diff --git a/otafault/Android.mk b/otafault/Android.mk
new file mode 100644
index 0000000..75617a1
--- /dev/null
+++ b/otafault/Android.mk
@@ -0,0 +1,58 @@
+# Copyright 2015 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 languae governing permissions and
+# limitations under the License.
+
+LOCAL_PATH := $(call my-dir)
+
+empty :=
+space := $(empty) $(empty)
+comma := ,
+
+ifneq ($(TARGET_INJECT_FAULTS),)
+TARGET_INJECT_FAULTS := $(subst $(comma),$(space),$(strip $(TARGET_INJECT_FAULTS)))
+endif
+
+include $(CLEAR_VARS)
+
+LOCAL_SRC_FILES := ota_io.cpp
+LOCAL_MODULE_TAGS := eng
+LOCAL_MODULE := libotafault
+LOCAL_CLANG := true
+
+ifneq ($(TARGET_INJECT_FAULTS),)
+$(foreach ft,$(TARGET_INJECT_FAULTS),\
+	$(eval LOCAL_CFLAGS += -DTARGET_$(ft)_FAULT=$(TARGET_$(ft)_FAULT_FILE)))
+LOCAL_CFLAGS += -Wno-unused-parameter
+LOCAL_CFLAGS += -DTARGET_INJECT_FAULTS
+endif
+
+LOCAL_STATIC_LIBRARIES := libc
+
+include $(BUILD_STATIC_LIBRARY)
+
+include $(CLEAR_VARS)
+
+LOCAL_SRC_FILES := ota_io.cpp test.cpp
+LOCAL_MODULE_TAGS := tests
+LOCAL_MODULE := otafault_test
+LOCAL_STATIC_LIBRARIES := libc
+LOCAL_FORCE_STATIC_EXECUTABLE := true
+LOCAL_CFLAGS += -Wno-unused-parameter -Wno-writable-strings
+
+ifneq ($(TARGET_INJECT_FAULTS),)
+$(foreach ft,$(TARGET_INJECT_FAULTS),\
+	$(eval LOCAL_CFLAGS += -DTARGET_$(ft)_FAULT=$(TARGET_$(ft)_FAULT_FILE)))
+LOCAL_CFLAGS += -DTARGET_INJECT_FAULTS
+endif
+
+include $(BUILD_EXECUTABLE)
diff --git a/otafault/ota_io.cpp b/otafault/ota_io.cpp
new file mode 100644
index 0000000..02e80f9
--- /dev/null
+++ b/otafault/ota_io.cpp
@@ -0,0 +1,160 @@
+/*
+ * Copyright (C) 2015 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.
+ */
+
+#if defined (TARGET_INJECT_FAULTS)
+#include <map>
+#endif
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include "ota_io.h"
+
+#if defined (TARGET_INJECT_FAULTS)
+static std::map<int, const char*> FilenameCache;
+static std::string FaultFileName =
+#if defined (TARGET_READ_FAULT)
+        TARGET_READ_FAULT;
+#elif defined (TARGET_WRITE_FAULT)
+        TARGET_WRITE_FAULT;
+#elif defined (TARGET_FSYNC_FAULT)
+        TARGET_FSYNC_FAULT;
+#endif // defined (TARGET_READ_FAULT)
+#endif // defined (TARGET_INJECT_FAULTS)
+
+int ota_open(const char* path, int oflags) {
+#if defined (TARGET_INJECT_FAULTS)
+    // Let the caller handle errors; we do not care if open succeeds or fails
+    int fd = open(path, oflags);
+    FilenameCache[fd] = path;
+    return fd;
+#else
+    return open(path, oflags);
+#endif
+}
+
+int ota_open(const char* path, int oflags, mode_t mode) {
+#if defined (TARGET_INJECT_FAULTS)
+    int fd = open(path, oflags, mode);
+    FilenameCache[fd] = path;
+    return fd;
+#else
+    return open(path, oflags, mode);
+#endif
+}
+
+FILE* ota_fopen(const char* path, const char* mode) {
+#if defined (TARGET_INJECT_FAULTS)
+    FILE* fh = fopen(path, mode);
+    FilenameCache[(intptr_t)fh] = path;
+    return fh;
+#else
+    return fopen(path, mode);
+#endif
+}
+
+int ota_close(int fd) {
+#if defined (TARGET_INJECT_FAULTS)
+    // descriptors can be reused, so make sure not to leave them in the cahce
+    FilenameCache.erase(fd);
+#endif
+    return close(fd);
+}
+
+int ota_fclose(FILE* fh) {
+#if defined (TARGET_INJECT_FAULTS)
+    FilenameCache.erase((intptr_t)fh);
+#endif
+    return fclose(fh);
+}
+
+size_t ota_fread(void* ptr, size_t size, size_t nitems, FILE* stream) {
+#if defined (TARGET_READ_FAULT)
+    if (FilenameCache.find((intptr_t)stream) != FilenameCache.end()
