binman: Store image fdtmap when loading from a file

This data provides all the information about the position and size of each
entry. Store it for later use when loading an image. It can be reused as
is if the image is modified without changing offsets/sizes.
Signed-off-by: NSimon Glass <sjg@chromium.org>

tools/binman/image.py

@@ -32,6 +32,9 @@ class Image(section.Entry_section):
 
     Attributes:
         filename: Output filename for image
+        image_node: Name of node containing the description for this image
+        fdtmap_dtb: Fdt object for the fdtmap when loading from a file
+        fdtmap_data: Contents of the fdtmap when loading from a file
 
     Args:
         test: True if this is being called from a test of Images. This this case
@@ -44,6 +47,8 @@ class Image(section.Entry_section):
         self.name = 'main-section'
         self.image_name = name
         self._filename = '%s.bin' % self.image_name
+        self.fdtmap_dtb = None
+        self.fdtmap_data = None
         if not test:
             filename = fdt_util.GetString(self._node, 'filename')
             if filename:
@@ -82,7 +87,11 @@ class Image(section.Entry_section):
         dtb.Scan()
 
         # Return an Image with the associated nodes
-        image = Image('image', dtb.GetRoot())
+        root = dtb.GetRoot()
+        image = Image('image', root)
+        image.image_node = fdt_util.GetString(root, 'image-node', 'image')
+        image.fdtmap_dtb = dtb
+        image.fdtmap_data = fdtmap_data
         image._data = data
         return image