Can anyone help with installing open core to install macOS 15 sequoia

If you are using a real Mac, then you should be using OCLP (Open Core Legacy Patcher), not Open Core. OCLP 2.4 works great on real macs.

Did you install root patches ? What is Boot Picker Timeout set to? Have you tried it with the GOP option off? Do you have full acceleration (tansparent dock)?

Mojave does not require root patches, but Sequoia does. You should be using OCLP 2.4.0 or 2.4.1, either should be fine. There is one gotcha, and that is the USB 1.1 dropped support. To get around that, make sure your installation USB is 2.0 or 3.0 and plug in a USB hub.

Main screen you should be familiar with.

Your target model should be picked automatically. I assume MacPro 2012 is a MacPro5,1 ? You can always click the "settings" button and get to this and change it. Build tab is where your Boot Picker Timeout is located.

Advanced tab is where you can turn on/off GOP.

Last month I created a drive for a friend's 5,1 on my 4,1 upgraded to 5,1 ROM. Here is the bootpicker (all APFS Volumes, Windows was a secondary drive). These are not default icons, I added them to each Volume after installation.

Booted into Sequoia. Once you have installed Sequoia, OCLP should pop up and tell you that you are running without root patches and offer to install them for you.

Hope that helps.

There is a lot going on in that paragraph. Let's dissect it piece by piece.

"I have enable_gop installed on the mother/logic board firmware/bios".
There is no bios on a real mac. Enable_GOP is a setting inside OCLP to enable non-Mac cards.

"I press option when booting"
This is for a real mac with a real apple compatible graphics card. NOT used with OCLP on a real mac. NOT used on a Hackintosh with Open Core installed. OCLP (Open Core) is your boot picker (what the option does on a real mac). Don't use the option key (with caveat below).

"It's so easy"
Yes it is.

"The seller said it was made to work with mac's"
Not sure what this means exactly. Was it firmware/VBIOS modified? I don't think an AMD RX580 was ever produced in a "Mac Edition" variant. If it was VBIOS modified (I did it on a GTX 770), then it would be considered a real mac graphics card and you could use the Option key at boot. No matter the VBIOS, you should still get the OCLP boot picker. If you are using the Option key, you should see an option for the EFI folder (to start OCLP).

-How long are you waiting at the black screen? It may take 10-30 seconds after the chime for the OCLP boot picker to appear.

-Do you have any other graphics cards to test options with? I think you have another mac because you are changing your USB stick with the OCLP options? Or are you waiting for login, and then you can use your mac to edit the OCLP settings? What drive are you installing the OCLP to (internal or USB)?

Let's back up a step. You have Mojave installed. You can boot the computer with black screen and log in, then you get the desktop.

The first step would be to install OCLP 2.4.1 onto the existing hard drive (don't even connect your USB Sequoia installer yet). OCLP should identify your existing hardware on it's own and choose the most appropriate modifications to apply. Don't change anything and leave it at the defaults. Mojave does NOT require root patches, so that button should be grayed out. Install it to the internal hard drive and reboot. You should get a boot picker screen.

Destroyer1976 said:

do I have to click 'AMD GOP Injection' at all?

Click to expand...

You should NOT have to if your card was bios modified to work on mac.