| Message ID | 164833880897.2575750.113875316750095499.stgit@devnote2 (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | bootconfig: Support embedding a bootconfig in kernel for non initrd boot | expand |
On Sun, Mar 27, 2022 at 8:53 AM Masami Hiramatsu <mhiramat@kernel.org> wrote: > > 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_EMBED_BOOT_CONFIG=y and set > the file path to CONFIG_EMBED_BOOT_CONFIG_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 <mhiramat@kernel.org> > --- > Changes in v3: > - Avoid updating the default.bconf if the file is not changed. > --- > include/linux/bootconfig.h | 10 ++++++++++ > init/Kconfig | 21 +++++++++++++++++++++ > init/main.c | 13 ++++++++----- > lib/.gitignore | 1 + > lib/Makefile | 10 ++++++++++ > lib/bootconfig.c | 23 +++++++++++++++++++++++ > 6 files changed, 73 insertions(+), 5 deletions(-) > > diff --git a/include/linux/bootconfig.h b/include/linux/bootconfig.h > index a4665c7ab07c..5dbda5e3e9bb 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_EMBED_BOOT_CONFIG > +char * __init xbc_get_embedded_bootconfig(size_t *size); > +#else > +static inline char *xbc_get_embedded_bootconfig(size_t *size) > +{ > + return NULL; > +} > +#endif > + > #endif > diff --git a/init/Kconfig b/init/Kconfig > index beb5b866c318..bff308a782f8 100644 > --- a/init/Kconfig > +++ b/init/Kconfig > @@ -1357,6 +1357,27 @@ config BOOT_CONFIG > > If unsure, say Y. > > +config EMBED_BOOT_CONFIG > + bool "Embed bootconfig file in the kernel" > + depends on BOOT_CONFIG > + default n > + help > + Embed a bootconfig file given by EMBED_BOOT_CONFIG_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 EMBED_BOOT_CONFIG_FILE > + string "Embedded bootconfig file path" > + default "" > + depends on EMBED_BOOT_CONFIG > + 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..180511324c95 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; > @@ -411,12 +411,15 @@ static void __init setup_boot_config(void) > static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata; > const char *msg; > int pos; > - u32 size; > + size_t 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); > + /* 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 +438,8 @@ 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 +452,7 @@ 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..30a2a5db7033 100644 > --- a/lib/.gitignore > +++ b/lib/.gitignore > @@ -6,3 +6,4 @@ > /oid_registry_data.c > /test_fortify.log > /test_fortify/*.log > +/default.bconf I think lib/.gitignore is alphabetically sorted. Please insert the new one to the proper line. > diff --git a/lib/Makefile b/lib/Makefile > index 353bc09ce38d..dd9f3ebb62ca 100644 > --- a/lib/Makefile > +++ b/lib/Makefile > @@ -276,6 +276,16 @@ $(foreach file, $(libfdt_files), \ > $(eval CFLAGS_$(file) = -I $(srctree)/scripts/dtc/libfdt)) > lib-$(CONFIG_LIBFDT) += $(libfdt_files) > > +ifeq ($(CONFIG_EMBED_BOOT_CONFIG),y) > +$(obj)/bootconfig.o: $(obj)/default.bconf > + > +targets += default.bconf I did not test this patch, but presumably "make clean" will miss to clean up default.bconf The 'targets' must exist outside the ifeq-block. Move the 'endif' up. ifeq ($(CONFIG_EMBED_BOOT_CONFIG),y) $(obj)/bootconfig.o: $(obj)/default.bconf endif targets += default.bconf ... > +filechk_defbconf = cat /dev/null $(CONFIG_EMBED_BOOT_CONFIG_FILE) > +$(obj)/default.bconf: FORCE > + $(call filechk,defbconf) This will work, but users will be confused when they try to build out-of-tree with the O= option. If CONFIG_EMBED_BOOT_CONFIG_FILE is a relative path, it is actually relative to the object tree, not the source tree. I am not sure if that is the expected behavior, but it is not documented anywhere. If you want to search both in the objtree and srctree, you can write like follows: [UNTESTED] filechk_defbconf = cat $(or $(real-prereqs), /dev/null) $(obj)/default.bconf: $(CONFIG_EMBED_BOOT_CONFIG_FILE) FORCE $(call filechk,defbconf) > + > +endif > + > lib-$(CONFIG_BOOT_CONFIG) += bootconfig.o > > obj-$(CONFIG_RBTREE_TEST) += rbtree_test.o > diff --git a/lib/bootconfig.c b/lib/bootconfig.c > index 74f3201ab8e5..3a3bf3a208e3 100644 > --- a/lib/bootconfig.c > +++ b/lib/bootconfig.c > @@ -12,6 +12,29 @@ > #include <linux/kernel.h> > #include <linux/memblock.h> > #include <linux/string.h> > + > +#ifdef CONFIG_EMBED_BOOT_CONFIG > +asm ( > +" .pushsection .init.data, \"aw\" \n" > +" .global embedded_bootconfig_data \n" > +"embedded_bootconfig_data: \n" > +" .incbin \"lib/default.bconf\" \n" > +" .global embedded_bootconfig_data_end \n" > +"embedded_bootconfig_data_end: \n" > +" .popsection \n" > +); > + > +extern __visible char embedded_bootconfig_data[]; > +extern __visible char embedded_bootconfig_data_end[]; > + > +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 >
