x86, boot: Add get_cmd_line_ptr()

Add an accessor function for the command line address.
Later we will add support for holding a 64-bit address via ext_cmd_line_ptr.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1359058816-7615-17-git-send-email-yinghai@kernel.org
Cc: Gokul Caushik <caushik1@gmail.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Joe Millenbach <jmillenbach@gmail.com>
Cc: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

arch/x86/boot/compressed/cmdline.c

@@ -13,13 +13,19 @@ static inline char rdfs8(addr_t addr)
 	return *((char *)(fs + addr));
 }
 #include "../cmdline.c"
+static unsigned long get_cmd_line_ptr(void)
+{
+	unsigned long cmd_line_ptr = real_mode->hdr.cmd_line_ptr;
+
+	return cmd_line_ptr;
+}
 int cmdline_find_option(const char *option, char *buffer, int bufsize)
 {
-	return __cmdline_find_option(real_mode->hdr.cmd_line_ptr, option, buffer, bufsize);
+	return __cmdline_find_option(get_cmd_line_ptr(), option, buffer, bufsize);
 }
 int cmdline_find_option_bool(const char *option)
 {
-	return __cmdline_find_option_bool(real_mode->hdr.cmd_line_ptr, option);
+	return __cmdline_find_option_bool(get_cmd_line_ptr(), option);
 }
 
 #endif