Blackscreen ... handcrafted solution

baronerosso

Donator
Original poster
Donator
Sep 29, 2020
47
5
8
Italy
Ok, I find a solution for my black screen problem; it’s not an orthodox solution, but … it works, for the moment.

I discovered we can solve the problem restarting WindowServer process, so I create a new user with admin privileges (I called it "reset”, but this is a personal choice) and i build a simple AppleScript to add in login element.

The script is very simple:

AppleScript:
do shell script "killall -HUP WindowServer" password "password" with administrator privileges

insert “reset” password and save it as application and then add to user “reset” elements login.

Now, you can use it in case of black screen; you can do a blind login into “reset” account.
Killing WindowsServer force a user logout and you are redirect in login windows.
 

sll1001

New member
Jan 25, 2021
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3
I have seen exactly the same symptom as you have when my Asrock Taichi x570 is at BIOS version 3.80. If I revert back to version 2.80, the symptom is gone. I also have RX5600X and 3900X cpu in my configuration.

When I was using BIOS ver 3.80, I find that killing the loginwindow process by logging in remotely will get back the login screen. Then I found that if I set the system to autologin, the auto login will fail and fell back to the login screen.

Eventually I gave up and reflash the BIOS to verion 2.8, then the problem goes away. However, I also notice that with ver 2.8 I must not enable "Above 4G decoding" and instead has to use npci=0x2000 as boot args. With BIOS ver 3.8, I must enable "Above 4G decoding" and do not use npci=0x2000. Otherwise, osx does not see some pci devices.

Hope the above provides some additional data point for finding a better solution.

Cheers.
 

baronerosso

Donator
Original poster
Donator
Sep 29, 2020
47
5
8
Italy
Thanks, but I can't downgrade to bios 2.8; I have a 5900x and it necessarily need a BIOS 3.40 or above.
I also tried to disable "Above 4G decoding" and set npci = 0x2000 as boot arg, but nothing changes.

bios 4.00 just came out, I'll try to update to see if anything changes,
meanwhile my solution avoids me 30 reboots to see login
 

kode54

New member
Jan 25, 2021
8
3
3
If you also have a "Resize PCI BAR support" or similar, macOS doesn't support that.
 

sll1001

New member
Jan 25, 2021
2
1
3
Good News! I finally got rid of the black screen and updated to BIOS ver 4.0

Firstly, in my setup I use all 3 x16 PCIE slots, one for graphics, one for 10G network card, one for RAID (Highpoint). I always assume that the BIOS would automatically configure and allocate the PCIE lanes sensibly to all cards.

Apparently this is not the case, it sort of work at ver 2.8 but got into this weird symptom beyond that.

Then I tried changing Advanced\AMD PBS\PCie x16 Switch from auto to "1x8 2x4". The problem goes away.

If you also use the other x16 PCIE slots for non-graphics cards, you may have the same problem.

I cannot find anywhere what that BIOS setting is suppose to do, just random guess. But apparently it solves the problem.

Hope this is helpful.

 
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