Anyone tried it already ?
Not that I know of. Looks like 5 people have downloaded it so far though. I would if I had one to try it on. But I'm setup with all the proper tools to fix it in a matter of minutes if it didn't work. I don't really think it will work either. If it's like previous Vega cards you can't really do a damn thing with the BIOS and get away with it. You can update the AMD UEFI GOP version(or change it to any version 2.0 or later) with previous Vega. But that's pretty much it. In fact...that is it AFAIK. I don't expect Radeon VII to be any different. Or, let me put it another way. You can't remove the UEFI support from, or disable the UEFI support in, a Vega BIOS(technically you can...but it won't boot if you do). So I doubt you can add it to a Radeon VII BIOS(also...you can...but it probably won't boot if you do). I'm thinking the same thing protecting the Vega BIOS from letting that happen, will also be protecting the Radeon VII BIOS from letting that happen. I could be wrong though.
A simple way to validate this would be to try to use UEFI secure boot.
I presume that's already been tried. Hence the need for "CSM enabled" mode. IOW...Secure Boot pitching a fit about not being able to find a UEFI GOP image is the only reason why you'd need
to do that(need
as in no boot period without disabling SB/enabling CSM mode). You'll just get a black screen during boot until the desktop appears with other UEFI features enabled(but without a VBIOS that supports UEFI GOP).
IT shouldn't boot without a proper UEFI image IIRC.
Well...define "proper"? With AMD cards, even if the Legacy ROM of the Hybrid BIOS has been edited you need a modded UEFI GOP image with a signature check bypass to use SB(or any UEFI GOP features). And even then some cards(and/or card + mobo combos) apparently can't use SB. Though other UEFI GOP features will work(fast boot etc.). My 280X doesn't have that issue on my MSI Z77 mobos. I'm able to use SB(and all the other UEFI GOP features) with an edited Legacy ROM and the modded UEFI GOP image.
On the old FuryX with dual BIOS i actually had to flash BOTH to the UEFI version for secure boot to work. Weird.
Not calling you a liar. But that makes absolutely no sense whatsoever. Only one VBIOS can be read at any given time on a dual/triple BIOS card. One with a switch anyway. Which they all have AFAIK.