From patchwork Tue Aug 23 21:30:39 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Will Deacon X-Patchwork-Id: 1089972 Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by demeter1.kernel.org (8.14.4/8.14.4) with ESMTP id p7NLWEFi015328 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Tue, 23 Aug 2011 21:32:35 GMT Received: from canuck.infradead.org ([2001:4978:20e::1]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1QvyZc-0008Jn-VX; Tue, 23 Aug 2011 21:31:53 +0000 Received: from localhost ([127.0.0.1] helo=canuck.infradead.org) by canuck.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1QvyZc-0004Mu-9o; Tue, 23 Aug 2011 21:31:52 +0000 Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]) by canuck.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1QvyYj-0004Bw-6k for linux-arm-kernel@lists.infradead.org; Tue, 23 Aug 2011 21:30:58 +0000 Received: from localhost.localdomain (e102144-lin.cambridge.arm.com [10.1.69.60]) by cam-admin0.cambridge.arm.com (8.12.6/8.12.6) with ESMTP id p7NLTS13024039; Tue, 23 Aug 2011 22:29:29 +0100 (BST) From: Will Deacon To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v2 2/5] ARM: debug: augment DEBUG_LL Kconfig help to clarify behaviour Date: Tue, 23 Aug 2011 22:30:39 +0100 Message-Id: <1314135042-19908-3-git-send-email-will.deacon@arm.com> X-Mailer: git-send-email 1.7.0.4 MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1314135042-19908-1-git-send-email-will.deacon@arm.com> References: <1314135042-19908-1-git-send-email-will.deacon@arm.com> X-CRM114-Version: 20090807-BlameThorstenAndJenny ( TRE 0.7.6 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20110823_173057_665734_45DFFA62 X-CRM114-Status: GOOD ( 16.39 ) X-Spam-Score: -2.8 (--) X-Spam-Report: SpamAssassin version 3.3.1 on canuck.infradead.org summary: Content analysis details: (-2.8 points) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at http://www.dnswl.org/, medium trust [217.140.96.50 listed in list.dnswl.org] -0.5 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain Cc: Will Deacon X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter1.kernel.org [140.211.167.41]); Tue, 23 Aug 2011 21:32:35 +0000 (UTC) Enabled DEBUG_LL hardcodes the UART address into the kernel and results in a non-portable kernel image. Since this option is only intended for use when debugging early boot failures, supporting multiple platforms in such a configuration is not the intended use-case. This patch documents this limitation in the DEBUG_LL Kconfig help text, so that users are aware of the portability restrictions that are associated with enabling low-level debugging support. Reported-by: Sascha Hauer Signed-off-by: Will Deacon --- arch/arm/Kconfig.debug | 7 ++++++- 1 files changed, 6 insertions(+), 1 deletions(-) diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug index 11604c9..60d1846 100644 --- a/arch/arm/Kconfig.debug +++ b/arch/arm/Kconfig.debug @@ -65,13 +65,18 @@ config DEBUG_USER # These options are only for real kernel hackers who want to get their hands dirty. config DEBUG_LL - bool "Kernel low-level debugging functions" + bool "Kernel low-level debugging functions (read help!)" depends on DEBUG_KERNEL help Say Y here to include definitions of printascii, printch, printhex in the kernel. This is helpful if you are debugging code that executes before the console is initialized. + Note that selecting this option will limit the kernel to a single + UART definition, as specified below. Attempting to boot the kernel + image on a different platform *will not work*, so this option should + not be enabled for kernels that are intended to be portable. + choice prompt "Kernel low-level debugging port" depends on DEBUG_LL