Man, I did not know that my picking on Legacy vBIOS, VBT, and legacy mechanisms will make such a noise. And so many responses.
I should say, I am glad that I provoked such an avalanche of info, since, I have to say, I am learning a lot reading this email thread. I hope others learn a lot too. And... We all are trying to connect missing puzzles. I certainly do (and pass to you what I do know - NOT always the case)!
I just came back from BBALL, and I am pretty dead, as dead cat's last jump... It was tough on my body (3:3 on full real court, two hoops, 2 hours)... I'll try reasonably to reply to these emails! :-(
> Intel provides a binary-only GOP driver (IntelGopDriver.efi) to OEMs who> embed it into their UEFI implementations. I don't know if it itself requires VBT.
Igor,
In present BIOSes (most of them are 64b, thus UEFI), as I understand, there are three modes of operations:
[1] Legacy only (CSM ON);
[2] Combined mode (have no idea how this does work);
[3] True UEFI (CSM OFF)!
Now, I never use/used mode [2]. I am NOT fan of mixing these modes. I use [1] if I must too, but my preferred mode is [3].
Regarding these two modes,:
[1] Legacy - does use vBIOS (maximum size 64KB), INT 10H, VBT, and all this is inherited by OS.
[3] UEFI - does use GOP driver (MORE that 64KB in size, there is no such a limit as for vBIOS).
These are The Facts. Matt (De Viller) can beat me with the baseball bat, but this I know, this is in concrete. I would NOT change (about what I wrote here above) my opinion.
It seems that, after GOP dies, still, orphaned VBT survives post mortem UEFI (as part of UEFI run time data passed to OS).
I (here, Matt makes me doubtful, and I will thank him for that) always was naive and thought that VBT is NOT part of GOP driver. But, apparently, I might be mistaken, and Matt (De Viller) is probably right.
Now... The bloody name VBT is one which confuses me: Video BIOS Table (VBT). This is my problem, but, if I better think, maybe INTEL CCG/OTC pros wanted just to continue to inherit the transparency. About what I think, about VBT, I'll reply to Matt (DaEmon) and Coreboot himself. ;-)
I am glad that I missed some points. :-)
Zoran