diff --git a/audio/aidl/default/Android.bp b/audio/aidl/default/Android.bp
index 65bbe9e..934c7ee 100644
--- a/audio/aidl/default/Android.bp
+++ b/audio/aidl/default/Android.bp
@@ -73,9 +73,9 @@
         "Configuration.cpp",
         "EngineConfigXmlConverter.cpp",
         "Module.cpp",
+        "ModulePrimary.cpp",
         "SoundDose.cpp",
         "Stream.cpp",
-        "StreamStub.cpp",
         "Telephony.cpp",
         "alsa/Mixer.cpp",
         "alsa/ModuleAlsa.cpp",
@@ -85,6 +85,8 @@
         "r_submix/RemoteSubmixUtils.cpp",
         "r_submix/SubmixRoute.cpp",
         "r_submix/StreamRemoteSubmix.cpp",
+        "stub/ModuleStub.cpp",
+        "stub/StreamStub.cpp",
         "usb/ModuleUsb.cpp",
         "usb/StreamUsb.cpp",
         "usb/UsbAlsaMixerControl.cpp",
diff --git a/audio/aidl/default/Configuration.cpp b/audio/aidl/default/Configuration.cpp
index d41ea67..a71c6ea 100644
--- a/audio/aidl/default/Configuration.cpp
+++ b/audio/aidl/default/Configuration.cpp
@@ -144,10 +144,6 @@
 //    - no profiles specified
 //  * "FM Tuner", IN_FM_TUNER
 //    - no profiles specified
-//  * "USB Out", OUT_DEVICE, CONNECTION_USB
-//    - no profiles specified
-//  * "USB In", IN_DEVICE, CONNECTION_USB
-//    - no profiles specified
 //
 // Mix ports:
 //  * "primary output", PRIMARY, 1 max open, 1 max active stream
@@ -172,8 +168,7 @@
 //
 // Routes:
 //  "primary out", "compressed offload" -> "Speaker"
-//  "primary out", "compressed offload" -> "USB Out"
-//  "Built-in Mic", "USB In" -> "primary input"
+//  "Built-in Mic" -> "primary input"
 //  "telephony_tx" -> "Telephony Tx"
 //  "Telephony Rx" -> "telephony_rx"
 //  "FM Tuner" -> "fm_tuner"
@@ -185,14 +180,6 @@
 //  * "Telephony Rx" device port: PCM 24-bit; MONO; 48000
 //  * "FM Tuner" device port: PCM 24-bit; STEREO; 48000
 //
-// Profiles for device port connected state:
-//  * USB Out":
-//    - profile PCM 16-bit; MONO, STEREO; 8000, 11025, 16000, 32000, 44100, 48000
-//    - profile PCM 24-bit; MONO, STEREO; 8000, 11025, 16000, 32000, 44100, 48000
-//  * USB In":
-//    - profile PCM 16-bit; MONO, STEREO; 8000, 11025, 16000, 32000, 44100, 48000
-//    - profile PCM 24-bit; MONO, STEREO; 8000, 11025, 16000, 32000, 44100, 48000
-//
 std::unique_ptr<Configuration> getPrimaryConfiguration() {
     static const Configuration configuration = []() {
         const std::vector<AudioProfile> standardPcmAudioProfiles = {
@@ -252,19 +239,6 @@
                                  AudioChannelLayout::LAYOUT_STEREO, 48000, 0, true,
                                  createDeviceExt(AudioDeviceType::IN_FM_TUNER, 0)));
 
-        AudioPort usbOutDevice =
-                createPort(c.nextPortId++, "USB Out", 0, false,
-                           createDeviceExt(AudioDeviceType::OUT_DEVICE, 0,
-                                           AudioDeviceDescription::CONNECTION_USB));
-        c.ports.push_back(usbOutDevice);
-        c.connectedProfiles[usbOutDevice.id] = standardPcmAudioProfiles;
-
-        AudioPort usbInDevice = createPort(c.nextPortId++, "USB In", 0, true,
-                                           createDeviceExt(AudioDeviceType::IN_DEVICE, 0,
-                                                           AudioDeviceDescription::CONNECTION_USB));
-        c.ports.push_back(usbInDevice);
-        c.connectedProfiles[usbInDevice.id] = standardPcmAudioProfiles;
-
         // Mix ports
 
         AudioPort primaryOutMix = createPort(c.nextPortId++, "primary output",
@@ -323,8 +297,7 @@
         c.ports.push_back(fmTunerInMix);
 
