因为当前的vxWorks都是用vxsys格式化后的引导，但如果要用dos测试时需换一个硬盘，本方法可免去如此麻烦。启动后按f8直接进dos。否则进vxWorks。-Because the current VxWorks are formatted with vxsys guide, but if the test is required to use dos for a hard drive, this method may be wa