M6800: internal screen with nVidia dGPU?

[draskostar]

I am confused now. Please help. Hacktool shows ldvs and intel edp. Is it possible that I have lvds screen after all? 

[Hervé]

You have an eDP display type. Connector type is the same in OS X/macOS at least for Intel iGPU. Please note that things are very different with nVidia dGPUs with which output port types are controlled by NVCAP (and the registered connector type does not really matter). As I said, none of this really matters if the built-in LCD is wired to/controlled by the Intel iGPU...On the other hand, you may find that external output such as HDMI are controlled by the dGPU. You'd have to check that out in IOReg having opted for iGPU as main graphics card with Optimus enabled in BIOS and the dGPU not disabled.

[draskostar]

Why posts were deleted? @Herve sent me some instructions and now they are gone

 

[Hervé]

Looks like our server took a hit this today and all posts/threads made since Sunday afternoon or Monday are gone. Rest assured there was no Moderator's/Admin's actions to deleted posts/threads.

 

Sorry but I can't remember all that I had posted but I believe I had stated that your posted IOReg showed built-in LCD attached to HD4600 iGPU and an external monitor attached to the nVidia dGPU (I think it was HDMI). I had re-affirmed my belief that the built-in LCD is probably wired to/controlled by the iGPU but, having looked at your OC config, you could try the following boot-args adjustments with Optimus disabled in BIOS (i.e. only nVidia dGPU active):

1. given that you are using MBP11,5 SMBIOS, i.e. a fully supported platform in Big Sur, you could remove the -no_compat_check boot arg of your OC config since it's unnecessary and will prevent Big Sur updates from being offered to you.
2. change your csr-active-config value from 0x7FF to something where the 2nd nibble does not set bit 5 to 1 which enables Apple Internal. When that SIP flag is enabled, Big Sur updates are not offered. As such, you may change your value to 0x7EF. I recommend you consult our dedicated thread on disabling SIP that's available in our FAQ section.
3. add boot arg agdpmod=pikera or agdpmod=vit9696 in case Apple Graphics Device Policy is somehow responsible for black built-in screen. With such boot arg, AGDP will be disabled/bypassed.

[draskostar]

@Hervé

Thank you very much for that. I appreciated it. You also sent me NVCAP for k4100m that I have to use in my config file. You are correct I was connected to my TV via hdmi. 

[Hervé]

Oh that's right, I had also mentioned NVCAP but not provided a specific value, just listed the one shown in your IOReg (which is gone now).

 

Basically, with Intel iGPUs, video outputs are handled through connectors and connector types (LVDS/eDP, DVI, DP, HDMI) whereas, with nVidia graphics, it's the NVCAP value that defines the video outputs. It's somehow detailed in the Dortania documentation at following URL but, with a Google search, you would also find old threads on the Net in other Hackintosh forums about it:

https://dortania.github.io/OpenCore-Post-Install/gpu-patching/nvidia-patching/

 

[draskostar]

Ok. Should I use the one from IOReg or I must create NVCAP with a calculator regarding to dgpu's bios. Probably it would be the same result.

[Hervé]

Obviously, the value shown in IOReg is the one in use... So you may try and experiment with the tool mentioned at Dortania. No guarantee that any of this will bring life to the built-in LCD with nVidia graphics-only of course.

 

One other thing to try is boot your Big Sur (or any other macOS version) USB installer and, once (or if) your reach the installation screen on the built-in LCD, open up Terminal to check the NVCAP value in IOReg with the following command:

ioreg -l | grep NVCAP

It may show a different value that what you previously had.

 

That's how I got VGA output to work on the GT730 fitted to my old C2D desktop: initially, I had no VGA output -only DVI-D and HDMI- and NVCAP was showing a given default value once system was booted up. One day, after my partition got corrupted, I rebooted the USB installer with dual DVI + VGA screens connected and, to my surprise, the VGA screen was active and displaying video once I reached the macOS installation screen. On checking the NVCAP value in IOReg, it showed a different value than the one I had before. Once I injected that value in my bootloader config file, I've had all outputs fully working ever since, including VGA.

[draskostar]

I used NVCAP that I get with your argument - for this I used usb installer to boot as new installation and then I used terminal to get it for internal screen (optimus enabled, if disabled I get BS). 

After that I used instructions from enclosed link but after reboot I always get same error (optimus disabled or enabled I cannot boot). I also put boot arg from your 3. point.

 

[Hervé]

Well, I think it's pretty much a closed matter: systematic black screen if you only run on the nVidia dGPU (Optimus disabled). All those tests are useless if they can only be completed with Optimus enabled, i.e. when you run on the HD4600 iGPU.

 

So, as far as I'm concerned, you'll have to accept that you need to run with the HD4600 iGPU knowing that the nVidia dGPU can clearly be used for external screens (at least HDMI). There's probably a good chance you would not get any HDMI output if you disabled the dGPU through ACPI patching. But do that if you're never gonna use an external screen and you want to save battery life when you run macOS.