Embedded system application requirements must be cut on the hardware and software
to meet the application functionality, reliability, cost, size and other requirements. So, if we can establish a relatively common hardware and software base, and to adapt their needs to develop a system, is a good development model. The current core of embedded systems is often a few tens of K to K micro-kernel, according to the actual function of the use of extension or reduction, but due to the presence of micro-kernel, so this expansion can be carried out very smoothly.