tools: kwbimage: Fill the real header size into the main header

Fill the real header size without padding into the main header

This allows to reduce final image when converting image to another format
which does not need additional padding.

Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Stefan Roese <sr@denx.de>

tools/kwbimage.c

@@ -1220,6 +1220,7 @@ static void *image_create_v1(size_t *imagesz, struct image_tool_params *params,
 {
 	struct image_cfg_element *e;
 	struct main_hdr_v1 *main_hdr;
+	struct opt_hdr_v1 *ohdr;
 	struct register_set_hdr_v1 *register_set_hdr;
 	struct secure_hdr_v1 *secure_hdr = NULL;
 	size_t headersz;
@@ -1370,6 +1371,14 @@ static void *image_create_v1(size_t *imagesz, struct image_tool_params *params,
 	main_hdr->checksum = image_checksum8(main_hdr, headersz);
 
 	*imagesz = headersz;
+
+	/* Fill the real header size without padding into the main header */
+	headersz = sizeof(*main_hdr);
+	for_each_opt_hdr_v1 (ohdr, main_hdr)
+		headersz += opt_hdr_v1_size(ohdr);
+	main_hdr->headersz_lsb = cpu_to_le16(headersz & 0xFFFF);
+	main_hdr->headersz_msb = (headersz & 0xFFFF0000) >> 16;
+
 	return image;
 }