Create image from Zephyr bin-file

Signed-off-by: Joakim Bech <joakim.bech@linaro.org>

1 files changed, 14 insertions, 50 deletions

diff --git a/patch_mynewt_img.py b/patch_mynewt_img.py
index 8720e7c..a7bd521 100755
--- a/patch_mynewt_img.py
+++ b/patch_mynewt_img.py
@@ -22,7 +22,7 @@ def create_header(img):
                     struct.pack('H', 0) + # PAD 2
                     struct.pack('I', image_size) + # TODO img size
                     struct.pack('I', IMAGE_F_SHA256) + # Flags
-                    struct.pack('B', 0) + # Major
+                    struct.pack('B', 1) + # Major
                     struct.pack('B', 0) + # Minor
                     struct.pack('H', 0) + # Revision
                     struct.pack('I', 0) + # Build number
@@ -34,60 +34,26 @@ def create_header(img):
 
     return hdr
 
-
-def patch_header(img):
-    """
-    Patch the image with the new header size and with the new image size.
-    """
-    image_size = os.path.getsize(img + ".elf.bin")
-    print("Image size (bin): %d" % image_size)
-
-    try:
-        with open(img + ".img", "r+b") as f:
-            print("[*] Loading : {0}".format(img))
-
-            # Patch the header size (Hardcoded to 0x80)
-            f.seek(OFFSET_IH_HDR_SIZE)
-            f.write('\x80\x00')
-
-            # Patch the image size, start by convert int to hex string.
-            image_size_hex = struct.pack('i', image_size)
-            f.seek(OFFSET_IH_IMG_SIZE)
-            f.write(image_size_hex)
-
-            f.close()
-    except IOError:
-        print("[*] Cannot open {0} (!) ".format(img))
-
-    return image_size
-
-
-def extend_image(img, img_size):
+def write_partial_img(image_name, hdr):
     try:
-        # Read the header and image locally
-        with open(img + ".img", "rb") as f:
-            print("[*] Loading %s (img_size: %d)" % (img, img_size))
-            hdr = f.read(IMAGE_HEADER_SIZE)
-            image = f.read(img_size)
+        with open(image_name + ".elf.bin", "rb") as f:
+            image = f.read()
             f.close()
+        print("image len: %d" % len(image))
 
-        # Clear the file (why doesn't truncate work?)
-        open(img + ".img").close()
-
-        # Store the header, pad it and then store the image itself
-        with open(img + ".img", "w+b") as f:
+        print("[*] Writing : {0}".format(image_name))
+        with open(image_name + ".img", "w+b") as f:
             f.write(hdr)
-            # Pad the header up til where the image itself begins
-            f.write(('\xFF' * (OFFSET_VECTOR_TABLE - IMAGE_HEADER_SIZE)))
+            f.write('\xFF' * (OFFSET_VECTOR_TABLE - IMAGE_HEADER_SIZE))
             f.write(image)
             f.close()
-    except IOError:
-        print("[*] Cannot open {0} (!) ".format(img))
 
+    except IOError:
+        print("[*] Cannot open {0} (!) ".format(image_name))
 
-def calculate_hash(img):
+def calculate_hash(image_name):
     sha256 = hashlib.sha256()
-    with open(img + ".img", "rb") as f:
+    with open(image_name + ".img", "rb") as f:
             sha256.update(f.read())
     return sha256.hexdigest()
 
@@ -113,10 +79,8 @@ def append_hash(img, digest):
 
 def main(img):
     # backup(img) # Backup original image
-    create_header(img)
-    size = patch_header(img)
-    extend_image(img, size)
-
+    hdr = create_header(img)
+    write_partial_img(img, hdr)
     digest = calculate_hash(img)
     print("Hash of intermediate image: %s" % digest)