From patchwork Wed Apr 6 02:30:59 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12803267 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1DA63C43217 for ; Wed, 6 Apr 2022 12:06:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231970AbiDFMII (ORCPT ); Wed, 6 Apr 2022 08:08:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48172 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233088AbiDFMHz (ORCPT ); Wed, 6 Apr 2022 08:07:55 -0400 Received: from sin.source.kernel.org (sin.source.kernel.org [IPv6:2604:1380:40e1:4800::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A2887274E59; Tue, 5 Apr 2022 19:31:06 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id 18A49CE2049; Wed, 6 Apr 2022 02:31:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 22770C385A1; Wed, 6 Apr 2022 02:31:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1649212263; bh=OEz1OieAEVLpYShok1rv8Y+hnxwh95YbTkBGw64pwW4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rDLdOejqAdW9XOVth+WrjU+baIxSjLNJPcLDSEueYZr2QjP9LMESEcvtOFLlgiewO Ps5fBlEm8jcfnSFUDjLKK2MW1JXiV5NHyKsbPRWzprAxblhXP6HPis+AAOt1Q1AdEq M5gsFaLhjIyTE1JAKGLphHUMKLy/oo+VPYNbfk/otKFbSk3U67nX8OeBlVoIBrYv9b G/iMDtWoX8KafxRdEb/a3aD2QEfzknVMK3HVwr28GGnk1EDt7veCWcOonOCuFSpDlK xusJTTlbBMm9a3uYjtm7F/cU8qm6tFgV2ToNFSRaT4s7iSbF9VzmFd2aTRs1FrO2UX GRec1GFwCjC1A== From: Masami Hiramatsu To: Steven Rostedt Cc: Masami Hiramatsu , Padmanabha Srinivasaiah , LKML , Jonathan Corbet , linux-doc@vger.kernel.org, Randy Dunlap , Nick Desaulniers , Sami Tolvanen , Nathan Chancellor , llvm@lists.linux.dev, Masahiro Yamada , Linux Kbuild mailing list Subject: [PATCH v8 1/4] bootconfig: Make the bootconfig.o as a normal object file Date: Wed, 6 Apr 2022 11:30:59 +0900 Message-Id: <164921225875.1090670.15565363126983098971.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <164921224829.1090670.9700650651725930602.stgit@devnote2> References: <164921224829.1090670.9700650651725930602.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org Since the APIs defined in the bootconfig.o are not individually used, it is meaningless to build it as library by lib-y. Use obj-y for that. Reported-by: Masahiro Yamada Signed-off-by: Masami Hiramatsu --- Changes in v6: - Newly added. --- lib/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/Makefile b/lib/Makefile index 353bc09ce38d..4fc48543dc8f 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -276,7 +276,7 @@ $(foreach file, $(libfdt_files), \ $(eval CFLAGS_$(file) = -I $(srctree)/scripts/dtc/libfdt)) lib-$(CONFIG_LIBFDT) += $(libfdt_files) -lib-$(CONFIG_BOOT_CONFIG) += bootconfig.o +obj-$(CONFIG_BOOT_CONFIG) += bootconfig.o obj-$(CONFIG_RBTREE_TEST) += rbtree_test.o obj-$(CONFIG_INTERVAL_TREE_TEST) += interval_tree_test.o From patchwork Wed Apr 6 02:31:09 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12803761 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 189B4C433FE for ; Wed, 6 Apr 2022 16:21:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237664AbiDFQX3 (ORCPT ); Wed, 6 Apr 2022 12:23:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51106 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237039AbiDFQXI (ORCPT ); Wed, 6 Apr 2022 12:23:08 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1EC8C1DEC07; Tue, 5 Apr 2022 19:31:15 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id AE050616CA; Wed, 6 Apr 2022 02:31:14 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4446DC385A4; Wed, 6 Apr 2022 