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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable 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 0B5FCC433E1 for ; Fri, 26 Mar 2021 06:45:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DD64F61A05 for ; Fri, 26 Mar 2021 06:45:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230259AbhCZGpM (ORCPT ); Fri, 26 Mar 2021 02:45:12 -0400 Received: from pegase1.c-s.fr ([93.17.236.30]:16148 "EHLO pegase1.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229839AbhCZGop (ORCPT ); Fri, 26 Mar 2021 02:44:45 -0400 Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 4F6CBf5pjtz9tyk1; Fri, 26 Mar 2021 07:44:42 +0100 (CET) X-Virus-Scanned: Debian amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [192.168.12.234]) (amavisd-new, port 10024) with ESMTP id SksxU02aQTWC; Fri, 26 Mar 2021 07:44:42 +0100 (CET) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase1.c-s.fr (Postfix) with ESMTP id 4F6CBf42D0z9tyk0; Fri, 26 Mar 2021 07:44:42 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 7DBA48B864; Fri, 26 Mar 2021 07:44:43 +0100 (CET) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id YE_mnW0J1lyl; Fri, 26 Mar 2021 07:44:43 +0100 (CET) Received: from [192.168.4.90] (unknown [192.168.4.90]) by messagerie.si.c-s.fr (Postfix) with ESMTP id C29DA8B834; Fri, 26 Mar 2021 07:44:42 +0100 (CET) Subject: Re: [PATCH v2 6/7] cmdline: Gives architectures opportunity to use generically defined boot cmdline manipulation To: Will Deacon Cc: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , danielwa@cisco.com, robh@kernel.org, daniel@gimpelevich.san-francisco.ca.us, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-arch@vger.kernel.org, devicetree@vger.kernel.org References: <2eb6fad3470256fff5c9f33cd876f344abb1628b.1614705851.git.christophe.leroy@csgroup.eu> <20210303175747.GD19713@willie-the-truck> From: Christophe Leroy Message-ID: Date: Fri, 26 Mar 2021 07:44:40 +0100 User-Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.9.0 MIME-Version: 1.0 In-Reply-To: <20210303175747.GD19713@willie-the-truck> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: fr Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le 03/03/2021 à 18:57, Will Deacon a écrit : > On Tue, Mar 02, 2021 at 05:25:22PM +0000, Christophe Leroy wrote: >> Most architectures have similar boot command line manipulation >> options. This patchs adds the definition in init/Kconfig, gated by >> CONFIG_HAVE_CMDLINE that the architectures can select to use them. >> >> In order to use this, a few architectures will have to change their >> CONFIG options: >> - riscv has to replace CMDLINE_FALLBACK by CMDLINE_FROM_BOOTLOADER >> - architectures using CONFIG_CMDLINE_OVERRIDE or >> CONFIG_CMDLINE_OVERWRITE have to replace them by CONFIG_CMDLINE_FORCE. >> >> Architectures also have to define CONFIG_DEFAULT_CMDLINE. >> >> Signed-off-by: Christophe Leroy >> --- >> init/Kconfig | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++++ >> 1 file changed, 56 insertions(+) >> >> diff --git a/init/Kconfig b/init/Kconfig >> index 22946fe5ded9..a0f2ad9467df 100644 >> --- a/init/Kconfig >> +++ b/init/Kconfig >> @@ -117,6 +117,62 @@ config INIT_ENV_ARG_LIMIT >> Maximum of each of the number of arguments and environment >> variables passed to init from the kernel command line. >> >> +config HAVE_CMDLINE >> + bool >> + >> +config CMDLINE_BOOL >> + bool "Default bootloader kernel arguments" >> + depends on HAVE_CMDLINE >> + help >> + On some platforms, there is currently no way for the boot loader to >> + pass arguments to the kernel. For these platforms, you can supply >> + some command-line options at build time by entering them here. In >> + most cases you will need to specify the root device here. > > Why is this needed as well as CMDLINE_FROM_BOOTLOADER? IIUC, the latter > will use CONFIG_CMDLINE if it fails to get anything from the bootloader, > which sounds like the same scenario. > >> +config CMDLINE >> + string "Initial kernel command string" > > s/Initial/Default > > which is then consistent with the rest of the text here. > >> + depends on CMDLINE_BOOL > > Ah, so this is a bit different and I don't think lines-up with the > CMDLINE_BOOL help text. You are right, the help text is duplicated, I will change the text for the CMDLINE_BOOL > >> + default DEFAULT_CMDLINE >> + help >> + On some platforms, there is currently no way for the boot loader to >> + pass arguments to the kernel. For these platforms, you can supply >> + some command-line options at build time by entering them here. In >> + most cases you will need to specify the root device here. > > (same stale text) > >> +choice >> + prompt "Kernel command line type" if CMDLINE != "" >> + default CMDLINE_FROM_BOOTLOADER >> + help >> + Selects the way you want to use the default kernel arguments. > > How about: > > "Determines how the default kernel arguments are combined with any > arguments passed by the bootloader" > >> +config CMDLINE_FROM_BOOTLOADER >> + bool "Use bootloader kernel arguments if available" >> + help >> + Uses the command-line options passed by the boot loader. If >> + the boot loader doesn't provide any, the default kernel command >> + string provided in CMDLINE will be used. >> + >> +config CMDLINE_EXTEND > > Can we rename this to CMDLINE_APPEND, please? There is code in the tree > which disagrees about what CMDLINE_EXTEND means, so that will need be > to be updated to be consistent (e.g. the EFI stub parsing order). Having > the generic option with a different name means we won't accidentally end > up with the same inconsistent behaviours. > >> + bool "Extend bootloader kernel arguments" > > "Append to the bootloader kernel arguments" > >> + help >> + The default kernel command string will be appended to the >> + command-line arguments provided during boot. > > s/provided during boot/provided by the bootloader/ > >> + >> +config CMDLINE_PREPEND >> + bool "Prepend bootloader kernel arguments" > > "Prepend to the bootloader kernel arguments" > >> + help >> + The default kernel command string will be prepend to the >> + command-line arguments provided during boot. > > s/prepend/prepended/ > s/provided during boot/provided by the bootloader/ > >> + >> +config CMDLINE_FORCE >> + bool "Always use the default kernel command string" >> + help >> + Always use the default kernel command string, even if the boot >> + loader passes other arguments to the kernel. >> + This is useful if you cannot or don't want to change the >> + command-line options your boot loader passes to the kernel. > > I find the "This is useful if ..." sentence really confusing, perhaps just > remove it? I'd then tweak it to be: > > "Always use the default kernel command string, ignoring any arguments > provided by the bootloader." > Taken all your suggested text. Thanks Christophe