The need of co-design systems, along with the FPGA complexity, is increasing dramatically, both in industrial and academic settings. New tools are necessary to ease the development of such systems. Altera supplies a development kit with a 200'000 equivalent gates FPGA; combined with its proprietary Nios configurable processor, it allows co-design and multi-processor architecture creation. In this paper, we present a new tool, CoDeNios, which lets a developer partition a C program at the function level, and automatically generates the whole system.