diff --git a/bootloader_message/bootloader_message.cpp b/bootloader_message/bootloader_message.cpp
index 4f7085d..b70d54e 100644
--- a/bootloader_message/bootloader_message.cpp
+++ b/bootloader_message/bootloader_message.cpp
@@ -45,7 +45,7 @@
   g_misc_device_for_test = misc_device;
 }
 
-static std::string get_misc_blk_device(std::string* err) {
+std::string get_misc_blk_device(std::string* err) {
   if (g_misc_device_for_test.has_value() && !g_misc_device_for_test->empty()) {
     return *g_misc_device_for_test;
   }
@@ -111,8 +111,8 @@
   return true;
 }
 
-static bool write_misc_partition(const void* p, size_t size, const std::string& misc_blk_device,
-                                 size_t offset, std::string* err) {
+bool write_misc_partition(const void* p, size_t size, const std::string& misc_blk_device,
+                          size_t offset, std::string* err) {
   android::base::unique_fd fd(open(misc_blk_device.c_str(), O_WRONLY));
   if (fd == -1) {
     *err = android::base::StringPrintf("failed to open %s: %s", misc_blk_device.c_str(),
@@ -261,37 +261,6 @@
                               WIPE_PACKAGE_OFFSET_IN_MISC, err);
 }
 
-static bool OffsetAndSizeInVendorSpace(size_t offset, size_t size) {
-  auto total_size = WIPE_PACKAGE_OFFSET_IN_MISC - VENDOR_SPACE_OFFSET_IN_MISC;
-  return size <= total_size && offset <= total_size - size;
-}
-
-bool ReadMiscPartitionVendorSpace(void* data, size_t size, size_t offset, std::string* err) {
-  if (!OffsetAndSizeInVendorSpace(offset, size)) {
-    *err = android::base::StringPrintf("Out of bound read (offset %zu size %zu)", offset, size);
-    return false;
-  }
-  auto misc_blk_device = get_misc_blk_device(err);
-  if (misc_blk_device.empty()) {
-    return false;
-  }
-  return read_misc_partition(data, size, misc_blk_device, VENDOR_SPACE_OFFSET_IN_MISC + offset,
-                             err);
-}
-
-bool WriteMiscPartitionVendorSpace(const void* data, size_t size, size_t offset, std::string* err) {
-  if (!OffsetAndSizeInVendorSpace(offset, size)) {
-    *err = android::base::StringPrintf("Out of bound write (offset %zu size %zu)", offset, size);
-    return false;
-  }
-  auto misc_blk_device = get_misc_blk_device(err);
-  if (misc_blk_device.empty()) {
-    return false;
-  }
-  return write_misc_partition(data, size, misc_blk_device, VENDOR_SPACE_OFFSET_IN_MISC + offset,
-                              err);
-}
-
 static bool ValidateSystemSpaceRegion(size_t offset, size_t size, std::string* err) {
   if (size <= SYSTEM_SPACE_SIZE_IN_MISC && offset <= (SYSTEM_SPACE_SIZE_IN_MISC - size)) {
     return true;
diff --git a/bootloader_message/include/bootloader_message/bootloader_message.h b/bootloader_message/include/bootloader_message/bootloader_message.h
index 3a3b862..a27e80b 100644
--- a/bootloader_message/include/bootloader_message/bootloader_message.h
+++ b/bootloader_message/include/bootloader_message/bootloader_message.h
@@ -212,11 +212,18 @@
 #include <string>
 #include <vector>
 
+// Gets the block device name of /misc partition.
+std::string get_misc_blk_device(std::string* err);
 // Return the block device name for the bootloader message partition and waits
 // for the device for up to 10 seconds. In case of error returns the empty
 // string.
 std::string get_bootloader_message_blk_device(std::string* err);
 
+// Writes |size| bytes of data from buffer |p| to |misc_blk_device| at |offset|. If the write fails,
+// sets the error message in |err|.
+bool write_misc_partition(const void* p, size_t size, const std::string& misc_blk_device,
+                          size_t offset, std::string* err);
+
 // Read bootloader message into boot. Error message will be set in err.
 bool read_bootloader_message(bootloader_message* boot, std::string* err);
 
