diff --git a/include/hardware/context_hub.h b/include/hardware/context_hub.h
new file mode 100644
index 0000000..01d2377
--- /dev/null
+++ b/include/hardware/context_hub.h
@@ -0,0 +1,288 @@
+/*
+ * 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.
+ */
+
+#ifndef CONTEXT_HUB_H
+#define CONTEXT_HUB_H
+
+#include <stdint.h>
+#include <sys/cdefs.h>
+#include <sys/types.h>
+
+#include <hardware/hardware.h>
+
+/**
+ * This header file defines the interface of a Context Hub Implementation to
+ * the Android service exposing Context hub capabilities to applications.
+ * The Context hub is expected to a low power compute domain with the following
+ * defining charecteristics -
+ *
+ *    1) Access to sensors like accelerometer, gyroscope, magenetometer.
+ *    2) Access to radios like GPS, Wifi, Bluetooth etc.
+ *    3) Access to low power audio sensing.
+ *
+ * Implementations of this HAL can add additional sensors not defined by the
+ * Android API. Such information sources shall be private to the implementation.
+ *
+ * The Context Hub HAL exposes the construct of code download. A piece of binary
+ * code can be pushed to the context hub through the supported APIs.
+ *
+ * This version of the HAL designs in the possibility of multiple context hubs.
+ */
+
+__BEGIN_DECLS
+
+/*****************************************************************************/
+
+#define CONTEXT_HUB_HEADER_VERSION          1
+#define CONTEXT_HUB_DEVICE_API_VERSION_1_0  HARDWARE_DEVICE_API_VERSION_2(1, 0, CONTEXT_HUB_HEADER_VERSION)
+
+/**
+ * The id of this module
+ */
+#define CONTEXT_HUB_MODULE_ID         "context_hub"
+
+/**
+ * Name of the device to open
+ */
+#define CONTEXT_HUB_HARDWARE_POLL     "ctxt_poll"
+
+/**
+ * Memory types for code upload. Device-specific. At least HUB_MEM_TYPE_MAIN must be supported
+ */
+#define HUB_MEM_TYPE_MAIN             0
+#define HUB_MEM_TYPE_SECONDARY        1
+#define HUB_MEM_TYPE_TCM              2
+
+
+#define HUB_MEM_TYPE_FIRST_VENDOR     0x80000000ul
+
+
+/**
+ * Other memory types (likely not writeable, informational only)
+ */
+#define HUB_MEM_TYPE_BOOTLOADER       0xfffffffful
+#define HUB_MEM_TYPE_OS               0xfffffffeul
+#define HUB_MEM_TYPE_EEDATA           0xfffffffdul
+#define HUB_MEM_TYPE_RAM              0xfffffffcul
+
+/**
+ * Types of memory blocks on the context hub
+ * */
+#define MEM_FLAG_READ  0x1  // Memory can be written to
+#define MEM_FLAG_WRITE 0x2  // Memory can be written to
+#define MEM_FLAG_EXEC  0x4  // Memory can be executed from
+
+/**
+ * The following structure defines each memory block in detail
+ */
+struct mem_range_t {
+    uint32_t total_bytes;
+    uint32_t free_bytes;
+    uint32_t type;        // HUB_MEM_TYPE_*
+    uint32_t mem_flags;   // MEM_FLAG_*
+};
+
+
+/**
+ * App names may be strings, bytes, uints, etc. This caovers all types of app names
+ */
+struct hub_app_name_t {
+    uint32_t app_name_len;
+    const void *app_name;
+};
+
+struct hub_app_info {
+    const struct hub_app_name_t *name;
+    uint32_t version;
+    uint32_t num_mem_ranges;
+    const struct mem_range_t *mem_usage;
+};
+
+/**
+ * Following enum defines the types of sensors that a hub may declare support
+ * for. Declaration for support would mean that the hub can access and process
+ * data from that particular sensor type.
+ */
+
+typedef enum {
+    CONTEXT_SENSOR_RESERVED,             // 0
+    CONTEXT_SENSOR_ACCELEROMETER,        // 1
+    CONTEXT_SENSOR_GYROSCOPE,            // 2
+    CONTEXT_SENSOR_MAGNETOMETER,         // 3
+    CONTEXT_SENSOR_BAROMETER,            // 4
+    CONTEXT_SENSOR_PROXIMITY_SENSOR,     // 5
+    CONTEXT_SENSOR_AMBIENT_LIGHT_SENSOR, // 6
+
+    CONTEXT_SENSOR_GPS = 0x100,          // 0x100
+    // Reserving this space for variants on GPS
+    CONTEXT_SENSOR_WIFI = 0x200,         // 0x200
+    // Reserving this space for variants on WIFI
+    CONTEXT_SENSOR_AUDIO = 0x300,        // 0x300
+    // Reserving this space for variants on Audio
+    CONTEXT_SENSOR_CAMERA = 0x400,       // 0x400
+    // Reserving this space for variants on Camera
+    CONTEXT_SENSOR_BLE = 0x500,          // 0x500
+
+    CONTEXT_SENSOR_MAX = 0xffffffff,     //make sure enum size is set
+} context_sensor_e;
+
+/**
+ * Sensor types beyond CONTEXT_HUB_TYPE_PRIVATE_SENSOR_BASE are custom types
+ */
+#define CONTEXT_HUB_TYPE_PRIVATE_SENSOR_BASE 0x10000
+
+/**
+ * The following structure describes a sensor
+ */
+struct physical_sensor_description_t {
+    uint32_t sensor_type;           // From the definitions above eg: 100
+    const char *type_string;        // Type as a string. eg: "GPS"
+    const char *name;               // Identifier eg: "Bosch BMI160"
+    const char *vendor;             // Vendor : eg "STM"
+    uint32_t version;               // Version : eg 0x1001
+    uint32_t fifo_reserverd_count;  // Batching possible in hardware. Please
+                                    // note that here hardware does not include
+                                    // the context hub itslef. Thus, this
+                                    // definition may be different from say the
+                                    // number advertised in the sensors HAL
+                                    // which allows for batching in a hub.
+    uint32_t fifo_max_count;        // maximum number of batchable events.
+    uint64_t min_delay_ms;          // in milliseconds, corresponding to highest
+                                    // sampling freq.
+    uint64_t max_delay_ms;          // in milliseconds, corresponds to minimum
+                                    // sampling frequency
+    float peak_power_mw;            // At max frequency & no batching, power
+                                    // in milliwatts
+};
+
+struct connected_sensor_t {
+    uint32_t sensor_id;             // identifier for this sensor
+
+    /* This union may be extended to other sensor types */
+    union {
+        struct physical_sensor_description_t physical_sensor;
+    };
+};
+
+
+
+/**
+ * Messages of this length or less must be supported by all implementations,
+ * longer lengths are supported up to max_supported_msg_len. This is exposed
+ * to third party apps, and since we do not know their msg data formats we
+ * cannot fragment for them. Our own messages are allowed to be bigger and
+ * this HAL will fragment as needed. "Our own" messages are messaegs defined
+ * in this file.
+ */
+#define HUB_REQUIRED_SUPPORTED_MSG_LEN  128
+
+struct hub_message_t {
+    const struct hub_app_name_t *app; /* To/From this nanoapp */
+    uint32_t message_type;
+    uint32_t message_len;
+    const void *message;
+};
+
+
+/**
+ * Definition of a context hub. A device may contain more than one low
+ * power domain. In that case, please add an entry for each hub. However,
+ * it is perfectly OK for a device to declare one context hub and manage
+ * them internally as several
+ */
+
+struct context_hub_t {
+    const char *name;                // descriptive name eg: "Awesome Hub #1"
+    const char *vendor;              // hub hardware vendor eg: "Qualcomm"
+    const char *toolchain;           // toolchain to make binaries eg:"gcc ARM"
+    uint32_t platform_version;       // Version of the hardware : eg 0x20
+    uint32_t toolchain_version;      // Version of the toolchain : eg: 0x484
+    uint32_t hub_id;                 // a device unique id for this hub
+
+    float peak_mips;                 // Peak MIPS platform can deliver
+    float stopped_power_draw_mw;     // if stopped, retention power, milliwatts
+    float sleep_power_draw_mw;       // if sleeping, retention power, milliwatts
+    float peak_power_draw_mw;        // for a busy CPUm power in milliwatts
+
+    const struct connected_sensor_t *connected_sensors; // array of connected sensors
+    uint32_t num_connected_sensors;  // number of connected sensors
+
+    uint32_t max_supported_msg_len;
+    const struct hub_app_name_t *os_app_name; /* send msgs here for OS functions */
+};
+
+/**
+ * All communication between the context hubs and the Context Hub Service is in
+ * the form of messages. Some message types are distinguished and their
+ * Semantics shall be well defined.
+ * Custom message types should be defined starting above
+ * CONTEXT_HUB_PRIVATE_MSG_BASE
+ */
+
+typedef enum {
+    CONTEXT_HUB_APPS_ENABLE = 1, // 1: Enables the loaded nano-apps
+    CONTEXT_HUB_APPS_DISABLE,    // 2: Disables any loaded nano-apps
+    CONTEXT_HUB_LOAD_APP,        // 3: Load a supplied app
+    CONTEXT_HUB_UNLOAD_APP,      // 4: Unload a specified app
+    CONTEXT_HUB_QUERY_APPS,      // 5: Query for apps info on hub (gets struct hub_app_info[])
+    CONTEXT_HUB_QUERY_MEMORY,    // 5: Query for memory info (gets struct mem_range_t[])
+    CONTEXT_HUB_LOAD_OS,         // 6: Load up OS update
+} hub_messages_e;
+
+#define CONTEXT_HUB_TYPE_PRIVATE_MSG_BASE 0x10000
+
+
+/**
+ * A callback registers with the context hub service to pass messages
+ * coming from the hub to the service/clients.
+ */
+typedef int context_hub_callback(uint32_t hub_id, const struct hub_message_t *rxed_msg, void *cookie);
+
+
+/**
+ * Every hardware module must have a data structure named HAL_MODULE_INFO_SYM
+ * and the fields of this data structure must begin with hw_module_t
+ * followed by module specific information.
+ */
+struct context_hub_module_t {
+    struct hw_module_t common;
+
+    /**
+     * Enumerate all available hubs.The list is returned in "list".
+     * @return result : 0 if successful, error code otherwise
+     *
+     * This method shall be called at device bootup.
+     */
+    int (*get_hubs)(struct context_hub_module_t* module, const struct context_hub_t ** list);
+
+    /**
+     * Registers a callback for the HAL implementation to communicate
+     * with the context hub service.
+     * @return result : 0 if successful, error code otherwise
+     */
+    int (*subscribe_messages)(uint32_t hub_id, context_hub_callback cbk, void *cookie);
+
+    /**
+     * Send a message to a hub
+     * @return result : 0 if successful, error code otherwise
+     */
+    int (*send_message)(uint32_t hub_id, const struct hub_message_t *msg);
+
+};
+
+__END_DECLS
+
+#endif  // CONTEXT_HUB_SENSORS_INTERFACE_H
diff --git a/include/hardware/gps.h b/include/hardware/gps.h
index 76b6cb7..6fd47a9 100644
--- a/include/hardware/gps.h
+++ b/include/hardware/gps.h
@@ -53,7 +53,7 @@
 #define GPS_POSITION_MODE_MS_BASED      1
 /**
  * AGPS MS-Assisted mode. This mode is not maintained by the platform anymore.
- * It is strongly recommended to use GPS_POSITION_MODE_MS_BASE instead.
+ * It is strongly recommended to use GPS_POSITION_MODE_MS_BASED instead.
  */
 #define GPS_POSITION_MODE_MS_ASSISTED   2
 
@@ -98,28 +98,31 @@
 
 /** Flags for the gps_set_capabilities callback. */
 
-/** GPS HAL schedules fixes for GPS_POSITION_RECURRENCE_PERIODIC mode.
-    If this is not set, then the framework will use 1000ms for min_interval
-    and will start and call start() and stop() to schedule the GPS.
+/**
+ * GPS HAL schedules fixes for GPS_POSITION_RECURRENCE_PERIODIC mode. If this is
+ * not set, then the framework will use 1000ms for min_interval and will start
+ * and call start() and stop() to schedule the GPS.
  */
-#define GPS_CAPABILITY_SCHEDULING       0x0000001
+#define GPS_CAPABILITY_SCHEDULING       (1 << 0)
 /** GPS supports MS-Based AGPS mode */
-#define GPS_CAPABILITY_MSB              0x0000002
+#define GPS_CAPABILITY_MSB              (1 << 1)
 /** GPS supports MS-Assisted AGPS mode */
-#define GPS_CAPABILITY_MSA              0x0000004
+#define GPS_CAPABILITY_MSA              (1 << 2)
 /** GPS supports single-shot fixes */
-#define GPS_CAPABILITY_SINGLE_SHOT      0x0000008
+#define GPS_CAPABILITY_SINGLE_SHOT      (1 << 3)
 /** GPS supports on demand time injection */
-#define GPS_CAPABILITY_ON_DEMAND_TIME   0x0000010
+#define GPS_CAPABILITY_ON_DEMAND_TIME   (1 << 4)
 /** GPS supports Geofencing  */
-#define GPS_CAPABILITY_GEOFENCING       0x0000020
+#define GPS_CAPABILITY_GEOFENCING       (1 << 5)
 /** GPS supports Measurements */
-#define GPS_CAPABILITY_MEASUREMENTS     0x0000040
+#define GPS_CAPABILITY_MEASUREMENTS     (1 << 6)
 /** GPS supports Navigation Messages */
-#define GPS_CAPABILITY_NAV_MESSAGES     0x0000080
+#define GPS_CAPABILITY_NAV_MESSAGES     (1 << 7)
 
