mtd - remove partition table assumption when writing fis table

When mtd alters the fis partition table it assumes that the first partition
table entry also is the first logical parition table entry. For instance our
table could look like this (irrelevant partitions put aside):
 * vmlinux.bin.l7 0xA8710000
 * rootfs         0xA8030000
Here mtd would assume vmlinux.bin.l7 being the first partition and use its
address to calculate the size and offset which ultimately leads to a broken
partition table.
This patch alters the behavior by checking what partition has the smaller
address to do the calculations based on that address.

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@32601 3c298f89-4303-0410-b956-a3cf2f4a3e73

1 files changed, 13 insertions, 3 deletions

diff --git a/package/mtd/src/fis.c b/package/mtd/src/fis.c
index 559ca9506..f825f590c 100644
--- a/package/mtd/src/fis.c
+++ b/package/mtd/src/fis.c
@@ -143,6 +143,8 @@ fis_remap(struct fis_part *old, int n_old, struct fis_part *new, int n_new)
 	struct fis_image_desc *redboot = NULL;
 	struct fis_image_desc *first = NULL;
 	struct fis_image_desc *last = NULL;
+	struct fis_image_desc *first_fb = NULL;
+	struct fis_image_desc *last_fb = NULL;
 	struct fis_image_desc *desc;
 	struct fis_part *part;
 	uint32_t offset = 0, size = 0;
@@ -184,13 +186,21 @@ fis_remap(struct fis_part *old, int n_old, struct fis_part *new, int n_new)
 	}
 	desc--;
 
+	first_fb = first;
+	last_fb = last;
+
+	if (first_fb->hdr.flash_base > last_fb->hdr.flash_base) {
+		first_fb = last;
+		last_fb = first;
+	}
+
 	/* determine size of available space */
 	desc = (struct fis_image_desc *) start;
 	while ((char *) desc < end) {
 		if (!desc->hdr.name[0] || (desc->hdr.name[0] == 0xff))
 			break;
 
-		if (desc->hdr.flash_base > last->hdr.flash_base &&
+		if (desc->hdr.flash_base > last_fb->hdr.flash_base &&
 		    desc->hdr.flash_base < offset)
 			offset = desc->hdr.flash_base;
 
@@ -198,7 +208,7 @@ fis_remap(struct fis_part *old, int n_old, struct fis_part *new, int n_new)
 	}
 	desc--;
 
-	size = offset - first->hdr.flash_base;
+	size = offset - first_fb->hdr.flash_base;
 
 #ifdef notyet
 	desc = first - 1;
@@ -214,7 +224,7 @@ fis_remap(struct fis_part *old, int n_old, struct fis_part *new, int n_new)
 
 	last++;
 	desc = first + n_new;
-	offset = first->hdr.flash_base;
+	offset = first_fb->hdr.flash_base;
 
 	if (desc != last) {
 		if (desc > last)