         c.routes.push_back(createRoute({primaryOutMix, compressedOffloadOutMix}, speakerOutDevice));
-        c.routes.push_back(createRoute({primaryOutMix, compressedOffloadOutMix}, usbOutDevice));
-        c.routes.push_back(createRoute({micInDevice, usbInDevice}, primaryInMix));
+        c.routes.push_back(createRoute({micInDevice}, primaryInMix));
         c.routes.push_back(createRoute({telephonyTxOutMix}, telephonyTxOutDevice));
         c.routes.push_back(createRoute({telephonyRxInDevice}, telephonyRxInMix));
         c.routes.push_back(createRoute({fmTunerInDevice}, fmTunerInMix));
@@ -406,22 +379,31 @@
 // Usb configuration:
 //
 // Device ports:
+//  * "USB Device Out", OUT_DEVICE, CONNECTION_USB
+//    - no profiles specified
 //  * "USB Headset Out", OUT_HEADSET, CONNECTION_USB
 //    - no profiles specified
+//  * "USB Device In", IN_DEVICE, CONNECTION_USB
+//    - no profiles specified
 //  * "USB Headset In", IN_HEADSET, CONNECTION_USB
 //    - no profiles specified
 //
 // Mix ports:
-//  * "usb_headset output", 1 max open, 1 max active stream
+//  * "usb_device output", 1 max open, 1 max active stream
 //    - no profiles specified
-//  * "usb_headset input", 1 max open, 1 max active stream
+//  * "usb_device input", 1 max open, 1 max active stream
 //    - no profiles specified
 //
+// Routes:
+//  * "usb_device output" -> "USB Device Out"
+//  * "usb_device output" -> "USB Headset Out"
+//  * "USB Device In", "USB Headset In" -> "usb_device input"
+//
 // Profiles for device port connected state:
-//  * USB Headset Out":
+//  * "USB Device Out", "USB Headset Out":
 //    - profile PCM 16-bit; MONO, STEREO, INDEX_MASK_1, INDEX_MASK_2; 44100, 48000
 //    - profile PCM 24-bit; MONO, STEREO, INDEX_MASK_1, INDEX_MASK_2; 44100, 48000
-//  * USB Headset In":
+//  * "USB Device In", "USB Headset In":
 //    - profile PCM 16-bit; MONO, STEREO, INDEX_MASK_1, INDEX_MASK_2; 44100, 48000
 //    - profile PCM 24-bit; MONO, STEREO, INDEX_MASK_1, INDEX_MASK_2; 44100, 48000
 //
@@ -440,6 +422,13 @@
 
         // Device ports
 
+        AudioPort usbOutDevice =
+                createPort(c.nextPortId++, "USB Device Out", 0, false,
+                           createDeviceExt(AudioDeviceType::OUT_DEVICE, 0,
+                                           AudioDeviceDescription::CONNECTION_USB));
+        c.ports.push_back(usbOutDevice);
+        c.connectedProfiles[usbOutDevice.id] = standardPcmAudioProfiles;
+
         AudioPort usbOutHeadset =
                 createPort(c.nextPortId++, "USB Headset Out", 0, false,
                            createDeviceExt(AudioDeviceType::OUT_HEADSET, 0,
@@ -447,6 +436,12 @@
         c.ports.push_back(usbOutHeadset);
         c.connectedProfiles[usbOutHeadset.id] = standardPcmAudioProfiles;
 
+        AudioPort usbInDevice = createPort(c.nextPortId++, "USB Device In", 0, true,
+                                           createDeviceExt(AudioDeviceType::IN_DEVICE, 0,
+                                                           AudioDeviceDescription::CONNECTION_USB));
+        c.ports.push_back(usbInDevice);
+        c.connectedProfiles[usbInDevice.id] = standardPcmAudioProfiles;
+
         AudioPort usbInHeadset =
                 createPort(c.nextPortId++, "USB Headset In", 0, true,
                            createDeviceExt(AudioDeviceType::IN_HEADSET, 0,
@@ -456,16 +451,110 @@
 
         // Mix ports
 
-        AudioPort usbHeadsetOutMix =
-                createPort(c.nextPortId++, "usb_headset output", 0, false, createPortMixExt(1, 1));
-        c.ports.push_back(usbHeadsetOutMix);
+        AudioPort usbDeviceOutMix =
+                createPort(c.nextPortId++, "usb_device output", 0, false, createPortMixExt(1, 1));
+        c.ports.push_back(usbDeviceOutMix);
 
-        AudioPort usbHeadsetInMix =
-                createPort(c.nextPortId++, "usb_headset input", 0, true, createPortMixExt(1, 1));
-        c.ports.push_back(usbHeadsetInMix);
+        AudioPort usbDeviceInMix =
+                createPort(c.nextPortId++, "usb_device input", 0, true, createPortMixExt(1, 1));
+        c.ports.push_back(usbDeviceInMix);
 