02:31:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1649212274; bh=SFAoQoDCZH9+H/cOjK0kYrO4Z6OtnYYL4lqW44mHkAk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GjpViAsODRnbAoMPNk6BDqbzbbKCcUsY272zWtNbKXvZAM9IhNkcRN1tvjXbgTyk0 CpqH9+3UWy5o2TouZsnQZySLUqtJZzlJTWZ9J1hxv7bCI9ARrxAl+JfvLIFQswOL5m QTNZdKEUymJTQIz5F+O5SMrvhFUWPJZREPigh6L5muaN+DcnoAqKvoUsGFeRkrrb6O xWGYR/eELKRzrbsdizj6flxRED6ChriiMXtOb/ohSS2AfniSFLMSmu1qOAgUFtO22n xZtobsnqvInAIYN9hNH39RYVyBXnJa1ZYfpbaHBbbLfVE8Gw59UM8FF4RDcUUzasUY 4eVkQZv0yK5Tg== From: Masami Hiramatsu To: Steven Rostedt Cc: Masami Hiramatsu , Padmanabha Srinivasaiah , LKML , Jonathan Corbet , linux-doc@vger.kernel.org, Randy Dunlap , Nick Desaulniers , Sami Tolvanen , Nathan Chancellor , llvm@lists.linux.dev, Masahiro Yamada , Linux Kbuild mailing list Subject: [PATCH v8 2/4] bootconfig: Check the checksum before removing the bootconfig from initrd Date: Wed, 6 Apr 2022 11:31:09 +0900 Message-Id: <164921226891.1090670.16955839243639298134.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <164921224829.1090670.9700650651725930602.stgit@devnote2> References: <164921224829.1090670.9700650651725930602.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org Check the bootconfig's checksum before removing the bootcinfig data from initrd to avoid modifying initrd by mistake. This will also simplifies the get_boot_config_from_initrd() interface. Signed-off-by: Masami Hiramatsu --- init/main.c | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-) diff --git a/init/main.c b/init/main.c index 560f45c27ffe..4f3ba3b84e34 100644 --- a/init/main.c +++ b/init/main.c @@ -265,7 +265,7 @@ static int __init loglevel(char *str) early_param("loglevel", loglevel); #ifdef CONFIG_BLK_DEV_INITRD -static void * __init get_boot_config_from_initrd(u32 *_size, u32 *_csum) +static void * __init get_boot_config_from_initrd(u32 *_size) { u32 size, csum; char *data; @@ -299,17 +299,20 @@ static void * __init get_boot_config_from_initrd(u32 *_size, u32 *_csum) return NULL; } + if (xbc_calc_checksum(data, size) != csum) { + pr_err("bootconfig checksum failed\n"); + return NULL; + } + /* Remove bootconfig from initramfs/initrd */ initrd_end = (unsigned long)data; if (_size) *_size = size; - if (_csum) - *_csum = csum; return data; } #else -static void * __init get_boot_config_from_initrd(u32 *_size, u32 *_csum) +static void * __init get_boot_config_from_initrd(u32 *_size) { return NULL; } @@ -408,12 +411,12 @@ static void __init setup_boot_config(void) static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata; const char *msg; int pos; - u32 size, csum; + u32 size; char *data, *err; int ret; /* Cut out the bootconfig data even if we have no bootconfig option */ - data = get_boot_config_from_initrd(&size, &csum); + data = get_boot_config_from_initrd(&size); strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE); err = parse_args("bootconfig", tmp_cmdline, NULL, 0, 0, 0, NULL, @@ -437,11 +440,6 @@ static void __init setup_boot_config(void) return; } - if (xbc_calc_checksum(data, size) != csum) { - pr_err("bootconfig checksum failed\n"); - return; - } - ret = xbc_init(data, size, &msg, &pos); if (ret < 0) { if (pos < 0) @@ -470,7 +468,7 @@ static void __init exit_boot_config(void) static void __init setup_boot_config(void) { /* Remove bootconfig data from initrd */ - get_boot_config_from_initrd(NULL, NULL); + get_boot_config_from_initrd(NULL); } static int __init warn_bootconfig(char *str) From patchwork Wed Apr 6 02:31:19 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12802990 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id F30C1C433EF for ; Wed, 6 Apr 2022 