST) X-Received: by 10.194.90.144 with SMTP id bw16mr2167968wjb.1.1391619927074; Wed, 05 Feb 2014 09:05:27 -0800 (PST) Received: from mail-wg0-f53.google.com (mail-wg0-f53.google.com [74.125.82.53]) by mx.google.com with ESMTPS id cr4si11019423wjc.137.2014.02.05.09.05.26 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Wed, 05 Feb 2014 09:05:27 -0800 (PST) Received-SPF: neutral (google.com: 74.125.82.53 is neither permitted nor denied by best guess record for domain of leif.lindholm@linaro.org) client-ip=74.125.82.53; Received: by mail-wg0-f53.google.com with SMTP id y10so501472wgg.20 for ; Wed, 05 Feb 2014 09:05:26 -0800 (PST) X-Received: by 10.180.73.173 with SMTP id m13mr17819194wiv.52.1391619926569; Wed, 05 Feb 2014 09:05:26 -0800 (PST) Received: from mohikan.mushroom.smurfnet.nu (cpc4-cmbg17-2-0-cust71.5-4.cable.virginm.net. [86.14.224.72]) by mx.google.com with ESMTPSA id p1sm47427211wie.1.2014.02.05.09.05.24 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 05 Feb 2014 09:05:25 -0800 (PST) From: Leif Lindholm To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-efi@vger.kernel.org Cc: patches@linaro.org, Leif Lindholm , Rob Landley , linux-doc@vger.kernel.org Subject: [PATCH 12/22] Documentation: arm: add UEFI support documentation Date: Wed, 5 Feb 2014 17:04:03 +0000 Message-Id: <1391619853-10601-13-git-send-email-leif.lindholm@linaro.org> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1391619853-10601-1-git-send-email-leif.lindholm@linaro.org> References: <1391619853-10601-1-git-send-email-leif.lindholm@linaro.org> X-Removed-Original-Auth: Dkim didn't pass. X-Original-Sender: leif.lindholm@linaro.org X-Original-Authentication-Results: mx.google.com; spf=neutral (google.com: 209.85.212.42 is neither permitted nor denied by best guess record for domain of patch+caf_=patchwork-forward=linaro.org@linaro.org) smtp.mail=patch+caf_=patchwork-forward=linaro.org@linaro.org Precedence: list Mailing-list: list patchwork-forward@linaro.org; contact patchwork-forward+owners@linaro.org List-ID: X-Google-Group-Id: 836684582541 List-Post: , List-Help: , List-Archive: List-Unsubscribe: , This patch provides documentation of the [U]EFI runtime service and configuration features for the arm architecture. Changes since v1/v2: - Complete rewrite. - New FDT bindings. Cc: Rob Landley Cc: linux-doc@vger.kernel.org Signed-off-by: Leif Lindholm Signed-off-by: Leif Lindholm Acked-by: Grant Likely --- Documentation/arm/00-INDEX | 3 +++ Documentation/arm/uefi.txt | 64 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 67 insertions(+) create mode 100644 Documentation/arm/uefi.txt diff --git a/Documentation/arm/00-INDEX b/Documentation/arm/00-INDEX index 36420e1..b3af704 100644 --- a/Documentation/arm/00-INDEX +++ b/Documentation/arm/00-INDEX @@ -34,3 +34,6 @@ nwfpe/ - NWFPE floating point emulator documentation swp_emulation - SWP/SWPB emulation handler/logging description + +uefi.txt + - [U]EFI configuration and runtime services documentation diff --git a/Documentation/arm/uefi.txt b/Documentation/arm/uefi.txt new file mode 100644 index 0000000..d60030a --- /dev/null +++ b/Documentation/arm/uefi.txt @@ -0,0 +1,64 @@ +UEFI, the Unified Extensible Firmware Interface, is a specification +governing the behaviours of compatible firmware interfaces. It is +maintained by the UEFI Forum - http://www.uefi.org/. + +UEFI is an evolution of its predecessor 'EFI', so the terms EFI and +UEFI are used somewhat interchangeably in this document and associated +source code. As a rule, anything new uses 'UEFI', whereas 'EFI' refers +to legacy code or specifications. + +UEFI support in Linux +===================== +Booting on a platform with firmware compliant with the UEFI specification +makes it possible for the kernel to support additional features: +- UEFI Runtime Services +- Retrieving various configuration information through the standardised + interface of UEFI configuration tables. (ACPI, SMBIOS, ...) + +For actually enabling [U]EFI support, enable: +- CONFIG_EFI=y +- CONFIG_EFI_VARS=y or m + +The implementation depends on receiving information about the UEFI environment +in a Flattened Device Tree (FDT) - so is only available with CONFIG_OF. + +UEFI stub +========= +The "stub" is a feature that extends the Image/zImage into a valid UEFI +PE/COFF executable, including a loader application that makes it possible to +load the kernel directly from the UEFI shell, boot menu, or one of the +lightweight bootloaders like Gummiboot or rEFInd. + +The kernel image built with stub support remains a valid kernel image for +booting in non-UEFI environments. + +UEFI kernel support on ARM +========================== +UEFI kernel support on the ARM architectures (arm and arm64) is only available +when boot is performed through the stub. + +When booting in UEFI mode, the stub deletes any memory nodes from a provided DT. +Instead, the kernel reads the UEFI memory map. + +The stub populates the FDT /chosen node with (and the kernel scans for) the +following parameters: +________________________________________________________________________________ +Name | Size | Description +================================================================================ +linux,uefi-system-table | 64-bit | Physical address of the UEFI System Table. +-------------------------------------------------------------------------------- +linux,uefi-mmap-start | 64-bit | Physical address of the UEFI memory map, + | | populated by the UEFI GetMemoryMap() call. +-------------------------------------------------------------------------------- +linux,uefi-mmap-size | 32-bit | Size in bytes of the UEFI memory map + | | pointed to in previous entry. +-------------------------------------------------------------------------------- +linux,uefi-mmap-desc-size | 32-bit | Size in bytes of each entry in the UEFI + | | memory map. +-------------------------------------------------------------------------------- +linux,uefi-mmap-desc-ver | 32-bit | Version of the mmap descriptor format. +-------------------------------------------------------------------------------- +linux,uefi-stub-kern-ver | string | Copy of linux_banner from build. +-------------------------------------------------------------------------------- + +For verbose debug messages, specify 'uefi_debug' on the kernel command line.