VGA port working on macOS Catalina 10.15.3 with a Haswell desktop GPU (no adapter)

[hacking2apple]

It's been known that there is indeed support for VGA in Coffe Lake and that support for prior iGPUs was deprecated as the VGA port was removed since Sierra. However, using port patches in Devices Properties (Open Core), I made the VGA port to work again with graphics acceleration.

But there's a catch, the port is glitchy. Once macOS displays the accounts, you can see the Enter Password box with the blur effect. But after some seconds, the whole display will turn to another color (depends on the background). I'm not sure why that happens.

I would suggest learning what are Ports, Connectors, Indexes, Types, and BusIDs before continuing, otherwise, you would get lost.

These are the patches that are supposed to enable the VGA port according to the Whatevergreen Intel guide:

06020000 02000000 30000000 // Option 1

06020000 01000000 30000000 // Option 2

None of those ports seem to work. The first problem is that the Index is 6, which does not make any sense as the Azul framebuffer only supports up to 3 Indexes (software ports). So we first have to change the Index for the VGA port on your motherboard, which is 2 (physical port is 0x06)) for me.

So that means that the target port is the Index 2, which is 02040A00 00040000 87000000.

bus-id 4 is for DP so we would change that to 2, which is VGA. That is according to what Hackintool says. I also proved other bus-ids but none of the other ones seem to work.

I have no idea what pipe does so I just type zeros.

I think pipe is basically another way group ports. So later I changed that to 10, which is 0A in hex. That means pipe remains the same as it was originally.  02020A00 01000000 87000000

The next part is the connector-type, for which I used 02000000.

Spoiler

I changed to another monitor with VGA, and surprisingly, I started getting a blank screen with 02000000, so I used the other option, 01000000, which works now.

I tried the VGA connector-types that Hackintool suggested but I noted some weird differences whereas 02000000 and 01000000 seem to work okay.

Finally, I don't know what flags do so I tried with 30000000 and 87000000. The only difference is that with 87000000 I'd gain more seconds before the whole screen turns to another color.

 

This is the final configuration:

AAPL,ig-platform-id <0300220D>
framebuffer-con1-alldata <02020A00 0100000 87000000>
framebuffer-con1-enable <01000000>
framebuffer-patch-enable <01000000>

This is the video proof:

https://i.imgur.com/bd6jtFh.mp4

 

macOS Catalina 10.15.3

Kexts: Whatevergreen 1.3.7

Boot loader: OpenCore 0.5.6

PC Specs:

Intel Core i5 4460

Intel HD Graphics 4600

ECS H81H3-M4

4GB RAM DDR3

[Rocky12]

@Hervé awesome,  very well done like a pro