09:37:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1355698AbiDFJjw (ORCPT ); Wed, 6 Apr 2022 05:39:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53384 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1585823AbiDFJgr (ORCPT ); Wed, 6 Apr 2022 05:36:47 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8674A19D61B; Tue, 5 Apr 2022 19:31:25 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 20AEB616B8; Wed, 6 Apr 2022 02:31:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 321F8C385A0; Wed, 6 Apr 2022 02:31:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1649212284; bh=aw2bq5SC6SuV7FHJKRzv7VxT/0OLDHfP3nbZybj0tO4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KhCwMTsQmGqmfrifRKhNYRshX9Xl9dg1YeS5en9OMMAb2Jvrns3OwcFsiRAk0ZCnd rI2Bg8FjLLLuBPzw9N72CUjdrH6EoTPNI7QW/FhqY4RF5e3FxcgaZT/2eRAK5pSjx4 Pp2l2FRn8bATi7BHqSjPCDXWCyIx+PdUDux/4dqcB1QnWlndoTVHb9WvwsRg57d/di JczJt0ogZ3iw3ZsLJYKLx3zH6dMSoFp4ggG2cg67QshCe4NQcbEYnQfvWENpLYOWSR dWsfEf5l6TJqokFrQ/yspb+QoqXysk+1geOPyW/O+erY/UXNXD3p89nq5iPqcObaZL yOfmu+Sc25IHA== From: Masami Hiramatsu To: Steven Rostedt Cc: Masami Hiramatsu , Padmanabha Srinivasaiah , LKML , Jonathan Corbet , linux-doc@vger.kernel.org, Randy Dunlap , Nick Desaulniers , Sami Tolvanen , Nathan Chancellor , llvm@lists.linux.dev, Masahiro Yamada , Linux Kbuild mailing list Subject: [PATCH v8 3/4] bootconfig: Support embedding a bootconfig file in kernel Date: Wed, 6 Apr 2022 11:31:19 +0900 Message-Id: <164921227943.1090670.14035119557571329218.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <164921224829.1090670.9700650651725930602.stgit@devnote2> References: <164921224829.1090670.9700650651725930602.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org This allows kernel developer to embed a default bootconfig file in the kernel instead of embedding it in the initrd. This will be good for who are using the kernel without initrd, or who needs a default bootconfigs. This needs to set two kconfigs: CONFIG_BOOT_CONFIG_EMBED=y and set the file path to CONFIG_BOOT_CONFIG_EMBED_FILE. Note that you still need 'bootconfig' command line option to load the embedded bootconfig. Also if you boot using an initrd with a different bootconfig, the kernel will use the bootconfig in the initrd, instead of the default bootconfig. Signed-off-by: Masami Hiramatsu --- Changes in v8: - Fix a build error in CONFIG_BLK_DEV_INITRD=n case. Changes in v7: - Change kconfig option name to share the common prefix so that we can search it easier. - Make embedded_bootconfig_data readonly. - Select CONFIG_BLK_DEV_INITRD only if CONFIG_BOOT_CONFIG_EMBED=n - Remove redundant default settings for new Kconfig options. Changes in v6: - Split out the .incbin asm part as bootconfig-data.S according to Masahiro's comment. Changes in v5: - Fix .gitignore to be sorted alphabetically. - Make default.bconf is cleaned up correctly. - Allow user to specify relative path to CONFIG_EMBED_BOOT_CONFIG_FILE. (Thanks Masahiro!) Changes in v4: - Avoid updating the default.bconf if the file is not changed. --- MAINTAINERS | 1 + include/linux/bootconfig.h | 10 ++++++++++ init/Kconfig | 21 ++++++++++++++++++++- init/main.c | 22 ++++++++++++---------- lib/.gitignore | 1 + lib/Makefile | 8 ++++++++ lib/bootconfig-data.S | 10 ++++++++++ lib/bootconfig.c | 13 +++++++++++++ 8 files changed, 75 insertions(+), 11 deletions(-) create mode 100644 lib/bootconfig-data.S diff --git a/MAINTAINERS b/MAINTAINERS index c10fbd13080a..88c9d62acd90 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -7318,6 +7318,7 @@ S: Maintained