[PATCHV2] addpart: support @<offset>

[Peter Korsgaard]

We claim to be compatible with the kernel's cmdlinepart parser, so
support <size>@<offset> like the kernel does.

Signed-off-by: Peter Korsgaard <jacmet at sunsite.dk>
---
 Changes since v1:
 - Update doxygen documentation to match.

 commands/partition.c |   28 ++++++++++++++++++----------
 1 files changed, 18 insertions(+), 10 deletions(-)

diff --git a/commands/partition.c b/commands/partition.c
index 3cb7b61..d7bd940 100755
--- a/commands/partition.c
+++ b/commands/partition.c
@@ -41,8 +41,10 @@
 #include <linux/stat.h>
 #include <libgen.h>
 
+#define SIZE_REMAINING ((ulong)-1)
+
 static int mtd_part_do_parse_one(char *devname, const char *partstr,
-				 char **endp, unsigned long offset,
+				 char **endp, unsigned long *offset,
 				 off_t devsize, size_t *retsize)
 {
 	ulong size;
@@ -54,12 +56,18 @@ static int mtd_part_do_parse_one(char *devname, const char *partstr,
 	memset(buf, 0, PATH_MAX);
 
 	if (*partstr == '-') {
-		size = devsize - offset;
+		size = SIZE_REMAINING;
 		end = (char *)partstr + 1;
 	} else {
 		size = strtoul_suffix(partstr, &end, 0);
 	}
 
+	if (*end == '@')
+		*offset = strtoul_suffix(end+1, &end, 0);
+
+	if (size == SIZE_REMAINING)
+		size = devsize - *offset;
+
 	partstr = end;
 
 	if (*partstr == '(') {
@@ -76,7 +84,7 @@ static int mtd_part_do_parse_one(char *devname, const char *partstr,
 		end++;
 	}
 
-	if (size + offset > devsize) {
+	if (size + *offset > devsize) {
 		printf("%s: partition end is beyond device\n", buf);
 		return -EINVAL;
 	}
@@ -93,7 +101,7 @@ static int mtd_part_do_parse_one(char *devname, const char *partstr,
 
 	*retsize = size;
 
-	ret = devfs_add_partition(devname, offset, size, flags, buf);
+	ret = devfs_add_partition(devname, *offset, size, flags, buf);
 	if (ret)
 		printf("cannot create %s: %s\n", buf, strerror(-ret));
 	return ret;
@@ -123,7 +131,7 @@ static int do_addpart(cmd_tbl_t * cmdtp, int argc, char *argv[])
 	while (1) {
 		size_t size = 0;
 
-		if (mtd_part_do_parse_one(devname, endp, &endp, offset, devsize, &size))
+		if (mtd_part_do_parse_one(devname, endp, &endp, &offset, devsize, &size))
 			return 1;
 
 		offset += size;
@@ -167,12 +175,12 @@ BAREBOX_CMD_END
  * Adds a partition description to a device. The partition description has the
  * form
  *
- * size1(name1)[ro],size2(name2)[ro],...
+ * size1[@offset1](name1)[ro],size2[@offset2](name2)[ro],...
  *
- * \<device> is the device name under. Sizes can be given in decimal or - if
- * prefixed with 0x - in hex. Sizes can have an optional suffix K,M,G. The
- * size of the last partition can be specified as '-' for the remaining space
- * of the device.
+ * \<device> is the device name under. Sizes and offsets can be given in
+ * decimal or - if prefixed with 0x - in hex. Both can have an optional suffix
+ * K,M,G. The size of the last partition can be specified as '-' for the
+ * remaining space of the device.
  *
  * @note The format is the same as used in the Linux kernel for cmdline mtd
  * partitions.
-- 
1.6.5