-        c.routes.push_back(createRoute({usbHeadsetOutMix}, usbOutHeadset));
-        c.routes.push_back(createRoute({usbInHeadset}, usbHeadsetInMix));
+        c.routes.push_back(createRoute({usbDeviceOutMix}, usbOutDevice));
+        c.routes.push_back(createRoute({usbDeviceOutMix}, usbOutHeadset));
+        c.routes.push_back(createRoute({usbInDevice, usbInHeadset}, usbDeviceInMix));
+
+        return c;
+    }();
+    return std::make_unique<Configuration>(configuration);
+}
+
+// Stub configuration:
+//
+// Device ports:
+//  * "Test Out", OUT_AFE_PROXY
+//    - no profiles specified
+//  * "Test In", IN_AFE_PROXY
+//    - no profiles specified
+//
+// Mix ports:
+//  * "test output", 1 max open, 1 max active stream
+//    - profile PCM 24-bit; MONO, STEREO; 8000, 11025, 16000, 32000, 44100, 48000
+//  * "compressed offload", DIRECT|COMPRESS_OFFLOAD|NON_BLOCKING, 1 max open, 1 max active stream
+//    - profile MP3; MONO, STEREO; 44100, 48000
+//  * "test input", 2 max open, 2 max active streams
+//    - profile PCM 24-bit; MONO, STEREO, FRONT_BACK;
+//        8000, 11025, 12000, 16000, 22050, 24000, 32000, 44100, 48000
+//
+// Routes:
+//  "test output", "compressed offload" -> "Test Out"
+//  "Test In" -> "test input"
+//
+// Initial port configs:
+//  * "Test Out" device port: PCM 24-bit; STEREO; 48000
+//  * "Test In" device port: PCM 24-bit; MONO; 48000
+//
+std::unique_ptr<Configuration> getStubConfiguration() {
+    static const Configuration configuration = []() {
+        Configuration c;
+
+        // Device ports
+
+        AudioPort testOutDevice = createPort(c.nextPortId++, "Test Out", 0, false,
+                                             createDeviceExt(AudioDeviceType::OUT_AFE_PROXY, 0));
+        c.ports.push_back(testOutDevice);
+        c.initialConfigs.push_back(
+                createPortConfig(testOutDevice.id, testOutDevice.id, PcmType::INT_24_BIT,
+                                 AudioChannelLayout::LAYOUT_STEREO, 48000, 0, false,
+                                 createDeviceExt(AudioDeviceType::OUT_AFE_PROXY, 0)));
+
+        AudioPort testInDevice = createPort(c.nextPortId++, "Test In", 0, true,
+                                            createDeviceExt(AudioDeviceType::IN_AFE_PROXY, 0));
+        c.ports.push_back(testInDevice);
+        c.initialConfigs.push_back(
+                createPortConfig(testInDevice.id, testInDevice.id, PcmType::INT_24_BIT,
+                                 AudioChannelLayout::LAYOUT_MONO, 48000, 0, true,
+                                 createDeviceExt(AudioDeviceType::IN_AFE_PROXY, 0)));
+
+        // Mix ports
+
+        AudioPort testOutMix =
+                createPort(c.nextPortId++, "test output", 0, false, createPortMixExt(1, 1));
+        testOutMix.profiles.push_back(
+                createProfile(PcmType::INT_24_BIT,
+                              {AudioChannelLayout::LAYOUT_MONO, AudioChannelLayout::LAYOUT_STEREO},
+                              {8000, 11025, 16000, 32000, 44100, 48000}));
+        c.ports.push_back(testOutMix);
+
+        AudioPort compressedOffloadOutMix =
+                createPort(c.nextPortId++, "compressed offload",
+                           makeBitPositionFlagMask({AudioOutputFlags::DIRECT,
+                                                    AudioOutputFlags::COMPRESS_OFFLOAD,
+                                                    AudioOutputFlags::NON_BLOCKING}),
+                           false, createPortMixExt(1, 1));
+        compressedOffloadOutMix.profiles.push_back(
+                createProfile(::android::MEDIA_MIMETYPE_AUDIO_MPEG,
+                              {AudioChannelLayout::LAYOUT_MONO, AudioChannelLayout::LAYOUT_STEREO},
+                              {44100, 48000}));
+        c.ports.push_back(compressedOffloadOutMix);
+
+        AudioPort testInMIx =
+                createPort(c.nextPortId++, "test input", 0, true, createPortMixExt(2, 2));
+        testInMIx.profiles.push_back(
+                createProfile(PcmType::INT_16_BIT,
+                              {AudioChannelLayout::LAYOUT_MONO, AudioChannelLayout::LAYOUT_STEREO,
+                               AudioChannelLayout::LAYOUT_FRONT_BACK},
+                              {8000, 11025, 12000, 16000, 22050, 24000, 32000, 44100, 48000}));
+        testInMIx.profiles.push_back(
+                createProfile(PcmType::INT_24_BIT,
+                              {AudioChannelLayout::LAYOUT_MONO, AudioChannelLayout::LAYOUT_STEREO,
+                               AudioChannelLayout::LAYOUT_FRONT_BACK},
+                              {8000, 11025, 12000, 16000, 22050, 24000, 32000, 44100, 48000}));
+        c.ports.push_back(testInMIx);
+
+        c.routes.push_back(createRoute({testOutMix, compressedOffloadOutMix}, testOutDevice));
+        c.routes.push_back(createRoute({testInDevice}, testInMIx));
+
+        c.portConfigs.insert(c.portConfigs.end(), c.initialConfigs.begin(), c.initialConfigs.end());
 
         return c;
     }();
diff --git a/audio/aidl/default/Module.cpp b/audio/aidl/default/Module.cpp
index 48d1458..12bbbb0 100644
--- a/audio/aidl/default/Module.cpp
+++ b/audio/aidl/default/Module.cpp
@@ -25,13 +25,12 @@
 #include <android/binder_ibinder_platform.h>
 #include <error/expected_utils.h>
 
