读书笔记《30天自制操作系统》day02

http://blog.csdn.net/ltbylc/article/details/8280488

1. 将第一天直接生成软盘映像的代码抽取出引导扇区部分，ipl.asm

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        ORG     0x7c00            
  
        JMP     entry  
        DB      0x90  
        DB      "HELLOIPL"        
        DW      512               
        DB      1                 
        DW      1                 
        DB      2                 
        DW      224               
        DW      2880              
        DB      0xf0              
        DW      9             
        DW      18                
        DW      2                 
        DD      0                 
        DD      2880              
        DB      0,0,0x29          
        DD      0xffffffff        
        DB      "HELLO-OS   "     
        DB      "FAT12   "        
        RESB    18              ?  
  
  
entry:  
        MOV     AX,0              
        MOV     SS,AX  
        MOV     SP,0x7c00  
        MOV     DS,AX  
        MOV     ES,AX  
  
        MOV     SI,msg  
putloop:  
        MOV     AL,[SI]  
        ADD     SI,1              
        CMP     AL,0  
        JE      fin  
        MOV     AH,0x0e           
        MOV     BX,15             
        INT     0x10              
        JMP     putloop  
fin:  
        HLT                       
        JMP     fin               
  
msg:  
        DB      0x0a, 0x0a        
        DB      "hello, world"  
        DB      0x0a              
        DB      0  
  
        ;RESB   0x7dfe-$          
        ;times 0x7dfe-($-$$) db 0  
                times 510-($-$$) db 0  
                DB              0x55,0xaa  

2. 将引导扇区部分并入软盘映像文件中 helloos3.asm

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incbin "ipl.bin"  
times 1474560 - ($ - $$) db 0  

3. 生成的img文件可以被WinImage软件以软盘方式打开了