@@ -261,14 +268,6 @@
 // Write the wipe package into BCB (to offset WIPE_PACKAGE_OFFSET_IN_MISC).
 bool write_wipe_package(const std::string& package_data, std::string* err);
 
-// Reads data from the vendor space in /misc partition, with the given offset and size. Note that
-// offset is in relative to the start of vendor space.
-bool ReadMiscPartitionVendorSpace(void* data, size_t size, size_t offset, std::string* err);
-
-// Writes the given data to the vendor space in /misc partition, at the given offset. Note that
-// offset is in relative to the start of the vendor space.
-bool WriteMiscPartitionVendorSpace(const void* data, size_t size, size_t offset, std::string* err);
-
 // Read or write the Virtual A/B message from system space in /misc.
 bool ReadMiscVirtualAbMessage(misc_virtual_ab_message* message, std::string* err);
 bool WriteMiscVirtualAbMessage(const misc_virtual_ab_message& message, std::string* err);
diff --git a/misc_writer/Android.bp b/misc_writer/Android.bp
index 567143c..73c44d2 100644
--- a/misc_writer/Android.bp
+++ b/misc_writer/Android.bp
@@ -14,14 +14,9 @@
 // limitations under the License.
 //
 
-cc_binary {
-    name: "misc_writer",
+cc_defaults {
+    name: "misc_writer_defaults",
     vendor: true,
-
-    srcs: [
-        "misc_writer.cpp",
-    ],
-
     cpp_std: "experimental",
 
     cflags: [
@@ -38,3 +33,78 @@
         "libfstab",
     ],
 }
+
+// TODO(xunchang) Remove duplicates after we convert the device specific librecovery_ui to recovery
+// module. Then libmisc_writer can build as a vendor module available in recovery.
+cc_library_static {
+    name: "libmisc_writer",
+    cpp_std: "experimental",
+
+    cflags: [
+        "-Wall",
+        "-Werror",
+    ],
+
+    shared_libs: [
+        "libbase",
+    ],
+
+    static_libs: [
+        "libbootloader_message",
+        "libfstab",
+    ],
+
+    srcs: [
+        "misc_writer.cpp",
+    ],
+
+    export_include_dirs: [
+        "include",
+    ],
+}
+
+cc_library_static {
+    name: "libmisc_writer_vendor",
+    defaults: [
+        "misc_writer_defaults",
+    ],
+
+    srcs: [
+        "misc_writer.cpp",
+    ],
+
+    export_include_dirs: [
+        "include",
+    ],
+}
+
+cc_binary {
+    name: "misc_writer",
+    defaults: [
+        "misc_writer_defaults",
+    ],
+
+    srcs: [
+        "misc_writer_main.cpp",
+    ],
+
+    static_libs: [
+        "libmisc_writer_vendor",
+    ]
+}
+
+cc_test {
+    name: "misc_writer_test",
+    defaults: [
+        "misc_writer_defaults",
+    ],
+
+    srcs: [
+        "misc_writer_test.cpp",
+    ],
+    test_suites: ["device-tests"],
+
+    static_libs: [
+        "libmisc_writer_vendor",
+    ]
+}
diff --git a/misc_writer/include/misc_writer/misc_writer.h b/misc_writer/include/misc_writer/misc_writer.h
new file mode 100644
index 0000000..6a32ffe
--- /dev/null
+++ b/misc_writer/include/misc_writer/misc_writer.h
@@ -0,0 +1,66 @@
+/*
+ * Copyright (C) 2019 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.
+ */
+
+#pragma once
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include <optional>
+#include <string>
+
+namespace android {
+namespace hardware {
+namespace google {
+namespace pixel {
+
+enum class MiscWriterActions : int32_t {
+  kSetDarkThemeFlag = 0,
+  kClearDarkThemeFlag,
+  kSetSotaFlag,
+  kClearSotaFlag,
+
+  kUnset = -1,
+};
+
+class MiscWriter {
+ public:
+  static constexpr uint32_t kThemeFlagOffsetInVendorSpace = 0;
+  static constexpr char kDarkThemeFlag[] = "theme-dark";
+  static constexpr uint32_t kSotaFlagOffsetInVendorSpace = 32;
+  static constexpr char kSotaFlag[] = "enable-sota";
+
+  // Returns true of |size| bytes data starting from |offset| is fully inside the vendor space.
+  static bool OffsetAndSizeInVendorSpace(size_t offset, size_t size);
+  // Writes the given data to the vendor space in /misc partition, at the given offset. Note that
+  // offset is in relative to the start of the vendor space.
+  static bool WriteMiscPartitionVendorSpace(const void* data, size_t size, size_t offset,
+                                            std::string* err);
+
+  explicit MiscWriter(const MiscWriterActions& action) : action_(action) {}
+
+  // Performs the stored MiscWriterActions. If |override_offset| is set, writes to the input offset
+  // in the vendor space of /misc instead of the default offset.
+  bool PerformAction(std::optional<size_t> override_offset = std::nullopt);
+
+ private:
+  MiscWriterActions action_{ MiscWriterActions::kUnset };
+};
+
+}  // namespace pixel
+}  // namespace google
+}  // namespace hardware
+}  // namespace android
diff --git a/misc_writer/misc_writer.cpp b/misc_writer/misc_writer.cpp
index 1d9702e..bf589d3 100644
--- a/misc_writer/misc_writer.cpp
+++ b/misc_writer/misc_writer.cpp
@@ -14,93 +14,70 @@
  * limitations under the License.
  */
 
