[Request] Asrock z87 extreme 4 mod to rebar and above 4g decode

Hello. I read here and on other site/forums about above 4g decoding option and rebar in bios. And I try it on my PC.
Asrock z87 extreme 4 with i5 4670k, 4x4GB RAM, some ssd , hdd, dvd and Rx6600xt 8GB from Asus. The neweest bios is from 2018 year 3.50 version - that I moded.
I read and try, and what I do is to added rebardxe to my bios patched
with some of this writed in patch.txe (not all, i think that patched only (haswell) section:

PciHostBridge | Remove <4GB BAR size limit in SubmitResources (Ivy Bridge)

8D6756B9-E55E-4D6A-A3A5-5E4D72DDF772 10 P:77B6488B0F493BCF73AE48FFC1E81BFFFFFF488B1748FFC8483BD0759B:669066909066909066906690909090669090488B176690906690906690

PciHostBridge | Replace 16GB MMIO region with complete use of physical address space (Ivy Bridge). MAY REQUIRE DSDT MODIFICATION

8D6756B9-E55E-4D6A-A3A5-5E4D72DDF772 10 P:48BA000000000100000049B80000000004000000483BDA8BCE480F47D3:49B800000000100000004929D8909090909090906690908BCE4889DA90

PciHostBridge | Replace 8-16GB MMIO region with complete use of 64GB address space (Haswell). MAY REQUIRE DSDT MODIFICATION

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

PciHostBridge | Replace 32/48GB - 63GB MMIO region with 32/48GB - 64GB (Haswell)

8D6756B9-E55E-4D6A-A3A5-5E4D72DDF772 10 P:3BC3771548BE000000C00F000000482B:3BC3771548BE0000000010000000482B

PciBus | Remove <16GB BAR size limit (Ivy Bridge/Haswell)

3C1DE39F-D207-408A-AACC-731CFB7F1DD7 10 P:B8FFFFFFFF030000004C3B:B8FFFFFFFFFFFFFF004C3B

PciBus | Remove <64GB BAR size limit (Skylake/Kaby Lake/Coffee Lake)

3C1DE39F-D207-408A-AACC-731CFB7F1DD7 10 P:B800000000100000004C3B:B8FFFFFFFFFFFFFF004C3B

PciBus | Don’t downgrade 64-bit BARs to 32-bit (Haswell)

3C1DE39F-D207-408A-AACC-731CFB7F1DD7 10 P:833E067506C70604000000833E077506C70605000000:66906690669066906690669066906690669066906690

PciBus | Don’t downgrade 64-bit BARs to 32-bit (by @Mak3rde)

3C1DE39F-D207-408A-AACC-731CFB7F1DD7 10 P:C70605000000833E067506C70604000000BE01000000:909090909090833E067506909090909090BE01000000

AMI APTIO V NvramSmiDxe (Socket 2011-v3 MB: C612, X99) NVRAM whitelist unlock

54B070F3-9EB8-47CC-ADAF-39029C853CBB 10 P:0F84B300000041F6:90E9B300000041F6

NvramSmi NVRAM whitelist unlock (by @vit9696)

842A454A-75E5-408B-8B1C-36420E4E3F21 10 P:9801000072:0000000072
run rebarstate and set rebar size (if that is call) to 1024 -more system not boot.
CSM in bios is disabled, Windows 10 x64 run in uefi mode.
In gpu-z shows that rebar is enabled (max working value BAR01024MB, BAR1 256MB), but “Above 4g decode enabled in bios” - Disabled.
I try to find variables to grub-mod-setup in uefi, but I have similar to other topic on this forum that Above 4g is in:
Unicode text “above 4g” found in 97E409E6-4CC1-11D9-81F6-000000000000 at offset 28E44h,
but in amibcp -in strinds it ishows, but in setup configuration its not in catalog (I search that adress from bios string “token” 0x0D2A).
I compare to z77 and z97 topic [Success] from this forum and In my bios there is not that part.





I try to take that from z97 and z77 bios from that “successed” thread, and replace to my bios. But then bios run, but its be unreadable because there change lot more.
In system device manager there is not Large memory.
Z87 is dual bios, so i easly can run from second bios and flash b>a and try again.
I read this:

and DSDT - I added Haswell sections to dsl file, and how to “Compile the modified DSDT by running iasl DSDTMod.dsl”- nothing happends with the file DSDTMod.dsl - new window runing iasl shows for second and gone and thats it.
Moded bios (its still 3.50, I just change to 3.65 to not mistake with changes):

Could someone look to added that Above 4g in advanced menu?
Thanks

Ed: Ok if Iedited DSDT.dsl file and later try to compile with iasl nothing happends, but if in catalog with iasl.exe is dsdt.aml file (that from amiboardinfo), then runnin compliation file aml gone, but when file dsdt.aml isn,t with iasl.exe nad try complie dsdt.dsl to aml nothing happends.
I read about that here:

Hello, are these modifications valid for an asus rampage iv exteme x79 and ivybridge.

tray this topic:

Asus has some different entries and bios layout than asrock, and different procesor sockek may has different entries and adress.

Ok. A do something, and DSDT.dsl from this:

6. Compile the modified DSDT by running iasl DSDTMod.dsl. If iasl reports any errors you will have to manually fix them.
And I see errors, and aml file no created

Someone help?

Strang. After last windows 10 update, and AMD software/drivers vers.23.x.x re Bar can be activated, without 4g decode.

Hi, I still have issues with Asrock Z87 Extreame4 to see 24GB GPU, I still can’t get Above 4g Decode active on the Bios.

Anyone here got it to work?

thanks

I write a question to asrock support, about 4gdecode option in asrock z87 extreme 4 uefi mainboard, but they answer, that:
"_Sorry no, this is not supported with our older mainboards like Z87.

We start support of rBar with Intel Z390 platform.

Seriously, we are not able to check and test this anymore.

The BIOS support for these older chipset has ended_"

I’ve been getting the same response from Asus for my Z87 mb. @karalux I don’t know how you convinced asrock to add that for your mb

Well, i just asked nicely, showed them the RebarUEFI mod and convinced them that its possible to make everything work on older systems too. My motherboard is an industrial one and i was communicating with AsRock Industrial division, those motherboards might be getting longer support than the mainstream ones.

1 Like

I see, thank you for replying.

ASRock are great at supporting older boards.

I purchased an SSD thet didn’t show up in the BIOS no matter what I tried.

I sent a request to ASRock and within one week I had a new BIOS update that resolved it.

2TB WD SN850x on a Z390 Gaming X . No idea why it din’t work, but it does now.

Thankyou ASRock :robot: