Jun Li

Bridging of Distributed and Component-Based Systems

A new class of smart devices is emerging that combines the efficiency of ROM-based C/C++ code with the flexibility of an embedded Java virtual machine. The firmware in these devices is usually burned into ROM, and therefore difficult to update or modify after product shipment. However, after product shipment, there is often a need to introduce a new feature not foreseen in the development phase. The new feature may be a customization of an existing feature (such as a custom logo on the front-panel of the device), or may be a new capability that extends the features of the device (such as adding secure authentication to the login procedure at the device, in order to access the user’s email account).

The Java virtual machine creates a safe sandbox in which these augmented fea-tures are added; however, extending, invoking and replacing ROM features requires bi-directional communication between Java and the underlying firmware.

We have developed a middleware bridging framework called JeCOM that enables bidirectional invocation and feature replacement between Java and embedded firmware. In our specific environment, the C/C++ firmware is written to an object model known as eCOM (based on the Microsoft COM model) and thus our solution also addresses Java/COM interoperability in the embedded environment.

The Java/COM bridge that is implemented as a new protocol in a Java-based Object Request Broker. This new protocol provides significant ease-of-use advantages over Java Native Interface, performance comparable to distributed object systems, while requiring no change to existing firmware implementation and infrastructure. The problem of bridging Java and C/C++ is not new. However, bridging these languages in the embedded domain and addressing object discovery, lifecycle management, and memory management within the ORB protocol for bidirectional communication is new.