F: Documentation/admin-guide/bootconfig.rst F: fs/proc/bootconfig.c F: include/linux/bootconfig.h +F: lib/bootconfig-data.S F: lib/bootconfig.c F: tools/bootconfig/* F: tools/bootconfig/scripts/* diff --git a/include/linux/bootconfig.h b/include/linux/bootconfig.h index a4665c7ab07c..1611f9db878e 100644 --- a/include/linux/bootconfig.h +++ b/include/linux/bootconfig.h @@ -289,4 +289,14 @@ int __init xbc_get_info(int *node_size, size_t *data_size); /* XBC cleanup data structures */ void __init xbc_exit(void); +/* XBC embedded bootconfig data in kernel */ +#ifdef CONFIG_BOOT_CONFIG_EMBED +const char * __init xbc_get_embedded_bootconfig(size_t *size); +#else +static inline const char *xbc_get_embedded_bootconfig(size_t *size) +{ + return NULL; +} +#endif + #endif diff --git a/init/Kconfig b/init/Kconfig index beb5b866c318..e7c75fb7d244 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1347,7 +1347,7 @@ endif config BOOT_CONFIG bool "Boot config support" - select BLK_DEV_INITRD + select BLK_DEV_INITRD if !BOOT_CONFIG_EMBED help Extra boot config allows system admin to pass a config file as complemental extension of kernel cmdline when booting. @@ -1357,6 +1357,25 @@ config BOOT_CONFIG If unsure, say Y. +config BOOT_CONFIG_EMBED + bool "Embed bootconfig file in the kernel" + depends on BOOT_CONFIG + help + Embed a bootconfig file given by BOOT_CONFIG_EMBED_FILE in the + kernel. Usually, the bootconfig file is loaded with the initrd + image. But if the system doesn't support initrd, this option will + help you by embedding a bootconfig file while building the kernel. + + If unsure, say N. + +config BOOT_CONFIG_EMBED_FILE + string "Embedded bootconfig file path" + depends on BOOT_CONFIG_EMBED + help + Specify a bootconfig file which will be embedded to the kernel. + This bootconfig will be used if there is no initrd or no other + bootconfig in the initrd. + choice prompt "Compiler optimization level" default CC_OPTIMIZE_FOR_PERFORMANCE diff --git a/init/main.c b/init/main.c index 4f3ba3b84e34..d00c6f77d0e0 100644 --- a/init/main.c +++ b/init/main.c @@ -265,7 +265,7 @@ static int __init loglevel(char *str) early_param("loglevel", loglevel); #ifdef CONFIG_BLK_DEV_INITRD -static void * __init get_boot_config_from_initrd(u32 *_size) +static void * __init get_boot_config_from_initrd(size_t *_size) { u32 size, csum; char *data; @@ -312,7 +312,7 @@ static void * __init get_boot_config_from_initrd(u32 *_size) return data; } #else -static void * __init get_boot_config_from_initrd(u32 *_size) +static void * __init get_boot_config_from_initrd(size_t *_size) { return NULL; } @@ -409,14 +409,16 @@ static int __init warn_bootconfig(char *str) static void __init setup_boot_config(void) { static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata; - const char *msg; - int pos; - u32 size; - char *data, *err; - int ret; + const char *msg, *data; + int pos, ret; + size_t size; + char *err; /* Cut out the bootconfig data even if we have no bootconfig option */ data = get_boot_config_from_initrd(&size); + /* If there is no bootconfig in initrd, try embedded one. */ + if (!data) + data = xbc_get_embedded_bootconfig(&size); strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE); err = parse_args("bootconfig", tmp_cmdline, NULL, 0, 0, 0, NULL, @@ -435,8 +437,8 @@ static void __init setup_boot_config(void) } if (size >= XBC_DATA_MAX) { - pr_err("bootconfig size %d greater than max size %d\n", - size, XBC_DATA_MAX); + pr_err("bootconfig size %ld greater than max size %d\n", + (long)size, XBC_DATA_MAX); return; } @@ -449,7 +451,7 @@ static void __init setup_boot_config(void) msg, pos); } else { xbc_get_info(&ret, NULL); - pr_info("Load bootconfig: %d bytes %d nodes\n", size, ret); + pr_info("Load bootconfig: %ld bytes %d nodes\n", (long)size, ret); /* keys starting with "kernel." are passed via cmdline */ extra_command_line = xbc_make_cmdline("kernel"); /* Also, "init." keys are init arguments */ diff --git a/lib/.gitignore b/lib/.gitignore index e5e217b8307b..54596b634ecb 100644 --- a/lib/.gitignore +++ b/lib/.gitignore @@ -1,6 +1,7 @@ # SPDX-License-Identifier: GPL-2.0-only /crc32table.h /crc64table.h +/default.bconf /gen_crc32table /gen_crc64table /oid_registry_data.c diff --git a/lib/Makefile b/lib/Makefile index 4fc48543dc8f..62a103aaabd4 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -277,6 +277,14 @@ $(foreach file, $(libfdt_files), \ lib-$(CONFIG_LIBFDT) += $(libfdt_files) obj-$(CONFIG_BOOT_CONFIG) += bootconfig.o +obj-$(CONFIG_BOOT_CONFIG_EMBED) += bootconfig-data.o + +$(obj)/bootconfig-data.o: $(obj)/default.bconf + +targets += default.bconf +filechk_defbconf = cat $(or $(real-prereqs), /dev/null) +$(obj)/default.bconf: $(CONFIG_BOOT_CONFIG_EMBED_FILE) FORCE + $(call filechk,defbconf) obj-$(CONFIG_RBTREE_TEST) += rbtree_test.o obj-$(CONFIG_INTERVAL_TREE_TEST) += interval_tree_test.o diff --git a/lib/bootconfig-data.S b/lib/bootconfig-data.S new file mode 100644 index 000000000000..ef85ba1a82f4 --- /dev/null +++ b/lib/bootconfig-data.S @@ -0,0 +1,10 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Embed default bootconfig in the kernel. + */ + .section .init.rodata, "aw" + .global embedded_bootconfig_data +embedded_bootconfig_data: + .incbin "lib/default.bconf" + .global embedded_bootconfig_data_end +embedded_bootconfig_data_end: diff --git a/lib/bootconfig.c b/lib/bootconfig.c index 74f3201ab8e5..c59d26068a64 100644 --- a/lib/bootconfig.c +++ b/lib/bootconfig.c @@ -12,6 +12,19 @@ #include #include #include + +#ifdef CONFIG_BOOT_CONFIG_EMBED +/* embedded_bootconfig_data is defined in bootconfig-data.S */ +extern __visible const char embedded_bootconfig_data[]; +extern __visible const char embedded_bootconfig_data_end[]; + +const char * __init xbc_get_embedded_bootconfig(size_t *size) +{ + *size = embedded_bootconfig_data_end - embedded_bootconfig_data; + return (*size) ? embedded_bootconfig_data : NULL; +} +#endif + #else /* !__KERNEL__ */ /* * NOTE: This is only for tools/bootconfig, because tools/bootconfig will From patchwork Wed Apr 6 02:31:30 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12803762 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 43D3BC433EF for ; Wed, 6 Apr 2022 16:21:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237182AbiDFQXc (ORCPT ); Wed, 6 Apr 2022 12:23:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52966 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238312AbiDFQXD (ORCPT ); Wed, 6 Apr 2022 12:23:03 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 202FA1DE6CA; Tue, 5 Apr 2022 19:31:37 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id B0645616CA; Wed, 6 Apr 2022 02:31:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 48457C385A1; Wed, 6 Apr 2022 02:31:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1649212296; bh=2MxGsdREcZcC5dPhVe4pegMYaaOwE0pzgrqWpuXtrGc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GXwGW062YdKL8+Jg+FwAV0W7WDkdIVsTVXDAEN7aXQNujZ35ZW3r/eAzX8retscRF R9mIWL8TtQRblz9fugeEJb203dMObcn5oNScGIeR3sTZoFengiBixG5/iVNGpYi/dU YhfsDDCZNrWTtqSUw78W6s1gQ9MH/u+xK5aE2Yiw/E+8AKSdcDiG/GAPzXuSu1RhLK