1 files changed, 9 insertions, 1 deletions

diff --git a/update_verifier/include/update_verifier/update_verifier.h b/update_verifier/include/update_verifier/update_verifier.h
index 16b394e98..534384e1d 100644
--- a/update_verifier/include/update_verifier/update_verifier.h
+++ b/update_verifier/include/update_verifier/update_verifier.h
@@ -20,5 +20,13 @@
 
 int update_verifier(int argc, char** argv);
 
-// Exposed for testing purpose.
+// Returns true to indicate a passing verification (or the error should be ignored); Otherwise
+// returns false on fatal errors, where we should reject the current boot and trigger a fallback.
+// This function tries to process the care_map.txt as protobuf message; and falls back to use the
+// plain text format if the parse failed.
+//
+// Note that update_verifier should be backward compatible to not reject care_map.txt from old
+// releases, which could otherwise fail to boot into the new release. For example, we've changed
+// the care_map format between N and O. An O update_verifier would fail to work with N care_map.txt.
+// This could be a result of sideloading an O OTA while the device having a pending N update.
 bool verify_image(const std::string& care_map_name);