Automatic generation of executable models from high-level system specifications has demonstrated to be a quite helpful tool for embedded system designers. Productivity boosts with the use of standard specification languages and design methodologies that settle common foundations for requirements capture, system definition, exploration of design space and early verification (functional and not functional parameters). In this context, this work presents a specification methodology and design flow for multimedia embedded system using UML/MARTE standards.First, system modeling is performed through a technology independent MARTE profile that captures application functionality. Then, the corresponding SystemC executable model is generated after a mapping transformation to a HW/SW platform description that includes reconfigurable hardware, software and bus resources.