diff --git a/camera/provider/2.4/default/Android.bp b/camera/provider/2.4/default/Android.bp
index 99c3e92..1f46b89 100644
--- a/camera/provider/2.4/default/Android.bp
+++ b/camera/provider/2.4/default/Android.bp
@@ -3,7 +3,8 @@
     defaults: ["hidl_defaults"],
     proprietary: true,
     relative_install_path: "hw",
-    srcs: ["CameraProvider.cpp"],
+    srcs: ["CameraProvider.cpp",
+           "ExternalCameraProvider.cpp"],
     shared_libs: [
         "libhidlbase",
         "libhidltransport",
@@ -17,6 +18,7 @@
         "camera.device@3.2-impl",
         "camera.device@3.3-impl",
         "camera.device@3.4-impl",
+        "camera.device@3.4-external-impl",
         "android.hardware.camera.provider@2.4",
         "android.hardware.camera.common@1.0",
         "android.hardware.graphics.mapper@2.0",
@@ -28,6 +30,7 @@
     ],
     header_libs: [
         "camera.device@3.4-impl_headers",
+        "camera.device@3.4-external-impl_headers"
     ],
     static_libs: [
         "android.hardware.camera.common@1.0-helper",
@@ -56,3 +59,25 @@
         "android.hardware.camera.common@1.0",
     ],
 }
+
+cc_binary {
+    name: "android.hardware.camera.provider@2.4-external-service",
+    defaults: ["hidl_defaults"],
+    proprietary: true,
+    relative_install_path: "hw",
+    srcs: ["external-service.cpp"],
+    compile_multilib: "32",
+    init_rc: ["android.hardware.camera.provider@2.4-external-service.rc"],
+    shared_libs: [
+        "libhidlbase",
+        "libhidltransport",
+        "libbinder",
+        "liblog",
+        "libutils",
+        "android.hardware.camera.device@1.0",
+        "android.hardware.camera.device@3.2",
+        "android.hardware.camera.device@3.3",
+        "android.hardware.camera.provider@2.4",
+        "android.hardware.camera.common@1.0",
+    ],
+}
diff --git a/camera/provider/2.4/default/CameraProvider.cpp b/camera/provider/2.4/default/CameraProvider.cpp
index e9588a7..2fb920c 100644
--- a/camera/provider/2.4/default/CameraProvider.cpp
+++ b/camera/provider/2.4/default/CameraProvider.cpp
@@ -19,6 +19,7 @@
 #include <android/log.h>
 
 #include "CameraProvider.h"
+#include "ExternalCameraProvider.h"
 #include "CameraDevice_1_0.h"
 #include "CameraDevice_3_3.h"
 #include "CameraDevice_3_4.h"
@@ -36,6 +37,7 @@
 
 namespace {
 const char *kLegacyProviderName = "legacy/0";
+const char *kExternalProviderName = "external/0";
 // "device@<version>/legacy/<id>"
 const std::regex kDeviceNameRE("device@([0-9]+\\.[0-9]+)/legacy/(.+)");
 const char *kHAL3_2 = "3.2";
@@ -571,20 +573,24 @@
 }
 
 ICameraProvider* HIDL_FETCH_ICameraProvider(const char* name) {
-    if (strcmp(name, kLegacyProviderName) != 0) {
-        return nullptr;
+    if (strcmp(name, kLegacyProviderName) == 0) {
+        CameraProvider* provider = new CameraProvider();
+        if (provider == nullptr) {
+            ALOGE("%s: cannot allocate camera provider!", __FUNCTION__);
+            return nullptr;
+        }
+        if (provider->isInitFailed()) {
+            ALOGE("%s: camera provider init failed!", __FUNCTION__);
+            delete provider;
+            return nullptr;
+        }
+        return provider;
+    } else if (strcmp(name, kExternalProviderName) == 0) {
+        ExternalCameraProvider* provider = new ExternalCameraProvider();
+        return provider;
     }
-    CameraProvider* provider = new CameraProvider();
-    if (provider == nullptr) {
-        ALOGE("%s: cannot allocate camera provider!", __FUNCTION__);
-        return nullptr;
-    }
-    if (provider->isInitFailed()) {
-        ALOGE("%s: camera provider init failed!", __FUNCTION__);
-        delete provider;
-        return nullptr;
-    }
-    return provider;
+    ALOGE("%s: unknown instance name: %s", __FUNCTION__, name);
+    return nullptr;
 }
 
 } // namespace implementation
diff --git a/camera/provider/2.4/default/ExternalCameraProvider.cpp b/camera/provider/2.4/default/ExternalCameraProvider.cpp
new file mode 100644
index 0000000..bb5c336
--- /dev/null
+++ b/camera/provider/2.4/default/ExternalCameraProvider.cpp
@@ -0,0 +1,276 @@
+/*
+ * Copyright (C) 2018 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.
