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macOS Tahoe 26 on Unsupported Macs Discussion

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The first post of this thread is a WikiPost and can be edited by anyone with the appropiate permissions. Your edits will be public.
mac OS Tahoe boot picker for OpenCore

my theme Flavours-FadeDisk support Dark and Light

macOS Tahoe-Dark.png
macOS Tahoe-Light.png


Setup Flavours theme in config.plist (Flavours-FadeDisk themes as exemple)

see Exemple ⤋

  • Misc -> Boot -> HideAuxiliary: false
  • Misc -> Boot -> PickerVariant: chris1111\Flavours-FadeDisk
  • Misc -> Boot -> PickerAtributes: 145
  • Misc -> Boot -> Picker Mode :-> External
  • Misc -> Boot -> Timeout -> : 5
  • Misc -> Boot -> ShowPicker: true
attaching theme zip
enjoy
 

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  • Flavours-FadeDisk.zip
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redheeler said:
Good to know. I suspect the challenge this year will be getting it to run on non-T2 Macs. Macs like the 2018 Mac mini and 2020 MacBook Air with T2 should be easier I'd think.

Although, if MacOS can still run in a VM environment with no T2, maybe not. Someone please confirm!
Click to expand...

I think you get it opposite, I think the challenge this year will getting it run on all T2 Macs. The 2018 MacBook Air has T2 and OCLP isn't support this version.

The 2020 iMac with Fusion Drive does not have T2 security chip, so the T2 security chip isn't the hardline system requirement for macOS Tahoe. Therefore, I think all the dropped Mac, which all have T2 chip wouldn't be patched to run macOS 26 anytime soon.
 
Aoligei said:
The 2020 iMac with Fusion Drive does not have T2 security chip, so the T2 security chip isn't the hardline system requirement for macOS Tahoe. Therefore, I think all the dropped Mac, which all have T2 chip wouldn't be patched to run macOS 26 anytime soon.
Click to expand...
No. The 2020 iMac has a T2 security chip, the 2019 iMac does not have T2. All macOS 26 supported Intel Macs have the T2. So, sadly, the T2 is a requirement.

I know enough that this is going to create a challenge for all non-T2 Macs, but not enough whether this is a full stop block, or not.
 
gilby101 said:
No. The 2020 iMac has a T2 security chip, the 2019 iMac does not have T2. All macOS 26 supported Intel Macs have the T2. So, sadly, the T2 is a requirement.

I know enough that this is going to create a challenge for all non-T2 Macs, but not enough whether this is a full stop block, or not.
Click to expand...
You are asking the wrong questions.
 
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Larsvonhier said:
Nope, see #14.
USB drive is disconnected during boot - currently only USB 3 works as a remedy. Of course not easily feasible on MacBooks as it is with PCIe slots in a Mac Pro.
Nothing to do with T2 (which is also not present in Mac Pro).

Same happens here on my MacBook Air 4,2 and MacBook 6,1.
Click to expand...
But my MBP 9,1 has usb3 ports. I try to update Sequoia to Tahoe on an external SSD plugged to a USB3 hub, and the hub is plugged to an USB3 port. At reboot I boot on the volume MacOS Installer, there is the progression bar during 2 minutes, then the prohibited sign.
 
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sinbad21 said:
But my MBP 9,1 has usb3 ports. I try to update Sequoia to Tahoe on an external SSD plugged to a USB3 hub, and the hub is plugged to an USB3 port. At reboot I boot on the volume MacOS Installer, there is the progression bar during 2 minutes, then the prohibited sign.
Click to expand...
Try booting with the installer on USB-2 without hub, in verbose mode. Then re-plug to USB-3 without hub (!) when the messages repeat "still waiting for root volume" or the crossed out circle appears (this is not the end of the process, just a timeout indicator, and booting resumes when valid drive is found!). This is how I get the Mac Pro to boot into the installer.

note: if your mac has USB-3 only and no USB-2, still try without any hub in between - and try re-plugging the stick. If detected as valid, the verbose output supplies info when stick is re-plugged
 
