mkimage: fit_image: Add option to make fit header align

The image is usually stored in block device like emmc, SD card, make the
offset of image data aligned to block(512 byte) can avoid data copy
during boot process.
eg. SPL boot from FIT image with external data:
- SPL read the first block of FIT image, and then parse the header;
- SPL read image data separately;
- The first image offset is the base_offset which is the header size;
- The second image offset is just after the first image;
- If the offset of imge does not aligned, SPL will do memcpy;
The header size is a ramdon number, which is very possible not aligned, so
add '-B size'to specify the align size in hex for better performance.

example usage:
  ./tools/mkimage -E -f u-boot.its -B 0x200 u-boot.itb

Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Reviewed-by: Punit Agrawal <punit1.agrawal@toshiba.co.jp>
Reviewed-by: Tom Rini <trini@konsulko.com>

1 files changed, 20 insertions, 13 deletions

diff --git a/tools/fit_image.c b/tools/fit_image.c
index 55efe12eeb8..f32ee49575b 100644
--- a/tools/fit_image.c
+++ b/tools/fit_image.c
@@ -422,7 +422,7 @@ err_buf:
  */
 static int fit_extract_data(struct image_tool_params *params, const char *fname)
 {
-	void *buf;
+	void *buf = NULL;
 	int buf_ptr;
 	int fit_size, new_size;
 	int fd;
@@ -431,26 +431,33 @@ static int fit_extract_data(struct image_tool_params *params, const char *fname)
 	int ret;
 	int images;
 	int node;
+	int image_number;
+	int align_size;
 
+	align_size = params->bl_len ? params->bl_len : 4;
 	fd = mmap_fdt(params->cmdname, fname, 0, &fdt, &sbuf, false, false);
 	if (fd < 0)
 		return -EIO;
 	fit_size = fdt_totalsize(fdt);
 
-	/* Allocate space to hold the image data we will extract */
-	buf = malloc(fit_size);
-	if (!buf) {
-		ret = -ENOMEM;
-		goto err_munmap;
-	}
-	buf_ptr = 0;
-
 	images = fdt_path_offset(fdt, FIT_IMAGES_PATH);
 	if (images < 0) {
 		debug("%s: Cannot find /images node: %d\n", __func__, images);
 		ret = -EINVAL;
 		goto err_munmap;
 	}
+	image_number = fdtdec_get_child_count(fdt, images);
+
+	/*
+	 * Allocate space to hold the image data we will extract,
+	 * extral space allocate for image alignment to prevent overflow.
+	 */
+	buf = malloc(fit_size + (align_size * image_number));
+	if (!buf) {
+		ret = -ENOMEM;
+		goto err_munmap;
+	}
+	buf_ptr = 0;
 
 	for (node = fdt_first_subnode(fdt, images);
 	     node >= 0;
@@ -478,17 +485,17 @@ static int fit_extract_data(struct image_tool_params *params, const char *fname)
 					buf_ptr);
 		}
 		fdt_setprop_u32(fdt, node, FIT_DATA_SIZE_PROP, len);
-
-		buf_ptr += (len + 3) & ~3;
+		buf_ptr += ALIGN(len, align_size);
 	}
 
 	/* Pack the FDT and place the data after it */
 	fdt_pack(fdt);
 
+	new_size = fdt_totalsize(fdt);
+	new_size = ALIGN(new_size, align_size);
+	fdt_set_totalsize(fdt, new_size);
 	debug("Size reduced from %x to %x\n", fit_size, fdt_totalsize(fdt));
 	debug("External data size %x\n", buf_ptr);
-	new_size = fdt_totalsize(fdt);
-	new_size = (new_size + 3) & ~3;
 	munmap(fdt, sbuf.st_size);
 
 	if (ftruncate(fd, new_size)) {