[PATCH] [MTD] cmdlinepart: allow zero offset value

[PATCH] [MTD] cmdlinepart: allow zero offset value

[Atsushi Nemoto]

Current cmdlinepart.c uses offset value 0 to specify a continuous
partition.  This prevents creating a second partition starting at 0.

For example, I can split 4MB device using "mtdparts=id:2M,2M", but I
can not do "mtdparts=id:2M@2M,2M@0" to swap mtd0 and mtd1.

This patch introduces special OFFSET_CONTINUOUS value for a continuous
partition and allows 0 for offset value.

Also this patch replaces 0xffffffff with ULONG_MAX for SIZE_REMAINING.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>

diff --git a/drivers/mtd/cmdlinepart.c b/drivers/mtd/cmdlinepart.c
index 6b8bb2e..e719883 100644
--- a/drivers/mtd/cmdlinepart.c
+++ b/drivers/mtd/cmdlinepart.c
@@ -42,7 +42,8 @@
 
 
 /* special size referring to all the remaining space in a partition */
-#define SIZE_REMAINING 0xffffffff
+#define SIZE_REMAINING ULONG_MAX
+#define OFFSET_CONTINUOUS ULONG_MAX
 
 struct cmdline_mtd_partition {
 	struct cmdline_mtd_partition *next;
@@ -75,7 +76,7 @@ static struct mtd_partition * newpart(ch
 {
 	struct mtd_partition *parts;
 	unsigned long size;
-	unsigned long offset = 0;
+	unsigned long offset = OFFSET_CONTINUOUS;
 	char *name;
 	int name_len;
 	unsigned char *extra_mem;
@@ -314,7 +315,7 @@ static int parse_cmdline_partitions(stru
 		{
 			for(i = 0, offset = 0; i < part->num_parts; i++)
 			{
-				if (!part->parts[i].offset)
+				if (part->parts[i].offset == OFFSET_CONTINUOUS)
 				  part->parts[i].offset = offset;
 				else
 				  offset = part->parts[i].offset;