diff --git a/patchoat/patchoat_test.cc b/patchoat/patchoat_test.cc
new file mode 100644
index 0000000..dc4c78b
--- /dev/null
+++ b/patchoat/patchoat_test.cc
@@ -0,0 +1,352 @@
+/*
+ * Copyright (C) 2017 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 <string>
+#include <vector>
+
+#include "android-base/stringprintf.h"
+#include "android-base/strings.h"
+
+#include "dexopt_test.h"
+#include "runtime.h"
+
+#include <gtest/gtest.h>
+
+namespace art {
+
+using android::base::StringPrintf;
+
+class PatchoatTest : public DexoptTest {
+ public:
+  static void AddRuntimeArg(std::vector<std::string>& args, const std::string& arg) {
+    args.push_back("--runtime-arg");
+    args.push_back(arg);
+  }
+
+  bool CompileBootImage(const std::vector<std::string>& extra_args,
+                        const std::string& image_file_name_prefix,
+                        uint32_t base_addr,
+                        std::string* error_msg) {
+    Runtime* const runtime = Runtime::Current();
+    std::vector<std::string> argv;
+    argv.push_back(runtime->GetCompilerExecutable());
+    AddRuntimeArg(argv, "-Xms64m");
+    AddRuntimeArg(argv, "-Xmx64m");
+    std::vector<std::string> dex_files = GetLibCoreDexFileNames();
+    for (const std::string& dex_file : dex_files) {
+      argv.push_back("--dex-file=" + dex_file);
+      argv.push_back("--dex-location=" + dex_file);
+    }
+    if (runtime->IsJavaDebuggable()) {
+      argv.push_back("--debuggable");
+    }
+    runtime->AddCurrentRuntimeFeaturesAsDex2OatArguments(&argv);
+
+    AddRuntimeArg(argv, "-Xverify:softfail");
+
+    if (!kIsTargetBuild) {
+      argv.push_back("--host");
+    }
+
+    argv.push_back("--image=" + image_file_name_prefix + ".art");
+    argv.push_back("--oat-file=" + image_file_name_prefix + ".oat");
+    argv.push_back("--oat-location=" + image_file_name_prefix + ".oat");
+    argv.push_back(StringPrintf("--base=0x%" PRIx32, base_addr));
+    argv.push_back("--compile-pic");
+    argv.push_back("--multi-image");
+    argv.push_back("--no-generate-debug-info");
+
+    std::vector<std::string> compiler_options = runtime->GetCompilerOptions();
+    argv.insert(argv.end(), compiler_options.begin(), compiler_options.end());
+
+    // We must set --android-root.
+    const char* android_root = getenv("ANDROID_ROOT");
+    CHECK(android_root != nullptr);
+    argv.push_back("--android-root=" + std::string(android_root));
+    argv.insert(argv.end(), extra_args.begin(), extra_args.end());
+
+    return RunDex2OatOrPatchoat(argv, error_msg);
+  }
+
+  bool RelocateBootImage(const std::string& input_image_location,
+                         const std::string& output_image_filename,
+                         off_t base_offset_delta,
+                         std::string* error_msg) {
+    Runtime* const runtime = Runtime::Current();
+    std::vector<std::string> argv;
+    argv.push_back(runtime->GetPatchoatExecutable());
+    argv.push_back("--input-image-location=" + input_image_location);
+    argv.push_back("--output-image-file=" + output_image_filename);
+    argv.push_back(StringPrintf("--base-offset-delta=0x%jx", (intmax_t) base_offset_delta));
+    argv.push_back(StringPrintf("--instruction-set=%s", GetInstructionSetString(kRuntimeISA)));
+
+    return RunDex2OatOrPatchoat(argv, error_msg);
+  }
+
+  bool RunDex2OatOrPatchoat(const std::vector<std::string>& args, std::string* error_msg) {
+    int link[2];
+
+    if (pipe(link) == -1) {
+      return false;
+    }
+
+    pid_t pid = fork();
+    if (pid == -1) {
+      return false;
+    }
+
+    if (pid == 0) {
+      // We need dex2oat to actually log things.