+ */
+
+#define LOG_TAG "CamPvdr@2.4-external"
+//#define LOG_NDEBUG 0
+#include <log/log.h>
+
+#include <regex>
+#include <sys/inotify.h>
+#include <errno.h>
+#include <linux/videodev2.h>
+#include "ExternalCameraProvider.h"
+#include "ExternalCameraDevice_3_4.h"
+
+namespace android {
+namespace hardware {
+namespace camera {
+namespace provider {
+namespace V2_4 {
+namespace implementation {
+
+namespace {
+// "device@<version>/external/<id>"
+const std::regex kDeviceNameRE("device@([0-9]+\\.[0-9]+)/external/(.+)");
+const int kMaxDevicePathLen = 256;
+const char* kDevicePath = "/dev/";
+
+bool matchDeviceName(const hidl_string& deviceName, std::string* deviceVersion,
+                     std::string* cameraId) {
+    std::string deviceNameStd(deviceName.c_str());
+    std::smatch sm;
+    if (std::regex_match(deviceNameStd, sm, kDeviceNameRE)) {
+        if (deviceVersion != nullptr) {
+            *deviceVersion = sm[1];
+        }
+        if (cameraId != nullptr) {
+            *cameraId = sm[2];
+        }
+        return true;
+    }
+    return false;
+}
+
+} // anonymous namespace
+
+ExternalCameraProvider::ExternalCameraProvider() : mHotPlugThread(this) {
+    mHotPlugThread.run("ExtCamHotPlug", PRIORITY_BACKGROUND);
+}
+
+ExternalCameraProvider::~ExternalCameraProvider() {
+    mHotPlugThread.requestExit();
+}
+
+
+Return<Status> ExternalCameraProvider::setCallback(
+        const sp<ICameraProviderCallback>& callback) {
+    Mutex::Autolock _l(mLock);
+    mCallbacks = callback;
+    return Status::OK;
+}
+
+Return<void> ExternalCameraProvider::getVendorTags(getVendorTags_cb _hidl_cb) {
+    // No vendor tag support for USB camera
+    hidl_vec<VendorTagSection> zeroSections;
+    _hidl_cb(Status::OK, zeroSections);
+    return Void();
+}
+
+Return<void> ExternalCameraProvider::getCameraIdList(getCameraIdList_cb _hidl_cb) {
+    std::vector<hidl_string> deviceNameList;
+    for (auto const& kvPair : mCameraStatusMap) {
+        if (kvPair.second == CameraDeviceStatus::PRESENT) {
+            deviceNameList.push_back(kvPair.first);
+        }
+    }
+    hidl_vec<hidl_string> hidlDeviceNameList(deviceNameList);
+    ALOGV("ExtCam: number of cameras is %zu", deviceNameList.size());
+    _hidl_cb(Status::OK, hidlDeviceNameList);
+    return Void();
+}
+
+Return<void> ExternalCameraProvider::isSetTorchModeSupported(
+        isSetTorchModeSupported_cb _hidl_cb) {
+    // No torch mode support for USB camera
+    _hidl_cb (Status::OK, false);
+    return Void();
+}
+
+Return<void> ExternalCameraProvider::getCameraDeviceInterface_V1_x(
+        const hidl_string&,
+        getCameraDeviceInterface_V1_x_cb _hidl_cb) {
+    // External Camera HAL does not support HAL1
+    _hidl_cb(Status::OPERATION_NOT_SUPPORTED, nullptr);
+    return Void();
+}
+
+Return<void> ExternalCameraProvider::getCameraDeviceInterface_V3_x(
+        const hidl_string& cameraDeviceName,
+        getCameraDeviceInterface_V3_x_cb _hidl_cb) {
+
+    std::string cameraId, deviceVersion;
+    bool match = matchDeviceName(cameraDeviceName, &deviceVersion, &cameraId);
+    if (!match) {
+        _hidl_cb(Status::ILLEGAL_ARGUMENT, nullptr);
+        return Void();
+    }
+
+    if (mCameraStatusMap.count(cameraDeviceName) == 0 ||
+            mCameraStatusMap[cameraDeviceName] != CameraDeviceStatus::PRESENT) {
+        _hidl_cb(Status::ILLEGAL_ARGUMENT, nullptr);
