diff --git a/contexthub/1.0/IContexthub.hal b/contexthub/1.0/IContexthub.hal
index 8d19aeb..8c792fd 100644
--- a/contexthub/1.0/IContexthub.hal
+++ b/contexthub/1.0/IContexthub.hal
@@ -60,9 +60,11 @@
      * After the init method for nanoApp returns success, this must be indicated
      * to the service by an asynchronous call to handleTxnResult.
      *
+     * Loading a nanoapp must not take more than 30 seconds.
+     *
      * @param hubId identifer of the contextHub
-     *        appBinary binary for the nanoApp
-     *        msg   message to be sent
+     *        appBinary serialized NanoApppBinary for the nanoApp
+     *        transactionId transactionId for this call
      *
      * @return result OK if transation started
      *                BAD_VALUE if parameters are not sane
@@ -71,7 +73,9 @@
      *                TRANSACTION_FAILED if load failed synchronously
      *
      */
-    loadNanoApp(uint32_t hubId, NanoAppBinary appBinary, uint32_t transactionId)
+    loadNanoApp(uint32_t hubId,
+                vec<uint8_t> appBinary,
+                uint32_t transactionId)
             generates (Result result);
 
     /**
@@ -79,6 +83,8 @@
      * After this, success must be indicated to the service through an
      * asynchronous call to handleTxnResult.
      *
+     * Unloading a nanoapp must not take more than 5 seconds.
+     *
      * @param hubId identifer of the contextHub
      *        appId appIdentifier returned by the HAL
      *        msg   message to be sent
@@ -98,6 +104,8 @@
      * After this, success must be indicated to the service through an
      * asynchronous message.
      *
+     * Enabling a nanoapp must not take more than 5 seconds.
+     *
      * @param hubId identifer of the contextHub
      *        appId appIdentifier returned by the HAL
      *        msg   message to be sent
@@ -117,6 +125,8 @@
      * After this, success must be indicated to the service through an
      * asynchronous message.
      *
+     * Disabling a nanoapp must not take more than 5 seconds.
+     *
      * @param hubId identifer of the contextHub
      *        appId appIdentifier returned by the HAL
      *        msg   message to be sent
@@ -136,7 +146,11 @@
      *
      * @param hubId identifer of the contextHub
      *
-     * @return apps all nanoApps on the hub
+     * @return apps all nanoApps on the hub.
+     *              All nanoApps that can be modified by the service must
+     *              be returned. A non-modifiable nanoapps must not be
+     *              returned. A modifiable nanoApp is one that can be
+     *              unloaded/disabled/enabled by the service.
      *
      */
     queryApps(uint32_t hubId) generates (Result result);
diff --git a/contexthub/1.0/IContexthubCallback.hal b/contexthub/1.0/IContexthubCallback.hal
index 29c41ce..9e9cf27 100644
--- a/contexthub/1.0/IContexthubCallback.hal
+++ b/contexthub/1.0/IContexthubCallback.hal
@@ -22,41 +22,44 @@
      * implementation to allow the HAL to send asynchronous messages back
      * to the service and registered clients of the ContextHub service.
      *
-     * @params hubId : identifier of the hub calling callback
-     *         msg   : message
+     * @params msg : message
      *
      */
-     handleClientMsg(uint32_t hubId, ContextHubMsg msg);
+     handleClientMsg(ContextHubMsg msg);
 
     /*
      * This callback is passed by the Contexthub service to the HAL
      * implementation to allow the HAL to send the response for a
      * transaction.
      *
-     * @params hubId : identifier of the hub calling callback
-     *         txnId : transaction id whose result is being sent
+     * @params txnId : transaction id whose result is being sent
      *                 passed in by the service at start of transacation.
      *         result: result of transaction.
      *
      */
-     handleTxnResult(uint32_t hubId, uint32_t txnId,
-             TransactionResult result);
+     handleTxnResult(uint32_t txnId, TransactionResult result);
 
     /*
      * This callback is passed by the Contexthub service to the HAL
      * implementation to allow the HAL to send an asynchronous event
      * to the ContextHub service.
      *
-     * @params hubId : identifier of the hub calling callback
-     *         msg   : message
+     * @params msg : message
      *
      */
-     handleHubEvent(uint32_t hubId, AsyncEventType evt);
+     handleHubEvent(AsyncEventType evt);
 
      /*
       * This callback is passed by the Contexthub service to the HAL
       * implementation to allow the HAL to send information about the
       * currently loaded and active nanoapps on the hub.
+      *
+      * @params appInfo : vector of HubAppinfo structure for each nanoApp
+      *                   on the hub that can be enabled, disabled and
+      *                   unloaded by the service. Any nanoApps that cannot
+      *                   be controlled by the service must not be reported.
+      *                   All nanoApps that can be controlled by the service
+      *                   must be reported.
       */
-      handleAppsInfo(uint32_t hubId, vec<HubAppInfo> appInfo);
+      handleAppsInfo(vec<HubAppInfo> appInfo);
 };
diff --git a/contexthub/1.0/types.hal b/contexthub/1.0/types.hal
index b9f014b..043bb39 100644
--- a/contexthub/1.0/types.hal
+++ b/contexthub/1.0/types.hal
@@ -18,6 +18,7 @@
 
 enum Result : uint32_t {
     OK,                  // Success
+    UNKNOWN_FAILURE,     // Failure, unknown reason
     BAD_PARAMS,          // Parameters not sane
     NOT_INIT,            // not initialized
     TRANSACTION_FAILED,  // transaction failed