Q: El Cap won't dual boot Windows 8.1 w/ EFI

Loner T wrote:

I have a W8.1/MBR installation on El Capitan, which works fine. This is an easily solvable issue. You can run Windows on the same disk as OSX, or on separate disks. The MP can also be booted on older OSX versions from external disks/different internal disks and Windows re-installed using MBRs.

 

Thats what I assumed, but I before I did my clean install of windows, I had my old MBR install, and it would not boot. I switched to EFI, it will not boot.

StartUp Disk > BootCamp > hangs on black screen. Obviously something changed in El Cap. I just need to know what it is.

Loner T wrote:

 

Did W8.1 Install successfully using EFI Boot? It could also be hanging because it is an MBR installation.

Yes,  for the most part. I can boot into it as long as my OS X drive is not plugged in. I did encounter some strange issues with it going into a boot cycle if I installed Chrome. But I assume that if I let all the updates install that would all sort itself out.

Loner T wrote:

 

Can you post the output of the following Terminal commands? Choose 'N' where it points to the BC/Windows disk.

 

diskutil list

diskutil cs list

sudo gpt -vv -r show /dev/diskN

sudo fdisk /dev/diskN

diskutil list

/dev/disk0 (internal, physical):

  #:                      TYPE NAME                    SIZE      IDENTIFIER

  0:      GUID_partition_scheme                        *512.1 GB  disk0

  1:          Windows Recovery                        314.6 MB  disk0s1

  2:                        EFI NO NAME                104.9 MB  disk0s2

  3:        Microsoft Reserved                        134.2 MB  disk0s3

  4:      Microsoft Basic Data BOOTCAMP                511.6 GB  disk0s4

/dev/disk1 (external, physical):

  #:                      TYPE NAME                    SIZE      IDENTIFIER

  0:      GUID_partition_scheme                        *479.9 GB  disk1

  1:                        EFI EFI                    209.7 MB  disk1s1

  2:                  Apple_HFS Macintosh SSD          479.1 GB  disk1s2

  3:                Apple_Boot Recovery HD            650.0 MB  disk1s3

/dev/disk2 (disk image):

  #:                      TYPE NAME                    SIZE      IDENTIFIER

  0:    Apple_partition_scheme                        +179.6 MB  disk2

  1:        Apple_partition_map                        32.3 KB    disk2s1

  2:                  Apple_HFS AdobeCameraRaw-9.3.1... 179.5 MB  disk2s2

/dev/disk3 (disk image):

  #:                      TYPE NAME                    SIZE      IDENTIFIER

  0:    Apple_partition_scheme                        +179.6 MB  disk3

  1:        Apple_partition_map                        32.3 KB    disk3s1

  2:                  Apple_HFS AdobeCameraRaw-9.3.1... 179.5 MB  disk3s2

diskutil cs list

No CoreStorage logical volume groups found

sudo gpt -vv -r show /dev/disk0

gpt show: /dev/disk0: mediasize=512110190592; sectorsize=512; blocks=1000215216

gpt show: /dev/disk0: PMBR at sector 0

gpt show: /dev/disk0: Pri GPT at sector 1

gpt show: /dev/disk0: Sec GPT at sector 1000215215

       start        size  index  contents

           0           1         PMBR

           1           1         Pri GPT header

           2          32         Pri GPT table

          34        2014        

        2048      614400      1  GPT part - DE94BBA4-06D1-4D40-A16A-BFD50179D6AC

      616448      204800      2  GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B

      821248      262144      3  GPT part - E3C9E316-0B5C-4DB8-817D-F92DF00215AE

     1083392   999131136      4  GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7

  1000214528         655        

  1000215183          32         Sec GPT table

  1000215215           1         Sec GPT header

sudo fdisk /dev/disk0

gpt show: /dev/disk0: mediasize=512110190592; sectorsize=512; blocks=1000215216

gpt show: /dev/disk0: PMBR at sector 0

gpt show: /dev/disk0: Pri GPT at sector 1

gpt show: /dev/disk0: Sec GPT at sector 1000215215

       start        size  index  contents

           0           1         PMBR

           1           1         Pri GPT header

           2          32         Pri GPT table

          34        2014        

        2048      614400      1  GPT part - DE94BBA4-06D1-4D40-A16A-BFD50179D6AC

      616448      204800      2  GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B

      821248      262144      3  GPT part - E3C9E316-0B5C-4DB8-817D-F92DF00215AE

     1083392   999131136      4  GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7

  1000214528         655        

  1000215183          32         Sec GPT table

  1000215215           1         Sec GPT header

Daniels-Mac-Pro:~ MacPro$ sudo fdisk /dev/disk0

Disk: /dev/disk0 geometry: 62260/255/63 [1000215216 sectors]

Signature: 0xAA55

         Starting       Ending

#: id  cyl  hd sec -  cyl  hd sec [     start -       size]

------------------------------------------------------------------------

1: EE    0   0   2 - 1023 255  63 [         1 - 4294967295] <Unknown ID>

2: 00    0   0   0 -    0   0   0 [         0 -          0] unused     

3: 00    0   0   0 -    0   0   0 [         0 -          0] unused     

4: 00    0   0   0 -    0   0   0 [         0 -          0] unused

Thanks for your help, it is very much appreciated.

