Embedded Linux Hard Real Time Performance Research And Implementation

This paper mainly discusses the research and implement of Linux hard real time performance in order to meet the needs in embedded field. Firstly, the paper introduces embedded system, embedded Linux operation system and real time operation system, deeply analyses advantages of Linux serving as embedded operation system and shortcomings in the aspect of hard real time performance. On the basis of study, the paper compares various scheme of embedded Linux implementing hard real time performance currently. Finally, the technology strategy through two-kernel mechanism is set up, added RTHAL for reducing the modification of the original kernel. The paper carefully describes important technology relevant of the new scheme .The thinking and purpose of realizing software interrupt emulation technology is explained in detail, and the concrete tactics of implementing the refined timer in two styles is set forth. The paper discusses two real time schedule arithmetic adopted by real time kernel such as rate monotonic analysis arithmetic and earlier deadline first arithmetic, and the resolvent of preventing priority inversion is made out. At the same time , the paper describes not only design and realization of the preemptive kernel,but also how to develop real time applications under the new system ,and a sample is given subsequently .In the end , the paper discusses the primary real time performace value of new Linux, proving the success of the scheme descrbied in the paper by comparison with the original Linux system . Moreover, the paper gives some foresight about the embeded real time Linux.