In recent years a lot of research efforts have been directed towards component-based approach in the development of embedded operating systems. This allows the system to easily adapt itself to different hardware chips and various embedded application subsystems. Most of the existing research on component-based embedded system development is directed towards adapting the system to different hardware chips. However, this approach is not sufficient to port the system from one embedded application to another. In this research we will address the importance of component-based design at the application domain and runtime environment level of embedded systems. Since JavaCard is gaining importance in SmartCard embedded systems, we will design a component-based Java Card Runtime Environment and Application Subsystem. Our approach will enable easy configuration of the system to support Java Card, EMV-compliant card and various other smartcard embedded applications. Our research will demonstrate that the component-based approach allows the embedded operating system to easily port itself to other resource-constrained devices such as cell phones and other embedded system application with relative ease.