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authorPaul E. McKenney <paulmck@kernel.org>2023-02-22 08:27:48 +0900
committerMasami Hiramatsu (Google) <mhiramat@kernel.org>2023-02-22 08:27:48 +0900
commitb743852ccc1d9630bb07dc65ef185dab7e2984f6 (patch)
treef9f53229560240ddf75faa83a7bfb61a632923b2 /init
parentcf8c59a3756b2735c409a9b3ac1e4ec556546a7a (diff)
downloadlinux-b743852ccc1d9630bb07dc65ef185dab7e2984f6.tar.gz
Allow forcing unconditional bootconfig processing
The BOOT_CONFIG family of Kconfig options allows a bootconfig file containing kernel boot parameters to be embedded into an initrd or into the kernel itself. This can be extremely useful when deploying kernels in cases where some of the boot parameters depend on the kernel version rather than on the server hardware, firmware, or workload. Unfortunately, the "bootconfig" kernel parameter must be specified in order to cause the kernel to look for the embedded bootconfig file, and it clearly does not help to embed this "bootconfig" kernel parameter into that file. Therefore, provide a new BOOT_CONFIG_FORCE Kconfig option that causes the kernel to act as if the "bootconfig" kernel parameter had been specified. In other words, kernels built with CONFIG_BOOT_CONFIG_FORCE=y will look for the embedded bootconfig file even when the "bootconfig" kernel parameter is omitted. This permits kernel-version-dependent kernel boot parameters to be embedded into the kernel image without the need to (for example) update large numbers of boot loaders. Link: https://lore.kernel.org/all/20230105005838.GA1772817@paulmck-ThinkPad-P17-Gen-1/ Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: <linux-doc@vger.kernel.org> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Diffstat (limited to 'init')
-rw-r--r--init/Kconfig12
-rw-r--r--init/main.c2
2 files changed, 13 insertions, 1 deletions
diff --git a/init/Kconfig b/init/Kconfig
index 44e90b28a30f12..04f0c5bb9e150a 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1380,6 +1380,18 @@ config BOOT_CONFIG
If unsure, say Y.
+config BOOT_CONFIG_FORCE
+ bool "Force unconditional bootconfig processing"
+ depends on BOOT_CONFIG
+ help
+ With this Kconfig option set, BOOT_CONFIG processing is carried
+ out even when the "bootconfig" kernel-boot parameter is omitted.
+ In fact, with this Kconfig option set, there is no way to
+ make the kernel ignore the BOOT_CONFIG-supplied kernel-boot
+ parameters.
+
+ If unsure, say N.
+
config BOOT_CONFIG_EMBED
bool "Embed bootconfig file in the kernel"
depends on BOOT_CONFIG
diff --git a/init/main.c b/init/main.c
index e1c3911d7c707d..669cb892e6c179 100644
--- a/init/main.c
+++ b/init/main.c
@@ -156,7 +156,7 @@ static char *extra_init_args;
#ifdef CONFIG_BOOT_CONFIG
/* Is bootconfig on command line? */
-static bool bootconfig_found;
+static bool bootconfig_found = IS_ENABLED(CONFIG_BOOT_CONFIG_FORCE);
static size_t initargs_offs;
#else
# define bootconfig_found false