binman: Add a return value to ProcessContentsUpdate()

At present if this function tries to update the contents such that the
size changes, it raises an error. We plan to add the ability to change
the size of entries after packing is completed, since in some cases it is
not possible to determine the size in advance.

An example of this is with a compressed device tree, where the values
of the device tree change in SetCalculatedProperties() or
ProcessEntryContents(). While the device tree itself does not change size,
since placeholders for any new properties have already bee added by
AddMissingProperties(), we cannot predict the size of the device tree
after compression. If a value changes from 0 to 0x1234 (say), then the
compressed device tree may expand.

As a first step towards supporting this, make ProcessContentsUpdate()
return a value indicating whether the content size is OK. For now this is
always True (since otherwise binman raises an error), but later patches
will adjust this.

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

10 files changed, 44 insertions, 15 deletions

diff --git a/tools/binman/bsection.py b/tools/binman/bsection.py
index 3e3d369..f49a6e9 100644
--- a/tools/binman/bsection.py
+++ b/tools/binman/bsection.py
@@ -317,9 +317,15 @@ class Section(object):
         """Call the ProcessContents() method for each entry
 
         This is intended to adjust the contents as needed by the entry type.
+
+        Returns:
+            True if no entries needed to change their size
         """
+        sizes_ok = True
         for entry in self._entries.values():
-            entry.ProcessContents()
+            if not entry.ProcessContents():
+                sizes_ok = False
+        return sizes_ok
 
     def WriteSymbols(self):
         """Write symbol values into binary files for access at run time"""
diff --git a/tools/binman/entry.py b/tools/binman/entry.py
index b19a3b0..7db1402 100644
--- a/tools/binman/entry.py
+++ b/tools/binman/entry.py
@@ -245,7 +245,8 @@ class Entry(object):
     def ProcessContentsUpdate(self, data):
         """Update the contents of an entry, after the size is fixed
 
-        This checks that the new data is the same size as the old.
+        This checks that the new data is the same size as the old. If the size
+        has changed, this triggers a re-run of the packing algorithm.
 
         Args:
             data: Data to set to the contents (bytes)
@@ -253,10 +254,12 @@ class Entry(object):
         Raises:
             ValueError if the new data size is not the same as the old
         """
+        size_ok = True
         if len(data) != self.contents_size:
             self.Raise('Cannot update entry size from %d to %d' %
                        (self.contents_size, len(data)))
         self.SetContents(data)
+        return size_ok
 
     def ObtainContents(self):
         """Figure out the contents of an entry.
@@ -401,7 +404,22 @@ class Entry(object):
         self.image_pos = image_pos + self.offset
 
     def ProcessContents(self):
-        pass
+        """Do any post-packing updates of entry contents
+
+        This function should call ProcessContentsUpdate() to update the entry
+        contents, if necessary, returning its return value here.
+
+        Args:
+            data: Data to set to the contents (bytes)
+
+        Returns:
+            True if the new data size is OK, False if expansion is needed
+
+        Raises:
+            ValueError if the new data size is not the same as the old and
+                state.AllowEntryExpansion() is False
+        """
+        return True
 
     def WriteSymbols(self, section):
         """Write symbol values into binary files for access at run time
diff --git a/tools/binman/etype/_testing.py b/tools/binman/etype/_testing.py
index ac62d2e..2204362 100644
--- a/tools/binman/etype/_testing.py
+++ b/tools/binman/etype/_testing.py
@@ -88,9 +88,10 @@ class Entry__testing(Entry):
 
     def ProcessContents(self):
         if self.bad_update_contents:
-            # Request to update the conents with something larger, to cause a
+            # Request to update the contents with something larger, to cause a
             # failure.
-            self.ProcessContentsUpdate('aa')
+            return self.ProcessContentsUpdate('aa')
+        return True
 