+        return Void();
+    }
+
+    ALOGV("Constructing v3.4 external camera device");
+    sp<device::V3_2::ICameraDevice> device;
+    sp<device::V3_4::implementation::ExternalCameraDevice> deviceImpl =
+            new device::V3_4::implementation::ExternalCameraDevice(
+                    cameraId);
+    if (deviceImpl == nullptr || deviceImpl->isInitFailed()) {
+        ALOGE("%s: camera device %s init failed!", __FUNCTION__, cameraId.c_str());
+        device = nullptr;
+        _hidl_cb(Status::INTERNAL_ERROR, nullptr);
+        return Void();
+    }
+    device = deviceImpl;
+
+    _hidl_cb (Status::OK, device);
+
+    return Void();
+}
+
+void ExternalCameraProvider::addExternalCamera(const char* devName) {
+    ALOGE("ExtCam: adding %s to External Camera HAL!", devName);
+    Mutex::Autolock _l(mLock);
+    std::string deviceName = std::string("device@3.4/external/") + devName;
+    mCameraStatusMap[deviceName] = CameraDeviceStatus::PRESENT;
+    if (mCallbacks != nullptr) {
+        mCallbacks->cameraDeviceStatusChange(deviceName, CameraDeviceStatus::PRESENT);
+    }
+}
+
+void ExternalCameraProvider::deviceAdded(const char* devName) {
+    int fd = -1;
+    if ((fd = ::open(devName, O_RDWR)) < 0) {
+        ALOGE("%s open v4l2 device %s failed:%s", __FUNCTION__, devName, strerror(errno));
+        return;
+    }
+
+    do {
+        struct v4l2_capability capability;
+        int ret = ioctl(fd, VIDIOC_QUERYCAP, &capability);
+        if (ret < 0) {
+            ALOGE("%s v4l2 QUERYCAP %s failed", __FUNCTION__, devName);
+            break;
+        }
+
+        if (!(capability.device_caps & V4L2_CAP_VIDEO_CAPTURE)) {
+            ALOGW("%s device %s does not support VIDEO_CAPTURE", __FUNCTION__, devName);
+            break;
+        }
+
+        addExternalCamera(devName);
+    } while (0);
+
+    close(fd);
+    return;
+}
+
+void ExternalCameraProvider::deviceRemoved(const char* devName) {
+    Mutex::Autolock _l(mLock);
+    std::string deviceName = std::string("device@3.4/external/") + devName;
+    if (mCameraStatusMap.find(deviceName) != mCameraStatusMap.end()) {
+        mCameraStatusMap.erase(deviceName);
+        if (mCallbacks != nullptr) {
+            mCallbacks->cameraDeviceStatusChange(deviceName, CameraDeviceStatus::NOT_PRESENT);
+        }
+    } else {
+        ALOGE("%s: cannot find camera device %s", __FUNCTION__, devName);
+    }
+}
+
+ExternalCameraProvider::HotplugThread::HotplugThread(ExternalCameraProvider* parent) :
+        Thread(/*canCallJava*/false), mParent(parent) {}
+
+ExternalCameraProvider::HotplugThread::~HotplugThread() {}
+
+bool ExternalCameraProvider::HotplugThread::threadLoop() {
+    // Find existing /dev/video* devices
+    DIR* devdir = opendir(kDevicePath);
+    if(devdir == 0) {
+        ALOGE("%s: cannot open %s! Exiting threadloop", __FUNCTION__, kDevicePath);
+        return false;
+    }
+
+    struct dirent* de;
+    // This list is device dependent. TODO: b/72261897 allow setting it from setprop/device boot
+    std::string internalDevices = "0,1";
+    while ((de = readdir(devdir)) != 0) {
+        // Find external v4l devices that's existing before we start watching and add them
+        if (!strncmp("video", de->d_name, 5)) {
+            // TODO: This might reject some valid devices. Ex: internal is 33 and a device named 3
+            //       is added.
