From patchwork Sun Apr 4 17:20:48 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christophe Leroy X-Patchwork-Id: 12182333 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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 88E55C43462 for ; Sun, 4 Apr 2021 17:20:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5EBA361364 for ; Sun, 4 Apr 2021 17:20:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231290AbhDDRU5 (ORCPT ); Sun, 4 Apr 2021 13:20:57 -0400 Received: from pegase1.c-s.fr ([93.17.236.30]:63707 "EHLO pegase1.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231272AbhDDRU4 (ORCPT ); Sun, 4 Apr 2021 13:20:56 -0400 Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 4FD0tP1t4vz9tymG; Sun, 4 Apr 2021 19:20:45 +0200 (CEST) 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 ffq992l6CBkv; Sun, 4 Apr 2021 19:20:45 +0200 (CEST) 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 4FD0tP0d2fz9tymF; Sun, 4 Apr 2021 19:20:45 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 9F2F08B78E; Sun, 4 Apr 2021 19:20:48 +0200 (CEST) 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 b-KtXSnASDF0; Sun, 4 Apr 2021 19:20:48 +0200 (CEST) Received: from po16121vm.idsi0.si.c-s.fr (unknown [192.168.4.90]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 4454D8B76A; Sun, 4 Apr 2021 19:20:48 +0200 (CEST) Received: by po16121vm.idsi0.si.c-s.fr (Postfix, from userid 0) id 06D3A67685; Sun, 4 Apr 2021 17:20:48 +0000 (UTC) Message-Id: <34d20d1dbb88f26d418b33985557b0475374a1a5.1617556785.git.christophe.leroy@csgroup.eu> From: Christophe Leroy Subject: [RFC PATCH v6 1/1] cmdline: Add capability to both append and prepend at the same time To: will@kernel.org, danielwa@cisco.com, robh@kernel.org, daniel@gimpelevich.san-francisco.ca.us, arnd@kernel.org, akpm@linux-foundation.org Cc: linux-arch@vger.kernel.org, devicetree@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org, microblaze , linux-mips@vger.kernel.org, nios2 , openrisc@lists.librecores.org, linux-hexagon@vger.kernel.org, linux-riscv@lists.infradead.org, x86@kernel.org, linux-xtensa@linux-xtensa.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-mm@kvack.org Date: Sun, 4 Apr 2021 17:20:48 +0000 (UTC) Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org One user has expressed the need to both append and prepend some built-in parameters to the command line provided by the bootloader. Allthough it is a corner case, it is easy to implement so let's do it. When the user chooses to prepend the bootloader provided command line with the built-in command line, he is offered the possibility to enter an additionnal built-in command line to be appended after the bootloader provided command line. It is a complementary feature which has no impact on the already existing ones and/or the existing defconfig. Suggested-by: Daniel Walker Signed-off-by: Christophe Leroy --- Sending this out as an RFC, applies on top of the series ("Implement GENERIC_CMDLINE"). I will add it to the series next spin unless someone is against it. --- include/linux/cmdline.h | 3 +++ init/Kconfig | 12 +++++++++++- 2 files changed, 14 insertions(+), 1 deletion(-) diff --git a/include/linux/cmdline.h b/include/linux/cmdline.h index 020028e2bdf0..fb274a4d5519 100644 --- a/include/linux/cmdline.h +++ b/include/linux/cmdline.h @@ -36,6 +36,9 @@ static __always_inline bool __cmdline_build(char *dst, const char *src) len = cmdline_strlcat(dst, src, COMMAND_LINE_SIZE); + if (IS_ENABLED(CONFIG_CMDLINE_PREPEND)) + len = cmdline_strlcat(dst, " " CONFIG_CMDLINE_MORE, COMMAND_LINE_SIZE); + if (IS_ENABLED(CONFIG_CMDLINE_APPEND)) len = cmdline_strlcat(dst, " " CONFIG_CMDLINE, COMMAND_LINE_SIZE); diff --git a/init/Kconfig b/init/Kconfig index fa002e3765ab..cd3087ff4f28 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -128,6 +128,14 @@ config CMDLINE If this string is not empty, additional choices are proposed below to determine how it will be used by the kernel. +config CMDLINE_MORE + string "Additional default kernel command string" if GENERIC_CMDLINE && CMDLINE_PREPEND + default "" + help + Defines an additional default kernel command string. + If this string is not empty, it is appended to the + command-line arguments provided by the bootloader + choice prompt "Kernel command line type" if CMDLINE != "" default CMDLINE_PREPEND if ARCH_WANT_CMDLINE_PREPEND_BY_DEFAULT @@ -154,7 +162,9 @@ config CMDLINE_PREPEND bool "Prepend to the bootloader kernel arguments" help The default kernel command string will be prepended to the - command-line arguments provided by the bootloader. + command-line arguments provided by the bootloader. When this + option is selected, another string can be added which will + be appended. config CMDLINE_FORCE bool "Always use the default kernel command string"