-#include <errno.h>
-#include <getopt.h>
-#include <stdint.h>
-#include <stdlib.h>
-#include <unistd.h>
+#include "misc_writer/misc_writer.h"
 
-#include <iostream>
-#include <string>
-#include <string_view>
-#include <vector>
+#include <string.h>
 
+#include <android-base/file.h>
 #include <android-base/logging.h>
-#include <android-base/parseint.h>
+#include <android-base/stringprintf.h>
 #include <bootloader_message/bootloader_message.h>
 
-using namespace std::string_literals;
+namespace android {
+namespace hardware {
+namespace google {
+namespace pixel {
 
-static std::vector<uint8_t> ParseHexString(std::string_view hex_string) {
-  auto length = hex_string.size();
-  if (length % 2 != 0 || length == 0) {
-    return {};
-  }
-
-  std::vector<uint8_t> result(length / 2);
-  for (size_t i = 0; i < length / 2; i++) {
-    auto sub = "0x" + std::string(hex_string.substr(i * 2, 2));
-    if (!android::base::ParseUint(sub, &result[i])) {
-      return {};
-    }
-  }
-  return result;
+bool MiscWriter::OffsetAndSizeInVendorSpace(size_t offset, size_t size) {
+  auto total_size = WIPE_PACKAGE_OFFSET_IN_MISC - VENDOR_SPACE_OFFSET_IN_MISC;
+  return size <= total_size && offset <= total_size - size;
 }
 
-static int Usage(std::string_view name) {
-  std::cerr << name << " usage:\n";
-  std::cerr << name << " [--vendor-space-offset <offset>] --hex-string 0xABCDEF\n";
-  std::cerr << "Writes the given hex string to the specified offset in vendor space in /misc "
-               "partition. Offset defaults to 0 if unspecified.\n";
-  return EXIT_FAILURE;
+bool MiscWriter::WriteMiscPartitionVendorSpace(const void* data, size_t size, size_t offset,
+                                               std::string* err) {
+  if (!OffsetAndSizeInVendorSpace(offset, size)) {
+    *err = android::base::StringPrintf("Out of bound write (offset %zu size %zu)", offset, size);
+    return false;
+  }
+  auto misc_blk_device = get_misc_blk_device(err);
+  if (misc_blk_device.empty()) {
+    return false;
+  }
+  return write_misc_partition(data, size, misc_blk_device, VENDOR_SPACE_OFFSET_IN_MISC + offset,
+                              err);
 }
 