lZ3q7+NR6Mvqb45MbN5emzUF4tUofgGHUgTqXZNN1GqMSi3+iIeRHrwmvyY3osNY8n KCqwT+BFAEC12NbbDkLtWy4gB1UYTjQ8Pj/h6lX4HUnT5sKKAgmF5yeqtbSj64VBMZ jf7B1pxWVkXmg== From: Masami Hiramatsu To: Steven Rostedt Cc: Masami Hiramatsu , Padmanabha Srinivasaiah , LKML , Jonathan Corbet , linux-doc@vger.kernel.org, Randy Dunlap , Nick Desaulniers , Sami Tolvanen , Nathan Chancellor , llvm@lists.linux.dev, Masahiro Yamada , Linux Kbuild mailing list Subject: [PATCH v8 4/4] docs: bootconfig: Add how to embed the bootconfig into kernel Date: Wed, 6 Apr 2022 11:31:30 +0900 Message-Id: <164921228987.1090670.16843569536974147213.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <164921224829.1090670.9700650651725930602.stgit@devnote2> References: <164921224829.1090670.9700650651725930602.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org Add a description how to embed the bootconfig file into kernel. Signed-off-by: Masami Hiramatsu --- Changes in v7: - Rename CONFIG_EMBED_BOOT_CONFIG* to CONFIG_BOOT_CONFIG_EMBED*. Changes in v5: - Update CONFIG_EMBED_BOOT_CONFIG_FILE which can accept relative path. Changes in v3: - Fix typos. Changes in v2: - Corrected the text accoding to Randy's suggestion. - Do not reccomend to use relative path for CONFIG_EMBED_BOOT_CONFIG_FILE. --- Documentation/admin-guide/bootconfig.rst | 31 +++++++++++++++++++++++++++--- 1 file changed, 28 insertions(+), 3 deletions(-) diff --git a/Documentation/admin-guide/bootconfig.rst b/Documentation/admin-guide/bootconfig.rst index a1860fc0ca88..d99994345d41 100644 --- a/Documentation/admin-guide/bootconfig.rst +++ b/Documentation/admin-guide/bootconfig.rst @@ -158,9 +158,15 @@ Each key-value pair is shown in each line with following style:: Boot Kernel With a Boot Config ============================== -Since the boot configuration file is loaded with initrd, it will be added -to the end of the initrd (initramfs) image file with padding, size, -checksum and 12-byte magic word as below. +There are two options to boot the kernel with bootconfig: attaching the +bootconfig to the initrd image or embedding it in the kernel itself. + +Attaching a Boot Config to Initrd +--------------------------------- + +Since the boot configuration file is loaded with initrd by default, +it will be added to the end of the initrd (initramfs) image file with +padding, size, checksum and 12-byte magic word as below. [initrd][bootconfig][padding][size(le32)][checksum(le32)][#BOOTCONFIG\n] @@ -196,6 +202,25 @@ To remove the config from the image, you can use -d option as below:: Then add "bootconfig" on the normal kernel command line to tell the kernel to look for the bootconfig at the end of the initrd file. +Embedding a Boot Config into Kernel +----------------------------------- + +If you can not use initrd, you can also embed the bootconfig file in the +kernel by Kconfig options. In this case, you need to recompile the kernel +with the following configs:: + + CONFIG_BOOT_CONFIG_EMBED=y + CONFIG_BOOT_CONFIG_EMBED_FILE="/PATH/TO/BOOTCONFIG/FILE" + +``CONFIG_BOOT_CONFIG_EMBED_FILE`` requires an absolute path or a relative +path to the bootconfig file from source tree or object tree. +The kernel will embed it as the default bootconfig. + +Just as when attaching the bootconfig to the initrd, you need ``bootconfig`` +option on the kernel command line to enable the embedded bootconfig. + +Note that even if you set this option, you can override the embedded +bootconfig by another bootconfig which attached to the initrd. Kernel parameters via Boot Config =================================