Thanks @jason098
May I just clarify please.
Do you mean where in the IFR file I see:
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Internal Forms Representation
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Offset: Instruction:
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0x80AC Form Set: AMD PBS [B863B959-0EC6-4033-99C1-8FD89F040222], ClassGuid0 [93039971-8545-4B04-B45E-32EB8326040E] {0E A7 59 B9 63 B8 C6 0E 33 40 99 C1 8F D8 9F 04 02 22 02 00 03 00 01 71 99 03 93 45 85 04 4B B4 5E 32 EB 83 26 04 0E}
0x80D3 Guid: [0F0B1735-87A0-4193-B266-538C38AF48CE] {5F 15 35 17 0B 0F A0 87 93 41 B2 66 53 8C 38 AF 48 CE 03 01 00}
0x80E8 Guid: [0F0B1735-87A0-4193-B266-538C38AF48CE] {5F 15 35 17 0B 0F A0 87 93 41 B2 66 53 8C 38 AF 48 CE 04 00 00}
0x80FD Default Store: en-US, DefaultId: 0x0 {5C 06 00 00 00 00}
0x8103 Default Store: en-US, DefaultId: 0x1 {5C 06 00 00 01 00}
I should then set the bytes:
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5F 15 35 17 0B 0F A0 87 93 41 B2 66 53 8C 38 AF 48 CE 03 01 00
5F 15 35 17 0B 0F A0 87 93 41 B2 66 53 8C 38 AF 48 CE 04 00 00
To zero in the extracted binary:
2: Do you know how/why that works?
3: Do you know what PBS stands for? It seems to be an AMD term for ‘advanced’ GPU settings.
You should do it like this: open your BIOS in UEFITool and do a GUID search for B1DA0ADF (AMITSE), then just do Extract as is… on the PE32 image https://i.imgur.com/NvGBmMZ.png
Open the file you just extracted with your favorite hex editor and search for “59 B9 63 B8 C6 0E 33 40 99 C1 8F D8 9F 04 02 22” and overwrite that with zeroes. Once you’ve done that you just gotta do Replace as is… on the PE32 image and select the file you modified
Edit: Here’s a modified AMITSE from the “B450I GAMING PLUS AC” BIOS 7A40vAA https://drive.google.com/open?id=1xz8k1G…PsIQYqHcI999iTT
Thanks again @jason098
So I extracted that section - the IFR of that looks almost empty, with no forms:
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UEFI Protocol Detected
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String Packages
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Offset: Language:
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0x38FEF8 en-US (0x0)
0x3A21D2 ko-KR (0x1)
0x3A4BC3 ja-JP (0x2)
0x3A7DDC de-DE (0x3)
0x3ABF29 ru-RU (0x4)
0x3B03D4 fr-FR (0x5)
Form Sets
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Offset: Title:
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Internal Forms Representation
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Offset: Instruction:
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However, in the binary I do see the bytes you mention above (and in your linked post).
I see now that the same bytes are in the PBS section I linked in my second post, it's the start of the curly braces in the "Form Set" line:
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0x80AC Form Set: AMD PBS [B863B959-0EC6-4033-99C1-8FD89F040222], ClassGuid0 [93039971-8545-4B04-B45E-32EB8326040E] {0E A7 59 B9 63 B8 C6 0E 33 40 99 C1 8F D8 9F 04 02 22 02 00 03 00 01 71 99 03 93 45 85 04 4B B4 5E 32 EB
83 26 04 0E}
I will try doing as you say - but can I ask again:
1) Do you know why zeroing out the PBS GUID, in the AMITSE section, achieves this effect
2) Do you know what PBS stands for?
Thanks again so much for you help.
I assume that MSI set in AMITSE to hide these menus so zeroing the GUIDs makes them appear again. As to what PBS and CBS means, I have no idea. Nowhere does anyone or anything tell what the abbreviations mean
@jason098 - thanks so much - that has enabled the PBS menu for me!
The downside is 2x8 doesn’t seem to work - won’t even post. I have to clear the CMOS to get back in.
So I guess the story continues.
Glad I could help. Well I just tried enabling 2x8 on my B450 Gaming Plus and it posted (no idea if it actually has any effect though)
Perhaps it’s something to do with whether the graphics card is compatible. I’ve got a Sapphire Radeon RX580 Nitro+
For anyone looking at this in the future, I’m also seeking help at https://hardforum.com/threads/pcie-bifur…1870298/page-21
Not sure what the next step is. I’d planned to get a second cheap GPU anyway, so perhaps I’ll go ahead and do so.
Regarding what effect you should see - your graphics card should report running on x8 (rather than x16) lanes. I think something like GPU-Z should show that. In Linux I use lspci to view what the actual PCI roots there are and what bandwidth.
So I don’t think that had any effect. Linux still reports a Width of x16 on my RX 570
What BIOS version did you modify from? What AGESA version are you seeing in PBS-> AMD firmware version?
7B86v1C with 1.0.0.3abba
Edit: don’t forget that I have this motherboard: https://www.msi.com/Motherboard/B450-GAMING-PLUS/Overview
I have the ITX version of that board. With the ATX version I suspect the bifurcation is on another slot.
Regarding the AGESA version - I see the same as you on the bios download page: https://www.msi.com/Motherboard/support/…US-AC#down-bios
What I was curious about in particular were the versions listed on your BIOS screen under the PBS menu. For me I see the AGESA version minus the abba qualifier.
Yeah it’s the same for me in the “AMD Firmware Version” menu. On what other slot would the bifurcation be though?
Not familiar with that board, but looks like it’s got 2 x16 slots?
As you have Linux, regardless you should see an extra PCIe bridge with ‘lspci | grep GPP’.
lspci -vvv would show what bandwidth
No new PCI Bridge shows up when I activate bifurcation
Oh well - thanks for checking.
Perhaps I do indeed just have to change board.
Certainly learned a lot, so thanks.
News flash - found a combination that worked.
1. Download A40vA6 2019-03-07 - the version just before Ryzen 3 / Zen 2 support http://download.msi.com/bos_exe/mb/7A40vA6.zip
2. Modify as per this thread
3. Flash from a flash utility of your choice (M-FLASH on BIOS will refuse to downgrade)
This time choosing the 2x8 option does the right thing!
Of course - the only downside to this is I can never update to a Zen2 processor with this board and keep the 2x8 functionality.
@jason098 - do you know a way to upload the rom to this site, so I can put mine up here? There’s various sharing sites, but they tend to bitrot.
Well, I’d just upload them to Google Drive, Dropbox or something and share the link.
Edit: You can attach files in posts, not sure how big they can be though