+            && FilenameCache[(intptr_t)stream] == FaultFileName) {
+        FaultFileName = "";
+        errno = EIO;
+        return 0;
+    } else {
+        return fread(ptr, size, nitems, stream);
+    }
+#else
+    return fread(ptr, size, nitems, stream);
+#endif
+}
+
+ssize_t ota_read(int fd, void* buf, size_t nbyte) {
+#if defined (TARGET_READ_FAULT)
+    if (FilenameCache.find(fd) != FilenameCache.end()
+            && FilenameCache[fd] == FaultFileName) {
+        FaultFileName = "";
+        errno = EIO;
+        return -1;
+    } else {
+        return read(fd, buf, nbyte);
+    }
+#else
+    return read(fd, buf, nbyte);
+#endif
+}
+
+size_t ota_fwrite(const void* ptr, size_t size, size_t count, FILE* stream) {
+#if defined (TARGET_WRITE_FAULT)
+    if (FilenameCache.find((intptr_t)stream) != FilenameCache.end()
+            && FilenameCache[(intptr_t)stream] == FaultFileName) {
+        FaultFileName = "";
+        errno = EIO;
+        return 0;
+    } else {
+        return fwrite(ptr, size, count, stream);
+    }
+#else
+    return fwrite(ptr, size, count, stream);
+#endif
+}
+
+ssize_t ota_write(int fd, const void* buf, size_t nbyte) {
+#if defined (TARGET_WRITE_FAULT)
+    if (FilenameCache.find(fd) != FilenameCache.end()
+            && FilenameCache[fd] == FaultFileName) {
+        FaultFileName = "";
+        errno = EIO;
+        return -1;
+    } else {
+        return write(fd, buf, nbyte);
+    }
+#else
+    return write(fd, buf, nbyte);
+#endif
+}
+
+int ota_fsync(int fd) {
+#if defined (TARGET_FSYNC_FAULT)
+    if (FilenameCache.find(fd) != FilenameCache.end()
+            && FilenameCache[fd] == FaultFileName) {
+        FaultFileName = "";
+        errno = EIO;
+        return -1;
+    } else {
+        return fsync(fd);
+    }
+#else
+    return fsync(fd);
+#endif
+}
diff --git a/otafault/ota_io.h b/otafault/ota_io.h
new file mode 100644
index 0000000..641a5ae
--- /dev/null
+++ b/otafault/ota_io.h
@@ -0,0 +1,49 @@
+/*
+ * Copyright (C) 2015 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.
+ */
+
+/*
+ * Provide a series of proxy functions for basic file accessors.
+ * The behavior of these functions can be changed to return different
+ * errors under a variety of conditions.
+ */
+
+#ifndef _UPDATER_OTA_IO_H_
+#define _UPDATER_OTA_IO_H_
+
+#include <stdio.h>
+#include <sys/stat.h>
+
+int ota_open(const char* path, int oflags);
+
+int ota_open(const char* path, int oflags, mode_t mode);
+
+FILE* ota_fopen(const char* filename, const char* mode);
+
+int ota_close(int fd);
+
+int ota_fclose(FILE* fh);
+
+size_t ota_fread(void* ptr, size_t size, size_t nitems, FILE* stream);
+
+ssize_t ota_read(int fd, void* buf, size_t nbyte);
+
+size_t ota_fwrite(const void* ptr, size_t size, size_t count, FILE* stream);
+
+ssize_t ota_write(int fd, const void* buf, size_t nbyte);
+
+int ota_fsync(int fd);
+
+#endif
diff --git a/otafault/test.cpp b/otafault/test.cpp
new file mode 100644
index 0000000..a0f7315
--- /dev/null
+++ b/otafault/test.cpp
@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) 2015 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.
+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+
+#include "ota_io.h"
+
+int main(int argc, char **argv) {
+    int fd = open("testdata/test.file", O_RDWR);
+    char buf[8];
+    char *out = "321";
+    int readv = ota_read(fd, buf, 4);
+    printf("Read returned %d\n", readv);
+    int writev = ota_write(fd, out, 4);
+    printf("Write returned %d\n", writev);
+    return 0;
+}