-#include "core-impl/Bluetooth.h"
 #include "core-impl/Module.h"
+#include "core-impl/ModulePrimary.h"
 #include "core-impl/ModuleRemoteSubmix.h"
+#include "core-impl/ModuleStub.h"
 #include "core-impl/ModuleUsb.h"
 #include "core-impl/SoundDose.h"
-#include "core-impl/StreamStub.h"
-#include "core-impl/Telephony.h"
 #include "core-impl/utils.h"
 
 using aidl::android::hardware::audio::common::getFrameSizeInBytes;
@@ -110,13 +109,14 @@
 // static
 std::shared_ptr<Module> Module::createInstance(Type type) {
     switch (type) {
-        case Module::Type::USB:
-            return ndk::SharedRefBase::make<ModuleUsb>(type);
-        case Type::R_SUBMIX:
-            return ndk::SharedRefBase::make<ModuleRemoteSubmix>(type);
         case Type::DEFAULT:
-        default:
-            return ndk::SharedRefBase::make<Module>(type);
+            return ndk::SharedRefBase::make<ModulePrimary>();
+        case Type::R_SUBMIX:
+            return ndk::SharedRefBase::make<ModuleRemoteSubmix>();
+        case Type::STUB:
+            return ndk::SharedRefBase::make<ModuleStub>();
+        case Type::USB:
+            return ndk::SharedRefBase::make<ModuleUsb>();
     }
 }
 
@@ -128,6 +128,9 @@
         case Module::Type::R_SUBMIX:
             os << "r_submix";
             break;
+        case Module::Type::STUB:
+            os << "stub";
+            break;
         case Module::Type::USB:
             os << "usb";
             break;
@@ -292,6 +295,9 @@
             case Type::R_SUBMIX:
                 mConfig = std::move(internal::getRSubmixConfiguration());
                 break;
+            case Type::STUB:
+                mConfig = std::move(internal::getStubConfiguration());
+                break;
             case Type::USB:
                 mConfig = std::move(internal::getUsbConfiguration());
                 break;
@@ -395,38 +401,26 @@
 }
 
 ndk::ScopedAStatus Module::getTelephony(std::shared_ptr<ITelephony>* _aidl_return) {
-    if (!mTelephony) {
-        mTelephony = ndk::SharedRefBase::make<Telephony>();
-    }
-    *_aidl_return = mTelephony.getPtr();
-    LOG(DEBUG) << __func__ << ": returning instance of ITelephony: " << _aidl_return->get();
+    *_aidl_return = nullptr;
+    LOG(DEBUG) << __func__ << ": returning null";
     return ndk::ScopedAStatus::ok();
 }
 
 ndk::ScopedAStatus Module::getBluetooth(std::shared_ptr<IBluetooth>* _aidl_return) {
-    if (!mBluetooth) {
-        mBluetooth = ndk::SharedRefBase::make<Bluetooth>();
-    }
-    *_aidl_return = mBluetooth.getPtr();
-    LOG(DEBUG) << __func__ << ": returning instance of IBluetooth: " << _aidl_return->get();
+    *_aidl_return = nullptr;
+    LOG(DEBUG) << __func__ << ": returning null";
     return ndk::ScopedAStatus::ok();
 }
 
 ndk::ScopedAStatus Module::getBluetoothA2dp(std::shared_ptr<IBluetoothA2dp>* _aidl_return) {
-    if (!mBluetoothA2dp) {
-        mBluetoothA2dp = ndk::SharedRefBase::make<BluetoothA2dp>();
-    }
-    *_aidl_return = mBluetoothA2dp.getPtr();
-    LOG(DEBUG) << __func__ << ": returning instance of IBluetoothA2dp: " << _aidl_return->get();
+    *_aidl_return = nullptr;
+    LOG(DEBUG) << __func__ << ": returning null";
     return ndk::ScopedAStatus::ok();
 }
 
 ndk::ScopedAStatus Module::getBluetoothLe(std::shared_ptr<IBluetoothLe>* _aidl_return) {
-    if (!mBluetoothLe) {
-        mBluetoothLe = ndk::SharedRefBase::make<BluetoothLe>();
-    }
-    *_aidl_return = mBluetoothLe.getPtr();
-    LOG(DEBUG) << __func__ << ": returning instance of IBluetoothLe: " << _aidl_return->get();
+    *_aidl_return = nullptr;
+    LOG(DEBUG) << __func__ << ": returning null";
     return ndk::ScopedAStatus::ok();
 }
 
@@ -1334,22 +1328,6 @@
     return mIsMmapSupported.value();
 }
 
-ndk::ScopedAStatus Module::createInputStream(const SinkMetadata& sinkMetadata,
-                                             StreamContext&& context,
-                                             const std::vector<MicrophoneInfo>& microphones,
-                                             std::shared_ptr<StreamIn>* result) {
-    return createStreamInstance<StreamInStub>(result, sinkMetadata, std::move(context),
-                                              microphones);
-}
-
-ndk::ScopedAStatus Module::createOutputStream(const SourceMetadata& sourceMetadata,
-                                              StreamContext&& context,
-                                              const std::optional<AudioOffloadInfo>& offloadInfo,
-                                              std::shared_ptr<StreamOut>* result) {
-    return createStreamInstance<StreamOutStub>(result, sourceMetadata, std::move(context),
-                                               offloadInfo);
-}
-
 ndk::ScopedAStatus Module::populateConnectedDevicePort(AudioPort* audioPort __unused) {
     LOG(VERBOSE) << __func__ << ": do nothing and return ok";
     return ndk::ScopedAStatus::ok();
diff --git a/audio/aidl/default/ModulePrimary.cpp b/audio/aidl/default/ModulePrimary.cpp
new file mode 100644
index 0000000..cbb6730
--- /dev/null
+++ b/audio/aidl/default/ModulePrimary.cpp
@@ -0,0 +1,60 @@
+/*
+ * Copyright (C) 2023 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 <vector>
+
+#define LOG_TAG "AHAL_ModulePrimary"
+#include <Utils.h>
+#include <android-base/logging.h>
+
+#include "core-impl/ModulePrimary.h"
+#include "core-impl/StreamStub.h"
+#include "core-impl/Telephony.h"
+
+using aidl::android::hardware::audio::common::SinkMetadata;
+using aidl::android::hardware::audio::common::SourceMetadata;
+using aidl::android::media::audio::common::AudioOffloadInfo;
+using aidl::android::media::audio::common::AudioPort;
+using aidl::android::media::audio::common::AudioPortConfig;
+using aidl::android::media::audio::common::MicrophoneInfo;
+
+namespace aidl::android::hardware::audio::core {
+
+ndk::ScopedAStatus ModulePrimary::getTelephony(std::shared_ptr<ITelephony>* _aidl_return) {
+    if (!mTelephony) {
+        mTelephony = ndk::SharedRefBase::make<Telephony>();
+    }
+    *_aidl_return = mTelephony.getPtr();
+    LOG(DEBUG) << __func__ << ": returning instance of ITelephony: " << _aidl_return->get();
+    return ndk::ScopedAStatus::ok();
+}
+
+ndk::ScopedAStatus ModulePrimary::createInputStream(const SinkMetadata& sinkMetadata,
+                                                    StreamContext&& context,
+                                                    const std::vector<MicrophoneInfo>& microphones,
+                                                    std::shared_ptr<StreamIn>* result) {
+    return createStreamInstance<StreamInStub>(result, sinkMetadata, std::move(context),
+                                              microphones);
+}
+
+ndk::ScopedAStatus ModulePrimary::createOutputStream(
+        const SourceMetadata& sourceMetadata, StreamContext&& context,
+        const std::optional<AudioOffloadInfo>& offloadInfo, std::shared_ptr<StreamOut>* result) {
+    return createStreamInstance<StreamOutStub>(result, sourceMetadata, std::move(context),
+                                               offloadInfo);
+}
+
+}  // namespace aidl::android::hardware::audio::core
diff --git a/audio/aidl/default/android.hardware.audio.service-aidl.xml b/audio/aidl/default/android.hardware.audio.service-aidl.xml
index 9636a58..c9d6314 100644
--- a/audio/aidl/default/android.hardware.audio.service-aidl.xml
+++ b/audio/aidl/default/android.hardware.audio.service-aidl.xml
@@ -12,6 +12,11 @@
   <hal format="aidl">
     <name>android.hardware.audio.core</name>
     <version>1</version>
+    <fqname>IModule/stub</fqname>
+  </hal>
+  <hal format="aidl">
+    <name>android.hardware.audio.core</name>
+    <version>1</version>
     <fqname>IModule/usb</fqname>
   </hal>
   <hal format="aidl">
diff --git a/audio/aidl/default/include/core-impl/ChildInterface.h b/audio/aidl/default/include/core-impl/ChildInterface.h
new file mode 100644
index 0000000..1b31691
--- /dev/null
+++ b/audio/aidl/default/include/core-impl/ChildInterface.h
@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) 2023 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 <memory>
+#include <utility>
+
+#include <android/binder_auto_utils.h>
+#include <android/binder_ibinder_platform.h>
+#include <system/thread_defs.h>
+
+namespace aidl::android::hardware::audio::core {
+
+// Helper used for interfaces that require a persistent instance. We hold them via a strong
+// pointer. The binder token is retained for a call to 'setMinSchedulerPolicy'.
+template <class C>
+struct ChildInterface : private std::pair<std::shared_ptr<C>, ndk::SpAIBinder> {
+    ChildInterface() = default;
+    ChildInterface& operator=(const std::shared_ptr<C>& c) {
+        return operator=(std::shared_ptr<C>(c));
+    }
+    ChildInterface& operator=(std::shared_ptr<C>&& c) {
+        this->first = std::move(c);
+        this->second = this->first->asBinder();
+        AIBinder_setMinSchedulerPolicy(this->second.get(), SCHED_NORMAL, ANDROID_PRIORITY_AUDIO);
+        return *this;
+    }
+    explicit operator bool() const { return !!this->first; }
+    C& operator*() const { return *(this->first); }
+    C* operator->() const { return this->first; }
+    std::shared_ptr<C> getPtr() const { return this->first; }
+};
+
+}  // namespace aidl::android::hardware::audio::core
diff --git a/audio/aidl/default/include/core-impl/Configuration.h b/audio/aidl/default/include/core-impl/Configuration.h
index 70320e4..25bf7af 100644
--- a/audio/aidl/default/include/core-impl/Configuration.h
+++ b/audio/aidl/default/include/core-impl/Configuration.h
@@ -45,6 +45,7 @@
 
 std::unique_ptr<Configuration> getPrimaryConfiguration();
 std::unique_ptr<Configuration> getRSubmixConfiguration();
+std::unique_ptr<Configuration> getStubConfiguration();
 std::unique_ptr<Configuration> getUsbConfiguration();
 
