diff --git a/libs/binder/tests/Android.bp b/libs/binder/tests/Android.bp
index 24afcf6..b29da3c 100644
--- a/libs/binder/tests/Android.bp
+++ b/libs/binder/tests/Android.bp
@@ -188,6 +188,33 @@
 }
 
 cc_test {
+    name: "binderRpcWireProtocolTest",
+    host_supported: true,
+    target: {
+        darwin: {
+            enabled: false,
+        },
+        android: {
+            test_suites: ["vts"],
+        },
+    },
+    defaults: [
+        "binder_test_defaults",
+    ],
+    srcs: [
+        "binderRpcWireProtocolTest.cpp",
+    ],
+    shared_libs: [
+        "libbinder",
+        "libbase",
+        "libutils",
+        "libcutils",
+        "liblog",
+    ],
+    test_suites: ["general-tests"],
+}
+
+cc_test {
     name: "binderThroughputTest",
     defaults: ["binder_test_defaults"],
     srcs: ["binderThroughputTest.cpp"],
diff --git a/libs/binder/tests/binderRpcWireProtocolTest.cpp b/libs/binder/tests/binderRpcWireProtocolTest.cpp
new file mode 100644
index 0000000..46e9630
--- /dev/null
+++ b/libs/binder/tests/binderRpcWireProtocolTest.cpp
@@ -0,0 +1,257 @@
+/*
+ * Copyright (C) 2021 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 <android-base/hex.h>
+#include <android-base/logging.h>
+#include <android-base/macros.h>
+#include <android-base/properties.h>
+#include <android-base/strings.h>
+#include <binder/Parcel.h>
+#include <binder/RpcSession.h>
+#include <gtest/gtest.h>
+
+#include "../Debug.h"
+
+namespace android {
+
+static const int32_t kInt32Array[] = {-1, 0, 17};
+static const uint8_t kByteArray[] = {0, 17, 255};
+enum EnumInt8 : int8_t { Int8A, Int8B };
+enum EnumInt32 : int32_t { Int32A, Int32B };
+enum EnumInt64 : int64_t { Int64A, Int64B };
+struct AParcelable : Parcelable {
+    status_t writeToParcel(Parcel* parcel) const { return parcel->writeInt32(37); }
+    status_t readFromParcel(const Parcel*) { return OK; }
+};
+
+// clang-format off
+constexpr size_t kFillFunIndexLineBase = __LINE__ + 2;
+static const std::vector<std::function<void(Parcel* p)>> kFillFuns {
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeInterfaceToken(String16(u"tok"))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeInt32(-1)); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeInt32(0)); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeInt32(17)); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeUint32(0)); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeUint32(1)); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeUint32(10003)); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeInt64(-1)); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeInt64(0)); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeInt64(17)); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeUint64(0)); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeUint64(1)); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeUint64(10003)); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeFloat(0.0f)); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeFloat(0.1f)); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeFloat(9.1f)); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeDouble(0.0)); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeDouble(0.1)); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeDouble(9.1)); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeCString("")); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeCString("a")); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeCString("baba")); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeString8(String8(""))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeString8(String8("a"))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeString8(String8("baba"))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeString16(String16(u""))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeString16(String16(u"a"))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeString16(String16(u"baba"))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeStrongBinder(nullptr)); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeInt32Array(arraysize(kInt32Array), kInt32Array)); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeByteArray(arraysize(kByteArray), kByteArray)); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeBool(true)); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeBool(false)); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeChar('a')); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeChar('?')); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeChar('\0')); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeByte(-128)); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeByte(0)); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeByte(127)); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeUtf8AsUtf16(std::string(""))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeUtf8AsUtf16(std::string("a"))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeUtf8AsUtf16(std::string("abab"))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeUtf8AsUtf16(std::nullopt)); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeUtf8AsUtf16(std::optional<std::string>(""))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeUtf8AsUtf16(std::optional<std::string>("a"))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeUtf8AsUtf16(std::optional<std::string>("abab"))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeByteVector(std::optional<std::vector<int8_t>>(std::nullopt))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeByteVector(std::optional<std::vector<int8_t>>({-1, 0, 17}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeByteVector(std::vector<int8_t>({}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeByteVector(std::vector<int8_t>({-1, 0, 17}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeByteVector(std::optional<std::vector<uint8_t>>(std::nullopt))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeByteVector(std::optional<std::vector<uint8_t>>({0, 1, 17}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeByteVector(std::vector<uint8_t>({}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeByteVector(std::vector<uint8_t>({0, 1, 17}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeInt32Vector(std::optional<std::vector<int32_t>>(std::nullopt))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeInt32Vector(std::optional<std::vector<int32_t>>({-1, 0, 17}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeInt32Vector(std::vector<int32_t>({}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeInt32Vector(std::vector<int32_t>({-1, 0, 17}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeInt64Vector(std::optional<std::vector<int64_t>>(std::nullopt))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeInt64Vector(std::optional<std::vector<int64_t>>({-1, 0, 17}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeInt64Vector(std::vector<int64_t>({}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeInt64Vector(std::vector<int64_t>({-1, 0, 