Repairing Boot Camp after creating new partition

Apologies, mistype. Yup, definitely no "Panther" folder in "C:\Windows\".

Is there something that could have flipped it from EFI to BIOS? I've had Windows 8 installed since I bought this laptop late last year and Windows has ran fine.

Not really.

As you haven't actually done any partitioning since Windows was installed your questions don't really belong in this thread.

I suggest you make a new thread describing exactly what's happened and where you are now.

And try to remember (or find out) whether Windows was installed in EFImode or in CSM (bios) mode.

Sorry I can't be more helpful.

jamie.shaw wrote:

Apologies, mistype. Yup, definitely no "Panther" folder in "C:\Windows\".

Is there something that could have flipped it from EFI to BIOS? I've had Windows 8 installed since I bought this laptop late last year and Windows has ran fine.

From the OS X Terminal, please run bless --info --verbose and look for the highlighted part...

filesystem[2] '/dev/disk0s4' => '/Volumes/BOOTCAMP'

Firmware feature mask: 0xE003FF37

Firmware features: 0xE003F537

Legacy mode suppported

Got IODeviceTree:/rom

Got start address ff990000

Got size 1a0000

Found PCI interconnect in protocol characteristics

IOGUIDPartitionScheme

APPLE SSD SM1024F Media

IOBlockStorageDriver

IOAHCIBlockStorageDevice

AppleAHCIDiskDriver

IOAHCIDevice

PRT0

AppleAHCI

SSD0

IOPP

RP05

AppleACPIPCI

PCI0

AppleACPIPlatformExpert

MacBookPro11,3

Root

Matching legacy device 'disk0s4'

Legacy boot device detected

mount: /Volumes/BOOTCAMP

Mount point for /Volumes/BOOTCAMP is /Volumes/BOOTCAMP

GPT detected

Booter partition required at index 5

System partition found

Preferred system partition found: disk0s1

Hi Loner T,

I ran "bless --info --verbose" in terminal and got the following results; none of which looks like what you have posted. :/

EFI found at IODeviceTree:/efi

Current EFI boot device string is: '<array><dict><key>IOMatch</key><dict><key>IOProviderClass</key><string>IOMedia </string><key>IOPropertyMatch</key><dict><key>UUID</key><string>3B757275-3373-46 3B-9F6D-FDEF74395D5F</string></dict></dict><key>BLLastBSDName</key><string>disk0 s2</string></dict></array>'

Boot option is 8BE4DF61-93CA-11D2-AA0D-00E098032B8C:Boot0080

Processing boot option 'Mac OS X'

Boot option matches XML representation

Found device: disk0s2

Disk boot device detected

mount: /

Mount point for / is /

GPT detected

No auxiliary booter partition required

System partition found

Preferred system partition found: disk0s1

Returning booter information dictionary:

<CFBasicHash 0x7f8e195001d0 [0x7fff74fbdf00]>{type = mutable dict, count = 3,

entries =>

0 : <CFString 0x10e3d3e70 [0x7fff74fbdf00]>{contents = "System Partitions"} = (

disk0s1

)

1 : <CFString 0x10e3d4650 [0x7fff74fbdf00]>{contents = "Data Partitions"} = (

disk0s2

)

2 : <CFString 0x10e3d4670 [0x7fff74fbdf00]>{contents = "Auxiliary Partitions"} = (

)

}

finderinfo[0]: 457078 => Blessed System Folder is /System/Library/CoreServices

finderinfo[1]: 8279379 => Blessed System File is /System/Library/CoreServices/boot.efi

finderinfo[2]: 0 => Open-folder linked list empty

finderinfo[3]: 0 => No alternate OS blessed file/folder

finderinfo[4]: 0 => Unused field unset

finderinfo[5]: 457078 => OS X blessed folder is /System/Library/CoreServices

64-bit VSDB volume id: 0x451C89A8F69D10BB

jamie.shaw wrote:

Hi Loner T,

I ran "bless --info --verbose" in terminal and got the following results; none of which looks like what you have posted. :/

Your EFI repair seems to have messed the MBR. For a Bootcamp installation, on my system, this is what I have in the MBR (I have an rMBP and it is a "regular" Bootcamp with W7 (not W8)).

sudo fdisk /dev/disk0

Disk: /dev/disk0 geometry: 121643/255/63 [1954210120 sectors]

Signature: 0xAA55

Starting Ending

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

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

1: EE 1023 254 63 - 1023 254 63 [ 1 - 409639] <Unknown ID>

2: AF 1023 254 63 - 1023 254 63 [ 409640 - 1452530904] HFS+

3: AB 1023 254 63 - 1023 254 63 [1452940544 - 1269536] Darwin Boot

*4: 07 1023 254 63 - 1023 254 63 [1454211072 - 499998720] HPFS/QNX/AUX

Your GPT looks good (I just did the start+size which does point to the start of the next GPT part).