 }  // namespace aidl::android::hardware::audio::core::internal
diff --git a/audio/aidl/default/include/core-impl/Module.h b/audio/aidl/default/include/core-impl/Module.h
index 4a23637..ee0458b 100644
--- a/audio/aidl/default/include/core-impl/Module.h
+++ b/audio/aidl/default/include/core-impl/Module.h
@@ -16,12 +16,14 @@
 
 #pragma once
 
+#include <iostream>
 #include <map>
 #include <memory>
 #include <set>
 
 #include <aidl/android/hardware/audio/core/BnModule.h>
 
+#include "core-impl/ChildInterface.h"
 #include "core-impl/Configuration.h"
 #include "core-impl/Stream.h"
 
@@ -31,7 +33,7 @@
   public:
     // This value is used for all AudioPatches and reported by all streams.
     static constexpr int32_t kLatencyMs = 10;
-    enum Type : int { DEFAULT, R_SUBMIX, USB };
+    enum Type : int { DEFAULT, R_SUBMIX, STUB, USB };
 
     static std::shared_ptr<Module> createInstance(Type type);
 
@@ -132,26 +134,6 @@
         bool forceTransientBurst = false;
         bool forceSynchronousDrain = false;
     };
-    // Helper used for interfaces that require a persistent instance. We hold them via a strong
-    // pointer. The binder token is retained for a call to 'setMinSchedulerPolicy'.
-    template <class C>
-    struct ChildInterface : private std::pair<std::shared_ptr<C>, ndk::SpAIBinder> {
-        ChildInterface() {}
-        ChildInterface& operator=(const std::shared_ptr<C>& c) {
-            return operator=(std::shared_ptr<C>(c));
-        }
-        ChildInterface& operator=(std::shared_ptr<C>&& c) {
-            this->first = std::move(c);
-            this->second = this->first->asBinder();
-            AIBinder_setMinSchedulerPolicy(this->second.get(), SCHED_NORMAL,
-                                           ANDROID_PRIORITY_AUDIO);
-            return *this;
-        }
-        explicit operator bool() const { return !!this->first; }
-        C& operator*() const { return *(this->first); }
-        C* operator->() const { return this->first; }
-        std::shared_ptr<C> getPtr() const { return this->first; }
-    };
     // ids of device ports created at runtime via 'connectExternalDevice'.
     // Also stores a list of ids of mix ports with dynamic profiles that were populated from
     // the connected port. This list can be empty, thus an int->int multimap can't be used.
@@ -164,10 +146,6 @@
     std::unique_ptr<internal::Configuration> mConfig;
     ModuleDebug mDebug;
     VendorDebug mVendorDebug;
-    ChildInterface<ITelephony> mTelephony;
-    ChildInterface<IBluetooth> mBluetooth;
-    ChildInterface<IBluetoothA2dp> mBluetoothA2dp;
-    ChildInterface<IBluetoothLe> mBluetoothLe;
     ConnectedDevicePorts mConnectedDevicePorts;
     Streams mStreams;
     Patches mPatches;
@@ -184,13 +162,13 @@
             const ::aidl::android::hardware::audio::common::SinkMetadata& sinkMetadata,
             StreamContext&& context,
             const std::vector<::aidl::android::media::audio::common::MicrophoneInfo>& microphones,
-            std::shared_ptr<StreamIn>* result);
+            std::shared_ptr<StreamIn>* result) = 0;
     virtual ndk::ScopedAStatus createOutputStream(
             const ::aidl::android::hardware::audio::common::SourceMetadata& sourceMetadata,
             StreamContext&& context,
             const std::optional<::aidl::android::media::audio::common::AudioOffloadInfo>&
                     offloadInfo,
-            std::shared_ptr<StreamOut>* result);
+            std::shared_ptr<StreamOut>* result) = 0;
     // If the module is unable to populate the connected device port correctly, the returned error
     // code must correspond to the errors of `IModule.connectedExternalDevice` method.
     virtual ndk::ScopedAStatus populateConnectedDevicePort(
@@ -232,4 +210,6 @@
                                                    const AudioPatch& newPatch);
 };
 
