binman: Add a null entry

It is sometimes useful to define an entry which does not have its own
contents but does appear in the image. The contents are set by the section
which contains it, even though it appears as an entry in the fdtmap.

Add support for this.

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

1 files changed, 6 insertions, 0 deletions

diff --git a/tools/binman/etype/section.py b/tools/binman/etype/section.py
index 85474f2411..28f04cb84a 100644
--- a/tools/binman/etype/section.py
+++ b/tools/binman/etype/section.py
@@ -320,6 +320,12 @@ class Entry_section(Entry):
             # earlier in the image description. See testCollectionSection().
             if not required and entry_data is None:
                 return None
+
+            if entry_data is None:
+                pad_byte = (entry._pad_byte if isinstance(entry, Entry_section)
+                            else self._pad_byte)
+                entry_data = tools.get_bytes(self._pad_byte, entry.size)
+
             data = self.GetPaddedDataForEntry(entry, entry_data)
             # Handle empty space before the entry
             pad = (entry.offset or 0) - self._skip_at_start - len(section_data)