Research On Kernel Transplantation And Real-Time Performance Of Embedded Operating System Based On ARM

Currently in the era of rapid development of Internet and electronic information technology, the most representative and popular technology of this era based on embedded technology, artificial intelligence technology and communication technology are also developing rapidly. With the promotion of a new innovation-driven model proposed by Chinese government called Internet Plus, those techniques will be the current leader of the era and in that case has a tremendous development. Among them, the embedded technology and embedded OS as the soul of Internet Plus will also enjoy a more complex and perfect development. Meanwhile, Linux, with its own specialties has already occupied half of the country, in a variety of embedded OS.This paper takes the ARM11 platform as the basis for the application of the Linux kernel transplantation. Different processors have a certain difference between the boot program and the kernel. Firstly, the principle of the guiding principle is studied deeply. Then, a self-coded USB download line driver is used to transplant the compiled u-boot image into the ARM. And this essay also implements the Linux kernel configuration compilation and transplantation of the specific process, as well as the root file system. To bridge the host and the target, TFTP network link is used. And u-boot command is used in the ARM debug window to set the IP address and Environmental variables of the target machine and other relevant parameters. The last is to transplant the Linux kernel image which has mounted the root file system to the ARM through the TFTP sever.Aiming at the problems of real-time, this essay makes a deep analysis and research of the Linux2.6 version of the kernel. Based on the evaluation criteria of Linux real-time performance, a few factors that hinder the performance are summarized. Interrupt mechanism, synchronization mechanism and priority inversion phenomenon are taken into serious consideration and further study. In this part, first of all, the original standards linux2.6 kernel interrupt mechanism was in-depth analysis. The original interrupt mechanism was made to meet the standard of standard universal distributed Linux OS. By using the method of threaded interrupt, the defects of using Interrupt mechanism of Linux in the real-time environment, especially under heavy network load can be solved. Then, by analyzing the standard Linux kernel synchronization mechanism, the improving plan of using mutex to replace the spinlock are made to solve the effects of real-time, which provided by using large amount of spinlock in the kernel. Finally, the phenomenon of tasks scheduling priority inversion produced by the above factors is analyzed. In view of the situation that tasks with lower priority will dispatch before these takes with higher priority. This essay applied the methods of priority inheritance to improve scheduling mechanism. And by taking those adjustments plans mentioned above, a test program was designed to testify those adjustments and the results are pretty effective. So it can come to an exclusion that the optimized Linux has a great good research value in real-time performance.