+std::ostream& operator<<(std::ostream& os, Module::Type t);
+
 }  // namespace aidl::android::hardware::audio::core
diff --git a/audio/aidl/default/include/core-impl/ModulePrimary.h b/audio/aidl/default/include/core-impl/ModulePrimary.h
new file mode 100644
index 0000000..bc808ab
--- /dev/null
+++ b/audio/aidl/default/include/core-impl/ModulePrimary.h
@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2023 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 "core-impl/Module.h"
+
+namespace aidl::android::hardware::audio::core {
+
+class ModulePrimary final : public Module {
+  public:
+    ModulePrimary() : Module(Type::DEFAULT) {}
+
+  protected:
+    ndk::ScopedAStatus getTelephony(std::shared_ptr<ITelephony>* _aidl_return) override;
+
+    ndk::ScopedAStatus createInputStream(
+            const ::aidl::android::hardware::audio::common::SinkMetadata& sinkMetadata,
+            StreamContext&& context,
+            const std::vector<::aidl::android::media::audio::common::MicrophoneInfo>& microphones,
+            std::shared_ptr<StreamIn>* result) override;
+    ndk::ScopedAStatus createOutputStream(
+            const ::aidl::android::hardware::audio::common::SourceMetadata& sourceMetadata,
+            StreamContext&& context,
+            const std::optional<::aidl::android::media::audio::common::AudioOffloadInfo>&
+                    offloadInfo,
+            std::shared_ptr<StreamOut>* result) override;
+
+  private:
+    ChildInterface<ITelephony> mTelephony;
+};
+
+}  // namespace aidl::android::hardware::audio::core
diff --git a/audio/aidl/default/include/core-impl/ModuleRemoteSubmix.h b/audio/aidl/default/include/core-impl/ModuleRemoteSubmix.h
index 7b1d375..ccfcdd9 100644
--- a/audio/aidl/default/include/core-impl/ModuleRemoteSubmix.h
+++ b/audio/aidl/default/include/core-impl/ModuleRemoteSubmix.h
@@ -22,7 +22,7 @@
 
 class ModuleRemoteSubmix : public Module {
   public:
-    explicit ModuleRemoteSubmix(Module::Type type) : Module(type) {}
+    ModuleRemoteSubmix() : Module(Type::R_SUBMIX) {}
 
   private:
     // IModule interfaces
diff --git a/audio/aidl/default/include/core-impl/ModuleStub.h b/audio/aidl/default/include/core-impl/ModuleStub.h
new file mode 100644
index 0000000..59c343f
--- /dev/null
+++ b/audio/aidl/default/include/core-impl/ModuleStub.h
@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2023 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 "core-impl/Module.h"
+
+namespace aidl::android::hardware::audio::core {
+
+class ModuleStub final : public Module {
+  public:
+    ModuleStub() : Module(Type::STUB) {}
+
+  protected:
+    ndk::ScopedAStatus getBluetooth(std::shared_ptr<IBluetooth>* _aidl_return) override;
+    ndk::ScopedAStatus getBluetoothA2dp(std::shared_ptr<IBluetoothA2dp>* _aidl_return) override;
+    ndk::ScopedAStatus getBluetoothLe(std::shared_ptr<IBluetoothLe>* _aidl_return) override;
+
+    ndk::ScopedAStatus createInputStream(
+            const ::aidl::android::hardware::audio::common::SinkMetadata& sinkMetadata,
+            StreamContext&& context,
+            const std::vector<::aidl::android::media::audio::common::MicrophoneInfo>& microphones,
+            std::shared_ptr<StreamIn>* result) override;
+    ndk::ScopedAStatus createOutputStream(
+            const ::aidl::android::hardware::audio::common::SourceMetadata& sourceMetadata,
+            StreamContext&& context,
+            const std::optional<::aidl::android::media::audio::common::AudioOffloadInfo>&
+                    offloadInfo,
+            std::shared_ptr<StreamOut>* result) override;
+
+  private:
+    ChildInterface<IBluetooth> mBluetooth;
+    ChildInterface<IBluetoothA2dp> mBluetoothA2dp;
+    ChildInterface<IBluetoothLe> mBluetoothLe;
+};
+
+}  // namespace aidl::android::hardware::audio::core
diff --git a/audio/aidl/default/include/core-impl/ModuleUsb.h b/audio/aidl/default/include/core-impl/ModuleUsb.h
index ea7cc48..e6b3e66 100644
--- a/audio/aidl/default/include/core-impl/ModuleUsb.h
+++ b/audio/aidl/default/include/core-impl/ModuleUsb.h
@@ -22,7 +22,7 @@
 
 class ModuleUsb final : public ModuleAlsa {
   public:
-    explicit ModuleUsb(Module::Type type) : ModuleAlsa(type) {}
+    ModuleUsb() : ModuleAlsa(Type::USB) {}
 
   private:
     // IModule interfaces
diff --git a/audio/aidl/default/main.cpp b/audio/aidl/default/main.cpp
index 12c0c4b..93fb366 100644
--- a/audio/aidl/default/main.cpp
+++ b/audio/aidl/default/main.cpp
@@ -16,20 +16,21 @@
 
 #include <cstdlib>
 #include <ctime>
+#include <sstream>
 #include <utility>
+#include <vector>
 
 #include <android-base/logging.h>
+#include <android-base/properties.h>
 #include <android/binder_ibinder_platform.h>
 #include <android/binder_manager.h>
 #include <android/binder_process.h>
 
 #include "core-impl/Config.h"
 #include "core-impl/Module.h"
-#include "core-impl/ModuleUsb.h"
 
 using aidl::android::hardware::audio::core::Config;
 using aidl::android::hardware::audio::core::Module;
-using aidl::android::hardware::audio::core::ModuleUsb;
 
 int main() {
     // Random values are used in the implementation.
@@ -52,18 +53,19 @@
     CHECK_EQ(STATUS_OK, status);
 