-/** Flags used to specify which aiding data to delete
-    when calling delete_aiding_data(). */
+/**
+ * Flags used to specify which aiding data to delete when calling
+ * delete_aiding_data().
+ */
 typedef uint16_t GpsAidingData;
 // IMPORTANT: Note that the following values must match
 // constants in GpsLocationProvider.java.
@@ -210,9 +213,11 @@
 /** AGPS data connection failed */
 #define GPS_AGPS_DATA_CONN_FAILED   5
 
+typedef uint16_t AGpsRefLocationType;
 #define AGPS_REF_LOCATION_TYPE_GSM_CELLID   1
 #define AGPS_REF_LOCATION_TYPE_UMTS_CELLID  2
 #define AGPS_REG_LOCATION_TYPE_MAC          3
+#define AGPS_REF_LOCATION_TYPE_LTE_CELLID   4
 
 /** Network types for update_network_state "type" parameter */
 #define AGPS_RIL_NETWORK_TYPE_MOBILE        0
@@ -246,9 +251,14 @@
  * Enumeration of the available values for the GPS Clock type.
  */
 typedef uint8_t GpsClockType;
-/** The type is not available ot it is unknown. */
+/** The type is not available or it is unknown. */
 #define GPS_CLOCK_TYPE_UNKNOWN                  0
-/** The source of the time value reported by GPS clock is the local hardware clock. */
+/**
+ * The source of the time value reported by GPS clock is the local hardware
+ * clock. This is a mandatory flag. When the GpsSystemInfo's year_of_hw is 2016
+ * or higher, it is mandatory that 'time' is populated with the local hardware
+ * clock value, and this flag must always be set.
+ */
 #define GPS_CLOCK_TYPE_LOCAL_HW_TIME            1
 /**
  * The source of the time value reported by GPS clock is the GPS time derived from satellites
@@ -296,7 +306,12 @@
 #define GPS_MEASUREMENT_HAS_DOPPLER_SHIFT_UNCERTAINTY         (1<<16)
 /** A valid 'used in fix' flag is stored in the data structure. */
 #define GPS_MEASUREMENT_HAS_USED_IN_FIX                       (1<<17)
-/** The value of 'pseudorange rate' is uncorrected. */
+/**
+ * The value of 'pseudorange rate' is uncorrected.
+ * This is a mandatory flag. It is mandatory that 'pseudorange rate' is
+ * populated with the uncorrected value, and this flag must always be set.
+ * See comments of GpsMeasurement::pseudorange_rate_mps for more details.
+ */
 #define GPS_MEASUREMENT_HAS_UNCORRECTED_PSEUDORANGE_RATE      (1<<18)
 
 /**
@@ -316,9 +331,9 @@
 typedef uint8_t GpsMultipathIndicator;
 /** The indicator is not available or unknown. */
 #define GPS_MULTIPATH_INDICATOR_UNKNOWN                 0
-/** The measurement has been indicated to use multipath. */
+/** The measurement is indicated to be affected by multipath. */
 #define GPS_MULTIPATH_INDICATOR_DETECTED                1
-/** The measurement has been indicated Not to use multipath. */
+/** The measurement is indicated to be not affected by multipath. */
 #define GPS_MULTIPATH_INDICATOR_NOT_USED                2
 
 /**
@@ -377,6 +392,27 @@
 #define NAV_MESSAGE_STATUS_PARITY_REBUILT  (1<<1)
 
 /**
+ * Flag that indicates which extra data GnssSvInfo includes.
+ */
+typedef uint8_t                                 GnssSvFlags;
+#define GNSS_SV_FLAGS_NONE                      0
+#define GNSS_SV_FLAGS_HAS_EPHEMERIS_DATA        (1 << 0)
+#define GNSS_SV_FLAGS_HAS_ALMANAC_DATA          (1 << 1)
+#define GNSS_SV_FLAGS_USED_IN_FIX               (1 << 2)
+
+/**
+ * Constellation type of GnssSvInfo
+ */
+typedef uint8_t                         GnssConstellationType;
+#define GNSS_CONSTELLATION_UNKNOWN      0
+#define GNSS_CONSTELLATION_GPS          1
+#define GNSS_CONSTELLATION_SBAS         2
+#define GNSS_CONSTELLATION_GLONASS      3
+#define GNSS_CONSTELLATION_QZSS         4
+#define GNSS_CONSTELLATION_BEIDOU       5
+#define GNSS_CONSTELLATION_GALILEO      6
+
+/**
  * Name for the GPS XTRA interface.
  */
 #define GPS_XTRA_INTERFACE      "gps-xtra"
@@ -437,8 +473,9 @@
     double          latitude;
     /** Represents longitude in degrees. */
     double          longitude;
-    /** Represents altitude in meters above the WGS 84 reference
-     * ellipsoid. */
+    /**
+     * Represents altitude in meters above the WGS 84 reference ellipsoid.
+     */
     double          altitude;
     /** Represents speed in meters per second. */
     float           speed;
@@ -471,43 +508,124 @@
     float   azimuth;
 } GpsSvInfo;
 
-/** Represents SV status. */
 typedef struct {
-    /** set to sizeof(GpsSvStatus) */
-    size_t          size;
-
-    /** Number of SVs currently visible. */
-    int         num_svs;
-
-    /** Contains an array of SV information. */
-    GpsSvInfo   sv_list[GPS_MAX_SVS];
-
-    /** Represents a bit mask indicating which SVs
-     * have ephemeris data.
-     */
-    uint32_t    ephemeris_mask;
-
-    /** Represents a bit mask indicating which SVs
-     * have almanac data.
-     */
-    uint32_t    almanac_mask;
+    /** set to sizeof(GnssSvInfo) */
+    size_t size;
 
     /**
-     * Represents a bit mask indicating which SVs
-     * were used for computing the most recent position fix.
+     * Pseudo-random number for the SV, or Amanac/slot number for Glonass. The
+     * distinction is made by looking at constellation field. Values should be
+     * in the range of:
+     *
+     * - GPS:     1-32
+     * - SBAS:    120-151, 183-192
+     * - GLONASS: 1-24 (slot number)
+     * - QZSS:    193-200
+     * - Galileo: 1-25
+     * - Beidou:  1-35
      */
-    uint32_t    used_in_fix_mask;
+    int prn;
+
+    /** Signal to noise ratio. */
+    float snr;
+
+    /** Elevation of SV in degrees. */
+    float elevation;
+
+    /** Azimuth of SV in degrees. */
+    float azimuth;
+
+    /**
+     * Contains additional data about the given SV. Value should be one of those
+     * GNSS_SV_FLAGS_* constants
+     */
+    GnssSvFlags flags;
+
+    /**
+     * Defines the constellation of the given SV. Value should be one of those
+     * GNSS_CONSTELLATION_* constants
+     */
+    GnssConstellationType constellation;
+
+} GnssSvInfo;
+
+/**
+ * Represents SV status.
+ *
+ * When switching from pre-N to N version of GpsSvStatus:
+ *
+ * 1) Fill in the fields from num_svs through used_in_fix_mask the same way as
+ * was done before, e.g. using the range of 65-88 to report Glonass info,
+ * 201-235 for Beidou, etc. (but with no used_in_fix_mask info - those are
+ * index by prn, and thus for GPS only). This will help ensure compatibility
+ * when a newer GPS HAL is used with an older version of Android.
+ *
+ * 2) Fill in the gnss_sv_list with information about SVs from all
+ * constellations (GPS & other GNSS's) - when this is filled in, this will be
+ * the only source of information about satellite status (e.g. for working with
+ * GpsStatus facing applications), the earlier fields will be ignored.
+ */
+typedef struct {
+    /** set to sizeof(GpsSvStatus) */
+    size_t size;
+
+    /** Number of GPS SVs currently visible, refers to the SVs stored in sv_list */
+    int num_svs;
+
+    /** Contains an array of GPS SV information in legacy GPS format. */
+    GpsSvInfo sv_list[GPS_MAX_SVS];
+
+    /**
+     * Represents a bit mask indicating which GPS SVs have ephemeris data,
+     * refers to sv_list.
+     */
+    uint32_t ephemeris_mask;
+
+    /**
+     * Represents a bit mask indicating which GPS SVs have almanac data, refers
+     * to sv_list.
+     */
+    uint32_t almanac_mask;
+
+    /**
+     * Represents a bit mask indicating which GPS SVs
+     * were used for computing the most recent position fix,
+     * refers to sv_list.
+     */
+    uint32_t used_in_fix_mask;
+
+    /**
+     * Size of the array which contains SV info for all GNSS constellation
+     * except for GPS.
+     */
+    size_t gnss_sv_list_size;
+
+    /**
+     * Pointer to an array of SVs information for all GNSS constellations,
+     * except GPS, which is reported using sv_list
+     */
+    GnssSvInfo* gnss_sv_list;
+
 } GpsSvStatus;
 
-
-/* 2G and 3G */
-/* In 3G lac is discarded */
+/* CellID for 2G, 3G and LTE, used in AGPS. */
 typedef struct {
-    uint16_t type;
+    AGpsRefLocationType type;
+    /** Mobile Country Code. */
     uint16_t mcc;
+    /** Mobile Network Code .*/
     uint16_t mnc;
+    /** Location Area Code in 2G, 3G and LTE. In 3G lac is discarded. In LTE,
+     * lac is populated with tac, to ensure that we don't break old clients that
+     * might rely in the old (wrong) behavior.
+     */
     uint16_t lac;
+    /** Cell id in 2G. Utran Cell id in 3G. Cell Global Id EUTRA in LTE. */
     uint32_t cid;
+    /** Tracking Area Code in LTE. */
+    uint16_t tac;
+    /** Physical Cell id in LTE (not used in 2G and 3G) */
+    uint16_t pcid;
 } AGpsRefLocationCellID;
 
 typedef struct {
@@ -516,20 +634,22 @@
 
 /** Represents ref locations */
 typedef struct {
-    uint16_t type;
+    AGpsRefLocationType type;
     union {
         AGpsRefLocationCellID   cellID;
         AGpsRefLocationMac      mac;
     } u;
 } AGpsRefLocation;
 
-/** Callback with location information.
- *  Can only be called from a thread created by create_thread_cb.
+/**
+ * Callback with location information. Can only be called from a thread created
+ * by create_thread_cb.
  */
 typedef void (* gps_location_callback)(GpsLocation* location);
 
-/** Callback with status information.
- *  Can only be called from a thread created by create_thread_cb.
+/**
+ * Callback with status information. Can only be called from a thread created by
+ * create_thread_cb.
  */
 typedef void (* gps_status_callback)(GpsStatus* status);
 
@@ -539,18 +659,21 @@
  */
 typedef void (* gps_sv_status_callback)(GpsSvStatus* sv_info);
 
-/** Callback for reporting NMEA sentences.
- *  Can only be called from a thread created by create_thread_cb.
+/**
+ * Callback for reporting NMEA sentences. Can only be called from a thread
+ * created by create_thread_cb.
  */
 typedef void (* gps_nmea_callback)(GpsUtcTime timestamp, const char* nmea, int length);
 
-/** Callback to inform framework of the GPS engine's capabilities.
- *  Capability parameter is a bit field of GPS_CAPABILITY_* flags.
+/**
+ * Callback to inform framework of the GPS engine's capabilities. Capability
+ * parameter is a bit field of GPS_CAPABILITY_* flags.
  */
 typedef void (* gps_set_capabilities)(uint32_t capabilities);
 
-/** Callback utility for acquiring the GPS wakelock.
- *  This can be used to prevent the CPU from suspending while handling GPS events.
+/**
+ * Callback utility for acquiring the GPS wakelock. This can be used to prevent
+ * the CPU from suspending while handling GPS events.
  */
 typedef void (* gps_acquire_wakelock)();
 
@@ -560,12 +683,57 @@
 /** Callback for requesting NTP time */
 typedef void (* gps_request_utc_time)();
 
-/** Callback for creating a thread that can call into the Java framework code.
- *  This must be used to create any threads that report events up to the framework.
+/**
+ * Callback for creating a thread that can call into the Java framework code.
+ * This must be used to create any threads that report events up to the
+ * framework.
  */
 typedef pthread_t (* gps_create_thread)(const char* name, void (*start)(void *), void* arg);
 
