Automatic generation of controls code from modelsfor real-time Linux platforms

We present our experience in the design and realization of a toolset for the extension of the simulation and modeling capabilities and the automatic generation of code from ScicosLab models running on embedded Linux and RTAI. ScicosLab — a free system modeler and simulator — has been extended with add-ons for the modeling of hierarchical Finite State Machines (FSMs) and a GUI prototyper based on the Qt graphical libraries. The code generator supports multirate models and maps the model blocks onto multiple periodic threads, with the automatic synthesis of thread scheduling, communication and access to the I/O primitives. We discuss the design challenges and options and the implementation issues encountered during the development of the toolset, including the mapping of functionality onto threads, the problem of semantics preservation in the implementation of communication, the methods used to abstract from the architecturespecific I/O details and the concurrent use of PCI and video peripherals. We show an example of generated code and a set of performance measurements on real hardware with a data acquisition peripheral.