diff --git a/soundtrigger/ISoundTriggerHwService.cpp b/soundtrigger/ISoundTriggerHwService.cpp
new file mode 100644
index 0000000..c9a0c24
--- /dev/null
+++ b/soundtrigger/ISoundTriggerHwService.cpp
@@ -0,0 +1,150 @@
+/*
+**
+** Copyright 2014, 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 "BpSoundTriggerHwService"
+//#define LOG_NDEBUG 0
+
+#include <utils/Log.h>
+#include <utils/Errors.h>
+
+#include <stdint.h>
+#include <sys/types.h>
+#include <binder/IMemory.h>
+#include <binder/Parcel.h>
+#include <binder/IPCThreadState.h>
+#include <binder/IServiceManager.h>
+
+#include <soundtrigger/ISoundTriggerHwService.h>
+#include <soundtrigger/ISoundTrigger.h>
+#include <soundtrigger/ISoundTriggerClient.h>
+
+namespace android {
+
+enum {
+    LIST_MODULES = IBinder::FIRST_CALL_TRANSACTION,
+    ATTACH,
+};
+
+class BpSoundTriggerHwService: public BpInterface<ISoundTriggerHwService>
+{
+public:
+    BpSoundTriggerHwService(const sp<IBinder>& impl)
+        : BpInterface<ISoundTriggerHwService>(impl)
+    {
+    }
+
+    virtual status_t listModules(struct sound_trigger_module_descriptor *modules,
+                                 uint32_t *numModules)
+    {
+        if (numModules == NULL || (*numModules != 0 && modules == NULL)) {
+            return BAD_VALUE;
+        }
+        Parcel data, reply;
+        data.writeInterfaceToken(ISoundTriggerHwService::getInterfaceDescriptor());
+        unsigned int numModulesReq = (modules == NULL) ? 0 : *numModules;
+        data.writeInt32(numModulesReq);
+        status_t status = remote()->transact(LIST_MODULES, data, &reply);
+        if (status == NO_ERROR) {
+            status = (status_t)reply.readInt32();
+            *numModules = (unsigned int)reply.readInt32();
+        }
+        ALOGV("listModules() status %d got *numModules %d", status, *numModules);
+        if (status == NO_ERROR) {
+            if (numModulesReq > *numModules) {
+                numModulesReq = *numModules;
+            }
+            if (numModulesReq > 0) {
+                reply.read(modules, numModulesReq * sizeof(struct sound_trigger_module_descriptor));
+            }
+        }
+        return status;
+    }
+
+    virtual status_t attach(const sound_trigger_module_handle_t handle,
+                            const sp<ISoundTriggerClient>& client,
+                            sp<ISoundTrigger>& module)
+    {
+        Parcel data, reply;
+        data.writeInterfaceToken(ISoundTriggerHwService::getInterfaceDescriptor());
+        data.write(&handle, sizeof(sound_trigger_module_handle_t));
+        data.writeStrongBinder(client->asBinder());
+        remote()->transact(ATTACH, data, &reply);
+        status_t status = reply.readInt32();
+        if (reply.readInt32() != 0) {
+            module = interface_cast<ISoundTrigger>(reply.readStrongBinder());
+        }
+        return status;
+    }
+
+};
+
+IMPLEMENT_META_INTERFACE(SoundTriggerHwService, "android.hardware.ISoundTriggerHwService");
+
+// ----------------------------------------------------------------------
+
+status_t BnSoundTriggerHwService::onTransact(
+    uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags)
+{
+    switch(code) {
+        case LIST_MODULES: {
+            CHECK_INTERFACE(ISoundTriggerHwService, data, reply);
+            unsigned int numModulesReq = data.readInt32();
+            unsigned int numModules = numModulesReq;
+            struct sound_trigger_module_descriptor *modules =
+                    (struct sound_trigger_module_descriptor *)calloc(numModulesReq,
+                                                   sizeof(struct sound_trigger_module_descriptor));
+            status_t status = listModules(modules, &numModules);
+            reply->writeInt32(status);
+            reply->writeInt32(numModules);
+            ALOGV("LIST_MODULES status %d got numModules %d", status, numModules);
+
+            if (status == NO_ERROR) {
+                if (numModulesReq > numModules) {
+                    numModulesReq = numModules;
+                }
+                reply->write(modules,
+                             numModulesReq * sizeof(struct sound_trigger_module_descriptor));
+            }
+            free(modules);
+            return NO_ERROR;
+        }
+
+        case ATTACH: {
+            CHECK_INTERFACE(ISoundTriggerHwService, data, reply);
+            sound_trigger_module_handle_t handle;
+            data.read(&handle, sizeof(sound_trigger_module_handle_t));
+            sp<ISoundTriggerClient> client =
+                    interface_cast<ISoundTriggerClient>(data.readStrongBinder());
+            sp<ISoundTrigger> module;
+            status_t status = attach(handle, client, module);
+            reply->writeInt32(status);
+            if (module != 0) {
+                reply->writeInt32(1);
+                reply->writeStrongBinder(module->asBinder());
+            } else {
+                reply->writeInt32(0);
+            }
+            return NO_ERROR;
+        } break;
+        default:
+            return BBinder::onTransact(code, data, reply, flags);
+    }
+}
+
+// ----------------------------------------------------------------------------
+
+}; // namespace android