linux0.01 引导启动过程

 tools/build boot/boot tools/system > Image                         //makefile中，直接用build把boot,system写入到image中

 

BOOTSEG = 0x07c0

INITSEG = 0x9000

SYSSEG  = 0x1000 

 

 rep

 movw

 jmpi go,INITSEG                                                               //把512个字节写入到0x9000:0=0x90000,386的段机制,执行之

 

 mov ax,#SYSSEG

 mov es,ax  | segment of 0x010000

 call read_it                                                                       //读取引导扇区后面的到64K内容到0x1000:0=0x10000处           

 

mov ax,#0x0000                                                             //读取0x1000:0的64K数据 复制到0x0000处

 

 lmsw ax    

 jmpi 0,8                                                                        //转跳到0X0000去