binman: Support updating entries in an existing image

While it is useful and efficient to build images in a single pass from a
unified description, it is sometimes desirable to update the image later.

Add support for replace an existing file with one of the same size. This
avoids needing to repack the file. Support for more advanced updates will
come in future patches.

Signed-off-by: Simon Glass <sjg@chromium.org>

1 files changed, 31 insertions, 2 deletions

diff --git a/tools/binman/control.py b/tools/binman/control.py
index 8700f48ad5..ab94f9d482 100644
--- a/tools/binman/control.py
+++ b/tools/binman/control.py
@@ -118,6 +118,32 @@ def ReadEntry(image_fname, entry_path, decomp=True):
     return entry.ReadData(decomp)
 
 
+def WriteEntry(image_fname, entry_path, data, decomp=True):
+    """Replace an entry in an image
+
+    This replaces the data in a particular entry in an image. This size of the
+    new data must match the size of the old data
+
+    Args:
+        image_fname: Image filename to process
+        entry_path: Path to entry to extract
+        data: Data to replace with
+        decomp: True to compress the data if needed, False if data is
+            already compressed so should be used as is
+    """
+    tout.Info("WriteEntry '%s', file '%s'" % (entry_path, image_fname))
+    image = Image.FromFile(image_fname)
+    entry = image.FindEntryPath(entry_path)
+    state.PrepareFromLoadedData(image)
+    image.LoadData()
+    tout.Info('Writing data to %s' % entry.GetPath())
+    if not entry.WriteData(data, decomp):
+        entry.Raise('Entry data size does not match, but resize is disabled')
+    tout.Info('Processing image')
+    ProcessImage(image, update_fdt=True, write_map=False, get_contents=False)
+    tout.Info('WriteEntry done')
+
+
 def ExtractEntries(image_fname, output_fname, outdir, entry_paths,
                    decomp=True):
     """Extract the data from one or more entries and write it to files
@@ -238,7 +264,7 @@ def PrepareImagesAndDtbs(dtb_fname, select_images, update_fdt):
     return images
 
 
-def ProcessImage(image, update_fdt, write_map):
+def ProcessImage(image, update_fdt, write_map, get_contents=True):
     """Perform all steps for this image, including checking and # writing it.
 
     This means that errors found with a later image will be reported after
@@ -249,8 +275,11 @@ def ProcessImage(image, update_fdt, write_map):
         image: Image to process
         update_fdt: True to update the FDT wth entry offsets, etc.
         write_map: True to write a map file
+        get_contents: True to get the image contents from files, etc., False if
+            the contents is already present
     """
-    image.GetEntryContents()
+    if get_contents:
+        image.GetEntryContents()
     image.GetEntryOffsets()
 
     # We need to pack the entries to figure out where everything