-/** GPS callback structure. */
+/**
+ * Provides information about how new the underlying GPS/GNSS hardware and
+ * software is.
+ *
+ * This information will be available for Android Test Applications. If a GPS
+ * HAL does not provide this information, it will be considered "2015 or
+ * earlier".
+ *
+ * If a GPS HAL does provide this information, then newer years will need to
+ * meet newer CTS standards. E.g. if the date are 2016 or above, then N+ level
+ * GpsMeasurement support will be verified.
+ */
+typedef struct {
+    /** Set to sizeof(GpsSystemInfo) */
+    size_t   size;
+    /* year in which the last update was made to the underlying hardware/firmware
+     * used to capture GNSS signals, e.g. 2016 */
+    uint16_t year_of_hw;
+} GpsSystemInfo;
+
+/**
+ * Callback to inform framework of the engine's hardware version information.
+ */
+typedef void (*gps_set_system_info)(const GpsSystemInfo* info);
+
+/**
+ * Legacy GPS callback structure.
+ * See GpsCallbacks for more information.
+ */
+typedef struct {
+    /** set to sizeof(GpsCallbacks_v1) */
+    size_t      size;
+    gps_location_callback location_cb;
+    gps_status_callback status_cb;
+    gps_sv_status_callback sv_status_cb;
+    gps_nmea_callback nmea_cb;
+    gps_set_capabilities set_capabilities_cb;
+    gps_acquire_wakelock acquire_wakelock_cb;
+    gps_release_wakelock release_wakelock_cb;
+    gps_create_thread create_thread_cb;
+    gps_request_utc_time request_utc_time_cb;
+} GpsCallbacks_v1;
+
+/** New GPS callback structure. */
 typedef struct {
     /** set to sizeof(GpsCallbacks) */
     size_t      size;
@@ -578,8 +746,17 @@
     gps_release_wakelock release_wakelock_cb;
     gps_create_thread create_thread_cb;
     gps_request_utc_time request_utc_time_cb;
-} GpsCallbacks;
 
+    /**
+     * Callback for the chipset to report system information.
+     *
+     * This field is newly introduced since N. The driver implementation must
+     * check 'size' field against 'sizeof(GpsCallbacks)' and
+     * 'sizeof(GpsCallbacks_v1)' to decide whether the new field is valid before
+     * calling it.
+     */
+    gps_set_system_info set_system_info_cb;
+} GpsCallbacks;
 
 /** Represents the standard GPS interface. */
 typedef struct {
@@ -604,10 +781,10 @@
     int   (*inject_time)(GpsUtcTime time, int64_t timeReference,
                          int uncertainty);
 
-    /** Injects current location from another location provider
-     *  (typically cell ID).
-     *  latitude and longitude are measured in degrees
-     *  expected accuracy is measured in meters
+    /**
+     * Injects current location from another location provider (typically cell
+     * ID). Latitude and longitude are measured in degrees expected accuracy is
+     * measured in meters
      */
     int  (*inject_location)(double latitude, double longitude, float accuracy);
 
@@ -623,10 +800,10 @@
      * preferred_accuracy represents the requested fix accuracy in meters.
      * preferred_time represents the requested time to first fix in milliseconds.
      *
-     * 'mode' parameter should be one of GPS_POSITION_MODE_MS_BASE
+     * 'mode' parameter should be one of GPS_POSITION_MODE_MS_BASED
      * or GPS_POSITION_MODE_STANDALONE.
      * It is allowed by the platform (and it is recommended) to fallback to
-     * GPS_POSITION_MODE_MS_BASE if GPS_POSITION_MODE_MS_ASSISTED is passed in, and
+     * GPS_POSITION_MODE_MS_BASED if GPS_POSITION_MODE_MS_ASSISTED is passed in, and
      * GPS_POSITION_MODE_MS_BASED is supported.
      */
     int   (*set_position_mode)(GpsPositionMode mode, GpsPositionRecurrence recurrence,
@@ -636,9 +813,10 @@
     const void* (*get_extension)(const char* name);
 } GpsInterface;
 
-/** Callback to request the client to download XTRA data.
- *  The client should download XTRA data and inject it by calling inject_xtra_data().
- *  Can only be called from a thread created by create_thread_cb.
+/**
+ * Callback to request the client to download XTRA data. The client should
+ * download XTRA data and inject it by calling inject_xtra_data(). Can only be
+ * called from a thread created by create_thread_cb.
  */
 typedef void (* gps_xtra_download_request)();
 
@@ -673,36 +851,11 @@
     size_t (*get_internal_state)(char* buffer, size_t bufferSize);
 } GpsDebugInterface;
 
-#pragma pack(push,4)
-// We need to keep the alignment of this data structure to 4-bytes, to ensure that in 64-bit
-// environments the size of this legacy definition does not collide with _v2. Implementations should
-// be using _v2 and _v3, so it's OK to pay the 'unaligned' penalty in 64-bit if an old
-// implementation is still in use.
-
-/** Represents the status of AGPS. */
+/*
+ * Represents the status of AGPS augmented to support IPv4 and IPv6.
+ */
 typedef struct {
-    /** set to sizeof(AGpsStatus_v1) */
-    size_t          size;
-
-    AGpsType        type;
-    AGpsStatusValue status;
-} AGpsStatus_v1;
-
-#pragma pack(pop)
-
-/** Represents the status of AGPS augmented with a IPv4 address field. */
-typedef struct {
-    /** set to sizeof(AGpsStatus_v2) */
-    size_t          size;
-
-    AGpsType        type;
-    AGpsStatusValue status;
-    uint32_t        ipaddr;
-} AGpsStatus_v2;
-
-/* Represents the status of AGPS augmented to support IPv4 and IPv6. */
-typedef struct {
-    /** set to sizeof(AGpsStatus_v3) */
+    /** set to sizeof(AGpsStatus) */
     size_t                  size;
 
     AGpsType                type;
@@ -717,14 +870,13 @@
     /**
      * Must contain the IPv4 (AF_INET) or IPv6 (AF_INET6) address to report.
      * Any other value of addr.ss_family will be rejected.
-     * */
+     */
     struct sockaddr_storage addr;
-} AGpsStatus_v3;
+} AGpsStatus;
 
-typedef AGpsStatus_v3     AGpsStatus;
-
-/** Callback with AGPS status information.
- *  Can only be called from a thread created by create_thread_cb.
+/**
+ * Callback with AGPS status information. Can only be called from a thread
+ * created by create_thread_cb.
  */
 typedef void (* agps_status_callback)(AGpsStatus* status);
 
@@ -734,42 +886,12 @@
     gps_create_thread create_thread_cb;
 } AGpsCallbacks;
 
-
-/** Extended interface for AGPS support. */
-typedef struct {
-    /** set to sizeof(AGpsInterface_v1) */
-    size_t          size;
-
-    /**
-     * Opens the AGPS interface and provides the callback routines
-     * to the implementation of this interface.
-     */
-    void  (*init)( AGpsCallbacks* callbacks );
-    /**
-     * Notifies that a data connection is available and sets
-     * the name of the APN to be used for SUPL.
-     */
-    int  (*data_conn_open)( const char* apn );
-    /**
-     * Notifies that the AGPS data connection has been closed.
-     */
-    int  (*data_conn_closed)();
-    /**
-     * Notifies that a data connection is not available for AGPS.
-     */
-    int  (*data_conn_failed)();
-    /**
-     * Sets the hostname and port for the AGPS server.
-     */
-    int  (*set_server)( AGpsType type, const char* hostname, int port );
-} AGpsInterface_v1;
-
 /**
  * Extended interface for AGPS support, it is augmented to enable to pass
  * extra APN data.
  */
 typedef struct {
-    /** set to sizeof(AGpsInterface_v2) */
+    /** set to sizeof(AGpsInterface) */
     size_t size;
 
     /**
@@ -803,9 +925,7 @@
     int (*data_conn_open_with_apn_ip_type)(
             const char* apn,
             ApnIpType apnIpType);
-} AGpsInterface_v2;
-
-typedef AGpsInterface_v2    AGpsInterface;
+} AGpsInterface;
 
 /** Error codes associated with certificate operations */
 #define AGPS_CERTIFICATE_OPERATION_SUCCESS               0
@@ -936,8 +1056,9 @@
 
 } GpsNiNotification;
 
-/** Callback with NI notification.
- *  Can only be called from a thread created by create_thread_cb.
+/**
+ * Callback with NI notification. Can only be called from a thread created by
+ * create_thread_cb.
  */
 typedef void (*gps_ni_notify_callback)(GpsNiNotification *notification);
 
@@ -1280,7 +1401,6 @@
    void (*remove_geofence_area) (int32_t geofence_id);
 } GpsGeofencingInterface;
 
-
 /**
  * Represents an estimate of the GPS clock time.
  */
@@ -1302,7 +1422,7 @@
 
     /**
      * Indicates the type of time reported by the 'time_ns' field.
-     * This is a Mandatory field.
+     * This is a mandatory field.
      */
     GpsClockType type;
 
@@ -1321,7 +1441,11 @@
      * Sub-nanosecond accuracy can be provided by means of the 'bias' field.
      * The value contains the 'time uncertainty' in it.
      *
-     * This is a Mandatory field.
+     * This field is mandatory.
+     *
+     * For devices where GpsSystemInfo's year_of_hw is set to 2016+, it is
+     * mandatory that it contains the value from the 'local hardware clock, and
+     * thus GPS_CLOCK_TYPE_LOCAL_HW_TIME must be set in 'type' field.
      */
     int64_t time_ns;
 
@@ -1329,8 +1453,9 @@
      * 1-Sigma uncertainty associated with the clock's time in nanoseconds.
      * The uncertainty is represented as an absolute (single sided) value.
      *
-     * This value should be set if GPS_CLOCK_TYPE_GPS_TIME is set.
-     * If the data is available 'flags' must contain GPS_CLOCK_HAS_TIME_UNCERTAINTY.
+     * If the data is available, 'flags' must contain
+     * GPS_CLOCK_HAS_TIME_UNCERTAINTY. If GPS has computed a position fix, this
+     * field is mandatory and must be populated.
      */
     double time_uncertainty_ns;
 
@@ -1345,8 +1470,9 @@
      *      true time (GPS time) = time_ns + (full_bias_ns + bias_ns)
      *
      * This value contains the 'bias uncertainty' in it.
-     * If the data is available 'flags' must contain GPS_CLOCK_HAS_FULL_BIAS.
-
+     * If GPS has computed a position fix this field is mandatory and must be
+     * populated. If the data is available 'flags' must contain
+     * GPS_CLOCK_HAS_FULL_BIAS.
      */
     int64_t full_bias_ns;
 
@@ -1354,7 +1480,9 @@
      * Sub-nanosecond bias.
      * The value contains the 'bias uncertainty' in it.
      *
-     * If the data is available 'flags' must contain GPS_CLOCK_HAS_BIAS.
+     * If the data is available 'flags' must contain GPS_CLOCK_HAS_BIAS. If GPS
+     * has computed a position fix, this field is mandatory and must be
+     * populated.
      */
     double bias_ns;
 
@@ -1362,7 +1490,9 @@
      * 1-Sigma uncertainty associated with the clock's bias in nanoseconds.
      * The uncertainty is represented as an absolute (single sided) value.
      *
-     * If the data is available 'flags' must contain GPS_CLOCK_HAS_BIAS_UNCERTAINTY.
+     * If the data is available 'flags' must contain
+     * GPS_CLOCK_HAS_BIAS_UNCERTAINTY. If GPS has computed a position fix this
+     * field is mandatory and must be populated.
      */
     double bias_uncertainty_ns;
 
@@ -1373,8 +1503,10 @@
      * The value contains the 'drift uncertainty' in it.
      * If the data is available 'flags' must contain GPS_CLOCK_HAS_DRIFT.
      *
-     * If GpsMeasurement's 'flags' field contains GPS_MEASUREMENT_HAS_UNCORRECTED_PSEUDORANGE_RATE,
-     * it is encouraged that this field is also provided.
+     * If GpsMeasurement's 'flags' field contains
+     * GPS_MEASUREMENT_HAS_UNCORRECTED_PSEUDORANGE_RATE, it is encouraged that
+     * this field is also provided. If GPS has computed a position fix this
+     * field is mandatory and must be populated.
      */
     double drift_nsps;
 
