diff --git a/core/Makefile b/core/Makefile
index 6a70bd2..1bd5127 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -2934,6 +2934,7 @@
   $(HOST_OUT_EXECUTABLES)/brillo_update_payload \
   $(HOST_OUT_EXECUTABLES)/lib/shflags/shflags \
   $(HOST_OUT_EXECUTABLES)/delta_generator \
+  $(HOST_OUT_EXECUTABLES)/care_map_generator \
   $(AVBTOOL) \
   $(BLK_ALLOC_TO_BASE_FS) \
   $(BROTLI) \
diff --git a/tools/releasetools/add_img_to_target_files.py b/tools/releasetools/add_img_to_target_files.py
index 66fe18b..22e7f4b 100755
--- a/tools/releasetools/add_img_to_target_files.py
+++ b/tools/releasetools/add_img_to_target_files.py
@@ -545,7 +545,7 @@
 
   Args:
     output_zip: The output zip file (needs to be already open), or None to
-        write images to OPTIONS.input_tmp/.
+        write care_map.txt to OPTIONS.input_tmp/.
     ab_partitions: The list of A/B partitions.
     image_paths: A map from the partition name to the image path.
   """
@@ -563,15 +563,32 @@
       assert os.path.exists(image_path)
       care_map_list += GetCareMap(partition, image_path)
 
-  if care_map_list:
-    care_map_path = "META/care_map.txt"
-    if output_zip and care_map_path not in output_zip.namelist():
-      common.ZipWriteStr(output_zip, care_map_path, '\n'.join(care_map_list))
-    else:
-      with open(os.path.join(OPTIONS.input_tmp, care_map_path), 'w') as fp:
-        fp.write('\n'.join(care_map_list))
-      if output_zip:
-        OPTIONS.replace_updated_files_list.append(care_map_path)
+  if not care_map_list:
+    return
+
+  # Converts the list into proto buf message by calling care_map_generator; and
+  # writes the result to a temp file.
+  temp_care_map_text = common.MakeTempFile(prefix="caremap_text-",
+                                           suffix=".txt")
+  with open(temp_care_map_text, 'w') as text_file:
+    text_file.write('\n'.join(care_map_list))
+
+  temp_care_map = common.MakeTempFile(prefix="caremap-", suffix=".txt")
+  care_map_gen_cmd = (["care_map_generator", temp_care_map_text, temp_care_map])
+  p = common.Run(care_map_gen_cmd, stdout=subprocess.PIPE,
+                 stderr=subprocess.STDOUT)
+  output, _ = p.communicate()
+  assert p.returncode == 0, "Failed to generate the care_map proto message."
+  if OPTIONS.verbose:
+    print(output.rstrip())
+
+  care_map_path = "META/care_map.txt"
+  if output_zip and care_map_path not in output_zip.namelist():
+    common.ZipWrite(output_zip, temp_care_map, arcname=care_map_path)
+  else:
+    shutil.copy(temp_care_map, os.path.join(OPTIONS.input_tmp, care_map_path))
+    if output_zip:
+      OPTIONS.replace_updated_files_list.append(care_map_path)
 
 
 def AddPackRadioImages(output_zip, images):
diff --git a/tools/releasetools/test_add_img_to_target_files.py b/tools/releasetools/test_add_img_to_target_files.py
index 3f2e5ea..834e989 100644
--- a/tools/releasetools/test_add_img_to_target_files.py
+++ b/tools/releasetools/test_add_img_to_target_files.py
@@ -16,6 +16,7 @@
 
 import os
 import os.path
+import subprocess
 import unittest
 import zipfile
 
@@ -38,6 +39,20 @@
   def tearDown(self):
     common.Cleanup()
 
+  def _verifyCareMap(self, expected, file_name):
+    """Parses the care_map proto; and checks the content in plain text."""
+    text_file = common.MakeTempFile(prefix="caremap-", suffix=".txt")
+
+    # Calls an external binary to convert the proto message.
+    cmd = ["care_map_generator", "--parse_proto", file_name, text_file]
+    p = common.Run(cmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
+    output, _ = p.communicate()
+    self.assertEqual(0, p.returncode)
+
+    with open(text_file, 'r') as verify_fp:
+      plain_text = verify_fp.read()
+    self.assertEqual('\n'.join(expected), plain_text)
+
   @staticmethod
   def _create_images(images, prefix):
     """Creates images under OPTIONS.input_tmp/prefix."""
@@ -155,15 +170,10 @@
     AddCareMapTxtForAbOta(None, ['system', 'vendor'], image_paths)
 
     care_map_file = os.path.join(OPTIONS.input_tmp, 'META', 'care_map.txt')
-    with open(care_map_file, 'r') as verify_fp:
-      care_map = verify_fp.read()
+    expected = ['system', RangeSet("0-5 10-15").to_string_raw(), 'vendor',
+                RangeSet("0-9").to_string_raw()]
 
-    lines = care_map.split('\n')
-    self.assertEqual(4, len(lines))
-    self.assertEqual('system', lines[0])
-    self.assertEqual(RangeSet("0-5 10-15").to_string_raw(), lines[1])
-    self.assertEqual('vendor', lines[2])
-    self.assertEqual(RangeSet("0-9").to_string_raw(), lines[3])
+    self._verifyCareMap(expected, care_map_file)
 
   def test_AddCareMapTxtForAbOta_withNonCareMapPartitions(self):
     """Partitions without care_map should be ignored."""
@@ -173,15 +183,10 @@
         None, ['boot', 'system', 'vendor', 'vbmeta'], image_paths)
 
     care_map_file = os.path.join(OPTIONS.input_tmp, 'META', 'care_map.txt')
-    with open(care_map_file, 'r') as verify_fp:
-      care_map = verify_fp.read()
+    expected = ['system', RangeSet("0-5 10-15").to_string_raw(), 'vendor',
+                RangeSet("0-9").to_string_raw()]
 
-    lines = care_map.split('\n')
-    self.assertEqual(4, len(lines))
-    self.assertEqual('system', lines[0])
-    self.assertEqual(RangeSet("0-5 10-15").to_string_raw(), lines[1])
-    self.assertEqual('vendor', lines[2])
-    self.assertEqual(RangeSet("0-9").to_string_raw(), lines[3])
+    self._verifyCareMap(expected, care_map_file)
 
   def test_AddCareMapTxtForAbOta_withAvb(self):
     """Tests the case for device using AVB."""
@@ -194,15 +199,10 @@
     AddCareMapTxtForAbOta(None, ['system', 'vendor'], image_paths)
 
     care_map_file = os.path.join(OPTIONS.input_tmp, 'META', 'care_map.txt')
-    with open(care_map_file, 'r') as verify_fp:
-      care_map = verify_fp.read()
+    expected = ['system', RangeSet("0-5 10-15").to_string_raw(), 'vendor',
+                RangeSet("0-9").to_string_raw()]
 
-    lines = care_map.split('\n')
-    self.assertEqual(4, len(lines))
-    self.assertEqual('system', lines[0])
-    self.assertEqual(RangeSet("0-5 10-15").to_string_raw(), lines[1])
-    self.assertEqual('vendor', lines[2])
-    self.assertEqual(RangeSet("0-9").to_string_raw(), lines[3])
+    self._verifyCareMap(expected, care_map_file)
 
   def test_AddCareMapTxtForAbOta_verityNotEnabled(self):
     """No care_map.txt should be generated if verity not enabled."""
@@ -228,15 +228,15 @@
     with zipfile.ZipFile(output_file, 'w') as output_zip:
       AddCareMapTxtForAbOta(output_zip, ['system', 'vendor'], image_paths)
 
+    care_map_name = "META/care_map.txt"
+    temp_dir = common.MakeTempDir()
     with zipfile.ZipFile(output_file, 'r') as verify_zip:
-      care_map = verify_zip.read('META/care_map.txt').decode('ascii')
+      self.assertTrue(care_map_name in verify_zip.namelist())
+      verify_zip.extract(care_map_name, path=temp_dir)
 
-    lines = care_map.split('\n')
-    self.assertEqual(4, len(lines))
-    self.assertEqual('system', lines[0])
-    self.assertEqual(RangeSet("0-5 10-15").to_string_raw(), lines[1])
-    self.assertEqual('vendor', lines[2])
-    self.assertEqual(RangeSet("0-9").to_string_raw(), lines[3])
+    expected = ['system', RangeSet("0-5 10-15").to_string_raw(), 'vendor',
+                RangeSet("0-9").to_string_raw()]
+    self._verifyCareMap(expected, os.path.join(temp_dir, care_map_name))
 
   def test_AddCareMapTxtForAbOta_zipOutput_careMapEntryExists(self):
     """Tests the case with ZIP output which already has care_map entry."""
@@ -252,15 +252,10 @@
 
     # The one under OPTIONS.input_tmp must have been replaced.
     care_map_file = os.path.join(OPTIONS.input_tmp, 'META', 'care_map.txt')
-    with open(care_map_file, 'r') as verify_fp:
-      care_map = verify_fp.read()
+    expected = ['system', RangeSet("0-5 10-15").to_string_raw(), 'vendor',
+                RangeSet("0-9").to_string_raw()]
 
-    lines = care_map.split('\n')
-    self.assertEqual(4, len(lines))
-    self.assertEqual('system', lines[0])
-    self.assertEqual(RangeSet("0-5 10-15").to_string_raw(), lines[1])
-    self.assertEqual('vendor', lines[2])
-    self.assertEqual(RangeSet("0-9").to_string_raw(), lines[3])
+    self._verifyCareMap(expected, care_map_file)
 
     # The existing entry should be scheduled to be replaced.
     self.assertIn('META/care_map.txt', OPTIONS.replace_updated_files_list)