This is a guide to setting MyBootMgr up for configuring and installing OpenCore and RefindPlus to multiboot Classic Mac Pros (3,1 to 5,1) as well as equivalent Xserve (2,1 and 3,1). The setup MyBootMgr creates involves chain loading Mac OS from system optimised OpenCore instances via RefindPlus and loading other items directly from RefindPlus

This post is the only required reading for implementation
The fewer other posts of the thread read, the better​

Due to significant automation as of MyBootMgr v062, the package is now too large to attach to this post
You can download it HERE​

The RefindPlus/OpenCore setup created by MyBootMgr is benign and can be implemented and removed without changing any fundamentals. As a result, it can be safely tested subject to ensuring it is implemented on a physical disk that only contains data, or as a minimum, that does not hold the default natively supported operating system. This allows disconnecting disks to isolate issues while still being able to operate the Mac afterwards

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why so complicated...

don't know how to start on my 3.1

Start from the first item under "STAGE 1: PRE INSTALLATION", that is, "Download and copy the attached zip file to your /Users/Shared folder and unzip it there". Then work your way down each item in order.

Expert Dayo:
Is this possible for a cMP 5,1 dual processor? Can I follow the instructions as written? I am a real Newbie!!
I want to use OC (I am using 0.5.5 on my startup disk) and remind so I can boot into my legacy bootcamp SSD- Any help will be greatly appreciated!!

First off, I'm no expert and this is basically a Noob to Noob Guide. The Experts tend to leave things out of their guides as they imagine everyone knows certain things.

Anyway, this is probably not such a good idea for the cMP 5,1 ... unless you are actually an expert and can navigate the potential pitfalls.

Main issue is that RefindPlus only shows Boot Screen on cMP 3,1 (Unless you have Apple EFI GPU I suppose)

RefindPlus now shows boot screen on all cMP models running GPUs with valid Usable or Fixable GOP

Thanks Anyway!
You are right-"The Experts tend to leave things out of their guides as they imagine everyone knows certain things."
If you come across a procedure for a cMP 5,1 please post on your thread!!

It will probably work on a CMP 5,1 running a GPU with Apple EFI but I haven't tested and can't say for certain.

It works on a cMP 3,1 to 5,1 running a GPU with valid Usable or Fixable GOP.

Dayo said:

Detailed, yes, but complicated, No.

Several of the steps are optional, meaning you can skip them but better to use them, and several are with clear instructions to skip. You just need to follow a simple sequence of actions.

For instance, in Stage 1, Only Steps 1 & 2 (plus Step 5 if on Retina Display) are required for most on a cMP 3,1.
That's only three actions.

If you do have observations on unnecessary complications, I will be very happy to make amendments.

Click to expand...

Do you know if I can boot from a PCIe nmve drive using this method?

George Deley said:

Do you know if I can boot from a PCIe nmve drive using this method?

OpenCore and RefindPlus can boot stuff on NMVe drives if setup to do so but that is not the subject of this thread.

Hi Dayo. Thank you very much for the detailed walkthrough. I can confirm that I managed to get Refind and OC working on my MacPro 3,1 with Asus Dual OC Radeon RX580 and Mac OS Mojave using DosDude1's install. However, the only issue I encountered was that when booting using both OC instances I got graphical glitches in some games, that were resolved on removing RadeonBoost.kext. I assume you had this issue too, so removed it from the latest release? What is the function of the RadeonBoost.kext?

The other issue I noticed, is that even if you change the SIP preferences in Refind, when booting into DosDude's Mojave SIP is always disabled. Is there a way to turn it back on, or does it always have to be disabled for DosDude's patching to work?

Thanks again.

Hi.

I run a cMP 3,1 with Dosdude Patched Mojave as well.

Dosdude patch always disables SIP. Can't recollect the details why but I think it is to allow the various unsigned kexts to work.

Basically most likely a lowest common denominator setting to allow a one click installation setup.

RadeonBoost is supposed to help Radeon GPUs. I use it but decided to remove from this distribution as it was making things a bit too opinionated.

Better to let people discover and decide whether they want it or not themselves. Many might not even use Radeons.

I.E., was not removed because of issues found.

It is not critical so if not working for you, you can just remove it or set up one instance of OC not to have it.

Updated for OpenCore v0.5.8

Please mention that Refind bootscreen is NOT working on cmp 4&5.1! OpenCore only. Otherwise your guide is very useful!

Thanks for the feedback. If you read the "Notes" section near the beginning, you would find this is already stated as being the case if you don't have a GPU with APPLE EFI.

RefindPlus now shows boot screen on all cMP models running GPUs with valid Usable or Fixable GOP.