@@ -1382,9 +1514,30 @@
      * 1-Sigma uncertainty associated with the clock's drift in nanoseconds (per second).
      * The uncertainty is represented as an absolute (single sided) value.
      *
-     * If the data is available 'flags' must contain GPS_CLOCK_HAS_DRIFT_UNCERTAINTY.
+     * If the data is available 'flags' must contain
+     * GPS_CLOCK_HAS_DRIFT_UNCERTAINTY. If GPS has computed a position fix this
+     * field is mandatory and must be populated.
      */
     double drift_uncertainty_nsps;
+
+    /**
+     * When the GPS_CLOCK_TYPE_LOCAL_HW_TIME is set, this field is mandatory.
+     *
+     * A "discontinuity" is meant to cover the case of a switch from one source
+     * of clock to another.  A single free-running crystal oscillator (XO)
+     * should generally not have any discontinuities, and this can be set to 0.
+     * If, however, the time_ns value (HW clock) is derived from a composite of
+     * sources, that is not as smooth as a typical XO, then this value shall be
+     * set to the time_ns value since which the time_ns has been derived from a
+     * single, high quality clock (XO like, or better, that's typically used
+     * during continuous GPS signal sampling.)
+     *
+     * It is expected, esp. during periods where there are few GNSS signals
+     * available, that the HW clock be discontinuity-free as long as possible,
+     * as this avoids the need to use (waste) a GPS measurement to fully
+     * re-solve for the clock bias and drift.
+     */
+    int64_t time_of_last_hw_clock_discontinuity_ns;
 } GpsClock;
 
 /**
@@ -1399,7 +1552,7 @@
 
     /**
      * Pseudo-random number in the range of [1, 32]
-     * This is a Mandatory value.
+     * This is a mandatory value.
      */
     int8_t prn;
 
@@ -1412,7 +1565,7 @@
      *      measurement time = GpsClock::time_ns + time_offset_ns
      *
      * It provides an individual time-stamp for the measurement, and allows sub-nanosecond accuracy.
-     * This is a Mandatory value.
+     * This is a mandatory value.
      */
     double time_offset_ns;
 
@@ -1420,7 +1573,7 @@
      * Per satellite sync state. It represents the current sync state for the associated satellite.
      * Based on the sync state, the 'received GPS tow' field should be interpreted accordingly.
      *
-     * This is a Mandatory value.
+     * This is a mandatory value.
      */
     GpsMeasurementState state;
 
@@ -1454,7 +1607,7 @@
      * Carrier-to-noise density in dB-Hz, in the range [0, 63].
      * It contains the measured C/N0 value for the signal at the antenna input.
      *
-     * This is a Mandatory value.
+     * This is a mandatory value.
      */
     double c_n0_dbhz;
 
@@ -1463,13 +1616,9 @@
      * The correction of a given Pseudorange Rate value includes corrections for receiver and
      * satellite clock frequency errors.
      *
-     * If GPS_MEASUREMENT_HAS_UNCORRECTED_PSEUDORANGE_RATE is set in 'flags' field, this field must
-     * be populated with the 'uncorrected' reading.
-     * If GPS_MEASUREMENT_HAS_UNCORRECTED_PSEUDORANGE_RATE is not set in 'flags' field, this field
-     * must be populated with the 'corrected' reading. This is the default behavior.
-     *
      * It is encouraged to provide the 'uncorrected' 'pseudorange rate', and provide GpsClock's
-     * 'drift' field as well.
+     * 'drift' field as well. When providing the uncorrected pseudorange rate,
+     * do not apply the corrections described above.
      *
      * The value includes the 'pseudorange rate uncertainty' in it.
      * A positive 'uncorrected' value indicates that the SV is moving away from the receiver.
@@ -1478,15 +1627,22 @@
      * shift' is given by the equation:
      *      pseudorange rate = -k * doppler shift   (where k is a constant)
      *
-     * This is a Mandatory value.
+     * This field should be based on the signal energy doppler measurement. (See
+     * also pseudorate_rate_carrier_mps for a similar field, based on carrier
+     * phase changes.)
+     *
+     * This is a mandatory value. It is mandatory (and expected) that it
+     * contains the 'uncorrected' reading, and
+     * GPS_MEASUREMENT_HAS_UNCORRECTED_PSEUDORANGE_RATE must be set in 'flags'
+     * field.
      */
     double pseudorange_rate_mps;
 
     /**
-     * 1-Sigma uncertainty of the pseudurange rate in m/s.
+     * 1-Sigma uncertainty of the pseudorange_rate_mps.
      * The uncertainty is represented as an absolute (single sided) value.
      *
-     * This is a Mandatory value.
+     * This is a mandatory value.
      */
     double pseudorange_rate_uncertainty_mps;
 
@@ -1494,7 +1650,7 @@
      * Accumulated delta range's state. It indicates whether ADR is reset or there is a cycle slip
      * (indicating loss of lock).
      *
-     * This is a Mandatory value.
+     * This is a mandatory value.
      */
     GpsAccumulatedDeltaRangeState accumulated_delta_range_state;
 
@@ -1651,7 +1807,7 @@
      * Azimuth in degrees, in the range [0, 360).
      * The value contains the 'azimuth uncertainty' in it.
      * If the data is available, 'flags' must contain GPS_MEASUREMENT_HAS_AZIMUTH.
-     *  */
+     */
     double azimuth_deg;
 
     /**
@@ -1667,6 +1823,41 @@
      * If the data is available, 'flags' must contain GPS_MEASUREMENT_HAS_USED_IN_FIX.
      */
     bool used_in_fix;
+
+    /**
+     * Pseudorange rate (based on carrier phase changes) at the timestamp in m/s.
+     *
+     * The correction of a given Pseudorange Rate value includes corrections for
+     * receiver and satellite clock frequency errors.
+     *
+     * It is mandatory to provide the 'uncorrected' 'pseudorange rate' in this
+     * field. (Do not apply the corrections described above.)
+     *
+     * The value includes the 'pseudorange rate (carrier) uncertainty' in it. A
+     * positive 'uncorrected' value indicates that the SV is moving away from
+     * the receiver.
+     *
+     * The sign of the 'uncorrected' 'pseudorange rate' and its relation to the
+     * sign of 'doppler shift' is given by the equation:
+     *
+     *      pseudorange rate = -k * doppler shift   (where k is a constant)
+     *
+     * This field must be based on changes in the carrier phase measurement.
+     * (See pseudorange_rate_mps for a similar field, based on signal energy
+     * doppler.)
+     *
+     * It is mandatory that this value be provided, when signals are
+     * sufficiently strong, e.g. signals from a GPS simulator at >= 30 dB-Hz.
+     */
+    double pseudorange_rate_carrier_mps;
+    /**
+     * 1-Sigma uncertainty of the pseudorange_rate_carrier_mps.
+     * The uncertainty is represented as an absolute (single sided) value.
+     *
+     * This is a mandatory value when pseudorange_rate_carrier_mps is provided.
+     */
+    double pseudorange_rate_carrier_uncertainty_mps;
+
 } GpsMeasurement;
 
 /** Represents a reading of GPS measurements. */
@@ -1740,13 +1931,13 @@
 
     /**
      * Pseudo-random number in the range of [1, 32]
-     * This is a Mandatory value.
+     * This is a mandatory value.
      */
     int8_t prn;
 
     /**
      * The type of message contained in the structure.
-     * This is a Mandatory value.
+     * This is a mandatory value.
      */
     GpsNavigationMessageType type;
 
@@ -1778,7 +1969,7 @@
      * If this value is different from zero, 'data' must point to an array of the same size.
      * e.g. for L1 C/A the size of the sub-frame will be 40 bytes (10 words, 30 bits/word).
      *
-     * This is a Mandatory value.
+     * This is a mandatory value.
      */
     size_t data_length;
 
