说明：  嵌入式实验指导,包含: 实验一 开发环境搭建实验 实验二 HelloWorld实验 实验三 烧写各部分到目标板 实验四 编译Bootloader 实验五 编译linux内核
(Embedded experimental guidance, include: a development environment set up experimental experimental experimental experimental experimental Second HelloWorld three parts of programmer to target board Bootloader experiment four experimental five compiler compiler linux kernel)