前一部分介绍了ARM的一些体系机构，后一部分介绍了bootloader的详细原理，设计流程（这部分写的很不错，适合初学者）。估计是一篇学生论文。-first part of the ARM system, after Bootloader part of the detailed principles of the design process (which was very good. for beginners). Estimate is a student thesis.