diff --git a/include/hardware/gps_internal.h b/include/hardware/gps_internal.h
new file mode 100644
index 0000000..cd83636
--- /dev/null
+++ b/include/hardware/gps_internal.h
@@ -0,0 +1,167 @@
+/*
+ * 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.
+ */
+
+#ifndef ANDROID_INCLUDE_HARDWARE_GPS_INTERNAL_H
+#define ANDROID_INCLUDE_HARDWARE_GPS_INTERNAL_H
+
+#include "hardware/gps.h"
+
+/****************************************************************************
+ * This file contains legacy structs that are deprecated/retired from gps.h *
+ ****************************************************************************/
+
+__BEGIN_DECLS
+
+/**
+ * Legacy struct to represent SV status.
+ * See GpsSvStatus_v2 for more information.
+ */
+typedef struct {
+    /** set to sizeof(GpsSvStatus_v1) */
+    size_t          size;
+    int         num_svs;
+    GpsSvInfo   sv_list[GPS_MAX_SVS];
+    uint32_t    ephemeris_mask;
+    uint32_t    almanac_mask;
+    uint32_t    used_in_fix_mask;
+} GpsSvStatus_v1;
+
+#pragma pack(push,4)
+// We need to keep the alignment of this data structure to 4-bytes, to ensure that in 64-bit
+// environments the size of this legacy definition does not collide with _v2. Implementations should
+// be using _v2 and _v3, so it's OK to pay the 'unaligned' penalty in 64-bit if an old
+// implementation is still in use.
+
+/**
+ * Legacy struct to represent the status of AGPS.
+ */
+typedef struct {
+    /** set to sizeof(AGpsStatus_v1) */
+    size_t          size;
+    AGpsType        type;
+    AGpsStatusValue status;
+} AGpsStatus_v1;
+
+#pragma pack(pop)
+
+/**
+ * Legacy struct to represent the status of AGPS augmented with a IPv4 address
+ * field.
+ */
+typedef struct {
+    /** set to sizeof(AGpsStatus_v2) */
+    size_t          size;
+    AGpsType        type;
+    AGpsStatusValue status;
+
+    /*-------------------- New fields in _v2 --------------------*/
+
+    uint32_t        ipaddr;
+} AGpsStatus_v2;
+
+/**
+ * Legacy extended interface for AGPS support.
+ * See AGpsInterface_v2 for more information.
+ */
+typedef struct {
+    /** set to sizeof(AGpsInterface_v1) */
+    size_t          size;
+    void  (*init)( AGpsCallbacks* callbacks );
+    int  (*data_conn_open)( const char* apn );
+    int  (*data_conn_closed)();
+    int  (*data_conn_failed)();
+    int  (*set_server)( AGpsType type, const char* hostname, int port );
+} AGpsInterface_v1;
+
+/**
+ * Legacy struct to represent an estimate of the GPS clock time.
+ * See GpsClock_v2 for more details.
+ */
+typedef struct {
+    /** set to sizeof(GpsClock_v1) */
+    size_t size;
+    GpsClockFlags flags;
+    int16_t leap_second;
+    GpsClockType type;
+    int64_t time_ns;
+    double time_uncertainty_ns;
+    int64_t full_bias_ns;
+    double bias_ns;
+    double bias_uncertainty_ns;
+    double drift_nsps;
+    double drift_uncertainty_nsps;
+} GpsClock_v1;
+
+/**
+ * Legacy struct to represent a GPS Measurement, it contains raw and computed
+ * information.
+ * See GpsMeasurement_v2 for more details.
+ */
+typedef struct {
+    /** set to sizeof(GpsMeasurement_v1) */
+    size_t size;
+    GpsMeasurementFlags flags;
+    int8_t prn;
+    double time_offset_ns;
+    GpsMeasurementState state;
+    int64_t received_gps_tow_ns;
+    int64_t received_gps_tow_uncertainty_ns;
+    double c_n0_dbhz;
+    double pseudorange_rate_mps;
+    double pseudorange_rate_uncertainty_mps;
+    GpsAccumulatedDeltaRangeState accumulated_delta_range_state;
+    double accumulated_delta_range_m;
+    double accumulated_delta_range_uncertainty_m;
+    double pseudorange_m;
+    double pseudorange_uncertainty_m;
+    double code_phase_chips;
+    double code_phase_uncertainty_chips;
+    float carrier_frequency_hz;
+    int64_t carrier_cycles;
+    double carrier_phase;
+    double carrier_phase_uncertainty;
+    GpsLossOfLock loss_of_lock;
+    int32_t bit_number;
+    int16_t time_from_last_bit_ms;
+    double doppler_shift_hz;
+    double doppler_shift_uncertainty_hz;
+    GpsMultipathIndicator multipath_indicator;
+    double snr_db;
+    double elevation_deg;
+    double elevation_uncertainty_deg;
+    double azimuth_deg;
+    double azimuth_uncertainty_deg;
+    bool used_in_fix;
+} GpsMeasurement_v1;
+
+/** Represents a reading of GPS measurements. */
+typedef struct {
+    /** set to sizeof(GpsData_v1) */
+    size_t size;
+
+    /** Number of measurements. */
+    size_t measurement_count;
+
+    /** The array of measurements. */
+    GpsMeasurement_v1 measurements[GPS_MAX_MEASUREMENT];
+
+    /** The GPS clock time reading. */
+    GpsClock_v1 clock;
+} GpsData_v1;
+
+__END_DECLS
+
+#endif /* ANDROID_INCLUDE_HARDWARE_GPS_INTERNAL_H */
diff --git a/include/hardware/nvram.h b/include/hardware/nvram.h
new file mode 100644
index 0000000..535a95b
--- /dev/null
+++ b/include/hardware/nvram.h
@@ -0,0 +1,348 @@
+/*
+ * Copyright (C) 2015 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_NVRAM_H
+#define ANDROID_HARDWARE_NVRAM_H
+
+#include <stdint.h>
+#include <sys/cdefs.h>
+
+#include <hardware/hardware.h>
+
+__BEGIN_DECLS
+
+/* The id of this module. */
+#define NVRAM_HARDWARE_MODULE_ID "nvram"
+#define NVRAM_HARDWARE_DEVICE_ID "nvram-dev"
+
+/* The version of this module. */
+#define NVRAM_MODULE_API_VERSION_0_1 HARDWARE_MODULE_API_VERSION(0, 1)
+#define NVRAM_DEVICE_API_VERSION_0_1 HARDWARE_DEVICE_API_VERSION(0, 1)
+
+/* Values returned by nvram_device methods. */
+typedef uint32_t nvram_result_t;
+
+const nvram_result_t NV_RESULT_SUCCESS = 0;
+const nvram_result_t NV_RESULT_INTERNAL_ERROR = 1;
+const nvram_result_t NV_RESULT_ACCESS_DENIED = 2;
+const nvram_result_t NV_RESULT_INVALID_PARAMETER = 3;
+const nvram_result_t NV_RESULT_SPACE_DOES_NOT_EXIST = 4;
+const nvram_result_t NV_RESULT_SPACE_ALREADY_EXISTS = 5;
+const nvram_result_t NV_RESULT_OPERATION_DISABLED = 6;
+
+/* Values describing available access controls. */
+typedef uint32_t nvram_control_t;
+
+const nvram_control_t NV_CONTROL_PERSISTENT_WRITE_LOCK = 1;
+const nvram_control_t NV_CONTROL_BOOT_WRITE_LOCK = 2;
+const nvram_control_t NV_CONTROL_BOOT_READ_LOCK = 3;
+const nvram_control_t NV_CONTROL_WRITE_AUTHORIZATION = 4;
+const nvram_control_t NV_CONTROL_READ_AUTHORIZATION = 5;
+const nvram_control_t NV_CONTROL_WRITE_EXTEND = 6;
+
+const uint32_t NV_UNLIMITED_SPACES = 0xFFFFFFFF;
+
+struct nvram_module {
+    /**
+     * Common methods of the nvram_module. This *must* be the first member of
+     * nvram_module as users of this structure will cast a hw_module_t to
+     * nvram_module pointer in contexts where it's known the hw_module_t
+     * references a nvram_module.
+     */
+    hw_module_t common;
+
+    /* There are no module methods other than the common ones. */
+};
+
+struct nvram_device {
+    /**
+     * Common methods of the nvram_device.  This *must* be the first member of
+     * nvram_device as users of this structure will cast a hw_device_t to
+     * nvram_device pointer in contexts where it's known the hw_device_t
+     * references a nvram_device.
+     */
+    struct hw_device_t common;
+
+    /**
+     * Outputs the total number of bytes available in NVRAM. This will
+     * always be at least 2048. If an implementation does not know the
+     * total size it may provide an estimate or 2048.
+     *
+     *   device - The nvram_device instance.
+     *   total_size - Receives the output. Cannot be NULL.
+     */
+    nvram_result_t (*get_total_size_in_bytes)(const struct nvram_device* device,
+                                              uint64_t* total_size);
+
+    /**
+     * Outputs the unallocated number of bytes available in NVRAM. If an
+     * implementation does not know the available size it may provide an
+     * estimate or the total size.
+     *
+     *   device - The nvram_device instance.
+     *   available_size - Receives the output. Cannot be NULL.
+     */
+    nvram_result_t (*get_available_size_in_bytes)(
+        const struct nvram_device* device, uint64_t* available_size);
+
+    /**
+     * Outputs the maximum total number of spaces that may be allocated.
+     * This will always be at least 8. Outputs NV_UNLIMITED_SPACES if any
+     * number of spaces are supported (limited only to available NVRAM
+     * bytes).
+     *
+     *   device - The nvram_device instance.
+     *   num_spaces - Receives the output. Cannot be NULL.
+     */
+    nvram_result_t (*get_max_spaces)(const struct nvram_device* device,
+                                     uint32_t* num_spaces);
+
+    /**
+     * Outputs a list of created space indices. If |max_list_size| is
+     * 0, only |list_size| is populated.
+     *
+     *   device - The nvram_device instance.
+     *   max_list_size - The number of items in the |space_index_list|
+     *                   array.
+     *   space_index_list - Receives the list of created spaces up to the
+     *                      given |max_list_size|. May be NULL if
+     *                      |max_list_size| is 0.
+     *   list_size - Receives the number of items populated in
+     *               |space_index_list|, or the number of items available
+     *               if |space_index_list| is NULL.
+     */
+    nvram_result_t (*get_space_list)(const struct nvram_device* device,
+                                     uint32_t max_list_size,
+                                     uint32_t* space_index_list,
+                                     uint32_t* list_size);
+
+    /**
+     * Outputs the size, in bytes, of a given space.
+     *
+     *   device - The nvram_device instance.
+     *   index - The space index.
+     *   size - Receives the output. Cannot be NULL.
+     */
+    nvram_result_t (*get_space_size)(const struct nvram_device* device,
+                                     uint32_t index, uint64_t* size);
+
+    /**
+     * Outputs the list of controls associated with a given space.
+     *
+     *   device - The nvram_device instance.
+     *   index - The space index.
+     *   max_list_size - The number of items in the |control_list| array.
+     *   control_list - Receives the list of controls up to the given
+     *                  |max_list_size|. May be NULL if |max_list_size|
+     *                  is 0.
+     *   list_size - Receives the number of items populated in
+     *               |control_list|, or the number of items available if
+     *               |control_list| is NULL.
+     */
+    nvram_result_t (*get_space_controls)(const struct nvram_device* device,
+                                         uint32_t index, uint32_t max_list_size,
+                                         nvram_control_t* control_list,
+                                         uint32_t* list_size);
+
+    /**
+     * Outputs whether locks are enabled for the given space. When a lock
+     * is enabled, the operation is disabled and any attempt to perform that
+     * operation will result in NV_RESULT_OPERATION_DISABLED.
+     *
+     *   device - The nvram_device instance.
+     *   index - The space index.
+     *   write_lock_enabled - Will be set to non-zero iff write
+     *                        operations are currently disabled.
+     *   read_lock_enabled - Will be set to non-zero iff read operations
+     *                       are currently disabled.
+     */
+    nvram_result_t (*is_space_locked)(const struct nvram_device* device,
+                                      uint32_t index, int* write_lock_enabled,
+                                      int* read_lock_enabled);
+
+    /**
+     * Creates a new space with the given index, size, controls, and
+     * authorization value.
+     *
+     *   device - The nvram_device instance.
+     *   index - An index for the new space. The index can be any 32-bit
+     *           value but must not already be assigned to an existing
+     *           space.
+     *   size_in_bytes - The number of bytes to allocate for the space.
+     *   control_list - An array of controls to enforce for the space.
+     *   list_size - The number of items in |control_list|.
+     *   authorization_value - If |control_list| contains
+     *                         NV_CONTROL_READ_AUTHORIZATION and / or
+     *                         NV_CONTROL_WRITE_AUTHORIZATION, then this
+     *                         parameter provides the authorization value
+     *                         for these policies (if both controls are
+     *                         set then this value applies to both).
+     *                         Otherwise, this value is ignored and may
+     *                         be NULL.
+     *   authorization_value_size - The number of bytes in
+     *                              |authorization_value|.
+     */
+    nvram_result_t (*create_space)(const struct nvram_device* device,
+                                   uint32_t index, uint64_t size_in_bytes,
+                                   nvram_control_t* control_list,
+                                   uint32_t list_size,
+                                   uint8_t* authorization_value,
+                                   uint32_t authorization_value_size);
+
+    /**
+     * Deletes a space.
+     *
+     *   device - The nvram_device instance.
+     *   index - The space index.
+     *   authorization_value - If the space has the
+     *                         NV_CONTROL_WRITE_AUTHORIZATION policy,
+     *                         then this parameter provides the
+     *                         authorization value. Otherwise, this value
+     *                         is ignored and may be NULL.
+     *   authorization_value_size - The number of bytes in
+     *                              |authorization_value|.
+     */
+    nvram_result_t (*delete_space)(const struct nvram_device* device,
+                                   uint32_t index, uint8_t* authorization_value,
+                                   uint32_t authorization_value_size);
+
+    /**
+     * Disables any further creation of spaces until the next full device
+     * reset (as in factory reset, not reboot). Subsequent calls to
+     * NV_CreateSpace should return NV_RESULT_OPERATION_DISABLED.
+     *
+     *   device - The nvram_device instance.
+     */
+    nvram_result_t (*disable_create)(const struct nvram_device* device);
+
+    /**
+     * Writes the contents of a space. If the space is configured with
+     * NV_CONTROL_WRITE_EXTEND then the input data is used to extend the
+     * current data.
+     *
+     *   device - The nvram_device instance.
+     *   index - The space index.
+     *   buffer - The data to write.
+     *   buffer_size - The number of bytes in |buffer|. If this is less
+     *                 than the size of the space, the remaining bytes
+     *                 will be set to 0x00. If this is more than the size
+     *                 of the space, returns NV_RESULT_INVALID_PARAMETER.
+     *   authorization_value - If the space has the
+     *                         NV_CONTROL_WRITE_AUTHORIZATION policy,
+     *                         then this parameter provides the
+     *                         authorization value. Otherwise, this value
+     *                         is ignored and may be NULL.
+     *   authorization_value_size - The number of bytes in
+     *                              |authorization_value|.
+     */
+    nvram_result_t (*write_space)(const struct nvram_device* device,
+                                  uint32_t index, const uint8_t* buffer,
+                                  uint64_t buffer_size,
+                                  uint8_t* authorization_value,
+                                  uint32_t authorization_value_size);
+
+    /**
+     * Reads the contents of a space. If the space has never been
+     * written, all bytes read will be 0x00.
+     *
+     *   device - The nvram_device instance.
+     *   index - The space index.
+     *   num_bytes_to_read - The number of bytes to read; |buffer| must
+     *                       be large enough to hold this many bytes. If
+     *                       this is more than the size of the space, the
+     *                       entire space is read. If this is less than
+     *                       the size of the space, the first bytes in
+     *                       the space are read.
+     *   authorization_value - If the space has the
+     *                         NV_CONTROL_READ_AUTHORIZATION policy, then
+     *                         this parameter provides the authorization
+     *                         value. Otherwise, this value is ignored
+     *                         and may be NULL.
+     *   authorization_value_size - The number of bytes in
+     *                              |authorization_value|.
+     *   buffer - Receives the data read from the space. Must be at least
+     *            |num_bytes_to_read| bytes in size.
+     *   bytes_read - The number of bytes read. If NV_RESULT_SUCCESS is
+     *                returned this will be set to the smaller of
+     *                |num_bytes_to_read| or the size of the space.
+     */
+    nvram_result_t (*read_space)(const struct nvram_device* device,
+                                 uint32_t index, uint64_t num_bytes_to_read,
+                                 uint8_t* authorization_value,
+                                 uint32_t authorization_value_size,
+                                 uint8_t* buffer, uint64_t* bytes_read);
+
+    /**
+     * Enables a write lock for the given space according to its policy.
+     * If the space does not have NV_CONTROL_PERSISTENT_WRITE_LOCK or
+     * NV_CONTROL_BOOT_WRITE_LOCK set then this function has no effect
+     * and may return an error.
+     *
+     *   device - The nvram_device instance.
+     *   index - The space index.
+     *   authorization_value - If the space has the
+     *                         NV_CONTROL_WRITE_AUTHORIZATION policy,
+     *                         then this parameter provides the
+     *                         authorization value. Otherwise, this value
+     *                         is ignored and may be NULL.
+     *   authorization_value_size - The number of bytes in
+     *                              |authorization_value|.
+     */
+    nvram_result_t (*enable_write_lock)(const struct nvram_device* device,
+                                        uint32_t index,
+                                        uint8_t* authorization_value,
+                                        uint32_t authorization_value_size);
+
+    /**
+     * Enables a read lock for the given space according to its policy.
+     * If the space does not have NV_CONTROL_BOOT_READ_LOCK set then this
+     * function has no effect and may return an error.
+     *
+     *   device - The nvram_device instance.
+     *   index - The space index.
+     *   authorization_value - If the space has the
+     *                         NV_CONTROL_READ_AUTHORIZATION policy, then
+     *                         this parameter provides the authorization
+     *                         value. (Note that there is no requirement
+     *                         for write access in order to lock for
+     *                         reading. A read lock is always volatile.)
+     *                         Otherwise, this value is ignored and may
+     *                         be NULL.
+     *   authorization_value_size - The number of bytes in
+     *                              |authorization_value|.
+     */
+    nvram_result_t (*enable_read_lock)(const struct nvram_device* device,
+                                       uint32_t index,
+                                       uint8_t* authorization_value,
+                                       uint32_t authorization_value_size);
+};
+
+typedef struct nvram_device nvram_device_t;
+
+/* Convenience API for opening and closing nvram devices. */
+static inline int nvram_open(const struct hw_module_t* module,
+                             nvram_device_t** device) {
+    return module->methods->open(module, NVRAM_HARDWARE_DEVICE_ID,
+                                 (struct hw_device_t**)device);
+}
+
+static inline int nvram_close(nvram_device_t* device) {
+    return device->common.close(&device->common);
+}
+
+__END_DECLS
+
+#endif  // ANDROID_HARDWARE_NVRAM_H
diff --git a/include/hardware/power.h b/include/hardware/power.h
index 10612f3..29ef4dc 100644
--- a/include/hardware/power.h
+++ b/include/hardware/power.h
@@ -28,6 +28,7 @@
 #define POWER_MODULE_API_VERSION_0_1  HARDWARE_MODULE_API_VERSION(0, 1)
 #define POWER_MODULE_API_VERSION_0_2  HARDWARE_MODULE_API_VERSION(0, 2)
 #define POWER_MODULE_API_VERSION_0_3  HARDWARE_MODULE_API_VERSION(0, 3)
+#define POWER_MODULE_API_VERSION_0_4  HARDWARE_MODULE_API_VERSION(0, 4)
 