17}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeUint64Vector(std::optional<std::vector<uint64_t>>(std::nullopt))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeUint64Vector(std::optional<std::vector<uint64_t>>({0, 1, 17}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeUint64Vector(std::vector<uint64_t>({}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeUint64Vector(std::vector<uint64_t>({0, 1, 17}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeFloatVector(std::optional<std::vector<float>>(std::nullopt))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeFloatVector(std::optional<std::vector<float>>({0.0f, 0.1f, 9.1f}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeFloatVector(std::vector<float>({}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeFloatVector(std::vector<float>({0.0f, 0.1f, 9.1f}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeDoubleVector(std::optional<std::vector<double>>(std::nullopt))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeDoubleVector(std::optional<std::vector<double>>({0.0, 0.1, 9.1}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeDoubleVector(std::vector<double>({}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeDoubleVector(std::vector<double>({0.0, 0.1, 9.1}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeBoolVector(std::optional<std::vector<bool>>(std::nullopt))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeBoolVector(std::optional<std::vector<bool>>({true, false}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeBoolVector(std::vector<bool>({}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeBoolVector(std::vector<bool>({true, false}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeCharVector(std::optional<std::vector<char16_t>>(std::nullopt))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeCharVector(std::optional<std::vector<char16_t>>({'a', '\0', '?'}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeCharVector(std::vector<char16_t>({}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeCharVector(std::vector<char16_t>({'a', '\0', '?'}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeString16Vector(std::optional<std::vector<std::optional<String16>>>(std::nullopt))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeString16Vector(std::optional<std::vector<std::optional<String16>>>({std::nullopt, String16(), String16(u"a")}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeString16Vector(std::vector<std::optional<String16>>({}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeString16Vector(std::vector<std::optional<String16>>({std::nullopt, String16(), String16(u"a")}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeUtf8VectorAsUtf16Vector(std::optional<std::vector<std::optional<std::string>>>(std::nullopt))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeUtf8VectorAsUtf16Vector(std::optional<std::vector<std::optional<std::string>>>({std::nullopt, std::string(), std::string("a")}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeUtf8VectorAsUtf16Vector(std::vector<std::optional<std::string>>({}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeUtf8VectorAsUtf16Vector(std::vector<std::optional<std::string>>({std::nullopt, std::string(), std::string("a")}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeStrongBinderVector(std::optional<std::vector<sp<IBinder>>>(std::nullopt))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeStrongBinderVector(std::optional<std::vector<sp<IBinder>>>({nullptr}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeStrongBinderVector(std::vector<sp<IBinder>>({}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeStrongBinderVector(std::vector<sp<IBinder>>({nullptr}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeEnumVector(std::optional<std::vector<EnumInt8>>(std::nullopt))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeEnumVector(std::optional<std::vector<EnumInt8>>({Int8A, Int8B}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeEnumVector(std::vector<EnumInt8>({Int8A, Int8B}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeEnumVector(std::optional<std::vector<EnumInt32>>(std::nullopt))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeEnumVector(std::optional<std::vector<EnumInt32>>({Int32A, Int32B}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeEnumVector(std::vector<EnumInt32>({Int32A, Int32B}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeEnumVector(std::optional<std::vector<EnumInt64>>(std::nullopt))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeEnumVector(std::optional<std::vector<EnumInt64>>({Int64A, Int64B}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeEnumVector(std::vector<EnumInt64>({Int64A, Int64B}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeParcelableVector(std::optional<std::vector<std::optional<AParcelable>>>(std::nullopt))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeParcelableVector(std::optional<std::vector<std::optional<AParcelable>>>({AParcelable()}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeParcelableVector(std::vector<AParcelable>({AParcelable()}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeNullableParcelable(std::optional<AParcelable>(std::nullopt))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeNullableParcelable(std::optional<AParcelable>(AParcelable()))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeParcelable(AParcelable())); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeVectorSize(std::vector<int32_t>({0, 1, 17}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeVectorSize(std::vector<AParcelable>({}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeVectorSize(std::optional<std::vector<int32_t>>(std::nullopt))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeVectorSize(std::optional<std::vector<int32_t>>({0, 1, 17}))); },
+    [](Parcel* p) { ASSERT_EQ(OK, p->writeNoException()); },
+};
+// clang-format on
+
+static void setParcelForRpc(Parcel* p, uint32_t version) {
+    auto session = RpcSession::make();
+    CHECK(session->setProtocolVersion(version));
+    CHECK_EQ(OK, session->addNullDebuggingClient());
+    p->markForRpc(session);
+}
+
+static std::string buildRepr(uint32_t version) {
+    std::string result;
+    for (size_t i = 0; i < kFillFuns.size(); i++) {
+        if (i != 0) result += "|";
+        Parcel p;
+        setParcelForRpc(&p, version);
+        kFillFuns[i](&p);
+
+        result += base::HexString(p.data(), p.dataSize());
+    }
+    return result;
+}
+
+static void checkRepr(const std::string& repr, uint32_t version) {
+    const std::string actualRepr = buildRepr(version);
+
+    auto expected = base::Split(repr, "|");
+    ASSERT_EQ(expected.size(), kFillFuns.size());
+
+    auto actual = base::Split(actualRepr, "|");
+    ASSERT_EQ(actual.size(), kFillFuns.size());
+
+    for (size_t i = 0; i < kFillFuns.size(); i++) {
+        EXPECT_EQ(expected[i], actual[i])
+                << "Format mismatch, see " __FILE__ " line " << (kFillFunIndexLineBase + i);
+    }
+
+    // same check as in the loop, but the above error is more clear to debug,
+    // and this error is more clear to be able to update the source file here.