+      setenv("ANDROID_LOG_TAGS", "*:e", 1);
+      dup2(link[1], STDERR_FILENO);
+      close(link[0]);
+      close(link[1]);
+      std::vector<const char*> c_args;
+      for (const std::string& str : args) {
+        c_args.push_back(str.c_str());
+      }
+      c_args.push_back(nullptr);
+      execv(c_args[0], const_cast<char* const*>(c_args.data()));
+      exit(1);
+      UNREACHABLE();
+    } else {
+      close(link[1]);
+      char buffer[128];
+      memset(buffer, 0, 128);
+      ssize_t bytes_read = 0;
+
+      while (TEMP_FAILURE_RETRY(bytes_read = read(link[0], buffer, 128)) > 0) {
+        *error_msg += std::string(buffer, bytes_read);
+      }
+      close(link[0]);
+      int status = -1;
+      if (waitpid(pid, &status, 0) != -1) {
+        return (status == 0);
+      }
+      return false;
+    }
+  }
+
+  bool CompileBootImageToDir(
+      const std::string& output_dir,
+      const std::vector<std::string>& dex2oat_extra_args,
+      uint32_t base_addr,
+      std::string* error_msg) {
+    return CompileBootImage(dex2oat_extra_args, output_dir + "/boot", base_addr, error_msg);
+  }
+
+  bool CopyImageChecksumAndSetPatchDelta(
+      const std::string& src_image_filename,
+      const std::string& dest_image_filename,
+      off_t dest_patch_delta,
+      std::string* error_msg) {
+    std::unique_ptr<File> src_file(OS::OpenFileForReading(src_image_filename.c_str()));
+    if (src_file.get() == nullptr) {
+      *error_msg = StringPrintf("Failed to open source image file %s", src_image_filename.c_str());
+      return false;
+    }
+    ImageHeader src_header;
+    if (!src_file->ReadFully(&src_header, sizeof(src_header))) {
+      *error_msg = StringPrintf("Failed to read source image file %s", src_image_filename.c_str());
+      return false;
+    }
+
+    std::unique_ptr<File> dest_file(OS::OpenFileReadWrite(dest_image_filename.c_str()));
+    if (dest_file.get() == nullptr) {
+      *error_msg =
+          StringPrintf("Failed to open destination image file %s", dest_image_filename.c_str());
+      return false;
+    }
+    ImageHeader dest_header;
+    if (!dest_file->ReadFully(&dest_header, sizeof(dest_header))) {
+      *error_msg =
+          StringPrintf("Failed to read destination image file %s", dest_image_filename.c_str());
+      return false;
+    }
+    dest_header.SetOatChecksum(src_header.GetOatChecksum());
+    dest_header.SetPatchDelta(dest_patch_delta);
+    if (!dest_file->ResetOffset()) {
+      *error_msg =
+          StringPrintf(
+              "Failed to seek to start of destination image file %s", dest_image_filename.c_str());
+      return false;
+    }
+    if (!dest_file->WriteFully(&dest_header, sizeof(dest_header))) {
+      *error_msg =
+          StringPrintf("Failed to write to destination image file %s", dest_image_filename.c_str());
+      dest_file->Erase();
+      return false;
+    }
+    if (dest_file->FlushCloseOrErase() != 0) {
+      *error_msg =
+          StringPrintf(
+              "Failed to flush/close destination image file %s", dest_image_filename.c_str());
+      return false;
+    }
+
+    return true;
+  }
+
+  bool ReadFully(
+      const std::string& filename, std::vector<uint8_t>* contents, std::string* error_msg) {
+    std::unique_ptr<File> file(OS::OpenFileForReading(filename.c_str()));
+    if (file.get() == nullptr) {
+      *error_msg = "Failed to open";
+      return false;
+    }
+    int64_t size = file->GetLength();
+    if (size < 0) {
+      *error_msg = "Failed to get size";
+      return false;
+    }
+    contents->resize(size);
+    if (!file->ReadFully(&(*contents)[0], size)) {
+      *error_msg = "Failed to read";
+      contents->clear();
+      return false;
+    }
+    return true;
+  }
+
+  bool BinaryDiff(
+      const std::string& filename1, const std::string& filename2, std::string* error_msg) {
+    std::string read_error_msg;
+    std::vector<uint8_t> image1;
+    if (!ReadFully(filename1, &image1, &read_error_msg)) {
+      *error_msg = StringPrintf("Failed to read %s: %s", filename1.c_str(), read_error_msg.c_str());
+      return true;
+    }
+    std::vector<uint8_t> image2;
+    if (!ReadFully(filename2, &image2, &read_error_msg)) {
+      *error_msg = StringPrintf("Failed to read %s: %s", filename2.c_str(), read_error_msg.c_str());
+      return true;
+    }
+    if (image1.size() != image2.size()) {
+      *error_msg =
+          StringPrintf(
+              "%s and %s are of different size: %zu vs %zu",
+              filename1.c_str(),
+              filename2.c_str(),
+              image1.size(),
+              image2.size());
+      return true;
+    }
+    size_t size = image1.size();
+    for (size_t i = 0; i < size; i++) {
+      if (image1[i] != image2[i]) {
+        *error_msg =
+            StringPrintf("%s and %s differ at offset %zu", filename1.c_str(), filename2.c_str(), i);
+        return true;
+      }
+    }
+
+    return false;
+  }
+};
+
+TEST_F(PatchoatTest, PatchoatRelocationSameAsDex2oatRelocation) {
+#if defined(ART_USE_READ_BARRIER)
+  // This test checks that relocating a boot image using patchoat produces the same result as
+  // producing the boot image for that relocated base address using dex2oat. To be precise, these
+  // two files will have two small differences: the OAT checksum and base address. However, this
+  // test takes this into account.