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Larsvonhier said:
Try booting with the installer on USB-2 without hub, in verbose mode. Then re-plug to USB-3 without hub (!) when the messages repeat "still waiting for root volume" or the crossed out circle appears (this is not the end of the process, just a timeout indicator, and booting resumes when valid drive is found!). This is how I get the Mac Pro to boot into the installer.

note: if your mac has USB-3 only and no USB-2, still try without any hub in between - and try re-plugging the stick. If detected as valid, the verbose output supplies info when stick is re-plugged
Click to expand...
I can't do that. My MBP has no usb2 port, only 2 usb3 ports.

Also I try to install Tahoe with an OTA update, I don't use an usb stick. But the target drive of the installation is on an external ssd plugged on an usb3 port.
 
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Hi everyone, I've read a lot of guides around but nothing that explains how to install tahoe on macbook air intel 2020. Can you give me some advice? I downloaded OCLP but it only lets me create the USB stick. When the guide says to click on "Build and install OpenCore" the button always remains gray. Thanks for the answers and sorry for the inconvenience
 
sinbad21 said:
I can't do that. My MBP has no usb2 port, only 2 usb3 ports.

Also I try to install Tahoe with an OTA update, I don't use an usb stick. But the target drive of the installation is on an external ssd plugged on an usb3 port.
Click to expand...
That´s complicating it further. I´d suggest to install a fresh drive into the MacBook to use the SATA/nVM link there for the time being. Or wait until the USB link issue is adressed somehow.
 
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amaze1499 said:
What I meant by that, is did you try to install it at all (of course on an experimental drive only)? What kind of errors did you run into? Can it be addressed by OCLP?
Click to expand...
All I have done so far is to attempt to install in a VMware virtual machine on a 2019 iMac. Got as far as the steps in the GUI installation asking about language, accessibility, etc. But the following reboot just repeated those steps, with no further progress.
 
After reading about the USB issues, I tried with the destination USB 3.0 SSD attached to a LED Cinema Display (which has a built-in USB 2.0 hub), and also without any USB device attached (except of course the USB 3.0 flash drive from which to install Tahoe); with always the same result: boot halts with a prohibition sign after about a minute (BTW, also the MBP11,3 has only USB 3.0 ports). So, it’s best to wait, for now…
 
… Forgot to say that it doesn’t work booting with the installer flash drive attached to the USB 2.0 Cinema Display, either: always a prohibition sign.
 
Sven G said:
After reading about the USB issues, I tried with the destination USB 3.0 SSD attached to a LED Cinema Display (which has a built-in USB 2.0 hub), and also without any USB device attached (except of course the USB 3.0 flash drive from which to install Tahoe); with always the same result: boot halts with a prohibition sign after about a minute (BTW, also the MBP11,3 has only USB 3.0 ports). So, it’s best to wait, for now…
Click to expand...
The thing is: On my MP5,1 the re-located stick (from initially USB2 to USB3) only works directly on the USB3 port, not with any hub in between...
 
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gilby101 said:
No. The 2020 iMac has a T2 security chip, the 2019 iMac does not have T2. All macOS 26 supported Intel Macs have the T2. So, sadly, the T2 is a requirement.
Click to expand...
According to this guy, the 21,5" fusion variant of 2020 does not have T2.

edit: But I am unsure there even was an 2020 21,5", so maybe he got it wrong.
 
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I´m currently doing another workaround test for the setup/migration crashes - I install a fresh Sequoia with no additional apps and only one admin user. Then install Tahoe ontop. Let´s see, takes a couple of minutes now.
 
Larsvonhier said:
Just as a trigger for re-consideration to the "T2" and "metal-4" doomsdayers: I got a MP5,1 booting into an fresh install of Tahoe with no patches so far, but the frontier now is getting past either migration assistant or setup assistant - both crash or do not finish their job...
Click to expand...
Are you able to import another user from a Time Machine backup during setup?
 
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