-// misc_writer is a vendor tool that writes data to the vendor space in /misc.
-int main(int argc, char** argv) {
-  constexpr struct option OPTIONS[] = {
-    { "vendor-space-offset", required_argument, nullptr, 0 },
-    { "hex-string", required_argument, nullptr, 0 },
-    { nullptr, 0, nullptr, 0 },
-  };
-
-  // Offset defaults to 0 if unspecified.
+bool MiscWriter::PerformAction(std::optional<size_t> override_offset) {
   size_t offset = 0;
-  std::string_view hex_string;
-
-  int arg;
-  int option_index;
-  while ((arg = getopt_long(argc, argv, "", OPTIONS, &option_index)) != -1) {
-    if (arg != 0) {
-      LOG(ERROR) << "Invalid command argument";
-      return Usage(argv[0]);
-    }
-    auto option_name = OPTIONS[option_index].name;
-    if (option_name == "vendor-space-offset"s) {
-      if (!android::base::ParseUint(optarg, &offset)) {
-        LOG(ERROR) << "Failed to parse the offset: " << optarg;
-        return Usage(argv[0]);
-      }
-    } else if (option_name == "hex-string"s) {
-      hex_string = optarg;
-    }
+  std::string content;
+  switch (action_) {
+    case MiscWriterActions::kSetDarkThemeFlag:
+    case MiscWriterActions::kClearDarkThemeFlag:
+      offset = override_offset.value_or(kThemeFlagOffsetInVendorSpace);
+      content = (action_ == MiscWriterActions::kSetDarkThemeFlag)
+                    ? kDarkThemeFlag
+                    : std::string(strlen(kDarkThemeFlag), 0);
+      break;
+    case MiscWriterActions::kSetSotaFlag:
+    case MiscWriterActions::kClearSotaFlag:
+      offset = override_offset.value_or(kSotaFlagOffsetInVendorSpace);
+      content = (action_ == MiscWriterActions::kSetSotaFlag) ? kSotaFlag
+                                                             : std::string(strlen(kSotaFlag), 0);
+      break;
+    case MiscWriterActions::kUnset:
+      LOG(ERROR) << "The misc writer action must be set";
+      return false;
   }
 
