Thinkpad P51S IGPU HD620 fails booting BigSur FakeCPU works with 32MB

[Wunder1]

Hello,

I struggle setting up Big Sur with my Thinkpad. I am able to boot with a fakeCPU 12345678. I limited the settings in Device Properties. When I remove enable-hdmi20 the setup will not boot in High Sierra or Catalina as well. Attached more technical data about GPU and Audio.

 

[Feartech]

Hello,

I struggle setting up Big Sur with my Thinkpad. I am able to boot with a fakeCPU 12345678. I limited the settings in Device Properties. When I remove enable-hdmi20 the setup will not boot in High Sierra or Catalina as well. Attached more technical data about GPU and Audio.

you may need this to PciRoot(0x0)/Pci(0x2,0x0):
device-id -> 16590000

may not need:
AAPL,GfxYTile

may also be a better choice:
MacBookPro14,1

 

[Wunder1]

I can confirm that
device-id -> 16590000
AAPL,GfxYTile
MacBookPro14,1
work fine on High Sierra. Nonetheless all fail on booting Big Sur.

As enable-hdmi20 does not work on BigSur (read it somewhere) is there an alternative ?
Any idea what else to try?

 

[Wunder1]

Thanks for the support. Boots in Big Sur so far.
As enable-hdmi20 is not supported in Big Sur, I had to enable-max-pixel-clock-overide in DeviceProperties. The Nvidia was only disabled in ACPI with GPUoff, not inside DeviceProperties. Macbookpro14,1 set to I7.

So Thunderbolt port is working with Input of my Firewire Focusrite Saffire DSP 24 Audio Device. Output from Garageband to Saffire MixControl not yet. My next hurdle.

 

[Feartech]

Thanks for the support. Boots in Big Sur so far.
As enable-hdmi20 is not supported in Big Sur, I had to enable-max-pixel-clock-overide in DeviceProperties. The Nvidia was only disabled in ACPI with GPUoff, not inside DeviceProperties. Macbookpro14,1 set to I7.

So Thunderbolt port is working with Input of my Firewire Focusrite Saffire DSP 24 Audio Device. Output from Garageband to Saffire MixControl not yet. My next hurdle.

glad you got it working!

this may help with your USB:

The New Beginner's Guide to USB Port Configuration

Important Update: June 2023 From Big Sur 11.3 on the built-in OpenCore XhciPortLimit quirk no-longer worked as described. This became a known "bug", though in reality it was Apple changing their internal code, making a simple "peek and poke" to keep it operating, a difficult task. However, with...

www.tonymacx86.com

 

[Wunder1]

Solved as well. Issue was only that I had to set DisableIOMapper to false instead of true.
Moving for the rest to Monterey, as I updated.