From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DAD57C00A89 for ; Thu, 5 Nov 2020 05:40:57 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1BEA12083B for ; Thu, 5 Nov 2020 05:40:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="V/P82Bhx"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="S/I4mVvo" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1BEA12083B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=HGZeI/v+WNzMcvHN8NXXP5SqZC1ZcMgPmiknZNZDvsU=; b=V/P82Bhx1sB/sGq1qLhBwi0NG 9P6lTbNDi2i9euG9vrQjATnU6Bbe9zU4dk7qd59FurLDWUaH6nQvRAU4g3YqX6cokhaw66DLGwTMd zVICtJ1EC4en8FGfxpUHYmO6aaFxeiLdmt1KR/5oQogNBO+AGot3sR+wJal97UEdh9OgD/VOJusTi JlAj/mZrm0/Mdfhz0ZG1V2nn+o7dvrqFJzn1RXLvWzkd8fH5noxU4FcJBqf3IfUWqDukmE3UD5+uM tnc8x47Kll1duRUVHR2/i0KxHnvSS+xLLi/EkS2lXlHosA3RK73qjkNXhoY3MgwOnyG6arYzaqX41 o7obGQcaw==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kaY0g-00036y-7n; Thu, 05 Nov 2020 05:40:34 +0000 Received: from linux.microsoft.com ([13.77.154.182]) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kaY0d-00036I-Ue for linux-arm-kernel@lists.infradead.org; Thu, 05 Nov 2020 05:40:33 +0000 Received: from sequoia (162-237-133-238.lightspeed.rcsntx.sbcglobal.net [162.237.133.238]) by linux.microsoft.com (Postfix) with ESMTPSA id C9AF720B4905; Wed, 4 Nov 2020 21:40:28 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com C9AF720B4905 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1604554829; bh=nycdqD/aGTqhH/3wzV/NMDtydgpe4EqjBTUc+O8mIyk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=S/I4mVvo8ADCOQLLkCUKLY5W1CGEy9eEyeUrUCuQ9zbeTfZaEV3FZIFn8u523luii mMKQ6yAbO+m7c12HpuvB3dwDMwMM2+/klhPXfbHCyJeZB395gX35k7KjCJU5fZd8hb MzLEUS1CD8yeo6Lim5tj5Ek+W9YsSkK/yhzgz7Sg= Date: Wed, 4 Nov 2020 23:40:09 -0600 From: Tyler Hicks To: Will Deacon Subject: Re: [PATCH 0/2] arm64: Implement CONFIG_CMDLINE_EXTEND Message-ID: <20201105054009.GA4472@sequoia> References: <20200921191557.350256-1-tyhicks@linux.microsoft.com> <20201103155952.GA4335@sequoia> <20201104120812.GA6632@willie-the-truck> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20201104120812.GA6632@willie-the-truck> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201105_004032_185872_F88C2038 X-CRM114-Status: GOOD ( 20.80 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Catalin Marinas , Rob Herring , Pavel Tatashin , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 2020-11-04 12:08:12, Will Deacon wrote: > On Tue, Nov 03, 2020 at 09:59:52AM -0600, Tyler Hicks wrote: > > On 2020-09-21 14:15:55, Tyler Hicks wrote: > > > Provide the CONFIG_CMDLINE_EXTEND config option for arm64 kernels. This > > > config option can be used to extend the kernel command line parameters, > > > specified by the bootloader, with additional command line parameters > > > specified in the kernel configuration. > > > > Hi Catalin and Will - Friendly ping on this series now that we're > > on the other side of the 5.10 merge window. I hope it can be considered > > for 5.10+1. Let me know if I need to rebase/resubmit. Thanks! > > Can you use bootconfig to achieve what you need? Thanks for mentioning bootconfig. I hadn't considered it. After reading the docs and code, I see a few reasons why I can't use it out of the box: 1) It requires "bootconfig" to be appended to the kernel command line. My proposed patch series makes it possible to append new options to the kernel command line in situations where the bootloader is not interactive. This presents a circular dependency problem for my use case. A new config option could be added to force the enablement of bootconfig but that would sort of be a single-use duplicate of CONFIG_CMDLINE_EXTEND's functionality. 2) Not all kernel command line options can be configured using bootconfig. For example, the "nokaslr" and "crashkernel=" parameters are parsed/handled before setup_boot_config() is called. KASLR can be disabled via a kernel config change but there's no config option equivalent for "crashkernel=". Changing the "crashkernel=" command line option is something that I need to support because a development/debug kernel build often requires a larger reservation and we find ourselves adjusting the "crashkernel=" value fairly often. 3) External FIT image build systems do not yet support bootconfig since it is so new. It is completely fair if you file this away in your not-my-problem folder but simple kernel config modifications, as needed for CONFIG_CMDLINE_EXTEND, are something that every image build system is likely to support today. All that said, I do really like the look of bootconfig. Unfortunately, it doesn't let me achieve everything I need. Tyler > > Will > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel