Allow recovery to return error codes

Write error code, cause code, and retry count into last_install. So we
can have more information about the reason of a failed OTA.

Example of new last_install:
@/cache/recovery/block.map     package name
0                              install result
retry: 1                       retry count (new)
error: 30                      error code (new)
cause: 12                      error cause (new)

Details in:
go/android-ota-errorcode

Bug: 28471955
Change-Id: I00e7153c821e7355c1be81a86c7f228108f3dc37
diff --git a/error_code.h b/error_code.h
new file mode 100644
index 0000000..259319a
--- /dev/null
+++ b/error_code.h
@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef _ERROR_CODE_H_
+#define _ERROR_CODE_H_
+
+enum ErrorCode {
+    kNoError = -1,
+    kLowBattery = 20,
+    kZipVerificationFailure,
+    kZipOpenFailure
+};
+
+enum CauseCode {
+    kNoCause = -1,
+    kArgsParsingFailure = 100,
+    kStashCreationFailure,
+    kFileOpenFailure,
+    kLseekFailure,
+    kFreadFailure,
+    kFwriteFailure,
+    kFsyncFailure,
+    kLibfecFailure,
+    kFileGetPropFailure,
+    kFileRenameFailure,
+    kSymlinkFailure,
+    kSetMetadataFailure,
+    kTune2FsFailure,
+    kRebootFailure,
+    kVendorFailure = 200
+};
+
+#endif