binman: Allow extracting a file in an alternative format

In some cases entries encapsulate other data and it is useful to access
the data within. An example is the fdtmap which consists of a 16-byte
header, followed by a devicetree.

Provide an option to specify an alternative format when extracting files.
In the case of fdtmap, this is 'fdt', which produces an FDT file which can
be viewed with fdtdump.

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

1 files changed, 31 insertions, 6 deletions

diff --git a/tools/binman/entry.py b/tools/binman/entry.py
index e7a8365fd5..61642bf501 100644
--- a/tools/binman/entry.py
+++ b/tools/binman/entry.py
@@ -815,7 +815,7 @@ features to produce new behaviours.
         self.AddEntryInfo(entries, indent, self.name, self.etype, self.size,
                           self.image_pos, self.uncomp_size, self.offset, self)
 
-    def ReadData(self, decomp=True):
+    def ReadData(self, decomp=True, alt_format=None):
         """Read the data for an entry from the image
 
         This is used when the image has been read in and we want to extract the
@@ -832,19 +832,20 @@ features to produce new behaviours.
         # although compressed sections are currently not supported
         tout.Debug("ReadChildData section '%s', entry '%s'" %
                    (self.section.GetPath(), self.GetPath()))
-        data = self.section.ReadChildData(self, decomp)
+        data = self.section.ReadChildData(self, decomp, alt_format)
         return data
 
-    def ReadChildData(self, child, decomp=True):
+    def ReadChildData(self, child, decomp=True, alt_format=None):
         """Read the data for a particular child entry
 
         This reads data from the parent and extracts the piece that relates to
         the given child.
 
         Args:
-            child: Child entry to read data for (must be valid)
-            decomp: True to decompress any compressed data before returning it;
-                False to return the raw, uncompressed data
+            child (Entry): Child entry to read data for (must be valid)
+            decomp (bool): True to decompress any compressed data before
+                returning it; False to return the raw, uncompressed data
+            alt_format (str): Alternative format to read in, or None
 
         Returns:
             Data for the child (bytes)
@@ -857,6 +858,20 @@ features to produce new behaviours.
         self.ProcessContentsUpdate(data)
         self.Detail('Loaded data size %x' % len(data))
 
+    def GetAltFormat(self, data, alt_format):
+        """Read the data for an extry in an alternative format
+
+        Supported formats are list in the documentation for each entry. An
+        example is fdtmap which provides .
+
+        Args:
+            data (bytes): Data to convert (this should have been produced by the
+                entry)
+            alt_format (str): Format to use
+
+        """
+        pass
+
     def GetImage(self):
         """Get the image containing this entry
 
@@ -997,3 +1012,13 @@ features to produce new behaviours.
         tout.Info("Node '%s': etype '%s': %s selected" %
                   (node.path, etype, new_etype))
         return True
+
+    def CheckAltFormats(self, alt_formats):
+        """Add any alternative formats supported by this entry type
+
+        Args:
+            alt_formats (dict): Dict to add alt_formats to:
+                key: Name of alt format
+                value: Help text
+        """
+        pass