Loner T wrote:

Is it possible to re-install W8.1 without too much pain and grief?

It is possible, its a relatively quick process. I'm embarrassed to ask this, but could you list out the steps I should follow?

I guess I need to format the drive in OS X and then install Windows? I originally used diskpart in command line from my Windows installer to convert the drive to GPT and then formatted the drive through the installer.

Sadly that doesn't seem to work. I run the command, format the drive to OS X extended journals (as described by the Boot Camp Assistant steps you linked to), let BCA split the drive up, the computer reboots and takes me into the windows installer where it tells me it can't install windows on that partition because it has an MBR table. It seems that when BCA partitions the drive, it writes the windows half to FAT32 (which it tells you to re-format once in the windows installer) but I guess in that process is converts the disk to MBR?

The only way Ive gotten it to to install is to "clean" the disk, then hit "new" in the windows disk manager. it makes the 100 MB EFI partition and names it something generic. I can get to OS X fine through BC, but going back to windows still leaves me on a black screen.

I even tried to manually build the partitions with diskpart. create partition efi/msr/primary but that didn't work either. Is there a newer version of BCA that I'm missing? My Mac Pro is running the latest version of el cap and I edited the plist so I could boot from a USB thumb drive.

Loner T wrote:

 

diskutil list

sudo gpt -vv -r show /dev/disk0

gpt show: /dev/disk1: mediasize=512110190592; sectorsize=512; blocks=1000215216

gpt show: /dev/disk1: PMBR at sector 0

gpt show: /dev/disk1: Pri GPT at sector 1

gpt show: /dev/disk1: Sec GPT at sector 1000215215

       start        size  index  contents

           0           1         PMBR

           1           1         Pri GPT header

           2          32         Pri GPT table

          34           6        

          40      409600      1  GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B

      409640        2008        

      411648      262144      2  GPT part - E3C9E316-0B5C-4DB8-817D-F92DF00215AE

      673792   999540736      3  GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7

  1000214528         655        

  1000215183          32         Sec GPT table

  1000215215           1         Sec GPT header

I should have clarified a little. I keep trying your instructions (which Im sure of correct, I think I have a ghost in my machine that really hates me) and it would not let me install windows if I formatted it the disk in BCA. So, after more research I saw someone mention that with Windows 8.1 and pure EFI booting, you didn't necessarily need to let BCA format the drive for you, as it is a sort of work around to get MBR and EFI to play nice together. The poster suggested just formatting the disk in Disk Utility, then booting from the thumb drive that BCA made and reformatting the resulting partition to NTFS. So thats what I did. It gave me an EFI system partition that was the correct size (209.7 MB), a MSR partition, and the primary partition. Windows installed without a hitch. But it still hangs when I try to boot back into Windows from OS X.

With all that said, here are the results you asked for

     Disk: /dev/disk1 geometry: 62260/255/63 [1000215216 sectors]

     Signature: 0xAA55

              Starting       Ending

      #: id  cyl  hd sec -  cyl  hd sec [     start -       size]

     ------------------------------------------------------------------------

      1: EE 1023 254  63 - 1023 254  63 [         1 - 1000215215] <Unknown ID>

      2: 00    0   0   0 -    0   0   0 [         0 -          0] unused    

      3: 00    0   0   0 -    0   0   0 [         0 -          0] unused    

      4: 00    0   0   0 -    0   0   0 [         0 -          0] unused

Loner T wrote:

 

Was the OSX disk attached to the MP when Windows was installed? It is possible (since you are using two separate disks) that the Microsoft Windows EFI is sitting on the Windows disk, while OSX is trying to find the EFI for Windows on the OSX disk. You can check by mounting both EFI partitions (OSX disk and Windows disk) and see where the BCD for Windows is sitting.

I did pull the OS X disk while installing Windows, it seemed to cause the installer to kick back some strange errors and prevent the install from going forward.

I have both disks mounted, though shamefully, I don't know what BCD is. Boot Camp Disk?

Also, since I didn't go through BCA could the disk be labeled incorrectly? Holding alt brings up the various boot disks, and I CAN boot into windows this way, but it looks like this.

http://imgur.com/share/i/XvsxmAd

Does that shed any light on the situation?

Again, thank you for your help.