     def ProcessFdt(self, fdt):
         """Force reprocessing the first time"""
diff --git a/tools/binman/etype/blob_dtb.py b/tools/binman/etype/blob_dtb.py
index d80c3d7..09d5d72 100644
--- a/tools/binman/etype/blob_dtb.py
+++ b/tools/binman/etype/blob_dtb.py
@@ -30,4 +30,4 @@ class Entry_blob_dtb(Entry_blob):
     def ProcessContents(self):
         """Re-read the DTB contents so that we get any calculated properties"""
         _, data = state.GetFdtContents(self._filename)
-        self.ProcessContentsUpdate(data)
+        return self.ProcessContentsUpdate(data)
diff --git a/tools/binman/etype/fdtmap.py b/tools/binman/etype/fdtmap.py
index ddac148..bfd7962 100644
--- a/tools/binman/etype/fdtmap.py
+++ b/tools/binman/etype/fdtmap.py
@@ -106,4 +106,4 @@ class Entry_fdtmap(Entry):
         This is necessary since new data may have been written back to it during
         processing, e.g. the image-pos properties.
         """
-        self.ProcessContentsUpdate(self._GetFdtmap())
+        return self.ProcessContentsUpdate(self._GetFdtmap())
diff --git a/tools/binman/etype/fmap.py b/tools/binman/etype/fmap.py
index 45d6db1..3a80948 100644
--- a/tools/binman/etype/fmap.py
+++ b/tools/binman/etype/fmap.py
@@ -62,4 +62,4 @@ class Entry_fmap(Entry):
         return True
 
     def ProcessContents(self):
-        self.ProcessContentsUpdate(self._GetFmap())
+        return self.ProcessContentsUpdate(self._GetFmap())
diff --git a/tools/binman/etype/image_header.py b/tools/binman/etype/image_header.py
index d6de58c..b1c4f8a 100644
--- a/tools/binman/etype/image_header.py
+++ b/tools/binman/etype/image_header.py
@@ -73,4 +73,4 @@ class Entry_image_header(Entry):
         This is necessary since image_pos is not available when ObtainContents()
         is called, since by then the entries have not been packed in the image.
         """
-        self.ProcessContentsUpdate(self._GetHeader())
+        return self.ProcessContentsUpdate(self._GetHeader())
diff --git a/tools/binman/etype/section.py b/tools/binman/etype/section.py
index 3681a48..51eddcd 100644
--- a/tools/binman/etype/section.py
+++ b/tools/binman/etype/section.py
@@ -85,8 +85,9 @@ class Entry_section(Entry):
         self._section.SetCalculatedProperties()
 
     def ProcessContents(self):
-        self._section.ProcessEntryContents()
-        super(Entry_section, self).ProcessContents()
+        sizes_ok = self._section.ProcessEntryContents()
+        sizes_ok_base = super(Entry_section, self).ProcessContents()
+        return sizes_ok and sizes_ok_base
 
     def CheckOffset(self):
         self._section.CheckEntries()
diff --git a/tools/binman/etype/u_boot_with_ucode_ptr.py b/tools/binman/etype/u_boot_with_ucode_ptr.py
index da0e124..4104bf8 100644
--- a/tools/binman/etype/u_boot_with_ucode_ptr.py
+++ b/tools/binman/etype/u_boot_with_ucode_ptr.py
@@ -91,6 +91,6 @@ class Entry_u_boot_with_ucode_ptr(Entry_blob):
         # Write the microcode offset and size into the entry
         offset_and_size = struct.pack('<2L', offset, size)
         self.target_offset -= self.image_pos
-        self.ProcessContentsUpdate(self.data[:self.target_offset] +
-                                   offset_and_size +
-                                   self.data[self.target_offset + 8:])
+        return self.ProcessContentsUpdate(self.data[:self.target_offset] +
+                                          offset_and_size +
+                                          self.data[self.target_offset + 8:])
diff --git a/tools/binman/image.py b/tools/binman/image.py
index f237ae3..c8bce39 100644
--- a/tools/binman/image.py
+++ b/tools/binman/image.py
@@ -122,8 +122,11 @@ class Image:
         """Call the ProcessContents() method for each entry
 
         This is intended to adjust the contents as needed by the entry type.
+
+        Returns:
+            True if the new data size is OK, False if expansion is needed
         """
-        self._section.ProcessEntryContents()
+        return self._section.ProcessEntryContents()
 
     def WriteSymbols(self):
         """Write symbol values into binary files for access at run time"""