I have installed Windows 8.1 Pro via Boot Camp on my MacBook Pro Retina 15-inch mid-2015, with OS X Yosemite 10.10.4 and Boot Camp Assistant version 5.1.4. I can prove that this version of Boot Camp is no longer creating hybrid GPT/MBR partition scheme to install Windows 8 x64 on Intel-based Macs, and Windows is directly booted in EFI mode. Here are what I have tried:
- Running Ubuntu on its installation flash drive, I ran
sudo disk -l /dev/sda to check my local Mac SSD; results:
MBR: protective, BSD: not present, APM: not present, GPT: present Found valid GPT with protective MBR; using GPT Therefore Windows is not booting from and running on a disk with hybrid GPT/MBR scheme.
- In Windows,
C:\Windows\panther\setupact.log has one entry: Callback_BootEnvironmentDetect: Detected boot environment: EFI How to tell if windows 7 installer boot in EFI or BIOS?
Therefore theoretically Boot Camp is not needed to install Windows 7/8 x64, which support booting from GPT disks on UEFI(that is EFI 2.x)-based systems. But still it's better to use Boot Camp to create the Windows Installation flash drive and download drivers for Windows. The guide: How to install Windows 8.1 on Mac without Boot Camp To sum it up:
- Partition your disk as you wish in
Disk Utility in OS X; just format your desired Windows OS and data partitions as FAT32.
- Since Retina MacBook Pros do not come with a SuperDrive, you need to create a Windows Installation flash drive from the ISO file. Please do this in Boot Camp Assistant. I have tried run
dd command on Mac's Terminal to copy the ISO, but the created flash drive is not bootable on UEFI Macs: the Apple boot manager simply does not recognize the flash disk.
- Plug in the flash drive, restart the computer and hold
option to open Apple boot manager. You will see a yellow drive called "EFI Boot", which is the Windows Installation. Continue the installation as normal, and format your Windows OS partition as NTFS when asked.
- Whenever the computer restarts, you need to hold
option key and select "Windows" drive on your local SSD to continue installation. Finally go into the system and drivers from Boot Camp will automatically install.
You should keep a Time Machine backup before these operations. Even if things really mess up, you can just create a OS X Yosemite installation flash drive, re-format the SSD to one partition and re-install OS X. How to make a bootable OS X 10.10 Yosemite install driveThe newest version of Recovery HD partition will automatically come back. This worked successfully when I wrongly operated the disk in Ubuntu.
Hope this works!
I'll post this as an answer, even though it didn't fix my problem – this was a lost case in the end. Aftermath: I dd'ed a backup of the Windows partition to my OS X partition:
sudo dd bs=512 if=/dev/disk0 of=windows_backup skip=732993496 count=173955112
Now I had a 80 gig hex dump which I could examine safely. I used a hex editor to search for all kinds of metadata:
- "NTFS" (encoded in ASCII) which starts a NTFS volume.
- "FILE" (encoded in ASCII) which starts a file entry record in the $MFT or master file table in NTFS.
- NTFS system file names (like "MFT", tried with little-endian UTF-16 and ASCII)
... and so on. But without success. I was able to find all kinds of data from the dump, but all the metadata, including the boot record (the first sector of the volume), the $Boot file (the first 15 sectors after the boot record), the $MFT file which keeps record of all the files on the file system, were gone.
The thing that baffles me that I couldn't even find $MFTMirr file, which is the backup file of the metadata files and stored halfway of the volume.
I was able to find a backup of the boot sector from its standard location, the last sector of the volume. However, the data was old, from the era before resizing the volume. The boot sector has stored the offset of the $MFT file metadata file, but inspecting the references was moot, there was nothing of value there.
In the end, I concluded that the volume was totally borked. The moral of the story? Hybrid Master Boot Record is evil. Also, it seems that the program that resized the volume did a subpar job, failing to update some of the metadata.
Best Answer
The short answer is yes. Starting with the 2015 Mac models, you can not use the "hybrid MBR" mode. You must use GPT partition scheme for all operating systems installed. Installation is fairly straight forward. When installing Ubuntu, I would advise that you create a second EFI partition. This would allow you to use the Startup Manager to select the current and default operating system to boot from.
The order of installation would be OS X, Windows and finally Ubuntu. This allows you to use the Boot Camp Assistant to install Windows. After installing Ubuntu, you will need to copy some files from the first EFI partition to the second EFI partition in order for the Startup Manager recognize the Ubuntu operating system.
To get Ubuntu to appear in the Startup Manager, you have to manually mount the both EFI partitions and copy the files in the
\EFI\UBUNTUfolder of the first EFI partition to the\EFI\BOOTfolder of the second EFI partition. Also, the copied grubx64.efi file needs to be renamed to BOOTX64.EFI.You can also use rEFInd as a boot manager. While rEFInd is not required, it does have the advantage of not having to hold down the option key a startup to switch operating systems. Personally, I have it installed in its own EFI partition, but I rarely use it.