If Windows does not boot AND your MBR is corrupted, more than likely you have a "legacy" (aka CSM-BIOS) installation.

My recommendation is to use gdisk (GPT fdisk) from SourceForge and correct your MBR to see if W8 will boot. Number88 has a good set of steps to recreate the MBR via gdisk. I suggest you create a backup of the whole disk and your bootcamp partitions, both, before you start tinkering with the MBR.

Hi again,

I've installed gdisk and created a new Hybrid MBR using the resources found on the author's website, and using the brief tutorial that solved the original poster of this thread. The following is now output from "fdisk /dev/disk0":

Disk: /dev/disk0 geometry: 60821/255/63 [977105060 sectors]

Signature: 0xAA55

Starting Ending

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

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

1: EE 0 0 2 - 25 127 14 [ 1 - 409639] <Unknown ID>

2: AF 25 127 15 - 1023 254 63 [ 409640 - 876953152] HFS+

3: AB 1023 254 63 - 1023 254 63 [ 877362792 - 1269536] Darwin Boot

*4: 07 1023 254 63 - 1023 254 63 [ 878632960 - 97755136] HPFS/QNX/AUX

This now appears to match yours (I installed Windows 8 via Boot Camp Assistant also).

However, this still no longer lists Windows as a bootable volume through OS X's bootloader. Checking the other outputs I previously posted, the only difference is now that the first partition in the GPT is no longer protected and instead listed as "MBR" instead of "MBR".

I'm curious now, having corrected the MBR (or seemingly done so), I wonder if my Windows 8 installation was done through EFI? From what I've read, BCA still would use the legacy alternative?

Any ideas? And thanks for all the help so far – really appreciate it 🙂

For reference, here's my new "sudo gpt -r -vv show disk0":

gpt show: disk0: mediasize=500277790720; sectorsize=512; blocks=977105060

gpt show: disk0: Suspicious MBR at sector 0

gpt show: disk0: Pri GPT at sector 1

gpt show: disk0: Sec GPT at sector 977105059

start size index contents

0 1 MBR

1 1 Pri GPT header

2 32 Pri GPT table

34 6

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

409640 876953152 2 GPT part - 48465300-0000-11AA-AA11-00306543ECAC

877362792 1269536 3 GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC

878632328 632

878632960 97755136 4 GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7

976388096 716931

977105027 32 Sec GPT table

977105059 1 Sec GPT header

I'm curious about the partitions before and after the 4th (bootcamp) partition. People seem to have one nearing 200,000 before the bootcamp partition and a much smaller value after it. Could this be an indiciation something is incorrect?

BCA still uses Legacy Mode. I have checked another 13-in MBP (older though than the rMBP you have) and it shows legacy installation.

Do you have an option to select Bootcamp in System Preferences? If you do, and try to bring up W8, does it hang?

jamie.shaw I too am curious as to which mode was used to install Windows. As you didn't install it yourself (iirc) it leaves us wondering. I know that some later rMBP's can use EFI.

If you mount the EFI partition you can then view what's in it in a Finder window. PLEASE NOTE that once mounted you shouldn't change anything at all!

In a terminal do

diskutil list

you should see an output like this

/dev/disk0

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *251.0 GB disk0

1: EFI 209.7 MB disk0s1

2: Apple_HFS Macintosh HD 250.1 GB disk0s2

3: Apple_Boot Recovery HD 650.0 MB disk0s3

Check the diskXsY number of your EFI partition (209.7 MB)

It's probably as above, if it is do

mkdir /Volumes/efi

then do

sudo mount -t msdos /dev/disk0s1 /Volumes/efi

Now open a Finder window and at the bottom of the left pane you'll see EFI

click on that and you'll see its contents in the right pane.

There should be one folder (EFI, or maybe APPLE)

double-click that folder to open.

What folders are inside that folder?

the first partition in the GPT is no longer protected

I'm not sure why you think this. The first partition in the MBR is type 0xEE which is "GPT Protective" and it starts at sector1 (the GPT header) and goes all the way to the end of the EFI System partition, which is how it should be.

I'm curious about the partitions before and after the 4th (bootcamp) partition.

The 632 sectors of free space is less than 1MB and is just favoring alignment to 1MB boundaries, which is fine. However, the following 716931 unallocated sectors is 350MB of space which I'd say is unexpected but doesn't definitively mean it's a problem. I'd go back to all of your earliest fdisk and gpt outputs and see if the start/size value is still correct or if something has changed.