+            if (internalDevices.find(de->d_name + 5) == std::string::npos) {
+                ALOGV("Non-internal v4l device %s found", de->d_name);
+                char v4l2DevicePath[kMaxDevicePathLen];
+                snprintf(v4l2DevicePath, kMaxDevicePathLen,
+                        "%s%s", kDevicePath, de->d_name);
+                mParent->deviceAdded(v4l2DevicePath);
+            }
+        }
+    }
+    closedir(devdir);
+
+    // Watch new video devices
+    mINotifyFD = inotify_init();
+    if (mINotifyFD < 0) {
+        ALOGE("%s: inotify init failed! Exiting threadloop", __FUNCTION__);
+        return true;
+    }
+
+    mWd = inotify_add_watch(mINotifyFD, kDevicePath, IN_CREATE | IN_DELETE);
+    if (mWd < 0) {
+        ALOGE("%s: inotify add watch failed! Exiting threadloop", __FUNCTION__);
+        return true;
+    }
+
+    ALOGI("%s start monitoring new V4L2 devices", __FUNCTION__);
+
+    bool done = false;
+    char eventBuf[512];
+    while (!done) {
+        int offset = 0;
+        int ret = read(mINotifyFD, eventBuf, sizeof(eventBuf));
+        if (ret >= (int)sizeof(struct inotify_event)) {
+            while (offset < ret) {
+                struct inotify_event* event = (struct inotify_event*)&eventBuf[offset];
+                if (event->wd == mWd) {
+                    if (!strncmp("video", event->name, 5)) {
+                        char v4l2DevicePath[kMaxDevicePathLen];
+                        snprintf(v4l2DevicePath, kMaxDevicePathLen,
+                                "%s%s", kDevicePath, event->name);
+                        if (event->mask & IN_CREATE) {
+                            mParent->deviceAdded(v4l2DevicePath);
+                        }
+                        if (event->mask & IN_DELETE) {
+                            mParent->deviceRemoved(v4l2DevicePath);
+                        }
+                    }
+                }
+                offset += sizeof(struct inotify_event) + event->len;
+            }
+        }
+    }
+
+    return true;
+}
+
+}  // namespace implementation
+}  // namespace V2_4
+}  // namespace provider
+}  // namespace camera
+}  // namespace hardware
+}  // namespace android
diff --git a/camera/provider/2.4/default/ExternalCameraProvider.h b/camera/provider/2.4/default/ExternalCameraProvider.h
new file mode 100644
index 0000000..c7ed99e
--- /dev/null
+++ b/camera/provider/2.4/default/ExternalCameraProvider.h
@@ -0,0 +1,102 @@
+/*
+ * Copyright (C) 2018 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.
+ */
+
+#ifndef ANDROID_HARDWARE_CAMERA_PROVIDER_V2_4_EXTCAMERAPROVIDER_H
+#define ANDROID_HARDWARE_CAMERA_PROVIDER_V2_4_EXTCAMERAPROVIDER_H
+
+#include <unordered_map>
+#include "utils/Mutex.h"
+#include "utils/Thread.h"
+#include <android/hardware/camera/provider/2.4/ICameraProvider.h>
+#include <hidl/Status.h>
+#include <hidl/MQDescriptor.h>
+
+namespace android {
+namespace hardware {
+namespace camera {
+namespace provider {
+namespace V2_4 {
+namespace implementation {
+
+using ::android::hardware::camera::common::V1_0::CameraDeviceStatus;
+using ::android::hardware::camera::common::V1_0::Status;
+using ::android::hardware::camera::common::V1_0::VendorTagSection;
+using ::android::hardware::camera::provider::V2_4::ICameraProvider;
+using ::android::hardware::camera::provider::V2_4::ICameraProviderCallback;
+using ::android::hardware::Return;
+using ::android::hardware::Void;
+using ::android::hardware::hidl_vec;
+using ::android::hardware::hidl_string;
+using ::android::sp;
+using ::android::Mutex;
+
+struct ExternalCameraProvider : public ICameraProvider {
+    ExternalCameraProvider();
+    ~ExternalCameraProvider();
+
+    // Methods from ::android::hardware::camera::provider::V2_4::ICameraProvider follow.
