Research Of Embedded Operating System Tailoring

In order to increase data transmission rates of the plotter, this paper tailoring a embedded Linux operating system.Firstly this paper introduces the embedded operating systems and the embedded Linux, then introduces some of the popular embedded Linux tailoring methods, analyzes the advantages and disadvantages of various methods. Thus deduces a suitable tailoring method for the application of this paper. The method is make menuconfig configuration combined with modifying the kernel source code of embedded Linux.For the purpose of increasing data transmission rate of the Plotter, essentially speaking is to improve the process scheduling efficiency of Linux,a systematic analysis of the overall structure of the Linux kernel, the directory tree of Linux source code, and the process of starting and compiling kernel are presented in this paper. Two key points are concluded which affects the efficiency of the process scheduling: the ordinary time shareing process scheduling strategy and the virtual memory management mechanism. Then the major subsystems which are closely related with these two key points, such as source code of process management subsystem and memory management subsystem, are detailed analyzed.Based on the analysis of source code, a fixed-priority preemptive process scheduling strategy and method of cutting the virtual memory management mechanisms are given in this paper. The tailoring process is kernel configuring,redundant processes deleting and source code modifting.Specific configure options and modified source code, such as function schedule() and do_mmap(), are presented in this paper.Finally, experimental environment which we used to test the efficiency of the tailoring is introduced. The experimental results show that after the embedded Linux tailoring, the scheduling time of the output process is shorted by 15% than before.