03.彩色显示调用、清屏调用以及ASCII 0x07蜂鸣实验

A very simple bootloader (size <512Bytes) which can show ASCII chars. 一个bootloader程序，可以显示ASCII字符。(A very simple bootloader (size <512Bytes) which can show ASCII chars.)

bootloader:加载一个简单的操作系统，可以显示ASCII字符(bootloader which can load ELF format OS Image)