binman: Update Entry.WriteData() to handle special sections

At present this method assumes that the parent section does not need
to recalculate its position or adjust any metadata it may contain. But
when the entry changes size this may not be true. Also if the parent
section is more than just a container (e.g. it is a CBFS) then the
section may need to regenerate its output.

Add a new WriteChildData() method to sections and call this from the
WriteData() method, to handle this situation.

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

tools/binman/entry.py

@@ -751,7 +751,26 @@ features to produce new behaviours.
         self.contents_size = self.size
         ok = self.ProcessContentsUpdate(data)
         self.Detail('WriteData: size=%x, ok=%s' % (len(data), ok))
-        return ok
+        section_ok = self.section.WriteChildData(self)
+        return ok and section_ok
+
+    def WriteChildData(self, child):
+        """Handle writing the data in a child entry
+
+        This should be called on the child's parent section after the child's
+        data has been updated. It
+
+        This base-class implementation does nothing, since the base Entry object
+        does not have any children.
+
+        Args:
+            child: Child Entry that was written
+
+        Returns:
+            True if the section could be updated successfully, False if the
+                data is such that the section could not updat
+        """
+        return True
 
     def GetSiblingOrder(self):
         """Get the relative order of an entry amoung its siblings

tools/binman/etype/cbfs.py

@@ -169,7 +169,7 @@ class Entry_cbfs(Entry):
         self._cbfs_entries = OrderedDict()
         self._ReadSubnodes()
 
-    def ObtainContents(self):
+    def ObtainContents(self, skip=None):
         arch = cbfs_util.find_arch(self._cbfs_arg)
         if arch is None:
             self.Raise("Invalid architecture '%s'" % self._cbfs_arg)
@@ -179,7 +179,7 @@ class Entry_cbfs(Entry):
         for entry in self._cbfs_entries.values():
             # First get the input data and put it in a file. If not available,
             # try later.
-            if not entry.ObtainContents():
+            if entry != skip and not entry.ObtainContents():
                 return False
             data = entry.GetData()
             cfile = None
@@ -274,3 +274,7 @@ class Entry_cbfs(Entry):
         reader = self.reader
         cfile = reader.files.get(child.name)
         return cfile.data if decomp else cfile.orig_data
+
+    def WriteChildData(self, child):
+        self.ObtainContents(skip=child)
+        return True

tools/binman/etype/section.py

@@ -520,3 +520,6 @@ class Entry_section(Entry):
                             (child.GetPath(), len(indata), child.compress,
                             len(data)))
         return data
+
+    def WriteChildData(self, child):
+        return True