[Release] Resizable BAR DXE driver

I used the following on the two Dell mobos: “setup_var 0x2 0x1” following the instructions from Xcuri0’s site. On my Gigabyte board, I used “setup_var 0x3 0x0”, rebooted, then “setup_var 0x3 0x1”. I was kinda’ surprised the “0x2” and “0x3” numbers seemed so “low,” but that’s what IFR told me to use.

I’m surprised to see the 9020 supported as coreboot has such a small number of boards listed as supported on its site. Of all the Dell mobos in the world, only the 7010/9010 show as officially supported. I’m going to look at those 9020 instructions as the only coreboot BIOS I have been able to install so far was the Dasharo one, and it’s not UEFI unless you build it.

Thanks, i’ll try that and report on it if it works (fingers crossed :sweat_smile:)
the variables at offset 0x2 and 0x3 are not in the form of 0xX, but 0xXX. I don’t think really matters anyways, as unfortunately no combination seems to activate above 4G decode. Maybe the board simply does not have that option, despite having the ability?

Also for Coreboot, I was going off this code, but to be honest this is quite far from my area of expertise. Then again, resizable bar is not officially supported on sandy/ivy bridges, so i’m willing to take the chance even if it takes some tinkering…
Thanks for the massive help so far though!

Hello, sorry for the delay.
I see that everything happens to you the same as to me.
Yes, as she had said before… when connecting via igpu she could enable maximum rebar capability. I did quick tests, and I found no noticeable differences vs 1gb. So I recommend you use 1gb and don’t worry (I do the same, right now I even upgraded to a rtx 4080, everything still works OK).

NOTE: I was able to verify that in windows 10 everything appears enabled in gpuz, but in windows 11 it appears “above 4g off” (rebar also appears ON for me, like the rest of the options). It’s weird, but I imagine it’s something with the operating system. I went back to windows 10 and everything is perfect (currently using the same equipment as before, just upgraded to an rtx4080).

Thank you!

I have a Supermicro X11DPH-T mainboard, with an Intel Arc A770 LE 16GB graphics card, and this ‘works’; the only caveat is that I have to have my monitors off until I hear the windows sound, at which point I can turn them on and log in and everything works just fine with a setting of ‘32’. I get a 16GB BAR, and the driver reports Resizable BAR as enabled (even if GPU-Z says it’s not enabled (and shows the 16GB BAR; I don’t know what that’s about)). No stuttering, everything is smooth and awesome.

If I don’t have the monitors off, I get a magenta/green garbled screen, and the computer hangs for a while there before it reboots and repeats.

I did try the patches, plus a couple extra that @Kuri0 graciously provided, but none of them would apply. I think that means that they’re not needed? I did try to apply them to a different firmware for a different board I have, and one of them did apply, so I do think I did it correctly.

Anyone have any ideas?

Hello @fiskvik,

What does the GPU Z checklist show?

SOmething like this?

Hi @68k-dude,

It looks exactly like that, except ‘resizable bar’ is ‘Disabled’. The checklist below all say ‘Yes’, and at the bottom is ‘BAR0’ at ‘16384MB’.


Hello @fiskvik ,

There are users reporting things like this are fixed in the new BETA drivers. Not sure if it patching the VBIOS .

Good luck,