The Research Of Two Kinds Of Embedded Realtime Linux Implementation Technologies And Applications Based On Multi-Core Platform

With the increasing demand for complexity and realtime in embedded applications, the embedded Real-Time Operating Sytstem(RTOS) plays a more important role as its core. Most of the existing embedded RTOS are only designed for realtime from the start, so they are lack of support for complex applications and are hard to port. Meanwhile, the source code of many commercial RTOSes are not accessible, and they are also expensive. There is a lack of open, low cost, general support and efficient RTOS. So, many reasearch institutions and open source communities start to turn General Purpose Operating System(GPOS) to RTOS. Under this circumstance, Linux becomes the frist choice because of its low cost, strong functions and ease porting, especially open source.There are two ways to enhance Linux to support real-time requirements. One is the fully preemptible kernel approach, the other is the co-kernel approach.The former is to frankly change the Linux kernel source code, such as the fully preemptible kernel Preempt-RT. And the latter found for adding real-time capabilities to Linux was to place a small real-time kernel running side by side with Linux on the same hardware, such as RTAI.However, in order to make use of them to build realtime multi-core application development, we must first have a good understanding of their implementation and sum up the application methods because of the complexity of embedded realtime Linux and the lack of resources,.So based on the analysis of real-time characteristics and disadvantages of standard Linux 2.6, the implementation and modification technologies of Preempt-RT are deeply studied. Then we analyze the principle and implementation of ADEOS/IPIPE nano-kenel based on Linux. Finally, the design and implementation of RTAI kernel based on Linux is illustrated clearly.Different real-time tests are made between Standand Linux 2.6 and Preempt-RT Linux, and we have also tested some real-time characteristics of RTAI to verify their real-time. At last, the two open source realtime Linuxs are built on the "Star of Embedded" dual core x86 platform and Standard PC. And the corresponding real-time applications are also implemented and analyzed .