Mac OS X磁盘重新分区后 BootCamp Windows启动项丢失

前言

我有一台Mac，装有OS X和Windows两系统，因Windows和OS X都能读写exFAT分区，

故若在Machintosh HD和Windows HD之间开辟一个exFAT分区，可以作为共享文件区。

我在OS X中用磁盘工具对Machintosh HD进行分区，在Machintosh HD和Windows HD之间开辟一个exFAT分区。

重启启动时，我按住了option，之后出现的启动选项中没有Windows。这因为刚才给磁盘分了区才导致的。

解决

重启MAC ，按住COMMAND+R进入恢复模式，打开Terminal

csrutil disable #关闭rootless

修改完，重启MAC，打开终端

sudo fdisk -e /dev/disk0

yanghaodeMacBook-Pro:~ yanghao$ sudo fdisk -e /dev/disk0
Password:
fdisk: could not open MBR file /usr/standalone/i386/boot0: No such file or directory
Enter 'help' for information
fdisk: > p
Disk: /dev/disk0    geometry: // [ sectors]
Offset:     Signature: 0xAA55
         Starting       Ending
 #: id  cyl  hd sec -  cyl  hd sec [     start -       size]
------------------------------------------------------------------------
 : EE     -     [          -     ] <Unknown ID>
 : AC     -     [     -  ] <Unknown ID>
 : AB     -     [  -    ] Darwin Boot
*:      -     [  -  ] HPFS/QNX/AUX
fdisk: >    

修改分区表

fdisk: 1> p
Disk: /dev/disk0    geometry: // [ sectors]
Offset:     Signature: 0xAA55
         Starting       Ending
 #: id  cyl  hd sec -  cyl  hd sec [     start -       size]
------------------------------------------------------------------------
 : EE     -     [          -     ] <Unknown ID>
 : AC     -     [     -  ] <Unknown ID>
 : AB     -     [  -    ] Darwin Boot
*:      -     [  -  ] HPFS/QNX/AUX
fdisk: 1> setpid 4
         Starting       Ending
 #: id  cyl  hd sec -  cyl  hd sec [     start -       size]
------------------------------------------------------------------------
*:      -     [  -  ] HPFS/QNX/AUX
Partition id ('' to disable)  [ - FF]: [] (? for help) 
fdisk: 1> flag 4
Partition  marked active.
fdisk:*> p
Disk: /dev/disk0    geometry: // [ sectors]
Offset:     Signature: 0xAA55
         Starting       Ending
 #: id  cyl  hd sec -  cyl  hd sec [     start -       size]
------------------------------------------------------------------------
 : EE     -     [          -     ] <Unknown ID>
 : AC     -     [     -  ] <Unknown ID>
 : AB     -     [  -    ] Darwin Boot
*:      -     [  -  ] HPFS/QNX/AUX
fdisk:*1> write
Device could not be accessed exclusively.
A reboot will be needed for changes to take effect. OK? [n] y
Writing MBR at offset .

 重启电脑按OPTION