binman: Allow state functions to fail to return data

At present these state functions raise an exception if they cannot find
what is requested. But in some cases the information is optional (e.g. an
fdtmap in a coming patch) so it is better to return gracefully.

Update these two functions to return None when the data cannot be found.

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

diff --git a/tools/binman/state.py b/tools/binman/state.py
index 7c3a987..8767410 100644 (file)
--- a/tools/binman/state.py
+++ b/tools/binman/state.py
@@ -49,7 +49,10 @@ def GetFdtForEtype(etype):
     Returns:
         Fdt object associated with the entry type
     """
-    return output_fdt_files[etype][0]
+    value = output_fdt_files.get(etype);
+    if not value:
+        return None
+    return value[0]
 
 def GetFdtPath(etype):
     """Get the full pathname of a particular Fdt object
@@ -80,7 +83,9 @@ def GetFdtContents(etype='u-boot-dtb'):
             pathname to Fdt
             Fdt data (as bytes)
     """
-    if etype in output_fdt_files and not use_fake_dtb:
+    if etype not in output_fdt_files:
+        return None, None
+    if not use_fake_dtb:
         pathname = GetFdtPath(etype)
         data = GetFdtForEtype(etype).GetContents()
     else: