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[2001:1868:205::9]) by mx.google.com with ESMTPS id ll3si16145253pbc.130.2015.03.02.03.51.05 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 02 Mar 2015 03:51:06 -0800 (PST) Received-SPF: none (google.com: linux-arm-kernel-bounces+patch=linaro.org@lists.infradead.org does not designate permitted sender hosts) client-ip=2001:1868:205::9; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1YSOqr-0008NR-0m; Mon, 02 Mar 2015 11:49:33 +0000 Received: from mail-wi0-f170.google.com ([209.85.212.170]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1YSOqn-0008HI-E4 for linux-arm-kernel@lists.infradead.org; Mon, 02 Mar 2015 11:49:30 +0000 Received: by widem10 with SMTP id em10so14169977wid.1 for ; Mon, 02 Mar 2015 03:49:07 -0800 (PST) X-Received: by 10.180.84.133 with SMTP id z5mr10967093wiy.25.1425296947475; Mon, 02 Mar 2015 03:49:07 -0800 (PST) Received: from ards-macbook-pro.local ([213.143.61.132]) by mx.google.com with ESMTPSA id r3sm18927064wjw.7.2015.03.02.03.49.03 (version=TLSv1.1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Mon, 02 Mar 2015 03:49:05 -0800 (PST) From: Ard Biesheuvel To: mark.rutland@arm.com, catalin.marinas@arm.com, will.deacon@arm.com, linux-arm-kernel@lists.infradead.org Subject: [PATCH] arm64: Documentation: clarify Image placement in physical RAM Date: Mon, 2 Mar 2015 11:48:55 +0000 Message-Id: <1425296935-19097-1-git-send-email-ard.biesheuvel@linaro.org> X-Mailer: git-send-email 1.8.3.2 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20150302_034929_632231_12D82422 X-CRM114-Status: GOOD ( 12.30 ) X-Spam-Score: -0.7 (/) X-Spam-Report: SpamAssassin version 3.4.0 on bombadil.infradead.org summary: Content analysis details: (-0.7 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [209.85.212.170 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record -0.0 RCVD_IN_MSPIKE_H3 RBL: Good reputation (+3) [209.85.212.170 listed in wl.mailspike.net] -0.0 RCVD_IN_MSPIKE_WL Mailspike good senders Cc: Ard Biesheuvel X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 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+patch=linaro.org@lists.infradead.org X-Removed-Original-Auth: Dkim didn't pass. X-Original-Sender: ard.biesheuvel@linaro.org X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of patch+caf_=patchwork-forward=linaro.org@linaro.org designates 209.85.215.43 as permitted sender) smtp.mail=patch+caf_=patchwork-forward=linaro.org@linaro.org Mailing-list: list patchwork-forward@linaro.org; contact patchwork-forward+owners@linaro.org X-Google-Group-Id: 836684582541 The early init code maps the kernel image using statically allocated page tables. This means that we can only allow Image to be placed such that we can map its entire static footprint using a single table entry at all but the lowest level. So update the documentation to reflect that the Image should not cross a 512 MB boundary, which ensures the above on both 4k and 64k pages kernels. Signed-off-by: Ard Biesheuvel --- Documentation/arm64/booting.txt | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/Documentation/arm64/booting.txt b/Documentation/arm64/booting.txt index f3c05b5f9f08..728de8b9116c 100644 --- a/Documentation/arm64/booting.txt +++ b/Documentation/arm64/booting.txt @@ -113,8 +113,9 @@ The Image must be placed text_offset bytes from a 2MB aligned base address near the start of usable system RAM and called there. Memory below that base address is currently unusable by Linux, and therefore it is strongly recommended that this location is the start of system RAM. -At least image_size bytes from the start of the image must be free for -use by the kernel. +The physical memory region consisting of image_size bytes counting from +the start of the image must be free for use by the kernel, and must not +cross a 512 MB physical alignment boundary. Any memory described to the kernel (even that below the 2MB aligned base address) which is not marked as reserved from the kernel e.g. with a