[GUIDE] General Framebuffer Patching Guide (HDMI Black Screen Problem)

[pbryanw]

@pbryanw Thank you for testing the second configuration! If you look at Post #1 now you'll see that it has been completely overhauled based on new learning. The results you just posted are in agreement with the revised Guide.

A big thank you from me Your new guide was really easy to understand & follow - to an average user like me. And after reading the overhauled version, it all made a lot more sense to me (I hope).

So, in a nutshell (if I understand correctly), macOS provides three software connectors which by default are configured as DP ports. These then need mapping to your motherboard's physical video ports via a simple "Framebuffer Table" - which macOS can use - and which your guide describes how to do.

I also got around to testing the DP port on my Prime Z390-A motherboard, and the port worked perfectly, with full acceleration. I also looked up its port number in FBPatcher, and it was in agreement with your revised guide (I've included an FBPatcher screenshot of it below):

Spoiler: ASUS Prime Z390-A: DP Port Configuration

Thanks again

 

[MadDan]

@CaseySJ

Babysitting the grand kids this weekend, as such, lost my HDTV, so no Hackintoshing. Been following your thread on my Macbook though. I also wanted to thank you for providing (basic) instructions that don't scare off the average user. Seems like most guides expect the end user to have a strong technical background, as well as prior experience with making the necessary mods. I'll be interested to see if a relationship is made with the framebuffer patch and my auto reboot/sleep issues. Seems like there's a link somewhere. I will get back to testing next week. In the meantime, keep manning the help desk!

 

[kundhali]

If I could give you 100 likes for this post, I would! Your approach to problem solving was brilliant -- and it defied every rule in the book. Rule breakers sometimes get the job done when others can't!

Your screenshot in Post #114 shows clearly shows that your LG HDR 4K monitor is on Port 5. Even the monitor's serial number is displayed. So conventional thinking suggested that we try all possible BusIDs on Port 5 (Index 1). Conventional thinking also says, do NOT use the same BusID more than once.

But you decided to break the rules!

You used the same BusID for all 3 ports and found your desktop lurking somewhere in the shadows. This little ray of hope allowed you to eventually find it on Port 7. Well done.

Now, however, we must ask the questions:

1. Why did Case C not work? Maybe the other BusIDs needed to be zero?
2. Why does your first screenshot say Port 5? Is that a bug in the software or something else?

Thank you for the kind words, but what it really boiled down to was naivety: I had no idea I couldn't use the same BusID multiple times.

With respect to your questions:

1) Perhaps you are correct that other BusIDs needed to be zero'd out, but another variable also changed. After running through your cases and failing I became frustrated and began to think that some setting beyond mapping these video outputs must be off. For all tests until this point I had the HDMI20 option enabled so I decided to double check if my motherboard actually supported HDMI20. Turns out it didnt, so for future tests I turned that setting off. This may have had something to do with it.

2) If you are referring to the screenshot in Post #114, that screenshot was acquired from Screen Share, I actually didn't have a working video at that point. I should also note, that I was able to get the monitor detected on all ports (see another screenshot attached where I was able to identify it on Port 6 and 7 in Cases B and C, respectively). Reflecting back on question 1, the fact that the monitor could be detected, but not display video on all ports during my run through your cases does seem to suggest that the other BusIDs did in fact need to be zero'd out to get it working correctly.

Thanks again for all your help.

 

[CaseySJ]

A big thank you from me Your new guide was really easy to understand & follow - to an average user like me. And after reading the overhauled version, it all made a lot more sense to me (I hope).

So, in a nutshell (if I understand correctly), macOS provides three software connectors which by default are configured as DP ports. These then need mapping to your motherboard's physical video ports via a simple "Framebuffer Table" - which macOS can use - and which your guide describes how to do.

I also got around to testing the DP port on my Prime Z390-A motherboard, and the port worked perfectly, with full acceleration. I also looked up its port number in FBPatcher, and it was in agreement with your revised guide (I've included an FBPatcher screenshot of it below):

Spoiler: ASUS Prime Z390-A: DP Port Configuration

View attachment 380810

Thanks again

Yes, your understanding is correct. And thank you for the confirmation! I've updated the respective spoiler in the Guide.

 

[fixpol]

Does this mean you were able to activate HDMI port, but the monitor is displaying an image that extends beyond the sides of the display (stretched out)?

Can you please post 2 screenshots as follows:

1. Screenshot of Hackintool --> Connectors with only HDMI connected. And click on the red line so that we can see the "Port" number on the bottom right.
2. Screenshot of Hackintool --> Connectors with only DVI connected. And click on the red line so that we can see the "Port" number on the bottom right.

Please find attached screenshots:

 

[CaseySJ]

Please find attached screenshots:

Please change Index 3 to HDMI as shown and try again...

 

[fixpol]

Please change Index 3 to HDMI as shown and try again...

View attachment 380862

Its not possible in Hackintool. DP is always back. It accepts Digital DVI but don't know if this is enough.

 

[fixpol]

Its not possible in Hackintool. DP is always back. It accepts Digital DVI but don't know if this is enough.

Sorry DVI is also no acceptable. Only DP comes when ally patch.

 

[CaseySJ]

Sorry DVI is also no acceptable. Only DP comes when ally patch.

You can drag and drop a row to a new location, so click-and-hold row 1 and drag it below row. It will move to the 4th position. Make the changes shown and try again:

 

[CaseySJ]

@CaseySJ
I'll be interested to see if a relationship is made with the framebuffer patch and my auto reboot/sleep issues. Seems like there's a link somewhere. I will get back to testing next week. In the meantime, keep manning the help desk!

There may well be a link between the two! The Hotplug Reboot Fix option in Hackintool sets all Pipe values to 18. So this can be the first thing to check -- whether your existing framebuffer patch has these values.