-  if (hex_string.starts_with("0x") || hex_string.starts_with("0X")) {
-    hex_string = hex_string.substr(2);
+  if (std::string err;
+      !WriteMiscPartitionVendorSpace(content.data(), content.size(), offset, &err)) {
+    LOG(ERROR) << "Failed to write " << content << " at offset " << offset << " : " << err;
+    return false;
   }
-  if (hex_string.empty()) {
-    LOG(ERROR) << "Invalid input hex string: " << hex_string;
-    return Usage(argv[0]);
-  }
-
-  auto data = ParseHexString(hex_string);
-  if (data.empty()) {
-    LOG(ERROR) << "Failed to parse the input hex string: " << hex_string;
-    return EXIT_FAILURE;
-  }
-  if (std::string err; !WriteMiscPartitionVendorSpace(data.data(), data.size(), offset, &err)) {
-    LOG(ERROR) << "Failed to write to misc partition: " << err;
-    return EXIT_FAILURE;
-  }
-  return EXIT_SUCCESS;
+  return true;
 }
+
+}  // namespace pixel
+}  // namespace google
+}  // namespace hardware
+}  // namespace android
diff --git a/misc_writer/misc_writer_main.cpp b/misc_writer/misc_writer_main.cpp
new file mode 100644
index 0000000..69a9fe3
--- /dev/null
+++ b/misc_writer/misc_writer_main.cpp
@@ -0,0 +1,109 @@
+/*
+ * Copyright (C) 2019 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 <getopt.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#include <iostream>
+#include <map>
+#include <memory>
+#include <optional>
+#include <string>
+#include <string_view>
+
+#include <android-base/logging.h>
+#include <android-base/parseint.h>
+
+#include "misc_writer/misc_writer.h"
+
+using namespace std::string_literals;
+using android::hardware::google::pixel::MiscWriter;
+using android::hardware::google::pixel::MiscWriterActions;
+
+static int Usage(std::string_view name) {
+  std::cerr << name << " usage:\n";
+  std::cerr << name << " [--override-vendor-space-offset <offset>] --<misc_writer_action>\n";
+  std::cerr << "Supported misc_writer_action is one of: \n";
+  std::cerr << "  --set-dark-theme     Write the dark theme flag\n";
+  std::cerr << "  --clear-dark-theme   Clear the dark theme flag\n";
+  std::cerr << "  --set-sota           Write the silent OTA flag\n";
+  std::cerr << "  --clear-sota         Clear the silent OTA flag\n";
+  std::cerr << "Writes the given hex string to the specified offset in vendor space in /misc "
+               "partition.\nDefault offset is used for each action unless "
+               "--override-vendor-space-offset is specified.\n";
+  return EXIT_FAILURE;
+}
+
+// misc_writer is a vendor tool that writes data to the vendor space in /misc.
+int main(int argc, char** argv) {
+  constexpr struct option OPTIONS[] = {
+    { "set-dark-theme", no_argument, nullptr, 0 },
+    { "clear-dark-theme", no_argument, nullptr, 0 },
+    { "set-sota", no_argument, nullptr, 0 },
+    { "clear-sota", no_argument, nullptr, 0 },
+    { "override-vendor-space-offset", required_argument, nullptr, 0 },
+    { nullptr, 0, nullptr, 0 },
+  };
+
+  std::map<std::string, MiscWriterActions> action_map{
+    { "set-dark-theme", MiscWriterActions::kSetDarkThemeFlag },
+    { "clear-dark-theme", MiscWriterActions::kClearDarkThemeFlag },
+    { "set-sota", MiscWriterActions::kSetSotaFlag },
+    { "clear-sota", MiscWriterActions::kClearSotaFlag },
+  };
+
+  std::unique_ptr<MiscWriter> misc_writer;
+  std::optional<size_t> override_offset;
+
+  int arg;
+  int option_index = 0;
+  while ((arg = getopt_long(argc, argv, "", OPTIONS, &option_index)) != -1) {
+    if (arg != 0) {
+      LOG(ERROR) << "Invalid command argument";
+      return Usage(argv[0]);
+    }
+    auto option_name = OPTIONS[option_index].name;
+    if (option_name == "override-vendor-space-offset"s) {
+      LOG(WARNING) << "Overriding the vendor space offset in misc partition to " << optarg;
+      size_t offset;
+      if (!android::base::ParseUint(optarg, &offset)) {