     // Make modules
-    auto createModule = [](Module::Type type, const std::string& instance) {
+    auto createModule = [](Module::Type type) {
         auto module = Module::createInstance(type);
         ndk::SpAIBinder moduleBinder = module->asBinder();
-        const std::string moduleName = std::string(Module::descriptor).append("/").append(instance);
+        std::stringstream moduleName;
+        moduleName << Module::descriptor << "/" << type;
         AIBinder_setMinSchedulerPolicy(moduleBinder.get(), SCHED_NORMAL, ANDROID_PRIORITY_AUDIO);
-        binder_status_t status = AServiceManager_addService(moduleBinder.get(), moduleName.c_str());
+        binder_status_t status =
+                AServiceManager_addService(moduleBinder.get(), moduleName.str().c_str());
         CHECK_EQ(STATUS_OK, status);
         return std::make_pair(module, moduleBinder);
     };
-    auto modules = {createModule(Module::Type::DEFAULT, "default"),
-                    createModule(Module::Type::R_SUBMIX, "r_submix"),
-                    createModule(Module::Type::USB, "usb")};
+    auto modules = {createModule(Module::Type::DEFAULT), createModule(Module::Type::R_SUBMIX),
+                    createModule(Module::Type::USB), createModule(Module::Type::STUB)};
     (void)modules;
 
     ABinderProcess_joinThreadPool();
diff --git a/audio/aidl/default/stub/ModuleStub.cpp b/audio/aidl/default/stub/ModuleStub.cpp
new file mode 100644
index 0000000..a600752
--- /dev/null
+++ b/audio/aidl/default/stub/ModuleStub.cpp
@@ -0,0 +1,78 @@
+/*
+ * Copyright (C) 2023 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 <vector>
+
+#define LOG_TAG "AHAL_ModuleStub"
+#include <Utils.h>
+#include <android-base/logging.h>
+
+#include "core-impl/Bluetooth.h"
+#include "core-impl/ModuleStub.h"
+#include "core-impl/StreamStub.h"
+
+using aidl::android::hardware::audio::common::SinkMetadata;
+using aidl::android::hardware::audio::common::SourceMetadata;
+using aidl::android::media::audio::common::AudioOffloadInfo;
+using aidl::android::media::audio::common::AudioPort;
+using aidl::android::media::audio::common::AudioPortConfig;
+using aidl::android::media::audio::common::MicrophoneInfo;
+
+namespace aidl::android::hardware::audio::core {
+
+ndk::ScopedAStatus ModuleStub::getBluetooth(std::shared_ptr<IBluetooth>* _aidl_return) {
+    if (!mBluetooth) {
+        mBluetooth = ndk::SharedRefBase::make<Bluetooth>();
+    }
+    *_aidl_return = mBluetooth.getPtr();
+    LOG(DEBUG) << __func__ << ": returning instance of IBluetooth: " << _aidl_return->get();
+    return ndk::ScopedAStatus::ok();
+}
+
+ndk::ScopedAStatus ModuleStub::getBluetoothA2dp(std::shared_ptr<IBluetoothA2dp>* _aidl_return) {
+    if (!mBluetoothA2dp) {
+        mBluetoothA2dp = ndk::SharedRefBase::make<BluetoothA2dp>();
+    }
+    *_aidl_return = mBluetoothA2dp.getPtr();
+    LOG(DEBUG) << __func__ << ": returning instance of IBluetoothA2dp: " << _aidl_return->get();
+    return ndk::ScopedAStatus::ok();
+}
+
+ndk::ScopedAStatus ModuleStub::getBluetoothLe(std::shared_ptr<IBluetoothLe>* _aidl_return) {
+    if (!mBluetoothLe) {
+        mBluetoothLe = ndk::SharedRefBase::make<BluetoothLe>();
+    }
+    *_aidl_return = mBluetoothLe.getPtr();
+    LOG(DEBUG) << __func__ << ": returning instance of IBluetoothLe: " << _aidl_return->get();
+    return ndk::ScopedAStatus::ok();
+}
+
+ndk::ScopedAStatus ModuleStub::createInputStream(const SinkMetadata& sinkMetadata,
+                                                 StreamContext&& context,
+                                                 const std::vector<MicrophoneInfo>& microphones,
+                                                 std::shared_ptr<StreamIn>* result) {
+    return createStreamInstance<StreamInStub>(result, sinkMetadata, std::move(context),
+                                              microphones);
+}
+
+ndk::ScopedAStatus ModuleStub::createOutputStream(
+        const SourceMetadata& sourceMetadata, StreamContext&& context,
+        const std::optional<AudioOffloadInfo>& offloadInfo, std::shared_ptr<StreamOut>* result) {
+    return createStreamInstance<StreamOutStub>(result, sourceMetadata, std::move(context),
+                                               offloadInfo);
+}
+
+}  // namespace aidl::android::hardware::audio::core
diff --git a/audio/aidl/default/StreamStub.cpp b/audio/aidl/default/stub/StreamStub.cpp
similarity index 100%
rename from audio/aidl/default/StreamStub.cpp
rename to audio/aidl/default/stub/StreamStub.cpp