parse_area_spec():

- No need to handle strings where only size or end is given. This
  form is confusing and does not give real benefit.
- Fix start-end form. The calculation was wrong.
- Return an error if end < start.
- Add function description.

1 files changed, 25 insertions, 15 deletions

diff --git a/lib/misc.c b/lib/misc.c
index cc4e49d9f2..ea0ffc2b19 100644
--- a/lib/misc.c
+++ b/lib/misc.c
@@ -26,6 +26,10 @@
 #include <fs.h>
 #include <linux/ctype.h>
 
+/*
+ * Like simple_strtoul() but handles an optional G, M, K or k
+ * suffix for Gigabyte, Megabyte or Kilobyte
+ */
 unsigned long strtoul_suffix(const char *str, char **endp, int base)
 {
         unsigned long val;
@@ -42,6 +46,8 @@ unsigned long strtoul_suffix(const char *str, char **endp, int base)
         case 'K':
                 val *= 1024;
                 end++;
+	default:
+		break;
         }
 
         if (endp)
@@ -51,23 +57,22 @@ unsigned long strtoul_suffix(const char *str, char **endp, int base)
 }
 EXPORT_SYMBOL(strtoul_suffix);
 
+/*
+ * This function parses strings in the form <startadr>[-endaddr]
+ * or <startadr>[+size] and fills in start and size accordingly.
+ * <startadr> and <endadr> can be given in decimal or hex (with 0x prefix)
+ * and can have an optional G, M, K or k suffix.
+ *
+ * examples:
+ * 0x1000-0x2000 -> start = 0x1000, size = 0x1001
+ * 0x1000+0x1000 -> start = 0x1000, size = 0x1000
+ * 0x1000        -> start = 0x1000, size = ~0
+ * 1M+1k         -> start = 0x100000, size = 0x400
+ */
 int parse_area_spec(const char *str, ulong *start, ulong *size)
 {
 	char *endp;
-
-	if (*str == '+') {
-		/* no beginning given but size so start is 0 */
-		*start = 0;
-		*size = strtoul_suffix(str + 1, &endp, 0);
-		return 0;
-	}
-
-	if (*str == '-') {
-		/* no beginning given but end, so start is 0 */
-		*start = 0;
-		*size = strtoul_suffix(str + 1, &endp, 0) + 1;
-		return 0;
-	}
+	ulong end;
 
 	if (!isdigit(*str))
 		return -1;
@@ -84,7 +89,12 @@ int parse_area_spec(const char *str, ulong *start, ulong *size)
 
 	if (*str == '-') {
                 /* beginning and end given */
-		*size = strtoul_suffix(str + 1, NULL, 0) + 1;
+		end = strtoul_suffix(str + 1, NULL, 0);
+		if (end < *start) {
+			printf("end < start\n");
+			return -1;
+		}
+		*size = end - *start + 1;
 		return 0;
 	}