Dayo said:

Thanks for the feedback. If you read the "Notes" section near the beginning, you would find this is already stated as being the case if you don't have a GPU with APPLE EFI.

Yes, now I noticed. Just didn't understand that while reading for the first time.

By the way, do you know how can I install Windows 10 in UEFI mode, to boot it from OpenCore? Some simple detailed guide, like this one? I had MBR installation of Windows 10 on the separate SSD, I used command mbr2gpt, converted the disk, and now when I try to boot Windows from OpenCome it boots, but results in error no bootable drive; what is interesting that I can boot in safe mode. And none of recovery options help. So I thought better I reinstall Windows 10.

byally said:

By the way, do you know how can I install Windows 10 in UEFI mode, to boot it from OpenCore?

If you refer to the same "Notes" section, you will find information on installing Windows which would answer your question.

I had MBR installation of Windows 10 on the separate SSD, I used command mbr2gpt, converted the disk, and now when I try to boot Windows from OpenCore it boots, but results in error no bootable drive

OpenCore does not support Legacy Windows. It could be that the conversion did not take.

byally said:

try to boot Windows from OpenCome it boots, but results in error no bootable drive; what is interesting that I can boot in safe mode.

You may need to re-examine the BCD store inside the ESP partition and make sure it points to the correct partition. You can use bootice:

To have multiple copies of the same boot loader, I would put them into different partitions. That way you don't need a patch like OC_ALT. A FAT partition is required for writing log files or other files but normally, I use an HFS+ partition because a long time ago when I tried FAT, there was a 30 second delay in startup of the boot loader (using rEFIt or rEFInd). I haven't tried recently though but MacPro3,1 firmware hasn't changed since then so I don't expect a difference. Maybe boot loader from EFI folder doesn't have the 30 second delay - I forget the actual situation.

joevt said:

To have multiple copies of the same boot loader, I would put them into different partitions. That way you don't need a patch like OC_ALT. A FAT partition is required for writing log files or other files but normally, I use an HFS+ partition because a long time ago when I tried FAT, there was a 30 second delay in startup of the boot loader (using rEFIt or rEFInd). I haven't tried recently though but MacPro3,1 firmware hasn't changed since then so I don't expect a difference. Maybe boot loader from EFI folder doesn't have the 30 second delay - I forget the actual situation.

I put my OC on an HFS+ partition in EFI folder but the log file is not written. Maybe any HFS.efi will do loaded during boot?

startergo said:

I put my OC on an HFS+ partition in EFI folder but the log file is not written. Maybe any HFS.efi will do loaded during boot?

Do any EFI file system drivers support writing, other than the default FAT driver? I don't know if I'd want to load a third party HFS EFI driver to support writing. I guess it would be nice to have OpenCore or Clover be able to write to HFS partition for their logs. The other option is to patch them so they write logs to a specific folder in an EFI or FAT partition so that you can tell which boot loader created the log.

joevt said:

To have multiple copies of the same boot loader, I would put them into different partitions. That way you don't need a patch like OC_ALT.

That's an option and I had such for a while but in the case of chain loading from RefindPlus which is the aim here, such partitions must be "USB" (HFS+) Volumes unless possible to point the RefindPlus config to another EFI which I have not been able to figure out.

In any case, I later decided I preferred to have all my boot stuff in one location which this gives.

joevt said:

A FAT partition is required for writing log files or other files but normally, I use an HFS+ partition because a long time ago when I tried FAT, there was a 30 second delay in startup of the boot loader (using rEFIt or rEFInd). I haven't tried recently though but MacPro3,1 firmware hasn't changed since then so I don't expect a difference. Maybe boot loader from EFI folder doesn't have the 30 second delay - I forget the actual situation.

The 30 second thing doesn't seem to affect me on EFI (mostly). I do have instances where it happens and I have noticed that when this is the case, a drive I have in a PCIe slot does not mount. Immediately rebooting from RefindPlus or OpenCore (I requested the option to reboot from OpenCore that was added in v0.5.8) solves this.

It's not the typical rEFInd 30 Second thing I suppose as the reboot cures it.

i try this tutorial on my 3.1 dual Quad-core Xeon Harpertown..
is that work...??

ryderpat said:

i try this tutorial on my 3.1 dual Quad-core Xeon Harpertown..
is that work...??

Sorry. Not clear what you mean. Do you mean you want to try the tutorial or that you have tried it already?

Dayo said:

Sorry. Not clear what you mean. Do you mean you want to try the tutorial or that you have tried it already?

sorry, I mean try to install open core..in my 3.1
step by step as the tutorial .