+        LOG(ERROR) << "Failed to parse the offset: " << optarg;
+        return Usage(argv[0]);
+      }
+      override_offset = offset;
+    } else if (auto iter = action_map.find(option_name); iter != action_map.end()) {
+      if (misc_writer) {
+        LOG(ERROR) << "Misc writer action has already been set";
+        return Usage(argv[0]);
+      }
+      misc_writer = std::make_unique<MiscWriter>(iter->second);
+    } else {
+      LOG(FATAL) << "Unreachable path, option_name: " << option_name;
+    }
+  }
+
+  if (!misc_writer) {
+    LOG(ERROR) << "An action must be specified for misc writer";
+    return Usage(argv[0]);
+  }
+
+  if (!misc_writer->PerformAction(override_offset)) {
+    return EXIT_FAILURE;
+  }
+
+  return EXIT_SUCCESS;
+}
diff --git a/misc_writer/misc_writer_test.cpp b/misc_writer/misc_writer_test.cpp
new file mode 100644
index 0000000..e8b207a
--- /dev/null
+++ b/misc_writer/misc_writer_test.cpp
@@ -0,0 +1,140 @@
+/*
+ * 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.
+ */
+
+#include <memory>
+#include <string>
+#include <string_view>
+#include <vector>
+
+#include <android-base/file.h>
+#include <bootloader_message/bootloader_message.h>
+#include <gtest/gtest.h>
+
+#include "misc_writer/misc_writer.h"
+
+using namespace std::string_literals;
+
+namespace android {
+namespace hardware {
+namespace google {
+namespace pixel {
+
+class MiscWriterTest : public ::testing::Test {
+ protected:
+  void TearDown() override {
+    // Clear the vendor space.
+    auto zeros = std::string(WIPE_PACKAGE_OFFSET_IN_MISC - VENDOR_SPACE_OFFSET_IN_MISC, 0);
+    std::string err;
+    ASSERT_TRUE(MiscWriter::WriteMiscPartitionVendorSpace(zeros.data(), zeros.size(), 0, &err))
+        << err;
+  }
+
+  void CheckMiscPartitionVendorSpaceContent(size_t offset, const std::string& expected);
+
+  std::unique_ptr<MiscWriter> misc_writer_;
+};
+
+void MiscWriterTest::CheckMiscPartitionVendorSpaceContent(size_t offset,
+                                                          const std::string& expected) {
+  ASSERT_TRUE(MiscWriter::OffsetAndSizeInVendorSpace(offset, expected.size()));
+  std::string err;
+  auto misc_blk_device = get_misc_blk_device(&err);
+  ASSERT_FALSE(misc_blk_device.empty());
+  android::base::unique_fd fd(open(misc_blk_device.c_str(), O_RDONLY));
+  ASSERT_NE(-1, fd);
+
+  std::string content(expected.size(), 0);
+  ASSERT_TRUE(android::base::ReadFullyAtOffset(fd, content.data(), content.size(),
+                                               VENDOR_SPACE_OFFSET_IN_MISC + offset));
+  ASSERT_EQ(expected, content);
+}
+
+TEST_F(MiscWriterTest, SetClearDarkTheme) {
+  misc_writer_ = std::make_unique<MiscWriter>(MiscWriterActions::kSetDarkThemeFlag);
+  ASSERT_TRUE(misc_writer_);
+  ASSERT_TRUE(misc_writer_->PerformAction());
+  std::string expected = "theme-dark";
+  CheckMiscPartitionVendorSpaceContent(0, expected);
+
+  misc_writer_ = std::make_unique<MiscWriter>(MiscWriterActions::kClearDarkThemeFlag);
+  ASSERT_TRUE(misc_writer_->PerformAction());
+  std::string zeros(expected.size(), 0);
+  CheckMiscPartitionVendorSpaceContent(0, zeros);
+}
+
+TEST_F(MiscWriterTest, SetClearDarkTheme_OffsetOverride) {
+  misc_writer_ = std::make_unique<MiscWriter>(MiscWriterActions::kSetDarkThemeFlag);
+  size_t offset = 12360;
+  ASSERT_TRUE(misc_writer_->PerformAction(offset));
+  std::string expected = "theme-dark";
+  CheckMiscPartitionVendorSpaceContent(offset, expected);
+
+  misc_writer_ = std::make_unique<MiscWriter>(MiscWriterActions::kClearDarkThemeFlag);
+  ASSERT_TRUE(misc_writer_->PerformAction(offset));
+  std::string zeros(expected.size(), 0);
+  CheckMiscPartitionVendorSpaceContent(offset, zeros);
+}
+
+TEST_F(MiscWriterTest, SetClearSota) {
+  misc_writer_ = std::make_unique<MiscWriter>(MiscWriterActions::kSetSotaFlag);
