On board compiling in the very small

Smart cards and embedded devices are well known for being low end platforms with limited resources and computing power. Thus they are not provided with embedded compilers which are said to be expensive and prefer using byte code interpreters rather than just in time or on the fly compilers. The following paper will challenge this idea and motivate the expected benefits of an embedded on the fly compilation process. Tracks will be given to succeed in compiling in the very small. This paper presents the component binding model implemented in CAMILLE, an extensible operating system for resource-limited devices. Modern embedded systems need on the first hand to fully exploit the limited hardware on which they run and and the other hand to dynamically adapt themselves to changes in their runtime environment. CAMILLE is an exokernel which support static customization of components and dynamic loading of system extensions. Dynamic kernel and application adaptation is implemented by an inter-component communication model. This model is based on flexible bindings which permit to fully customize the way components interact with each others. Bindings can be static, virtual or compiled to guarantee performances of intercomponent communications. This paper shows that it is possible to build a flexible operating system without sacrificing runtime performances, even for devices as constrained as smart cards. Some architectural and experimental results will be extracted from the CAMILLE generic embedded on the fly code compiler.