Full-fledged softare radio platforms are complex and expensive systems, focused on signal processing, and not very suitable for easy development and large scale experimentation. We propose a Multi-Processor System-on-Chip (MPSoC) prototyping platform targeting the support for flexible radio. This platform is fully customizable at every layer of the wireless networking stack, making it easy to prototype new protocols from the radio to application layers. Our goal was threefold: provide support for a full system on the platform so that it can run autonomously, use "standard" components as much as possible and a modular design to esnure fast and simple development and testing to network de velopers. We rely on a highly modular Field-Programmable Gate Array (FPGA) based architecture. The practical results achieved so far show the effectiveness of the proposed solution in term of flexibility and cost.