On Mon, 28 Mar 2022 15:27:43 +0900 Masahiro Yamada <masahiroy@kernel.org> wrote: > On Sun, Mar 27, 2022 at 8:53 AM Masami Hiramatsu <mhiramat@kernel.org> wrote: > > > > 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_EMBED_BOOT_CONFIG=y and set > > the file path to CONFIG_EMBED_BOOT_CONFIG_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 <mhiramat@kernel.org> > > --- > > Changes in v3: > > - Avoid updating the default.bconf if the file is not changed. > > --- > > include/linux/bootconfig.h | 10 ++++++++++ > > init/Kconfig | 21 +++++++++++++++++++++ > > init/main.c | 13 ++++++++----- > > lib/.gitignore | 1 + > > lib/Makefile | 10 ++++++++++ > > lib/bootconfig.c | 23 +++++++++++++++++++++++ > > 6 files changed, 73 insertions(+), 5 deletions(-) > > > > diff --git a/include/linux/bootconfig.h b/include/linux/bootconfig.h > > index a4665c7ab07c..5dbda5e3e9bb 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_EMBED_BOOT_CONFIG > > +char * __init xbc_get_embedded_bootconfig(size_t *size); > > +#else > > +static inline char *xbc_get_embedded_bootconfig(size_t *size) > > +{ > > + return NULL; > > +} > > +#endif > > + > > #endif > > diff --git a/init/Kconfig b/init/Kconfig > > index beb5b866c318..bff308a782f8 100644 > > --- a/init/Kconfig > > +++ b/init/Kconfig > > @@ -1357,6 +1357,27 @@ config BOOT_CONFIG > > > > If unsure, say Y. > > > > +config EMBED_BOOT_CONFIG > > + bool "Embed bootconfig file in the kernel" > > + depends on BOOT_CONFIG > > + default n > > + help > > + Embed a bootconfig file given by EMBED_BOOT_CONFIG_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 EMBED_BOOT_CONFIG_FILE > > + string "Embedded bootconfig file path" > > + default "" > > + depends on EMBED_BOOT_CONFIG > > + 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..180511324c95 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; > > @@ -411,12 +411,15 @@ static void __init setup_boot_config(void) > > static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata; > > const char *msg; > > int pos; > > - u32 size; > > + size_t 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); > > + /* 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 +438,8 @@ 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 +452,7 @@ 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..30a2a5db7033 100644 > > --- a/lib/.gitignore > > +++ b/lib/.gitignore > > @@ -6,3 +6,4 @@ > > /oid_registry_data.c > > /test_fortify.log > > /test_fortify/*.log > > +/default.bconf > > > I think lib/.gitignore is alphabetically sorted. > > Please insert the new one > to the proper line. Ah, OK. Let me fix that. > > diff --git a/lib/Makefile b/lib/Makefile > > index 353bc09ce38d..dd9f3ebb62ca 100644 > > --- a/lib/Makefile > > +++ b/lib/Makefile > > @@ -276,6 +276,16 @@ $(foreach file, $(libfdt_files), \ > > $(eval CFLAGS_$(file) = -I $(srctree)/scripts/dtc/libfdt)) > > lib-$(CONFIG_LIBFDT) += $(libfdt_files) > > > > +ifeq ($(CONFIG_EMBED_BOOT_CONFIG),y) > > +$(obj)/bootconfig.o: $(obj)/default.bconf > > + > > +targets += default.bconf > > > I did not test this patch, but presumably > "make clean" will miss to clean up default.bconf > > The 'targets' must exist outside the ifeq-block. > Move the 'endif' up. > > > ifeq ($(CONFIG_EMBED_BOOT_CONFIG),y) > $(obj)/bootconfig.o: $(obj)/default.bconf > endif > > targets += default.bconf > > ... You're right! I didn't know this behavior. Thanks for the notice. I misunderstood that the files in targets always be built... After moving the 'targets' out of ifeq-block, I confirmed that the default.bconf was not generated when CONFIG_EMBED_BOOT_CONFIG is not set, and it is cleaned up when CONFIG_EMBED_BOOT_CONFIG=y. Thanks! > > > +filechk_defbconf = cat /dev/null $(CONFIG_EMBED_BOOT_CONFIG_FILE) > > +$(obj)/default.bconf: FORCE > > + $(call filechk,defbconf) > > > This will work, but users will be confused when they > try to build out-of-tree with the O= option. > > If CONFIG_EMBED_BOOT_CONFIG_FILE is a relative path, > it is actually relative to the object tree, not the source tree. Yes, that's right. I would like to fix this issue. > I am not sure if that is the expected behavior, but it is not documented > anywhere. > > > If you want to search both in the objtree and srctree, > you can write like follows: [UNTESTED] > > > filechk_defbconf = cat $(or $(real-prereqs), /dev/null) > $(obj)/default.bconf: $(CONFIG_EMBED_BOOT_CONFIG_FILE) FORCE > $(call filechk,defbconf) Great! let me check it works. Thank you, > > > > > > + > > +endif > > + > > lib-$(CONFIG_BOOT_CONFIG) += bootconfig.o > > > > obj-$(CONFIG_RBTREE_TEST) += rbtree_test.o > > diff --git a/lib/bootconfig.c b/lib/bootconfig.c > > index 74f3201ab8e5..3a3bf3a208e3 100644 > > --- a/lib/bootconfig.c > > +++ b/lib/bootconfig.c > > @@ -12,6 +12,29 @@ > > #include <linux/kernel.h> > > #include <linux/memblock.h> > > #include <linux/string.h> > > + > > +#ifdef CONFIG_EMBED_BOOT_CONFIG > > +asm ( > > +" .pushsection .init.data, \"aw\" \n" > > +" .global embedded_bootconfig_data \n" > > +"embedded_bootconfig_data: \n" > > +" .incbin \"lib/default.bconf\" \n" > > +" .global embedded_bootconfig_data_end \n" > > +"embedded_bootconfig_data_end: \n" > > +" .popsection \n" > > +); > > + > > +extern __visible char embedded_bootconfig_data[]; > > +extern __visible char embedded_bootconfig_data_end[]; > > + > > +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 > > > > > -- > Best Regards > Masahiro Yamada
diff --git a/include/linux/bootconfig.h b/include/linux/bootconfig.h index a4665c7ab07c..5dbda5e3e9bb 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_EMBED_BOOT_CONFIG +char * __init xbc_get_embedded_bootconfig(size_t *size); +#else +static inline char *xbc_get_embedded_bootconfig(size_t *size) +{ + return NULL; +} +#endif + #endif diff --git a/init/Kconfig b/init/Kconfig index beb5b866c318..bff308a782f8 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1357,6 +1357,27 @@ config BOOT_CONFIG If unsure, say Y. +config EMBED_BOOT_CONFIG + bool "Embed bootconfig file in the kernel" + depends on BOOT_CONFIG + default n + help + Embed a bootconfig file given by EMBED_BOOT_CONFIG_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 EMBED_BOOT_CONFIG_FILE + string "Embedded bootconfig file path" + default "" + depends on EMBED_BOOT_CONFIG + 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..180511324c95 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; @@ -411,12 +411,15 @@ static void __init setup_boot_config(void) static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata; const char *msg; int pos; - u32 size; + size_t 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); + /* 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 +438,8 @@ 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 +452,7 @@ 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..30a2a5db7033 100644 --- a/lib/.gitignore +++ b/lib/.gitignore @@ -6,3 +6,4 @@ /oid_registry_data.c /test_fortify.log /test_fortify/*.log +/default.bconf diff --git a/lib/Makefile b/lib/Makefile index 353bc09ce38d..dd9f3ebb62ca 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -276,6 +276,16 @@ $(foreach file, $(libfdt_files), \ $(eval CFLAGS_$(file) = -I $(srctree)/scripts/dtc/libfdt)) lib-$(CONFIG_LIBFDT) += $(libfdt_files) +ifeq ($(CONFIG_EMBED_BOOT_CONFIG),y) +$(obj)/bootconfig.o: $(obj)/default.bconf + +targets += default.bconf +filechk_defbconf = cat /dev/null $(CONFIG_EMBED_BOOT_CONFIG_FILE) +$(obj)/default.bconf: FORCE + $(call filechk,defbconf) + +endif + lib-$(CONFIG_BOOT_CONFIG) += bootconfig.o obj-$(CONFIG_RBTREE_TEST) += rbtree_test.o diff --git a/lib/bootconfig.c b/lib/bootconfig.c index 74f3201ab8e5..3a3bf3a208e3 100644 --- a/lib/bootconfig.c +++ b/lib/bootconfig.c @@ -12,6 +12,29 @@ #include <linux/kernel.h> #include <linux/memblock.h> #include <linux/string.h> + +#ifdef CONFIG_EMBED_BOOT_CONFIG +asm ( +" .pushsection .init.data, \"aw\" \n" +" .global embedded_bootconfig_data \n" +"embedded_bootconfig_data: \n" +" .incbin \"lib/default.bconf\" \n" +" .global embedded_bootconfig_data_end \n" +"embedded_bootconfig_data_end: \n" +" .popsection \n" +); + +extern __visible char embedded_bootconfig_data[]; +extern __visible char embedded_bootconfig_data_end[]; + +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
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_EMBED_BOOT_CONFIG=y and set the file path to CONFIG_EMBED_BOOT_CONFIG_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 <mhiramat@kernel.org> --- Changes in v3: - Avoid updating the default.bconf if the file is not changed. --- include/linux/bootconfig.h | 10 ++++++++++ init/Kconfig | 21 +++++++++++++++++++++ init/main.c | 13 ++++++++----- lib/.gitignore | 1 + lib/Makefile | 10 ++++++++++ lib/bootconfig.c | 23 +++++++++++++++++++++++ 6 files changed, 73 insertions(+), 5 deletions(-)