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Ahmed Osama

Can't install High Sierra on Inspiron 5558 Broadwell

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I have disabled Nvidia again and tried 5558_A14_disableFromBios.zip and it worked great, even though installer crashed in the second step of installation, but rebooted and tried again and it gone well. But for sure I can't boot when Nvidia is enabled, is there any solution for this??

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According to your DSDT:

  • HD5500 iGPU is ACPI device GFX0 at usual IOReg addresss 0x00020000
  • nVidia dGPU is ACPI device PEG0.NVID or PEG0.PEGP at usual address 0x00010000

 

We can try and disable the dGPU by patching the DSDT and/or SSDT tables. Could you post a compressed IOReg saved from IORegistryExplorer app? This would help to confirm the ACPI device used for the nVidia dGPU.

 

What's weird is that SSDT tables #5 and #6 appear to show the dGPU as if it were attached to RP05 parent device and that clearly differs from the DSDT; functions to enable and disable a dGPU device are clearly defined there. In addition SSDT table #4 clearly defines functions for PEG0 and PEG0.PEGP. So we need to clarify the matter as it would not be the 1st time ACPI tables are terribly/poorly coded by the manufacturer...

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Impossible to say. Go and do it if you want.

 

With regards, to the IOReg, I assume you still run with dGPU disabled in BIOS because I'm not seeing it in the IOReg. On the other hand, I'm seeing RP05 root device with nothing attached to it. To me this confirms my suspicion of bad ACPI coding... RP05.PEGP is definitely NOT the dGPU, it's PEG0.NVID or PEG0.PEGP.

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Thanks Jake, it works great! Much appreciation.

 

Now I'm curious about how it can be done. I was trying to fix it using this approach, but I had to uncheck "Drop OEM" and delete patched files so there is SSDT-DiscreteSpoof.aml file only in patched folder, and it worked and I managed to boot with Nvidia enabled, but of course, everything else wasn't working. Then tried this one, I patched SSDT-5 to call _OFF form _INI, and there wasn't EC call, so nothing else to do, then added SSDT-5 and SSDT-6 (as it has _OFF implementation) to patched folder and config.plist in SortedOrder, but without success, and it stuck at "Legacy Shim", where did I go wrong?

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The 1st approach is to spoof the VESA driver so system will boot, but you need to fully disable it after you installed the OS. You still need to patch for USB, graphics, audio...etc. etc.

The 2nd approach, you're able to disable the discrete card with SSDT-5, but you still need to include the other SSDT where the _OFF method is declare which you included in SSDT-6. What you should have done is just add the patched SSDT-5, enable autoMerge, but don't drop the OEM. You still need to patch the DSDT for USB, audio, graphics...of course that could be done in the Config too. You'll also have to use the rename of GFX->IGPU, HDAS->HDEF...etc etc.
 

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