lib: Add a generic cmdline parse function parse_option_str

There should be a generic function to parse params like a=b,c
Adding parse_option_str in lib/cmdline.c which will return true
if there's specified option set in the params.

Also updated efi=old_map parsing code to use the new function

Signed-off-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

1 files changed, 29 insertions, 0 deletions

diff --git a/lib/cmdline.c b/lib/cmdline.c
index 76a712e6e20e..8f13cf73c2ec 100644
--- a/lib/cmdline.c
+++ b/lib/cmdline.c
@@ -160,3 +160,32 @@ unsigned long long memparse(const char *ptr, char **retptr)
         return ret;
 }
 EXPORT_SYMBOL(memparse);
+
+/**
+ *      parse_option_str - Parse a string and check an option is set or not
+ *      @str: String to be parsed
+ *      @option: option name
+ *
+ *      This function parses a string containing a comma-separated list of
+ *      strings like a=b,c.
+ *
+ *      Return true if there's such option in the string, or return false.
+ */
+bool parse_option_str(const char *str, const char *option)
+{
+        while (*str) {
+                if (!strncmp(str, option, strlen(option))) {
+                        str += strlen(option);
+                        if (!*str || *str == ',')
+                                return true;
+                }
+
+                while (*str && *str != ',')
+                        str++;
+
+                if (*str == ',')
+                        str++;
+        }
+
+        return false;
+}