ARM: 6893/1: Allow for kernel command line concatenation

This patch allows the provided CONFIG_CMDLINE to be concatenated
with the one provided by the boot loader. This is useful to
merge the static values defined in CONFIG_CMDLINE with the
boot loader's (possibly) more dynamic values, such as startup
reasons and more.

Signed-off-by: Victor Boivie <victor.boivie@sonyericsson.com>
Reviewed-by: Bjorn Andersson <bjorn.andersson@sonyericsson.com>
Signed-off-by: Oskar Andero <oskar.andero@sonyericsson.com>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 9 insertions, 4 deletions

diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index 006c1e884eaf..6dce209a623b 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -672,11 +672,16 @@ __tagtable(ATAG_REVISION, parse_tag_revision);
 
 static int __init parse_tag_cmdline(const struct tag *tag)
 {
-#ifndef CONFIG_CMDLINE_FORCE
-        strlcpy(default_command_line, tag->u.cmdline.cmdline, COMMAND_LINE_SIZE);
-#else
+#if defined(CONFIG_CMDLINE_EXTEND)
+        strlcat(default_command_line, " ", COMMAND_LINE_SIZE);
+        strlcat(default_command_line, tag->u.cmdline.cmdline,
+                COMMAND_LINE_SIZE);
+#elif defined(CONFIG_CMDLINE_FORCE)
         pr_warning("Ignoring tag cmdline (using the default kernel command line)\n");
-#endif /* CONFIG_CMDLINE_FORCE */
+#else
+        strlcpy(default_command_line, tag->u.cmdline.cmdline,
+                COMMAND_LINE_SIZE);
+#endif
         return 0;
 }