The paper introduces a fast approach to prototype embedded systems. Software components are first modeled and formally verified using a SysML environment named AVATAR, supported by a free software named TTool. Simulation and formal verification of AVATAR components can be performed at the push of a button. The C/POSIX code of AVATAR components can also be generated directly from TTool. The generated code along with the selected operating system can then be compiled, linked together, and executed on the SoCLib virtual prototyping platform. The latter has simulation models to build custom hardware platforms simulators and supports several real-time and embedded operating systems, including MutekH. Debugging features provided by the SoCLib platform offers straightforward debugging features, either with a command-line debugger-such as the GNU debbuger-or directly in TTool which presents execution results in a UML way using sequence diagrams, thus requiring no specific skill on the target platform. An automotive embedded application is used to present the whole AVATAR methodology, with a particular focus on the prototyping phase.