Formatted macOS, BootCamp can't see macOS drive

[ifraaank]

Hi. So I upgraded to High Sierra, and I always do clean installs. Got it working like a charm, and had to go into Windows to do some CAD work. But now I want to go back into macOS, but I can't since the Boot Camp control panel no longer can see the macOS drive. Any ideas how to get it back? Without re-installing Windows. I can't use "alt" at startup since I use a non-flashed NVIDIA 980 Ti. The macOS partition is installed on a PCIe SSD, and Windows is installed on a 250GB SATA SSD in the drive bay. Mac Pro 4,1 to 5,1. Other specs in my sig.

Thanks!

 

[h9826790]

For APFS drive, sorry, Windows won't able to see it until Apple update the bootcamp driver.

Since you have unflashed GTX980, so PRAM reset may not be a good idea for you to go back to MacOS (Yes, reset PRAM will automatically bring you back to MacOS on next boot.

For you, in fact, the easiest way, may be use option boot. I know you can't see anything. However, the arrow key still works. So, hold option key during boot. Wait for at least 1 min. hit right arrow key once and then enter. Hopefully it will bring you back to the MacOS partition you want. If doesn't work, you may have to force shutdown and try again. (If you pull out the Windows drive before you do the option boot, you should not need to press any arrow key, but just enter should bring you back to MacOS)

Of course, if you don't mind to perform a PRAM reset, you can also do that, and than use your remote control to turn the web driver back on (I assume you've already setup the remote control since you are running an unflashed GTX980)

 

[Dr. Stealth]

The simplest solution for your issue is to use BootChamp (free) to boot into windows from macOS.

BootChamp lets you keep your macOS disk as default while still letting you boot to Windows. To get back to macOS just do a re-boot from Windows and your Back-to-Mac !

 

[ifraaank]

For APFS drive, sorry, Windows won't able to see it until Apple update the bootcamp driver.

Since you have unflashed GTX980, so PRAM reset may not be a good idea for you to go back to MacOS (Yes, reset PRAM will automatically bring you back to MacOS on next boot.

For you, in fact, the easiest way, may be use option boot. I know you can't see anything. However, the arrow key still works. So, hold option key during boot. Wait for at least 1 min. hit right arrow key once and then enter. Hopefully it will bring you back to the MacOS partition you want. If doesn't work, you may have to force shutdown and try again. (If you pull out the Windows drive before you do the option boot, you should not need to press any arrow key, but just enter should bring you back to MacOS)

Of course, if you don't mind to perform a PRAM reset, you can also do that, and than use your remote control to turn the web driver back on (I assume you've already setup the remote control since you are running an unflashed GTX980)

I imagined it was because of the APFS. I'll try holding option, but I'm pretty sure I tried that before. I'll see if it works! I didn't turn on remote control yet, since I've only had macOS open once because of this Thanks!

The simplest solution for your issue is to use BootChamp (free) to boot into windows from macOS.

BootChamp lets you keep your macOS disk as default while still letting you boot to Windows. To get back to macOS just do a re-boot from Windows and your Back-to-Mac !

I thought BootChamp did the same as going into settings and then choose the boot drive, had no idea that it was one-time only! I'll try it! Thanks

 

[h9826790]

The simplest solution for your issue is to use BootChamp (free) to boot into windows from macOS.

BootChamp lets you keep your macOS disk as default while still letting you boot to Windows. To get back to macOS just do a re-boot from Windows and your Back-to-Mac !

Discussed that with another member, BootChamp won't work, because that has conflict with the Nvidia web driver (BootChamp will mess up web driver's PRAM parameter)

 

[ifraaank]

Alright, so the only solution for me, right now, is to pop in the old GT120 gpu, reset PRAM and reset boot/disk and change to NVIDIA drivers. Then I can pop the 980 Ti in again. From now on I can use remote control after a PRAM reset, since I definitely turned that on now.

Holding alt/option didn't work for me. No matter what I did, it stayed at a black screen. I tried one right arrow then enter, two arrows then enter, and three arrows then enter... Also tried disconnecting the Windows drive and then only enter, and all of them gave a black screen.

 

[Dr. Stealth]

Discussed that with another member, BootChamp won't work, because that has conflict with the Nvidia web driver (BootChamp will mess up web driver's PRAM parameter)

Really ? I use BootChamp several times a day with no issues at all. That person must have had a different issue or didn't understand how SIP works.

High Sierra, Nvidia Web Drivers & BootChamp 1.7

1. Enable SIP and install the web drivers and CUDA drivers. (Add GateKeeper exceptions for both)

2. Install BootChamp, Disable SIP and everything works as expected.

I bounce back and forth between macOS High Sierra and Windows 10 Pro using BootChamp all day long.

 

[h9826790]

Really ? I use BootChamp several times a day with no issues at all. That person must have had a different issue or didn't understand how SIP works.

High Sierra, Nvidia Web Drivers & BootChamp 1.7

1. Enable SIP and install the web drivers and CUDA drivers. (Add GateKeeper exceptions for both)

2. Install BootChamp, Disable SIP and everything works as expected.

I bounce back and forth between macOS High Sierra and Windows 10 Pro using BootChamp all day long.

View attachment 723803

Interesting, it seems my initial suggestion in the following thread should work, but somehow didn't work out for another reason.

https://forums.macrumors.com/threads/dual-boot-with-a-pc-graphic-card.2074847/

 

[devon807]

I was having this same issue, but with my RX 580, about to try this before I buy a second hand GT120

 

[devon807]

I got Windows to boot, but I cant get the RX 580 to work in windows