 /**
  * The id of this module
@@ -46,7 +47,8 @@
      */
     POWER_HINT_VIDEO_ENCODE = 0x00000003,
     POWER_HINT_VIDEO_DECODE = 0x00000004,
-    POWER_HINT_LOW_POWER = 0x00000005
+    POWER_HINT_LOW_POWER = 0x00000005,
+    POWER_HINT_SUSTAINED_PERFORMANCE = 0x00000006
 } power_hint_t;
 
 typedef enum {
@@ -126,6 +128,14 @@
      *     parameter is non-zero when low power mode is activated, and zero
      *     when deactivated.
      *
+     * POWER_HINT_SUSTAINED_PERFORMANCE
+     *
+     *     Sustained Performance mode is actived or deactivated. Sustained
+     *     performance mode is intended to provide a consistent level of
+     *     performance for a prolonged amount of time. The data parameter is
+     *     non-zero when sustained performance mode is activated, and zero
+     *     when deactivated.
+     *
      * A particular platform may choose to ignore any hint.
      *
      * availability: version 0.2
diff --git a/include/hardware/sensors.h b/include/hardware/sensors.h
index b6f4a04..a2d9b2e 100644
--- a/include/hardware/sensors.h
+++ b/include/hardware/sensors.h
@@ -706,11 +706,133 @@
  *           . Camera
  *           . Depth Camera
  *
- * Implement only the wake-up version of this sensor.
  */
 #define SENSOR_TYPE_POSE_6DOF                         (28)
 #define SENSOR_STRING_TYPE_POSE_6DOF                  "android.sensor.pose_6dof"
 
+/*
+ * SENSOR_TYPE_STATIONARY_DETECT
+ * trigger mode: one shot
+ *
+ * A sensor of this type returns an event if the device is still/stationary for
+ * a while. The period of time to monitor for statinarity should be greater than
+ * 5 seconds, and less than 10 seconds.
+ *
+ * Stationarity here refers to absolute stationarity. eg: device on desk.
+ *
+ * The only allowed value to return is 1.0.
+ */
+#define SENSOR_TYPE_STATIONARY_DETECT                   (29)
+#define SENSOR_STRING_TYPE_STATIONARY_DETECT            "android.sensor.stationary_detect"
+
+/*
+ * SENSOR_TYPE_MOTION_DETECT
+ * trigger mode: one shot
+ *
+ * A sensor of this type returns an event if the device is not still for
+ * a while. The period of time to monitor for statinarity should be greater than
+ * 5 seconds, and less than 10 seconds.
+ *
+ * Motion here refers to any mechanism in which the device is causes to be
+ * moved in its inertial frame. eg: Pickin up the device and walking with it
+ * to a nearby room may trigger motion wherewas keeping the device on a table
+ * on a smooth train moving at constant velocity may not trigger motion.
+ *
+ * The only allowed value to return is 1.0.
+ */
+#define SENSOR_TYPE_MOTION_DETECT                       (30)
+#define SENSOR_STRING_TYPE_MOTION_DETECT                "android.sensor.motion_detect"
+
+/*
+ * SENSOR_TYPE_HEART_BEAT
+ * trigger mode: continuous
+ *
+ * A sensor of this type returns an event everytime a hear beat peak is
+ * detected.
+ *
+ * Peak here ideally corresponds to the positive peak in the QRS complex of
+ * and ECG signal.
+ *
+ * The sensor is not expected to be optimized for latency. As a guide, a
+ * latency of up to 10 seconds is acceptable. However the timestamp attached
+ * to the event should be accurate and should correspond to the time the peak
+ * occured.
+ *
+ * The sensor event contains a parameter for the confidence in the detection
+ * of the peak where 0.0 represent no information at all, and 1.0 represents
+ * certainty.
+ */
+#define SENSOR_TYPE_HEART_BEAT                          (31)
+#define SENSOR_STRING_TYPE_HEART_BEAT                   "android.sensor.heart_beat"
+
+/**
+ * SENSOR_TYPE_DYNAMIC_SENSOR_META
+ * trigger-mode: special
+ *
+ * A sensor event of this type is received when a dynamic sensor is added to or removed from the
+ * system. At most one sensor of this type can be present in one sensor HAL implementation and
+ * presence of a sensor of this type in sensor HAL implementation indicates that this sensor HAL
+ * supports dynamic sensor feature. Operations, such as batch, activate and setDelay, to this
+ * special purpose sensor should be treated as no-op and return successful.
+ *
+ * A dynamic sensor connection indicates connection of a physical device or instantiation of a
+ * virtual sensor backed by algorithm; and a dynamic sensor disconnection indicates the the
+ * opposite. A sensor event of SENSOR_TYPE_DYNAMIC_SENSOR_META type should be delivered regardless
+ * of the activation status of the sensor in the event of dynamic sensor connection and
+ * disconnection. In the sensor event, besides the common data entries, "dynamic_sensor_meta", which
+ * includes fields for connection status, handle of the sensor involved, pointer to sensor_t
+ * structure and a uuid field, should be populated.
+ *
+ * At a dynamic sensor connection event, fields of sensor_t structure referenced by a pointer in
+ * dynamic_sensor_meta should be filled as if it was regular sensors. Sensor HAL is responsible for
+ * recovery of memory if the corresponding data is dynamicially allocated. However, the the pointer
+ * must be valid until the first activate call to the sensor reported in this connection event. At a
+ * dynamic sensor disconnection, the sensor_t pointer should be NULL.
+ *
+ * The sensor handle assigned to dynamic sensors should never be the same as that of any regular
+ * static sensors, and should be unique until next boot. In another word, if a handle h is used for
+ * a dynamic sensor A, that same number cannot be used for the same dynamic sensor A or another
+ * dynamic sensor B even after disconnection of A until reboot.
+ *
+ * The UUID field will be used for identifying the sensor in addition to name, vendor and version
+ * and type. For physical sensors of the same model, all sensors will have the same values in
+ * sensor_t, but the UUID should be unique and persistent for each individual unit. An all zero UUID
+ * indicates it is not possible to differentiate individual sensor unit.
+ *
+ */
+#define SENSOR_TYPE_DYNAMIC_SENSOR_META                         (32)
+#define SENSOR_STRING_TYPE_DYNAMIC_SENSOR_META                  "android.sensor.dynamic_sensor_meta"
+
+/**
+ * SENSOR_TYPE_ADDITIONAL_INFO
+ * reporting-mode: N/A
+ *
+ * This sensor type is for delivering additional sensor information aside from sensor event data.
+ * Additional information may include sensor front-end group delay, internal calibration parameters,
+ * noise level metrics, device internal temperature, etc.
+ *
+ * This type will never bind to a sensor. In other words, no sensor in the sensor list should be of
+ * the type SENSOR_TYPE_ADDITIONAL_INFO. If a sensor HAL supports sensor additional information
+ * feature, it reports sensor_event_t with "sensor" field set to handle of the reporting sensor and
+ * "type" field set to SENSOR_TYPE_ADDITIONAL_INFO. Delivery of additional information events is
+ * triggered under two conditions: an enable activate() call or a flush() call to the corresponding
+ * sensor.
+ *
+ * A single additional information report consists of multiple frames. Sequences of these frames are
+ * ordered using timestamps, which means the timestamps of sequential frames have to be at least 1
+ * nanosecond apart from each other. Each frame is a sensor_event_t delivered through the HAL
+ * interface, with related data stored in the "additional_info" field, which is of type
+ * additional_info_event_t.  The "type" field of additional_info_event_t denotes the nature of the
+ * payload data (see additional_info_type_t).  The "serial" field is used to keep the sequence of
+ * payload data that spans multiple frames. The first frame of the entire report is always of type
+ * AINFO_BEGIN, and the last frame is always AINFO_END.
+ *
+ * All additional information frames have to be delivered after flush complete event if flush() was
+ * triggering the report.
+ */
+#define SENSOR_TYPE_ADDITIONAL_INFO                       (33)
+#define SENSOR_STRING_TYPE_ADDITIONAL_INFO                "android.sensor.additional_info"
+
 /**
  * Values returned by the accelerometer in various locations in the universe.
  * all values are in SI units (m/s^2)
@@ -733,6 +855,9 @@
 #define SENSOR_STATUS_ACCURACY_MEDIUM   2
 #define SENSOR_STATUS_ACCURACY_HIGH     3
 
+
+struct sensor_t;
+
 /**
  * sensor event data
  */
@@ -785,6 +910,17 @@
 } meta_data_event_t;
 
 /**
+ * Dynamic sensor meta event. See the description of SENSOR_TYPE_DYNAMIC_SENSOR_META type for
+ * details.
+ */
+typedef struct dynamic_sensor_meta_event {
+    int32_t  connected;
+    int32_t  handle;
+    const struct sensor_t * sensor; // should be NULL if connected == false
+    uint8_t uuid[16];               // UUID of a dynamic sensor (use platform endianess).
+} dynamic_sensor_meta_event_t;
+
+/**
  * Heart rate event data
  */
 typedef struct {
@@ -798,6 +934,85 @@
   int8_t status;
 } heart_rate_event_t;
 
+typedef struct {
+    int32_t type;                           // type of payload data, see additional_info_type_t
+    int32_t serial;                         // sequence number of this frame for this type
+    union {
+        // for each frame, a single data type, either int32_t or float, should be used.
+        int32_t data_int32[14];
+        float   data_float[14];
+    };
+} additional_info_event_t;
+
+typedef enum additional_info_type {
+    //
+    AINFO_BEGIN = 0x0,                      // Marks the beginning of additional information frames
+    AINFO_END   = 0x1,                      // Marks the end of additional information frames
+    // Basic information
+    AINFO_UNTRACKED_DELAY =  0x10000,       // Estimation of the delay that is not tracked by sensor
+                                            // timestamps. This includes delay introduced by
+                                            // sensor front-end filtering, data transport, etc.
+                                            // float[2]: delay in seconds
+                                            //           standard deviation of estimated value
+                                            //
+    AINFO_INTERNAL_TEMPERATURE,             // float: Celsius temperature.
+                                            //
+    AINFO_VEC3_CALIBRATION,                 // First three rows of a homogeneous matrix, which
+                                            // represents calibration to a three-element vector
+                                            // raw sensor reading.
+                                            // float[12]: 3x4 matrix in row major order
+                                            //
+    AINFO_SENSOR_PLACEMENT,                 // Location and orientation of sensor element in the
+                                            // device frame: origin is the geometric center of the
+                                            // mobile device screen surface; the axis definition
+                                            // corresponds to Android sensor definitions.
+                                            // float[12]: 3x4 matrix in row major order
+                                            //
+    AINFO_SAMPLING,                         // float[2]: raw sample period in seconds,
+                                            //           standard deviation of sampling period
+
+    // Sampling channel modeling information
+    AINFO_CHANNEL_NOISE = 0x20000,          // int32_t: noise type
+                                            // float[n]: parameters
+                                            //
+    AINFO_CHANNEL_SAMPLER,                  // float[3]: sample period
+                                            //           standard deviation of sample period,
+                                            //           quantization unit
+                                            //
+    AINFO_CHANNEL_FILTER,                   // Represents a filter:
+                                            //      \sum_j a_j y[n-j] == \sum_i b_i x[n-i]
+                                            //
+                                            // int32_t[3]: number of feedforward coefficients, M,
+                                            //             number of feedback coefficients, N, for
+                                            //               FIR filter, N=1.
+                                            //             bit mask that represents which element to
+                                            //               which the filter is applied, bit 0 == 1
+                                            //               means this filter applies to vector
+                                            //               element 0.
+                                            // float[M+N]: filter coefficients (b0, b1, ..., BM-1),
+                                            //             then (a0, a1, ..., aN-1), a0 is always 1.
+                                            //             Multiple frames may be needed for higher
+                                            //             number of taps.
+                                            //
+    AINFO_CHANNEL_LINEAR_TRANSFORM,         // int32_t[2]: size in (row, column) ... 1st frame
+                                            // float[n]: matrix element values in row major order.
+                                            //
+    AINFO_CHANNEL_NONLINEAR_MAP,            // int32_t[2]: extrapolate method
+                                            //             interpolate method
+                                            // float[n]: mapping key points in pairs, (in, out)...
+                                            //           (may be used to model saturation)
+                                            //
+    AINFO_CHANNEL_RESAMPLER,                // int32_t:  resample method (0-th order, 1st order...)
+                                            // float[1]: resample ratio (upsampling if < 1.0;
+                                            //           downsampling if > 1.0).
+                                            //
+
+    // Custom information
+    AINFO_CUSTOM_START =    0x10000000,     //
+    // Debugging
+    AINFO_DEBUGGING_START = 0x40000000,     //
+} additional_info_type_t;
+
 /**
  * Union of the various types of sensor data
  * that can be returned.
@@ -863,6 +1078,15 @@
              * SENSOR_TYPE_META_DATA. The handle is ignored and must be zero.
              */
             meta_data_event_t meta_data;
+
+            /* dynamic sensor meta event. See SENSOR_TYPE_DYNAMIC_SENSOR_META type for details */
+            dynamic_sensor_meta_event_t dynamic_sensor_meta;
+
+            /*
+             * special additional sensor information frame, see
+             * SENSOR_TYPE_ADDITIONAL_INFO for details.
+             */
+            additional_info_event_t additional_info;
         };
 
