boot/param: Move next_arg() function to lib/cmdline.c for later reuse

next_arg() will be used to parse boot parameters in the x86/boot/compressed code,
so move it to lib/cmdline.c for better code reuse.

No change in functionality.

Signed-off-by: Baoquan He <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Gustavo Padovan <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Jessica Yu <[email protected]>
Cc: Johannes Berg <[email protected]>
Cc: Josh Triplett <[email protected]>
Cc: Larry Finger <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Niklas Söderlund <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Petr Mladek <[email protected]>
Cc: Rasmus Villemoes <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: zijun_hu <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

1 files changed, 57 insertions, 0 deletions

diff --git a/lib/cmdline.c b/lib/cmdline.c
index 8f13cf73c2ec..3c6432df7e63 100644
--- a/lib/cmdline.c
+++ b/lib/cmdline.c
@@ -15,6 +15,7 @@
 #include <linux/export.h>
 #include <linux/kernel.h>
 #include <linux/string.h>
+#include <linux/ctype.h>
 
 /*
  *	If a hyphen was found in get_option, this will handle the
@@ -189,3 +190,59 @@ bool parse_option_str(const char *str, const char *option)
 
 	return false;
 }
+
+/*
+ * Parse a string to get a param value pair.
+ * You can use " around spaces, but can't escape ".
+ * Hyphens and underscores equivalent in parameter names.
+ */
+char *next_arg(char *args, char **param, char **val)
+{
+	unsigned int i, equals = 0;
+	int in_quote = 0, quoted = 0;
+	char *next;
+
+	if (*args == '"') {
+		args++;
+		in_quote = 1;
+		quoted = 1;
+	}
+
+	for (i = 0; args[i]; i++) {
+		if (isspace(args[i]) && !in_quote)
+			break;
+		if (equals == 0) {
+			if (args[i] == '=')
+				equals = i;
+		}
+		if (args[i] == '"')
+			in_quote = !in_quote;
+	}
+
+	*param = args;
+	if (!equals)
+		*val = NULL;
+	else {
+		args[equals] = '\0';
+		*val = args + equals + 1;
+
+		/* Don't include quotes in value. */
+		if (**val == '"') {
+			(*val)++;
+			if (args[i-1] == '"')
+				args[i-1] = '\0';
+		}
+	}
+	if (quoted && args[i-1] == '"')
+		args[i-1] = '\0';
+
+	if (args[i]) {
+		args[i] = '\0';
+		next = args + i + 1;
+	} else
+		next = args + i;
+
+	/* Chew up trailing spaces. */
+	return skip_spaces(next);
+	//return next;
+}