+
+  // Compile boot image into a random directory using dex2oat
+  ScratchFile dex2oat_orig_scratch;
+  dex2oat_orig_scratch.Unlink();
+  std::string dex2oat_orig_dir = dex2oat_orig_scratch.GetFilename();
+  ASSERT_EQ(0, mkdir(dex2oat_orig_dir.c_str(), 0700));
+  const uint32_t orig_base_addr = 0x60000000;
+  // Force deterministic output. We want the boot images created by this dex2oat run and the run
+  // below to differ only in their base address.
+  std::vector<std::string> dex2oat_extra_args;
+  dex2oat_extra_args.push_back("--force-determinism");
+  dex2oat_extra_args.push_back("-j1");  // Might not be needed. Causes a 3-5x slowdown.
+  std::string error_msg;
+  if (!CompileBootImageToDir(dex2oat_orig_dir, dex2oat_extra_args, orig_base_addr, &error_msg)) {
+    FAIL() << "CompileBootImage1 failed: " << error_msg;
+  }
+
+  // Compile a "relocated" boot image into a random directory using dex2oat. This image is relocated
+  // in the sense that it uses a different base address.
+  ScratchFile dex2oat_reloc_scratch;
+  dex2oat_reloc_scratch.Unlink();
+  std::string dex2oat_reloc_dir = dex2oat_reloc_scratch.GetFilename();
+  ASSERT_EQ(0, mkdir(dex2oat_reloc_dir.c_str(), 0700));
+  const uint32_t reloc_base_addr = 0x70000000;
+  if (!CompileBootImageToDir(dex2oat_reloc_dir, dex2oat_extra_args, reloc_base_addr, &error_msg)) {
+    FAIL() << "CompileBootImage2 failed: " << error_msg;
+  }
+  const off_t base_addr_delta = reloc_base_addr - orig_base_addr;
+
+  // Relocate the original boot image using patchoat. The image is relocated by the same amount
+  // as the second/relocated image produced by dex2oat.
+  ScratchFile patchoat_scratch;
+  patchoat_scratch.Unlink();
+  std::string patchoat_dir = patchoat_scratch.GetFilename();
+  ASSERT_EQ(0, mkdir(patchoat_dir.c_str(), 0700));
+  std::string dex2oat_orig_with_arch_dir =
+      dex2oat_orig_dir + "/" + GetInstructionSetString(kRuntimeISA);
+  // The arch-including symlink is needed by patchoat
+  ASSERT_EQ(0, symlink(dex2oat_orig_dir.c_str(), dex2oat_orig_with_arch_dir.c_str()));
+  if (!RelocateBootImage(
+      dex2oat_orig_dir + "/boot.art",
+      patchoat_dir + "/boot.art",
+      base_addr_delta,
+      &error_msg)) {
+    FAIL() << "RelocateBootImage failed: " << error_msg;
+  }
+
+  // dex2oat_reloc_image_filename is the boot image relocated using dex2oat
+  // patchoat_reloc_image_filename is the boot image relocated using patchoat
+  std::string dex2oat_reloc_image_filename = dex2oat_reloc_dir + "/boot.art";
+  std::string patchoat_reloc_image_filename = dex2oat_orig_dir + "/boot.art";
+  std::replace(
+      patchoat_reloc_image_filename.begin() + 1, patchoat_reloc_image_filename.end(), '/', '@');
+  patchoat_reloc_image_filename =
+      patchoat_dir
+      + (android::base::StartsWith(patchoat_reloc_image_filename, "/") ? "" : "/")
+      + patchoat_reloc_image_filename;
+
+  // Patch up the dex2oat-relocated image so that it looks as though it was relocated by patchoat.
+  // patchoat preserves the OAT checksum header field and sets patch delta header field.
+  if (!CopyImageChecksumAndSetPatchDelta(
+      dex2oat_orig_dir + "/boot.art",
+      dex2oat_reloc_dir + "/boot.art",
+      base_addr_delta,
+      &error_msg)) {
+    FAIL() << "Unable to copy image checksum: " << error_msg;
+  }
+
+  // Assert that the patchoat-relocated image is identical to the dex2oat-relocated image
+  if (BinaryDiff(dex2oat_reloc_image_filename, patchoat_reloc_image_filename, &error_msg)) {
+    FAIL() << "patchoat- and dex2oat-relocated images differ: " << error_msg;
+  }
+
+  ClearDirectory(dex2oat_orig_dir.c_str(), /*recursive*/ true);
+  ClearDirectory(dex2oat_reloc_dir.c_str(), /*recursive*/ true);
+  ClearDirectory(patchoat_dir.c_str(), /*recursive*/ true);
+  rmdir(dex2oat_orig_dir.c_str());
+  rmdir(dex2oat_reloc_dir.c_str());
+  rmdir(patchoat_dir.c_str());
+#else
+  LOG(INFO) << "Skipping PatchoatRelocationSameAsDex2oatRelocation";
+  // Force-print to std::cout so it's also outside the logcat.
+  std::cout << "Skipping PatchoatRelocationSameAsDex2oatRelocation" << std::endl;
+#endif
+}
+
+}  // namespace art