Component-based software development focuses on reuse of already available software components, reducing development time and cost and improving software quality and productivity. To enable composition, components must conform to a specific component model and target a specific component platform. This paper presents a component model for embedded systems called Flexcm and the execution environment in which the components will be running. The component model supports aspects like reflectivity, exceptions, events and lifecycle management. The execution environment supports update of specific components, registration of new components with new functionalities and adaptability based on its execution context. In order to achieve a concrete result, the presented component model and platform is driven by the development of a middleware submitted as a proposal to the Brazilian Digital TV System.