+  ASSERT_TRUE(misc_writer_);
+  ASSERT_TRUE(misc_writer_->PerformAction());
+  std::string expected = "enable-sota";
+  CheckMiscPartitionVendorSpaceContent(32, expected);
+
+  // Test we can write to the override offset.
+  size_t override_offset = 12360;
+  ASSERT_FALSE(misc_writer_->PerformAction(override_offset));
+  CheckMiscPartitionVendorSpaceContent(override_offset, expected);
+
+  misc_writer_ = std::make_unique<MiscWriter>(MiscWriterActions::kClearSotaFlag);
+  ASSERT_TRUE(misc_writer_->PerformAction());
+  std::string zeros(expected.size(), 0);
+  CheckMiscPartitionVendorSpaceContent(32, zeros);
+}
+
+TEST_F(MiscWriterTest, WriteMiscPartitionVendorSpace) {
+  std::string kTestMessage = "kTestMessage";
+  std::string err;
+  ASSERT_TRUE(
+      MiscWriter::WriteMiscPartitionVendorSpace(kTestMessage.data(), kTestMessage.size(), 0, &err));
+
+  CheckMiscPartitionVendorSpaceContent(0, kTestMessage);
+
+  // Write with an offset.
+  ASSERT_TRUE(MiscWriter::WriteMiscPartitionVendorSpace("\x00\x00", 2, 5, &err));
+  CheckMiscPartitionVendorSpaceContent(0, "kTest\x00\x00ssage"s);
+
+  // Write with the right size.
+  auto start_offset =
+      WIPE_PACKAGE_OFFSET_IN_MISC - VENDOR_SPACE_OFFSET_IN_MISC - kTestMessage.size();
+  ASSERT_TRUE(MiscWriter::WriteMiscPartitionVendorSpace(kTestMessage.data(), kTestMessage.size(),
+                                                        start_offset, &err));
+
+  // Out-of-bound write.
+  ASSERT_FALSE(MiscWriter::WriteMiscPartitionVendorSpace(kTestMessage.data(), kTestMessage.size(),
+                                                         start_offset + 1, &err));
+
+  // Message won't fit.
+  std::string long_message(WIPE_PACKAGE_OFFSET_IN_MISC - VENDOR_SPACE_OFFSET_IN_MISC + 1, 'a');
+  ASSERT_FALSE(
+      MiscWriter::WriteMiscPartitionVendorSpace(long_message.data(), long_message.size(), 0, &err));
+}
+
+}  // namespace pixel
+}  // namespace google
+}  // namespace hardware
+}  // namespace android
diff --git a/tests/unit/bootloader_message_test.cpp b/tests/unit/bootloader_message_test.cpp
index 95d875e..731c8fe 100644
--- a/tests/unit/bootloader_message_test.cpp
+++ b/tests/unit/bootloader_message_test.cpp
@@ -118,37 +118,3 @@
   ASSERT_EQ(std::string(sizeof(boot.reserved), '\0'),
             std::string(boot.reserved, sizeof(boot.reserved)));
 }
-
-TEST(BootloaderMessageTest, WriteMiscPartitionVendorSpace) {
-  TemporaryFile temp_misc;
-  ASSERT_TRUE(android::base::WriteStringToFile(std::string(4096, '\x00'), temp_misc.path));
-  SetMiscBlockDeviceForTest(temp_misc.path);
-
-  constexpr std::string_view kTestMessage = "kTestMessage";
-  std::string err;
-  ASSERT_TRUE(WriteMiscPartitionVendorSpace(kTestMessage.data(), kTestMessage.size(), 0, &err));
-
-  std::string message;
-  message.resize(kTestMessage.size());
-  ASSERT_TRUE(ReadMiscPartitionVendorSpace(message.data(), message.size(), 0, &err));
-  ASSERT_EQ(kTestMessage, message);
-
-  // Write with an offset.
-  ASSERT_TRUE(WriteMiscPartitionVendorSpace("\x00\x00", 2, 5, &err));
-  ASSERT_TRUE(ReadMiscPartitionVendorSpace(message.data(), message.size(), 0, &err));
-  ASSERT_EQ("kTest\x00\x00ssage"s, message);
-
-  // Write with the right size.
-  auto start_offset =
-      WIPE_PACKAGE_OFFSET_IN_MISC - VENDOR_SPACE_OFFSET_IN_MISC - kTestMessage.size();
-  ASSERT_TRUE(
-      WriteMiscPartitionVendorSpace(kTestMessage.data(), kTestMessage.size(), start_offset, &err));
-
-  // Out-of-bound write.
-  ASSERT_FALSE(WriteMiscPartitionVendorSpace(kTestMessage.data(), kTestMessage.size(),
-                                             start_offset + 1, &err));
-
-  // Message won't fit.
-  std::string long_message(WIPE_PACKAGE_OFFSET_IN_MISC - VENDOR_SPACE_OFFSET_IN_MISC + 1, 'a');
-  ASSERT_FALSE(WriteMiscPartitionVendorSpace(long_message.data(), long_message.size(), 0, &err));
-}