Embedded Linux Timely Research And Transformation

At present, the wide usage of the real-time operating system in various fields has drawn increasing attentions. Among these real-time operating systems, linux-based real-time operating system is welcomed by more people with its open-source and linux system stability. But linux itself is not true real-time operating system, it is necessary to upgrade its real-time. To carry out the real-time transformation of the Linux is one of the hot researching spots in the computer industry at home and abroad. Therefore, developing an open, standard, and efficient low-cost real-time operating system based on Linux is entirely feasible, and how to enhance the real-time of the Linux real-time operating system is a focus of study.Since Linux2.6 kernel was released in the end of 2003, it had been extensively tested and practically applied. It has been proved that it is a highly efficient and stable core. Compared with the core Linux2.4, Linux2.6 core adopting some new techniques makes real-time have great improvements, such as preemptive kernel, the new O(1) scheduling algorithm and so on. Although real-time operating system developers can benefit from these changes, Linux2.6 is still not a real-time kernel. But these changes make it possible to change the kernel into RTOS, thus, it is necessary to continue to carry out real-time kernel Linux2.6 transformation, and further enhance its real-time nature.In order to construct timely strong Linux operating system for electrical energy quantity gathers the terminal ,this paper studies the architecture and internal module dependencies of the newer version of the Linux kernel (2.6.22), and analyzes the reasons why the real-time Linux is not strong, and then on the basis of this study has a research on the common methods of transforming the real-time Linux kernel, and gives specific reconstructive ideas. Furthermore, this paper transforms the existing Linux kernel from the two major aspects of the real-time improvements: First of all, from the point of soft real-time transformation, according to the core of the core ideas, based on the analysis and research of the existing Linux kernel Scheduling mechanisms and the clock mechanism, the LSF algorithm is introduced under the premise of the original O (1) algorithm to improve the scheduling strategy. At the same time, using the programming methods of APIC carries on the transformation to the original coarse-grained clock mechanism. Secondly, in order to raise the hard real-time of Linux itself, according to the dual-core model of thinking, the paper has a real-time transformation to the existing Linux using the technology of RTAI.Finally, the paper has a re-configuration and compile to the Linux kernel after being transformed, and it makes corresponding test respectively from the three dimensions of the transformation and proves the modified kernel possesses the real-time requirements.And then, applies it in the low pressure user electrical energy quantity gathering terminal software development platform.