diff --git a/tools/releasetools/sparse_img.py b/tools/releasetools/sparse_img.py
index e824a64..a2f7e9e 100644
--- a/tools/releasetools/sparse_img.py
+++ b/tools/releasetools/sparse_img.py
@@ -80,7 +80,7 @@
     self.offset_map = offset_map = []
     self.clobbered_blocks = rangelib.RangeSet(data=clobbered_blocks)
 
-    for i in range(total_chunks):
+    for _ in range(total_chunks):
       header_bin = f.read(12)
       header = struct.unpack("<2H2I", header_bin)
       chunk_type = header[0]
@@ -166,6 +166,11 @@
   def ReadRangeSet(self, ranges):
     return [d for d in self._GetRangeData(ranges)]
 
+  def ReadBlocks(self, start=0, num_blocks=None):
+    if num_blocks is None:
+      num_blocks = self.total_blocks
+    return self._GetRangeData([(start, start + num_blocks)])
+
   def TotalSha1(self, include_clobbered_blocks=False):
     """Return the SHA-1 hash of all data in the 'care' regions.