text: /* Description of entry in partition table.  */
  #ifndef _PARTITION_H
  #define _PARTITION_H
  
  struct part_entry {
    unsigned char bootind;	/* boot indicator 0/ACTIVE_FLAG	 */
    unsigned char start_head;	/* head value for first sector	 */
    unsigned char start_sec;	/* sector value + cyl bits for first sector */
    unsigned char start_cyl;	/* track value for first sector	 */
    unsigned char sysind;		/* system indicator		 */
    unsigned char last_head;	/* head value for last sector	 */
    unsigned char last_sec;	/* sector value + cyl bits for last sector */
    unsigned char last_cyl;	/* track value for last sector	 */
    unsigned long lowsec;		/* logical first sector		 */
    unsigned long size;		/* size of partition in sectors	 */
  };
  
  #define ACTIVE_FLAG	0x80	/* value for active in bootind field (hd0) */
  #define NR_PARTITIONS	4	/* number of entries in partition table */
  #define	PART_TABLE_OFF	0x1BE /* offset of partition table in boot sector. 见Figure 1 */
  
  /* Partition types. */
  #define NO_PART		0x00	/* unused entry */
  #define MINIX_PART	0x81	/* Minix partition type */
  
  #endif /* _PARTITION_H */
  
   /* 0000   |------------------------------------------------|
  		   |                                                |
  		   |                                                |
  		   |                Master Boot Record	            |
  		   |                                                |
  		   |                                                |
  		   |                主引导记录(446字节)		        |
  		   |                                                |
  		   |                                                |
  		   |                                                |
  	01BD   |                                                |
      01BE 446------------------------------------------------|
  		   |                                                |
  	01CD   |              分区信息   1(16字节)              |
  	01CE   |------------------------------------------------|
  		   |                                                |
  	01DD   |              分区信息   2(16字节)              |
  	01DE   |------------------------------------------------|
  		   |                                                |
  	01ED   |              分区信息   3(16字节)              |
  	01EE   |------------------------------------------------|
  		   |                                                |
  	01FD   |              分区信息   4(16字节)              |
  		   |------------------------------------------------|
  		   | 01FE                    | 01FF                 |
  		   |          55             |            AA        |
  		   |------------------------------------------------|
  			Figure 1: Boot Sector(主引导分区)的具体结图
   */
  