Every Mac I've tested so far (not that many but more than a few), have a firmware that expects three things to be true in order to show a Windows icon in the option-key+bootchime startup manager; legacy bootstrap code in the first 440 bytes of the first sector (the whole first sector is called the MBR which includes a partition map and this code); the MBR contains more than the single GPT protective partition entry,i.e. it is a hybrid MBR; an MBR entry other than the GPT protective entry is flagged as bootable. The firmware doesn't check anything else. You clearly have two of those requirements, so it sounds like the bootstrap code is not present or corrupt. I forget if bootrec.exe /FixBoot or /FixMbr fixes that, but it doesn't hurt to do both.

As for EFI install, you can do this:

mkdir /Volumes/EFI

sudo mount -t msdos /dev/disk0s1 /Volumes/EFI

ls -l /Volumes/EFI/EFI/

That will mount the EFI System partition, and list the contents of its EFI folder. If you have a legacy BIOS install of Windows, then the only result is a directory called APPLE. If there's one for MICROSOFT then you have an EFI install of Windows 8.

Christopher Murphy wrote:

As for EFI install, you can do this:

mkdir /Volumes/EFI

sudo mount -t msdos /dev/disk0s1 /Volumes/EFI

ls -l /Volumes/EFI/EFI/

That will mount the EFI System partition, and list the contents of its EFI folder. If you have a legacy BIOS install of Windows, then the only result is a directory called APPLE. If there's one for MICROSOFT then you have an EFI install of Windows 8.

Number88 and Christopher... Good to know this. Thanks. 😎

Noted for future reference.

Do you have an option to select Bootcamp in System Preferences? If you do, and try to bring up W8, does it hang?

Hi Loner T, I do have the option, but unfortunately, yes, restarting through the Startup Disk pref pane does cause it to hang on boot.

the first partition in the GPT is no longer protected

I'm not sure why you think this. The first partition in the MBR is type 0xEE which is "GPT Protective" and it starts at sector1 (the GPT header) and goes all the way to the end of the EFI System partition, which is how it should be.

This is simply because in my previous GPT output (before I created the Hybrid MBR manually), it stated "PMBR" and this time it has dropped the 'P' and shows "MBR" – all this terminal-based disk manipulation is new to me so I'm just spitballing ideas.

I'm curious about the partitions before and after the 4th (bootcamp) partition.

The 632 sectors of free space is less than 1MB and is just favoring alignment to 1MB boundaries, which is fine. However, the following 716931 unallocated sectors is 350MB of space which I'd say is unexpected but doesn't definitively mean it's a problem. I'd go back to all of your earliest fdisk and gpt outputs and see if the start/size value is still correct or if something has changed.

The oldest I've got is the first fdisk I did yesterday, before I manipulated the MBR. The value is the same. As far as I'm aware, I've made no amends to the GPT (or at least conciously) – just the MBR so far.

Every Mac I've tested so far (not that many but more than a few), have a firmware that expects three things to be true in order to show a Windows icon in the option-key+bootchime startup manager; legacy bootstrap code in the first 440 bytes of the first sector (the whole first sector is called the MBR which includes a partition map and this code); the MBR contains more than the single GPT protective partition entry,i.e. it is a hybrid MBR; an MBR entry other than the GPT protective entry is flagged as bootable. The firmware doesn't check anything else. You clearly have two of those requirements, so it sounds like the bootstrap code is not present or corrupt. I forget if bootrec.exe /FixBoot or /FixMbr fixes that, but it doesn't hurt to do both.

I'll make a Windows 8 install disk, and give this a go. I'll post my findings as soon as I can.

As for EFI install, you can do this:

mkdir /Volumes/EFI

sudo mount -t msdos /dev/disk0s1 /Volumes/EFI

ls -l /Volumes/EFI/EFI/

That will mount the EFI System partition, and list the contents of its EFI folder. If you have a legacy BIOS install of Windows, then the only result is a directory called APPLE. If there's one for MICROSOFT then you have an EFI install of Windows 8.

Ran this – just the Apple directory. Definitely a legacy BIOS install.

Hopefully, the /FixMbr or /FixBoot might resolve the issue *fingers crossed*

Thanks again for all the help so far – really appreciate it. It's good to know the internet still has genuinely helpful people that don't quickly retort with sarcastic remarks 🙂

I followed these instructions (gdisk, as stated in the accepted answer) to the letter and everything went as stated here. However, I still don't see Windows as an option in the bootloader. What am I missing?

You clearly have two of those requirements, so it sounds like the bootstrap code is not present or corrupt. I forget if bootrec.exe /FixBoot or /FixMbr fixes that, but it doesn't hurt to do both.

Bingo. This did the trick - it's taken me a while to find a big enough USB drive. I'm living in a house of 2GB thumb drives!

Truth me told, on first boot into windows, it said the Boot Configuration was incorrect, but Windows 8's "Automatic Repair" feature fixed this.

Thanks Chris - really, really appreciate it!

Just FYI:

I finally caved and installed Win 8 to a brand new Bootcamp partition.

I currently know of no way to copy a legacy MBR volume over from another Mac to the new 2013MacPro6.1.