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View Full Version : [ubuntu] Grub loader on Windows boot - Triple boot Macbook 9,1



Fi5hy
September 27th, 2012, 12:28 AM
Hey all, I've had my triple boot working for a while, but every time I booted up Windows, it's given me the Grub loader first. This hasn't bothered me until this week. I started a programming (C++) class, and to simplify things, I installed VMWare Fusion. Apparently, from what I can tell, Grub loader prevents VMWare from booting into my Windows partition, so I would like fix this Grub loader issue.

I read something about a hybrid MBR fix somewhere, would someone like to clarify?

Fi5hy
October 9th, 2012, 09:29 PM
Bump.

Fi5hy
October 10th, 2012, 07:50 PM
Bump; again.

Fi5hy
October 16th, 2012, 08:29 PM
I really need some help on this still, guys...

Fi5hy
November 23rd, 2012, 11:46 AM
Bump

trogdor1138
December 5th, 2012, 05:51 PM
Do you still need help with this?

You have a couple of options; it really depends on whether Ubuntu is currently installed in EFI mode or BIOS emulation.

Basically, when you install Windows and then later Ubuntu, GRUB overwrites the MBR boot code. It's relatively simple to replace GRUB with the Windows boot loader, but simply doing this renders Ubuntu unbootable. If you installed Ubuntu in BIOS emulation, you'll need to:

- Boot into Ubuntu natively
- Use DD to copy the MBR boot code to a binary
- Boot Windows natively through GRUB
- Re-install the Windows boot loader
- Use BCDedit to chain-load the GRUB binary file

I'm guessing this is the case, since if you installed Ubuntu in EFI mode it wouldn't have any need to overwrite the MBR boot code.

Also, if you do indeed need to fix the hybrid MBR, you're going to need gdisk: http://www.rodsbooks.com/gdisk/hybrid.html

gdisk is used from OS X, and you can then select which GPT partitions to add to the MBR, and which to set as active.

Fi5hy
December 14th, 2012, 02:50 AM
Do you still need help with this?

You have a couple of options; it really depends on whether Ubuntu is currently installed in EFI mode or BIOS emulation.

Basically, when you install Windows and then later Ubuntu, GRUB overwrites the MBR boot code. It's relatively simple to replace GRUB with the Windows boot loader, but simply doing this renders Ubuntu unbootable. If you installed Ubuntu in BIOS emulation, you'll need to:

- Boot into Ubuntu natively
- Use DD to copy the MBR boot code to a binary
- Boot Windows natively through GRUB
- Re-install the Windows boot loader
- Use BCDedit to chain-load the GRUB binary file

I'm guessing this is the case, since if you installed Ubuntu in EFI mode it wouldn't have any need to overwrite the MBR boot code.

Also, if you do indeed need to fix the hybrid MBR, you're going to need gdisk: http://www.rodsbooks.com/gdisk/hybrid.html

gdisk is used from OS X, and you can then select which GPT partitions to add to the MBR, and which to set as active.
Could you explain a bit more? I don't understand what it is I need to do. If you could post a link to a tutorial, that would be great. :) I just don't want to mess anything up.

trogdor1138
December 15th, 2012, 08:56 PM
Sure, check out this TechNet post on how to get the GRUB code into a file: http://blogs.technet.com/b/port25/archive/2006/10/13/http-port25-technet-com-archive-2006-10-12-windows-and-linux-integration-3a00-a-conversation-with-the-author-aspx.aspx

If you need help using gdisk to correct the hybrid MBR information, check out the appropriate article on Rod Smith's site: http://www.rodsbooks.com/gdisk/hybrid.html