1.编写mbr汇编程序

SECTION MBR vstart=0x7c00
  mov ax,cs
  mov ds,ax
  mov es,ax
  mov ss,ax
  mov fs,ax
  mov sp,0x7c00
  
  ; 清屏
  mov ax,0x600
  mov bx,0x700
  mov cx,0
  mov dx, 0x184f
  int 0x10
  
  ; 设置光标结束
  mov ah,3
  mov bh,0
  
  int 0x10
  
  mov ax,message
  mov bp,ax
  
  mov cx,5
  mov ax,0x1301
  mov bx,0x2  ; bl=0x2 字符属性:黑底绿字
  int 0x10
  
  jmp $
  
  message db "1 MBR"
  times 510-($-$$) db 0
  db 0x55,0xaa

2.编译

nasm -o mbr.bin /home/truthos/oscode/c2/a/boot/mbr.S 

3.将mbr.bin通过dd工具写入到虚拟磁盘中。

dd if=/home/truthos/oscode/c2/a/boot/mbr.bin of=/home/truthos/bochs/hd60M.img bs=512 count=1 conv=notrunc

4.启动bochs

bin/bochs -f bochsrc.disk

程序运行成功。 "1 MBR"字符串正常显示。