print hello world on the serial port at Windway ARM development board

ARM 架构上裸机印出Hello world, 源码包含开机编汇语言start.S, uart 初始化, 最后透过uart FIFO印出字节-Bare printed on ARM architecture Hello world, contains the source code compiled languages boot start.S, uart initialization, and finally printed through uart FIFO byte

ARM架构，裸机开机程序，UART 初始化，并启动MMU，利用映射的记忆体位址印出Hello world.-ARM architecture, bare metal boot process, UART initialization and start MMU, memory addresses using the maps of print Hello world.