Research Of The Technology Of Device Driver Virtulazation Based On Microkernel System

With the development of computer operating system, its structure becomes diversified. For the advantages in performance, monolithic kernel has been the major structure of the operating system. But as the people increasing concern in system security and flexibility, the other operating systems architecture is gradually developed. Microkernel system in pursuit of greater security and better modular design as the goal formed a kernel architecture which is different from traditional monolithic kernel. However, for the first-generation microkernel have implemented system communication mechanism-IPC unsuccessfully, resulting in poor performance of the microkernel system and hasn't caused widespread concern of researchers. With the appearance of second-generation micro-kernel systems-L4 which achieved synchronous IPC communication mechanism has greatly improved the issue of microkernel system performance, it take the microkernel back in the people's field of vision.Microkernel only provides strategy, doesn't implement mechanism. Thus, almost all functions which original in the monolithic kernel are moved outside Microkernel, such as device drivers. At present, the device driver implementation for the microkernel system is still in the research stage, there is no uniform way.This article describes characteristics of L4 which is the second generation microkernel standard, and takes one of its API implementation-L4/Fiasco as instance, illustrates microkernel system structure and its core mechanism. By studying the existing device driven implementation approach for microkernel system, this article focuses on the process of implementing device drivers for the L4/Fiasco system, by using device driver environment DDE provided by DROPS project.This article first implements parport motor driver for the Linux system, as it's a basis, then designs the parallel port driver instance on L4/Fiasco, finally completes the parport driver server under the microkernel system. L4/Fiasco system functions are designed into the server mode, this parport driver also implements a server interface, so it's can providing services at the same time to the different applications which located on top of microkernel, and achieved the function of device driver virtualization. At last we test the performance of the parport driver server, in order to assess and analyze the manner which uses DDE building device driver for the microkernel.