Hi. I have my old macbook pro 15 mid 2012 High Sierra. I'm trying to format my second ssd (sata-optibay) for Windows 10 with legacy bios mode, because it's impossible to make cirrus logic sound card work with uefi win10.
Bootcamp Assistant keeps formatting it with UEFI.
Disk Utility allows me to make MBR disk, but in the end it is not bootable.
What am I doing wrong?
MacBook Pro 15", macOS 10.13
On 2012 and older Macs, the GPT is 'overlaid' with a Hybrid MBR (an excellent technical resource is http://www.rodsbooks.com/gdisk/hybrid.html ).
Except Fusion drives (CoreStorage and APFS), Windows must always be installed on the first disk in the Main bay, because of the Windows BCD used.
Tower MacPros (2012 and older) are different animals, because a disk can be moved into any of the four bays and used. You can
In Fusion configurations, the second disk (HDD in most cases for a CS or a 'Auxiliary Use' disk in APFS) is the default.
2012 iMac with 3TB Fusion drives is problematic with Mojave as documented in If you see the alert 'Installation cannot proceed with Boot Camp configured' - Apple Support. Primarily due to lack of a 'sandwich layout' being unsupported under APFS and secondly being a preUEFI Mac.
W7 support was deprecated in 2015 and later Macs in the march towards UEFI/GPT and the bugginess of W7 EFI implementation.
On the 13-in 2012 Mac (and similar ones with the SuperDrive), the Optibay modification causes problems, because of BCA's Model Identifier-driven logic, which gets confused between the Tower MP and the MBP logic. Once Windows is fully installed, the Optibay drive can be reconnected to the SATA bus and can contain macOS (+non-OS storage, if desired). Windows will treat it as D: (another drive letter, as the case may be).
There are other nuances, which would require a full tome to clarify.
OMG I solved my problem by switching windows SSD from dvd-bay to the main hdd-bay... This is ridiculous.
Loner_T was referring to Boot Camp and how Boot Camp presents the Mac hardware to Windows with that quoted image.
Intel Mac uses UEFI for its bootstrap. UEFI expects GPT partitioning.
The only MBR that’s present in the usual Mac configuration is the so-called protective MBR that’s intended to prevent the GPT from getting clobbered by the older MBR-only tools.
Boot Camp adds a layer atop that to allow Windows to recognize and boot on an Intel Mac.
Folks most knowledgeable in Boot Camp and its operations tend to be over in the Boot Camp forum, too.
Disk Utility allows three sorts of partitioning on macOS. GPT (with a protective MBR), MBR, and the older Apple Partition scheme. Recent Windows and macOS and most other systems use GPT, as does Boot Camp. You know this, of course.
Follow the link in my previous post for one possible way to enable the MBR legacy boot path that you want to try to use with Windows. Or follow the other link and use ESXi or equivalent, as that and similar packages can present different boot-time environments to the guest operating systems.
It also seems that Windows must be installed on the main boot device... And it appears Windows isn’t happy to find a GPT device.
But again, High Sierra is not the best spot on the Internet to ask Windows legacy bootstrap questions. The Boot Camp forum is probably the best fit, here at Apple.
All Intel Macs are UEFI, and that’s the path that all recent Boot Camp uses, and that’s the path that Microsoft now prefers.
As for your question? Ask the Cirrus Logic or maybe the Microsoft Windows support folks for help?
Or maybe ask in the Boot Camp forum? Or find a different sound card?
Or boot Windows 10, via VMware or similar? Might get to legacy MBR boot that way.
Or try this sequence that turned up with some DDG searches?
Asking macOS High Sierra folks about Windows MBR legacy boot and Cirrus driver support... is probably not a good option.
Well, if you read my first post you will see, that my question was not about drivers or windows. I asked how to properly format SSD in High Sierra.
As for UEFI, only 2013 and newer Macs have native support for EFI boot with Windows 8 and 10.
2012 models have some sort of half-semi hybrid support, but specifically Macbook Pro 15" and Retina mid 2012 have this problem with sound driver, in case of EFI + Windows 8/10. That's why I want to find out how to make my SSD bootable, because BC-assistant is not working for me.
diskutil screenshot
My Guess here is you'll have to remove that partition with bootcamp, then use different methods like Disk Utility...
https://www.intowindows.com/how-to-install-windows-8-1-on-mac-without-boot-camp/
As I mentioned, I already tried Disk Utility method. During Windows 10 installation I get this message.
Sorry, no idea how I missed that.
Is it possible to make a Bootable Win10 DVD?
Great work you part. :)
Dang, I should've caught that, been discussed on my site a couple of times, Windows® want First Partition on 1st drive on 1st bus...
How to format MBR legacy bios disk for Windows 10 on pre-UEFI macbook?