+    EXPECT_EQ(repr, actualRepr);
+}
+
+const std::string kCurrentRepr =
+        "0300000074006f006b000000|ffffffff|00000000|11000000|00000000|01000000|13270000|"
+        "ffffffffffffffff|0000000000000000|1100000000000000|0000000000000000|0100000000000000|"
+        "1327000000000000|00000000|cdcccc3d|9a991141|0000000000000000|9a9999999999b93f|"
+        "3333333333332240|00000000|61000000|6261626100000000|0000000000000000|0100000061000000|"
+        "040000006261626100000000|0000000000000000|0100000061000000|"
+        "04000000620061006200610000000000|0000000000000000|03000000ffffffff0000000011000000|"
+        "030000000011ff00|01000000|00000000|61000000|3f000000|00000000|80ffffff|00000000|7f000000|"
+        "0000000000000000|0100000061000000|04000000610062006100620000000000|ffffffff|"
+        "0000000000000000|0100000061000000|04000000610062006100620000000000|ffffffff|"
+        "03000000ff001100|00000000|03000000ff001100|ffffffff|0300000000011100|00000000|"
+        "0300000000011100|ffffffff|03000000ffffffff0000000011000000|00000000|"
+        "03000000ffffffff0000000011000000|ffffffff|"
+        "03000000ffffffffffffffff00000000000000001100000000000000|00000000|"
+        "03000000ffffffffffffffff00000000000000001100000000000000|ffffffff|"
+        "03000000000000000000000001000000000000001100000000000000|00000000|"
+        "03000000000000000000000001000000000000001100000000000000|ffffffff|"
+        "0300000000000000cdcccc3d9a991141|00000000|0300000000000000cdcccc3d9a991141|ffffffff|"
+        "0300000000000000000000009a9999999999b93f3333333333332240|00000000|"
+        "0300000000000000000000009a9999999999b93f3333333333332240|ffffffff|"
+        "020000000100000000000000|00000000|020000000100000000000000|ffffffff|"
+        "0300000061000000000000003f000000|00000000|0300000061000000000000003f000000|ffffffff|"
+        "03000000ffffffff00000000000000000100000061000000|00000000|"
+        "03000000ffffffff00000000000000000100000061000000|ffffffff|"
+        "03000000ffffffff00000000000000000100000061000000|00000000|"
+        "03000000ffffffff00000000000000000100000061000000|ffffffff|010000000000000000000000|"
+        "00000000|010000000000000000000000|ffffffff|0200000000010000|0200000000010000|ffffffff|"
+        "020000000000000001000000|020000000000000001000000|ffffffff|"
+        "0200000000000000000000000100000000000000|0200000000000000000000000100000000000000|"
+        "ffffffff|010000000100000025000000|010000000100000025000000|00000000|0100000025000000|"
+        "0100000025000000|03000000|00000000|ffffffff|03000000|00000000";
+
+TEST(RpcWire, CurrentVersion) {
+    checkRepr(kCurrentRepr, RPC_WIRE_PROTOCOL_VERSION);
+}
+
+static_assert(RPC_WIRE_PROTOCOL_VERSION == RPC_WIRE_PROTOCOL_VERSION_EXPERIMENTAL,
+              "you better update this test!");
+
+TEST(RpcWire, ReleaseBranchHasFrozenRpcWireProtocol) {
+    if (RPC_WIRE_PROTOCOL_VERSION == RPC_WIRE_PROTOCOL_VERSION_EXPERIMENTAL) {
+        EXPECT_FALSE(base::GetProperty("ro.build.version.codename", "") == "REL")
+                << "Binder RPC wire protocol must be frozen on a release branch!";
+    }
+}
+
+TEST(RpcWire, IfNotExperimentalCodeHasNoExperimentalFeatures) {
+    if (RPC_WIRE_PROTOCOL_VERSION == RPC_WIRE_PROTOCOL_VERSION_EXPERIMENTAL) {
+        GTEST_SKIP() << "Version is experimental, so experimental features are okay.";
+    }
+
+    // if we set the wire protocol version to experimental, none of the code
+    // should introduce a difference (if this fails, it means we have features
+    // which are enabled under experimental mode, but we aren't actually using
+    // or testing them!)
+    checkRepr(kCurrentRepr, RPC_WIRE_PROTOCOL_VERSION_EXPERIMENTAL);
+}
+
+} // namespace android