         union {
@@ -884,8 +1108,6 @@
 typedef sensors_event_t sensors_meta_data_event_t;
 
 
-struct sensor_t;
-
 /**
  * Every hardware module must have a data structure named HAL_MODULE_INFO_SYM
  * and the fields of this data structure must begin with hw_module_t
@@ -905,7 +1127,7 @@
      *  Place the module in a specific mode. The following modes are defined
      *
      *  0 - Normal operation. Default state of the module.
-     *  1 - Loopback mode. Data is injected for the the supported
+     *  1 - Loopback mode. Data is injected for the supported
      *      sensors by the sensor service in this mode.
      * @return 0 on success
      *         -EINVAL if requested mode is not supported
diff --git a/modules/soundtrigger/sound_trigger_hw.c b/modules/soundtrigger/sound_trigger_hw.c
index e7f9baf..8dba27a 100644
--- a/modules/soundtrigger/sound_trigger_hw.c
+++ b/modules/soundtrigger/sound_trigger_hw.c
@@ -14,10 +14,37 @@
  * limitations under the License.
  */
 
+
+/* This HAL simulates triggers from the DSP.
+ * To send a trigger from the command line you can type:
+ *
+ * adb forward tcp:14035 tcp:14035
+ * echo $'\001' | nc -q -1 localhost 14035
+ *
+ * $'\001' corresponds to the index_position of loaded sound
+ * model, you can also send $'\002' etc. $'\000' is the kill
+ * signal for the trigger listening thread.
+ *
+ * To enable this file, you must change the src file in this
+ * directory's Android.mk file, then change the sound_trigger
+ * product package in the device-specific device.mk file,
+ * for example, in device/htc/flounder
+ */
+
 #define LOG_TAG "sound_trigger_hw_default"
 /*#define LOG_NDEBUG 0*/
 
 #include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <arpa/inet.h>
+#include <sys/types.h>
+#include <netinet/in.h>
+#include <sys/socket.h>
+
+#include <errno.h>
 #include <pthread.h>
 #include <sys/prctl.h>
 #include <cutils/log.h>
@@ -26,12 +53,16 @@
 #include <system/sound_trigger.h>
 #include <hardware/sound_trigger.h>
 
+/* Although max_sound_models is specified in sound_trigger_properties, having a maximum maximum
+allows a dramatic simplification of data structures in this file */
+#define MAX_MAX_SOUND_MODELS 5
+
 static const struct sound_trigger_properties hw_properties = {
         "The Android Open Source Project", // implementor
         "Sound Trigger stub HAL", // description
         1, // version
         { 0xed7a7d60, 0xc65e, 0x11e3, 0x9be4, { 0x00, 0x02, 0xa5, 0xd5, 0xc5, 0x1b } }, // uuid
-        1, // max_sound_models
+        2, // max_sound_models
         1, // max_key_phrases
         1, // max_users
         RECOGNITION_MODE_VOICE_TRIGGER, // recognition_modes
@@ -42,68 +73,207 @@
         0 // power_consumption_mw
 };
 
-struct stub_sound_trigger_device {
-    struct sound_trigger_hw_device device;
-    sound_model_handle_t model_handle;
-    recognition_callback_t recognition_callback;
-    void *recognition_cookie;
+struct recognition_context {
+      /* Sound Model Information Modified On Load */
+    sound_model_handle_t loaded_sound_model;
     sound_model_callback_t sound_model_callback;
     void *sound_model_cookie;
-    pthread_t callback_thread;
+
+    /* Sound Model Information Modified On Recognition Start */
+    struct sound_trigger_recognition_config *config;
+    recognition_callback_t recognition_callback;
+    void *recognition_cookie;
+}
+
+struct stub_sound_trigger_device {
+    struct sound_trigger_hw_device device;
     pthread_mutex_t lock;
-    pthread_cond_t  cond;
+    pthread_t callback_thread;
+
+    struct recognition_context re_context[MAX_MAX_SOUND_MODELS];
+
+    int next_sound_model_id;
 };
 
+/* Will reuse ids when overflow occurs */
+static unsigned int generate_sound_model_id(const struct sound_trigger_hw_device *dev) {
+    struct stub_sound_trigger_device *stdev = (struct stub_sound_trigger_device *)dev;
+    int new_id = stdev->next_sound_model_id;
+    ++stdev->next_sound_model_id;
+    if (stdev->next_sound_model_id == 0) {
+        stdev->next_sound_model_id = 1;
+    }
+    return new_id;
+}
 
-static void *callback_thread_loop(void *context)
-{
+static char *sound_trigger_event_alloc(struct stub_sound_trigger_device *stdev,
+                                       sound_model_handle_t handle) {
+    struct sound_trigger_phrase_recognition_event *event;
+    char *data;
+    data = (char *)calloc(1, sizeof(struct sound_trigger_phrase_recognition_event));
+    if (!data)
+        return NULL;
+
+    unsigned int model_index;
+    bool found = false;
+    for(model_index = 0; model_index < hw_properties.max_sound_models; model_index++) {
+        if (stdev->re_context[model_index]->loaded_sound_model == handle) {
+            found = true;
+            break;
+        }
+    }
+    if (found == false) {
+        ALOGW("Can't find model");
+        return NULL;
+    }
+
+    event = (struct sound_trigger_phrase_recognition_event *)data;
+    event->common.status = RECOGNITION_STATUS_SUCCESS;
+    event->common.type = SOUND_MODEL_TYPE_KEYPHRASE;
+    event->common.model = handle;
+
+    if (stdev->re_context[model_index]->config) {
+        unsigned int i;
+
+        event->num_phrases = stdev->re_context[model_index]->config->num_phrases;
+        if (event->num_phrases > SOUND_TRIGGER_MAX_PHRASES)
+            event->num_phrases = SOUND_TRIGGER_MAX_PHRASES;
+        for (i=0; i < event->num_phrases; i++)
+            memcpy(&event->phrase_extras[i], &stdev->re_context[model_index]->config->phrases[i],
+                   sizeof(struct sound_trigger_phrase_recognition_extra));
+    }
+
+    event->num_phrases = 1;
+    event->phrase_extras[0].confidence_level = 100;
+    event->phrase_extras[0].num_levels = 1;
+    event->phrase_extras[0].levels[0].level = 100;
+    event->phrase_extras[0].levels[0].user_id = 0;
+    // Signify that all the data is comming through streaming, not through the buffer.
+    event->common.capture_available = true;
+
+    event->common.audio_config = AUDIO_CONFIG_INITIALIZER;
+    event->common.audio_config.sample_rate = 16000;
+    event->common.audio_config.channel_mask = AUDIO_CHANNEL_IN_MONO;
+    event->common.audio_config.format = AUDIO_FORMAT_PCM_16_BIT;
+
+    return data;
+}
+
+static void *callback_thread_loop(void *context) {
     struct stub_sound_trigger_device *stdev = (struct stub_sound_trigger_device *)context;
-    ALOGI("%s", __func__);
+    struct sockaddr_in incoming_info;
+    struct sockaddr_in self_info;
+    int self_socket;
+    socklen_t sock_size = sizeof(struct sockaddr_in);
+    memset(&self_info, 0, sizeof(self_info));
+    self_info.sin_family = AF_INET;
+    self_info.sin_addr.s_addr = htonl(INADDR_ANY);
+    self_info.sin_port = htons(14035);
 
-    prctl(PR_SET_NAME, (unsigned long)"sound trigger callback", 0, 0, 0);
+    bool exit = false;
+    while(!exit) {
+        int received_count;
+        int requested_count = 1;
+        char buffer[requested_count];
+        ALOGE("Opening socket");
+        self_socket = socket(AF_INET, SOCK_STREAM, 0);
+        if (self_socket < 0) {
+            ALOGE("Error on socket creation");
+            exit = true;
+        } else {
+            ALOGI("Socket created");
+        }
 
-    pthread_mutex_lock(&stdev->lock);
-    if (stdev->recognition_callback == NULL) {
-        goto exit;
+        int reuse = 1;
+        if (setsockopt(self_socket, SOL_SOCKET, SO_REUSEADDR, (const char*)&reuse, sizeof(reuse)) < 0) {
+            ALOGE("setsockopt(SO_REUSEADDR) failed");
+        }
+
+        int bind_result = bind(self_socket, (struct sockaddr *)&self_info, sizeof(struct sockaddr));
+        if (bind_result < 0) {
+            ALOGE("Error on bind");
+            exit = true;
+        }
+
+        int listen_result = listen(self_socket, 1);
+        if (listen_result < 0) {
+            ALOGE("Error on Listen");
+            exit = true;
+        }
+
+        while(!exit) {
+            int con_socket = accept(self_socket, (struct sockaddr *)&incoming_info, &sock_size);
+            if (!con_socket) {
+                ALOGE("Lost socket, cannot send trigger");
+                break;
+            }
+            ALOGI("Connection from %s", inet_ntoa(incoming_info.sin_addr));
+            received_count = recv(con_socket, buffer, requested_count, 0);
+            unsigned int index = buffer[0] - 1;
+            ALOGI("Received data");
+            pthread_mutex_lock(&stdev->lock);
+            if (received_count > 0) {
+                if (buffer[0] == 0) {
+                    ALOGI("Received kill signal: stop listening to incoming server messages");
+                    exit = true;
+                } else if (index < hw_properties.max_sound_models) {
+                    ALOGI("Going to send trigger for model #%d", index );
+                    if (stdev->re_context[index]->recognition_callback != NULL) {
+                        sound_model_handle_t handle = stdev->re_context[index]->loaded_sound_model;
+                        if (handle == 0) {
+                            ALOGW("This trigger is not loaded");
+                        } else {
+                            struct sound_trigger_phrase_recognition_event *event;
+                            event = (struct sound_trigger_phrase_recognition_event *)
+                                   sound_trigger_event_alloc(stdev, handle);
+                            if (event) {
+                               ALOGI("%s send callback model %d", __func__, index);
+                               stdev->re_context[index]->recognition_callback(&event->common,
+                                                     stdev->re_context[index]->recognition_cookie);
+                               free(event);
+                               stdev->re_context[index]->recognition_callback = NULL;
+                            }
+                            exit = true;
+                        }
+                    } else {
+                       ALOGI("%s No matching callback for %d", __func__, index);
+                    }
+                } else {
+                    ALOGI("Data is not recognized: %d", index);
+                }
+            } else {
+                ALOGI("Received sata is size 0");
+            }
+            pthread_mutex_unlock(&stdev->lock);
+            close(con_socket);
+        }
+        ALOGE("Closing socket");
+        close(self_socket);
     }
-    struct timespec ts;
-    clock_gettime(CLOCK_REALTIME, &ts);
-    ts.tv_sec += 3;
-    ALOGI("%s wait 3 sec", __func__);
-    int rc = pthread_cond_timedwait(&stdev->cond, &stdev->lock, &ts);
-    if (rc == ETIMEDOUT && stdev->recognition_callback != NULL) {
-        char *data = (char *)calloc(1, sizeof(struct sound_trigger_phrase_recognition_event) + 1);
-        struct sound_trigger_phrase_recognition_event *event =
-                (struct sound_trigger_phrase_recognition_event *)data;
-        event->common.status = RECOGNITION_STATUS_SUCCESS;
-        event->common.type = SOUND_MODEL_TYPE_KEYPHRASE;
-        event->common.model = stdev->model_handle;
-        event->num_phrases = 1;
-        event->phrase_extras[0].recognition_modes = RECOGNITION_MODE_VOICE_TRIGGER;
-        event->phrase_extras[0].confidence_level = 100;
-        event->phrase_extras[0].num_levels = 1;
-        event->phrase_extras[0].levels[0].level = 100;
-        event->phrase_extras[0].levels[0].user_id = 0;
-        event->common.data_offset = sizeof(struct sound_trigger_phrase_recognition_event);
-        event->common.data_size = 1;
-        data[event->common.data_offset] = 8;
-        ALOGI("%s send callback model %d", __func__, stdev->model_handle);
-        stdev->recognition_callback(&event->common, stdev->recognition_cookie);
-        free(data);
-    } else {
-        ALOGI("%s abort recognition model %d", __func__, stdev->model_handle);
-    }
-    stdev->recognition_callback = NULL;
-
-exit:
-    pthread_mutex_unlock(&stdev->lock);
 
