Dietmar

@reboot12 Hi Gelip, does this mean, that I can make a try with my B860 DS3H board without any CSM, to boot XP SP3 bit32 there Dietmar

@canonkong Oh..interesting. For which motherboard is this Bios and can it be used on other board also, have a nice day Dietmar

@Dibya @K4sum1 @Damnation I just upload it, Dietmar https://files.catbox.moe/5ayu7r.7z

@Dibya It is not possible, to upload a file correct to this server any more. Do you have another place, where I can upload it Dietmar

@Dibya Here they are, the server was down for upload Dietmar https://ufile.io/qlvhgily

And there are more files needed for CSM (legacy boot), for example 71ED12D1-250B-42FB-8C17-10DCFA771701 AmiLegacyInterrupt Dietmar

@reboot12 Here is the documentation of CSM from Intel. https://ufile.io/s8t2t9hw I wonder, why also an csmcore was build for the Arrow Lake Bios. May be, that UBU does not correct identify everything about CSM. For example, there is no GUIDE number in it. I also try the MMtool. No csmcore is listened in both Bios Dietmar

@reboot12 Yepp, I get via UBU from the 12900k Bios csmcore. It starts via Winhex with CSM. Now I just look, if this is already in my file CsmDxe Dietmar EDIT: Also in the 245k Bios a csmcore was build via UBU. But this one starts with CSM..MZ no VGA video there.

@reboot12 I just check: Csmcore has Guide A062CF1F-8473-4AA3-8793-600BC4FFE9A8 This is the same Guide as for the Bios from the 12900ks CsmDxe Dietmar Found Option ROM VBIOS in GUID A062CF1F-8473-4AA3-8793-600BC4FFE9A8

@reboot12 I notice, that in the Arrow Lake Bios this files are also missed: 67820532-7613-4DD3-9ED7-3D9BE3A7DA63 Aint13 4DF53F89-D421-4F9D-8392-BE3BECC6288E AhciInt13Dxe 4C006CD9-19BA-4617-8483-609194A1ACFC Usbint13 C9A6DE36-FDFF-4FAF-8343-85D9E3470F43 Nvmeint13 501F30E9-D14F-47DA-AE60-B101E4189D07 Ahciint13Smm So, some work is waiting;)) Dietmar

@reboot12 I heard about this tool UBU but never used and so I also dont know, how to handle it. Do you have an UBU version for me, that works for the 12900k and also for Arrow Lake (245k) here, Dietmar

@reboot12 How can I extract this csmcore? I do not see it with UEFITool. And I remember another part in the NVRAM: There has been a switch from Windows 10 ==> Other OS Dietmar

@reboot12 The Bios is NOT write protected, take a look at this AmiSetupWriter.efi 0xd25 0x2 NVRAM variable "Setup" read, data size 0x1270, attributes 0x7. Current Setup[0xD25] is 0x0 NVRAM variable "Setup" written. Updated Setup[0xD25] is 0x2 Dietmar EDIT: I just check with RU.efi, that indeed in UEFI name Setup now at adress 0xD25 is written 02. But still no harddisk with MBR is recogniced. Any idea, at which place I have to look for to enable CSM? The dump of all adresses with names via AmiSetupWriter.efi -d > all.txt does not work. EDIT2: I also wrote for to enable CSM AmiSetupWriter 0xCBE 0x1 The value at 0xCBE changed from 00 => 01 but still CSM is not working. EDIT3: May be, that a compare of the Bios, from where this 3 csm files are taken, can help to set all (in Bios unseen) variables in the Bios above, its NVRAM for CSM boot, correct. EDIT4: After checking about the risk, low, I did the following: I replace via UEFITool the whole Setup Guide 899407D7-99FE-43D8-9A21-79EC328CAC21 in the Bios from the 245k with the one from the board with 12900ks cpu. Before, I make a direct copy of the 12900ks Bios, fo to keep the settings for CSM. Q-Flash allows this crazy Bios implantat. But after reboot, I see only the screen, where I can choose between Delete (Bios Setup) or F12 (Boot menu). No other reaction. I also clear CMOS, does not help. Compi is frozen at this screen. But maybe this idea is not so bad, just you have to know, which parts of this Setup Guide have to be copied and which not. Just now I flash the original Bios f6c back to the 245k board, compi is alive;))..

@reboot12 I succeed to flash my modded Bios via Q-Flash. For this I just renamed my modded Bios to GIGABYTE.BIN and flash it with only Power Supply on, pressing the Q-Flash button. Lasts about 3 min. Oh,..soso much worry, but compi starts again ;)). Of course no switch for CSM in Boot menu, but I think I can handle this like on the N100, if there is any chance Dietmar

@reboot12 Hi Gelip, here is my first try. The Bios from Gigabyte for both boards are VERY similar. I put those 3 CSM files via UefiTool exact at those places where they where before in Bios F11. Please take a look at the modded Bios, which Bytes needs to be set for to enable CSM. Also I think, that Secure Boot has to be disabled. Thanks a lot Dietmar Bios for the gigabyte b860 ds3h original and mod for CSM https://ufile.io/ognrb00n