+    Return<Status> setCallback(const sp<ICameraProviderCallback>& callback) override;
+
+    Return<void> getVendorTags(getVendorTags_cb _hidl_cb) override;
+
+    Return<void> getCameraIdList(getCameraIdList_cb _hidl_cb) override;
+
+    Return<void> isSetTorchModeSupported(isSetTorchModeSupported_cb _hidl_cb) override;
+
+    Return<void> getCameraDeviceInterface_V1_x(
+            const hidl_string&,
+            getCameraDeviceInterface_V1_x_cb) override;
+    Return<void> getCameraDeviceInterface_V3_x(
+            const hidl_string&,
+            getCameraDeviceInterface_V3_x_cb) override;
+
+private:
+
+    void addExternalCamera(const char* devName);
+
+    void deviceAdded(const char* devName);
+
+    void deviceRemoved(const char* devName);
+
+    class HotplugThread : public android::Thread {
+    public:
+        HotplugThread(ExternalCameraProvider* parent);
+        ~HotplugThread();
+
+        virtual bool threadLoop() override;
+
+    private:
+        ExternalCameraProvider* mParent = nullptr;
+
+        int mINotifyFD = -1;
+        int mWd = -1;
+    } mHotPlugThread;
+
+    Mutex mLock;
+    sp<ICameraProviderCallback> mCallbacks = nullptr;
+    std::unordered_map<std::string, CameraDeviceStatus> mCameraStatusMap; // camera id -> status
+};
+
+
+
+}  // namespace implementation
+}  // namespace V2_4
+}  // namespace provider
+}  // namespace camera
+}  // namespace hardware
+}  // namespace android
+
+#endif  // ANDROID_HARDWARE_CAMERA_PROVIDER_V2_4_EXTCAMERAPROVIDER_H
diff --git a/camera/provider/2.4/default/android.hardware.camera.provider@2.4-external-service.rc b/camera/provider/2.4/default/android.hardware.camera.provider@2.4-external-service.rc
new file mode 100644
index 0000000..acdb200
--- /dev/null
+++ b/camera/provider/2.4/default/android.hardware.camera.provider@2.4-external-service.rc
@@ -0,0 +1,7 @@
+service vendor.camera-provider-2-4-ext /vendor/bin/hw/android.hardware.camera.provider@2.4-external-service
+    class hal
+    user cameraserver
+    group audio camera input drmrpc usb
+    ioprio rt 4
+    capabilities SYS_NICE
+    writepid /dev/cpuset/camera-daemon/tasks /dev/stune/top-app/tasks
diff --git a/camera/provider/2.4/default/external-service.cpp b/camera/provider/2.4/default/external-service.cpp
new file mode 100644
index 0000000..f91aa59
--- /dev/null
+++ b/camera/provider/2.4/default/external-service.cpp
@@ -0,0 +1,34 @@
+/*
+ * Copyright 2018 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.
+ */
+
+#define LOG_TAG "android.hardware.camera.provider@2.4-external-service"
+
+#include <android/hardware/camera/provider/2.4/ICameraProvider.h>
+#include <hidl/LegacySupport.h>
+
+#include <binder/ProcessState.h>
+
+using android::hardware::camera::provider::V2_4::ICameraProvider;
+using android::hardware::defaultPassthroughServiceImplementation;
+
+int main()
+{
+    ALOGI("External camera provider service is starting.");
+    // The camera HAL may communicate to other vendor components via
+    // /dev/vndbinder
+    android::ProcessState::initWithDriver("/dev/vndbinder");
+    return defaultPassthroughServiceImplementation<ICameraProvider>("external/0", /*maxThreads*/ 6);
+}