Add revision to README
diff --git a/README b/README
index d460f6e..2b8b5a5 100644
--- a/README
+++ b/README
@@ -2,6 +2,14 @@
 It also contains this file and the files BUILD.gn, boringssl_dart.gyp, and
 boringssl_configurations.gypi.
 
+The generated source is for boringssl from:
+
+https://boringssl.googlesource.com/boringssl.git
+
+at revision:
+
+8d343b44bbab829d1a28fdef650ca95f7db4412e
+
 To roll boringssl forward, delete all but this file and the above mentioned
 files, checkout the new boringssl into a subdirectory called src/, and run the
 script src/util/generate_build_files.py with appropriate arguments. It may also