In the state-of-the-art hardware/software (HW/SW) co- design of embedded systems, there is a lack of sufficient support for architectural specifications across HW/SW boundaries. Such an architectural specification ought to capture both hardware and software components and their interactions, and facilitate effective design exploitation of HW/SW trade-offs and scalable HW/SW co-verification. In this paper, we present the embedded architecture description language (EADL). It is based on a component model for embedded systems that unifies hardware and software components. EADL does not dictate execution and interface semantics of hardware and software components while supporting flexible platform-oriented semantics instantiation. EADL supports concise representation of embedded system architectures and also formulation of architectural patterns of embedded systems. Besides facilitating design reuse, architectural patterns also facilitate verification reuse via association of properly templates with these patterns. Effectiveness of EADL has been demonstrated by its successful application in integrating component-based co-design, co- simulation, co-verification, and system synthesis.