[SOLVED] Dual-Boot: Windows 7, CSM and POST/Clover/Boot Resolution Problem

[floodlitworld]

I'm trying to get a dual-boot system running Sierra (10.12.4) and Windows 7 (Ultimate) up and running and I've encountered an aesthetic hitch, but an annoying one nonetheless.

I've double-checked that my Win 7 installation is EFI ... and it is.

The facts are these:

• I'm using two drives: SSD for Sierra; HDD for Win7
• If I want to boot Windows, I have to ensure that CSM compatibility is enabled in my BIOS. If I don't, then the BIOS will restart and auto-change it for me, then hang, waiting for a continue key.
• If I do enable CSM, then want to boot Sierra, it screws up the output resolution of the POST screen, the Clover screen, and the first half of the Sierra booting screen (once the handoff to the SSD is complete, the resolution returns to normal, i.e 1920x1080). It looks like 800x600 because it's terribly lo-res, and the aspect ratio is all messed up too.
• I have the screen resolution set to 1920x1080 in the Clover GUI section of my plist.

Is there any way to either stop my Win7 boot requiring CSM, or conversely, to fix the resolution of the POST/Clover/Sierra-boot screens if I must leave CSM enabled? I fear this will get even worse when I change to an ultrawide monitor in the next few weeks.

Thanks for the help.

EDIT: I seem to have cracked the problem, so, as you were.

 

[doof]

and the solution is....

 

[floodlitworld]

Installing 'CsmVideoDxe' from the Clover Configurator drivers menu.

 

[shangjun2x]

I can't boot to MACOS after enable CSM with UEFI mode, do know how to resolve it? Thanks

 

[Going Bald]

I can't boot to MACOS after enable CSM with UEFI mode, do know how to resolve it? Thanks

If you installed both OS's UEFI and have no drives with an OS requiring Legacy boot, CSM should be disabled.

On the other hand, some older video graphics cards are not UEFI enabled. If you have one of these you either have to install legacy or use CSMVideoDxe driver in Clover.