     return NULL;
 }
 
+static void send_loop_kill_signal() {
+    ALOGI("Sending loop thread kill signal");
+    int self_socket = socket(AF_INET, SOCK_STREAM, 0);
+    struct sockaddr_in remote_info;
+    memset(&remote_info, 0, sizeof(remote_info));
+    remote_info.sin_family = AF_INET;
+    remote_info.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+    remote_info.sin_port = htons(14035);
+    if (connect(self_socket, (struct sockaddr *)&remote_info, sizeof(struct sockaddr)) == 0) {
+        char msg[] = {0};
+        send(self_socket, msg, 1, 0);
+    } else {
+        ALOGI("Could not connect");
+    }
+    close(self_socket);
+    ALOGI("Sent loop thread kill signal");
+}
+
 static int stdev_get_properties(const struct sound_trigger_hw_device *dev,
-                                struct sound_trigger_properties *properties)
-{
+                                struct sound_trigger_properties *properties) {
     struct stub_sound_trigger_device *stdev = (struct stub_sound_trigger_device *)dev;
 
     ALOGI("%s", __func__);
@@ -117,140 +287,177 @@
                                   struct sound_trigger_sound_model *sound_model,
                                   sound_model_callback_t callback,
                                   void *cookie,
-                                  sound_model_handle_t *handle)
-{
+                                  sound_model_handle_t *handle) {
     struct stub_sound_trigger_device *stdev = (struct stub_sound_trigger_device *)dev;
     int status = 0;
 
     ALOGI("%s stdev %p", __func__, stdev);
     pthread_mutex_lock(&stdev->lock);
+
     if (handle == NULL || sound_model == NULL) {
-        status = -EINVAL;
-        goto exit;
+        pthread_mutex_unlock(&stdev->lock);
+        return -EINVAL;
     }
     if (sound_model->data_size == 0 ||
             sound_model->data_offset < sizeof(struct sound_trigger_sound_model)) {
-        status = -EINVAL;
-        goto exit;
+        pthread_mutex_unlock(&stdev->lock);
+        return -EINVAL;
     }
 
-    if (stdev->model_handle == 1) {
-        status = -ENOSYS;
-        goto exit;
+    /* Find if there is space for this sound model */
+    unsigned int model_index;
+    bool found = false;
+    for(model_index = 0; model_index < hw_properties.max_sound_models; model_index++) {
+        if (stdev->re_context[model_index]->loaded_sound_model == 0) {
+            found = true;
+            break;
+        }
     }
+    if (found == false) {
+        ALOGW("Can't load model: reached max sound model limit");
+        pthread_mutex_unlock(&stdev->lock);
+        return -ENOSYS;
+    }
+
+    stdev->re_context[model_index]->loaded_sound_model = generate_sound_model_id(dev);
+    *handle = stdev->re_context[model_index]->loaded_sound_model;
+
     char *data = (char *)sound_model + sound_model->data_offset;
     ALOGI("%s data size %d data %d - %d", __func__,
           sound_model->data_size, data[0], data[sound_model->data_size - 1]);
-    stdev->model_handle = 1;
-    stdev->sound_model_callback = callback;
-    stdev->sound_model_cookie = cookie;
+    stdev->re_context[model_index]->sound_model_callback = callback;
+    stdev->re_context[model_index]->sound_model_cookie = cookie;
 
-    *handle = stdev->model_handle;
-
-exit:
     pthread_mutex_unlock(&stdev->lock);
     return status;
 }
 
 static int stdev_unload_sound_model(const struct sound_trigger_hw_device *dev,
-                                    sound_model_handle_t handle)
-{
+                                    sound_model_handle_t handle) {
     struct stub_sound_trigger_device *stdev = (struct stub_sound_trigger_device *)dev;
     int status = 0;
-
-    ALOGI("%s handle %d", __func__, handle);
+    ALOGI("unload_sound_model");
     pthread_mutex_lock(&stdev->lock);
-    if (handle != 1) {
-        status = -EINVAL;
-        goto exit;
+
+    unsigned int i;
+    unsigned int model_index;
+    bool found = false;
+    bool other_callbacks_found = false;
+    for(i = 0; i < hw_properties.max_sound_models; i++) {
+        if (stdev->re_context[i]->loaded_sound_model == handle) {
+            found = true;
+            model_index = i;
+            break;
+        } else if (stdev->re_context[i]->recognition_callback != NULL) {
+            other_callbacks_found = true;
+        }
     }
-    if (stdev->model_handle == 0) {
-        status = -ENOSYS;
-        goto exit;
-    }
-    stdev->model_handle = 0;
-    if (stdev->recognition_callback != NULL) {
-        stdev->recognition_callback = NULL;
-        pthread_cond_signal(&stdev->cond);
+    if (found == false) {
+        ALOGW("Can't sound model %d in registered list", handle);
         pthread_mutex_unlock(&stdev->lock);
-        pthread_join(stdev->callback_thread, (void **) NULL);
-        pthread_mutex_lock(&stdev->lock);
+        return -ENOSYS;
     }
 
-exit:
-    pthread_mutex_unlock(&stdev->lock);
+    stdev->re_context[i]->loaded_sound_model = 0;
+    stdev->re_context[i]->sound_model_callback = NULL;
+    stdev->re_context[i]->sound_model_cookie = NULL;
+
+    free(stdev->re_context[i]->config);
+    stdev->re_context[i]->config = NULL;
+    stdev->re_context[i]->recognition_callback = NULL;
+    stdev->re_context[i]->recognition_cookie = NULL;
+
+    /* If no more models running with callbacks, stop trigger thread */
+    if (!other_callbacks_found) {
+        send_loop_kill_signal();
+        pthread_mutex_unlock(&stdev->lock);
+        pthread_join(stdev->callback_thread, (void **)NULL);
+    } else {
+        pthread_mutex_unlock(&stdev->lock);
+    }
+
     return status;
 }
 
 static int stdev_start_recognition(const struct sound_trigger_hw_device *dev,
-                                   sound_model_handle_t sound_model_handle,
+                                   sound_model_handle_t handle,
                                    const struct sound_trigger_recognition_config *config,
                                    recognition_callback_t callback,
-                                   void *cookie)
-{
+                                   void *cookie) {
+    ALOGI("%s", __func__);
     struct stub_sound_trigger_device *stdev = (struct stub_sound_trigger_device *)dev;
-    int status = 0;
-    ALOGI("%s sound model %d", __func__, sound_model_handle);
     pthread_mutex_lock(&stdev->lock);
-    if (stdev->model_handle != sound_model_handle) {
-        status = -ENOSYS;
-        goto exit;
+    unsigned int i;
+    bool found = false;
+    for(i = 0; i < hw_properties.max_sound_models; i++) {
+        if (stdev->re_context[i]->loaded_sound_model == handle) {
+            found = true;
+            break;
+        }
     }
-    if (stdev->recognition_callback != NULL) {
-        status = -ENOSYS;
-        goto exit;
-    }
-    if (config->data_size != 0) {
-        char *data = (char *)config + config->data_offset;
-        ALOGI("%s data size %d data %d - %d", __func__,
-              config->data_size, data[0], data[config->data_size - 1]);
+    if (found == false) {
+        ALOGW("Can't sound model %d in registered list", handle);
+        pthread_mutex_unlock(&stdev->lock);
+        return -ENOSYS;
     }
 
-    stdev->recognition_callback = callback;
-    stdev->recognition_cookie = cookie;
+    free(stdev->re_context[i]->config);
+    stdev->re_context[i]->config = NULL;
+    if (config) {
+        stdev->re_context[i]->config = malloc(sizeof(*config));
+        if (!stdev->re_context[i]->config) {
+            pthread_mutex_unlock(&stdev->lock);
+            return -ENOMEM;
+        }
+        memcpy(stdev->re_context[i]->config, config, sizeof(*config));
+    }
+    stdev->re_context[i]->recognition_callback = callback;
+    stdev->re_context[i]->recognition_cookie = cookie;
+
     pthread_create(&stdev->callback_thread, (const pthread_attr_t *) NULL,
                         callback_thread_loop, stdev);
-exit:
     pthread_mutex_unlock(&stdev->lock);
-    return status;
+    return 0;
 }
 
 static int stdev_stop_recognition(const struct sound_trigger_hw_device *dev,
-                                 sound_model_handle_t sound_model_handle)
-{
+                                 sound_model_handle_t handle) {
     struct stub_sound_trigger_device *stdev = (struct stub_sound_trigger_device *)dev;
-    int status = 0;
-    ALOGI("%s sound model %d", __func__, sound_model_handle);
+    ALOGI("%s", __func__);
     pthread_mutex_lock(&stdev->lock);
-    if (stdev->model_handle != sound_model_handle) {
-        status = -ENOSYS;
-        goto exit;
+
+    unsigned int i;
+    bool found = false;
+    for(i = 0; i < hw_properties.max_sound_models; i++) {
+        if (stdev->re_context[i]->loaded_sound_model == handle) {
+            found = true;
+            break;
+        }
     }
-    if (stdev->recognition_callback == NULL) {
-        status = -ENOSYS;
-        goto exit;
+    if (found == false) {
+        ALOGW("Can't sound model %d in registered list", handle);
+        pthread_mutex_unlock(&stdev->lock);
+        return -ENOSYS;
     }
-    stdev->recognition_callback = NULL;
-    pthread_cond_signal(&stdev->cond);
+
+    free(stdev->re_context[i]->config);
+    stdev->re_context[i]->config = NULL;
+    stdev->re_context[i]->recognition_callback = NULL;
+    stdev->re_context[i]->recognition_cookie = NULL;
+
+    send_loop_kill_signal();
     pthread_mutex_unlock(&stdev->lock);
     pthread_join(stdev->callback_thread, (void **) NULL);
-    pthread_mutex_lock(&stdev->lock);
-
-exit:
-    pthread_mutex_unlock(&stdev->lock);
-    return status;
+    return 0;
 }
 
-
-static int stdev_close(hw_device_t *device)
-{
+static int stdev_close(hw_device_t *device) {
     free(device);
     return 0;
 }
 
 static int stdev_open(const hw_module_t* module, const char* name,
-                     hw_device_t** device)
-{
+                     hw_device_t** device) {
     struct stub_sound_trigger_device *stdev;
     int ret;
 
@@ -261,6 +468,22 @@
     if (!stdev)
         return -ENOMEM;
 
+    if (MAX_MAX_SOUND_MODELS < hw_properties.max_sound_models) {
+        ALOGW("max_sound_models is greater than the allowed %d", MAX_MAX_SOUND_MODELS);
+        return -EINVAL;
+    }
+
+    stdev->next_sound_model_id = 1;
+    unsigned int i;
+    for(i = 0; i < hw_properties.max_sound_models; i++) {
+        stdev->re_context[i]->loaded_sound_model = 0;
+        stdev->re_context[i]->sound_model_callback = NULL;
+        stdev->re_context[i]->sound_model_cookie = NULL;
+        stdev->re_context[i]->config = NULL;
+        stdev->re_context[i]->recognition_callback = NULL;
+        stdev->re_context[i]->recognition_cookie = NULL;
+    }
+
     stdev->device.common.tag = HARDWARE_DEVICE_TAG;
     stdev->device.common.version = SOUND_TRIGGER_DEVICE_API_VERSION_1_0;
     stdev->device.common.module = (struct hw_module_t *) module;
@@ -272,7 +495,6 @@
     stdev->device.stop_recognition = stdev_stop_recognition;
 
     pthread_mutex_init(&stdev->lock, (const pthread_mutexattr_t *) NULL);
-    pthread_cond_init(&stdev->cond, (const pthread_condattr_t *) NULL);
 
     *device = &stdev->device.common;