R9 390 Black screen after boot on Catalina 10.15.5

[JoeYu]

My R9 390 will display a black screen after boot. The monitor is ON and stayed on. This happens after the verbose screens. Lilu and Whatevergreen are installed. I applied FakeID 0x67B01002 and InjectATI in Clover.

My specs are:

• Dell T1600
• E3 1225
• R9 390 Reference Edition
• macOS 10.15.5, freshly installed

I did some research about this issue. Some people suggest enabling the iGPU along with the 390. There is no such options in the BIOS since it's an OEM machine. It appears to me that when a discrete GPU is installed, the IGPU is automatically disabled. Others said I need to disable CSM. There is also no such option in the BIOS and I believed CSM is enabled by default. I am really stuck now. I also tried my HD 7850, and it has the same issue. I also read it could be a vBIOS issue, but I don't think so since this exact R9 390 had worked with my previous hackintosh builds.

Can someone help me? Thank You in advance!

 

[JoeYu]

Attached is my EFI folder. I cannot provide other problem reporting files since I cannot boot at all if the 390 is installed in the system.

 

[donw35]

add agdpmod=pikera to boot args

make sure you are using display port from video card.

 

[JoeYu]

add agdpmod=pikera to boot args

Added. Same issue. Does not help.

make sure you are using display port from video card.

I don't have a display port monitor. I used a DP to HDMI cable. Could that be an issue?

I heard this could be an issue of framebuffer. How can I fix that?

Thanks.

 

[donw35]

look up the framebuffer for your video card and set it in clover

 

[JoeYu]

look up the framebuffer for your video card and set it in clover

Is there a guide for that?

 

[donw35]

This is how I did it, you will need to get the correct values for your GPU, this are for the 4th Gen Intel iGPU

 

[JoeYu]

This is how I did it, you will need to get the correct values for your GPU, this are for the 4th Gen Intel iGPU

Thanks for the example, but I am afraid we are not on the same track. We might be talking about completely different things. R9 390 is a AMD discrete GPU. Also, the Sandy Bridge iGPU I have is not supported at all in Catalina. And I am not saying it's 100% a framebuffer issue. In fact, I have no idea what is wrong. It could be other things such as CSM, vBIOS, connector's layout, SMBIOS choice.

 

[Namok88]

To make sure the iGPU is actually disabled with the R9 installed, try this boot argument (disables all discrete GPUs) and connect your monitor to your onboard video output.

-wegnoegpu

 

[JoeYu]

To make sure the iGPU is actually disabled with the R9 installed, try this boot argument (disables all discrete GPUs) and connect your monitor to your onboard video output.

-wegnoegpu

Thank you for the advice. I decided to give up with R9 390 for my build. I think it is impossible for my board since it's dell OEM and there is no option for CSM or IGPU. I think I will use the iGPU from now on until I can get a new motherboard. I don't do anything graphically demanding anyways. However, I do found the iGPU working very well. I followed a guide to get full acceleration in Catalina with HD 3000. It do turns out to be buggy as it is not natively supported. I decided to just install 10.13.6 which fully suppport HD 3000.