[PATCH 1/2 v2] x86/setup: update boot_command_line with builtin_cmdline in separate function

[Alexander Kuleshov <kuleshovmail@gmail.com>]

This patch introduces setup_cmdline function which appends/overrides
boot_command_linew with builtin_cmdline if CONFIG_CMDLINE_BOOL is set.
Previously this functional was in the setup_arch, but we need to move
it for getting actual command line as early as possible in the
arch/x86/kernel/head{32,64}.c

Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com>
---
 arch/x86/kernel/head32.c |  1 +
 arch/x86/kernel/head64.c |  1 +
 arch/x86/kernel/setup.c  | 31 ++++++++++++++++++-------------
 include/linux/init.h     |  6 +++++-
 4 files changed, 25 insertions(+), 14 deletions(-)

diff --git a/arch/x86/kernel/head32.c b/arch/x86/kernel/head32.c
index 2911ef3..7ad0ad0 100644
--- a/arch/x86/kernel/head32.c
+++ b/arch/x86/kernel/head32.c
@@ -31,6 +31,7 @@ static void __init i386_default_early_setup(void)
 
 asmlinkage __visible void __init i386_start_kernel(void)
 {
+	setup_cmdline();
 	cr4_init_shadow();
 	sanitize_boot_params(&boot_params);
 
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index c4f8d46..6eea2de 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -171,6 +171,7 @@ asmlinkage __visible void __init x86_64_start_kernel(char * real_mode_data)
 	load_idt((const struct desc_ptr *)&idt_descr);
 
 	copy_bootdata(__va(real_mode_data));
+	setup_cmdline();
 
 	/*
 	 * Load microcode early on BSP.
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 0a2421c..d578f37 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -841,6 +841,24 @@ dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p)
 }
 
 /*
+ * Append/Override boot command line with builtin command line if need
+ */
+void __init setup_cmdline(void) {
+#ifdef CONFIG_CMDLINE_BOOL
+#ifdef CONFIG_CMDLINE_OVERRIDE
+	strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
+#else
+	if (builtin_cmdline[0]) {
+		/* append boot loader cmdline to builtin */
+		strlcat(builtin_cmdline, " ", COMMAND_LINE_SIZE);
+		strlcat(builtin_cmdline, boot_command_line, COMMAND_LINE_SIZE);
+		strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
+	}
+#endif
+#endif
+}
+
+/*
  * Determine if we were loaded by an EFI loader.  If so, then we have also been
  * passed the efi memmap, systab, etc., so we should use these data structures
  * for initialization.  Note, the efi init code path is determined by the
@@ -968,19 +986,6 @@ void __init setup_arch(char **cmdline_p)
 	bss_resource.start = __pa_symbol(__bss_start);
 	bss_resource.end = __pa_symbol(__bss_stop)-1;
 
-#ifdef CONFIG_CMDLINE_BOOL
-#ifdef CONFIG_CMDLINE_OVERRIDE
-	strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
-#else
-	if (builtin_cmdline[0]) {
-		/* append boot loader cmdline to builtin */
-		strlcat(builtin_cmdline, " ", COMMAND_LINE_SIZE);
-		strlcat(builtin_cmdline, boot_command_line, COMMAND_LINE_SIZE);
-		strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
-	}
-#endif
-#endif
-
 	strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
 	*cmdline_p = command_line;
 
diff --git a/include/linux/init.h b/include/linux/init.h
index 2df8e8d..af8f2ec 100644
--- a/include/linux/init.h
+++ b/include/linux/init.h
@@ -152,7 +152,11 @@ void setup_arch(char **);
 void prepare_namespace(void);
 void __init load_default_modules(void);
 int __init init_rootfs(void);
+void __init setup_cmdline(void);
 extern void (*late_time_init)(void);
 
 extern bool initcall_debug;
-- 
2.3.3.611.g09038fc.dirty