Described is a mechanism for receiving new data at an auxiliary device associated with a main computer system, and processing that new data within the auxiliary device firmware to take some action. The receipt and processing of the data is independent of whether the main computer system is in a powered-up state (online) or powered-down state (offline). A cache that maintains the user application data for offline navigation may be updated with new data, either to change existing data in the cache or add a new navigation path. The received data can be processed to perform other actions, depending on the context of that data as determined by auxiliary processing.