本程序执行了MMU初始化,使能,设置domain,目的是使0x10000000开始的地址映射到0x0处.

以便可以修改异常向量表.-　The MMU initialization process carried out so that they can set up domain, aimed at the beginning of the address 0x10000000 is mapped to 0x0 Department.　In order to modify the scale anomaly.