Dietmar

@Gelip Hi, I do not mean restart of compi. Just the second boot stage of XP, when you see the running bar. Then, connection is lost Dietmar

@Gelip I did step by step exact what you wrote. Does not work. On second boot step of XP there is no connection to the PCIe slotcard on the Asrock z370 k6 board, no matter which (now I have 5 different cards) you use for this Dietmar PS: Sundos shows D000 & COM1 and an extra test confirm this with debug -d 40:0 confirms Com port on COM1 with 00 D0.

@Gelip Do you have the XP driver installed and working for the Sun card in XP Dietmar

@Mov AX, 0xDEAD Do you think, that there is a chance to modify ntldr_dbg (we have Source Code for this one) so that the Serial connection to an PCIe card during second phase of XP is not destroyed Dietmar

I make the ultimative test, for what is going on with Serial Debug on XP SP3 and the Asrock z370 gaming k6 board. This test works only with the Lindy card, not with the Sun card! The Sun card shows in Device Manager an extra Pci-to-Pci bridge, that makes Windbg impossible, boot debug and also normal debug. I switch COM port (on board) off via Bios. I install the ntldr_dbg from Sources @infuscomus instead of normal ntldr. And now I can see: On the Lindy card, Windbg starts the at 3 places for 03F8 => D010 modded boot debugger DB (ntldr_dbg) at once, but then crashes after first XP process load (ends with mup.sys). Also kdcom.dll is modded from 03F8 => D010. When the progress bar can be seen (second boot process of XP) there is no longer any output from Windbg (via ntldr_dbg). And now comes the ultimative test: I use the normal onboard COM1 port, enabled via Bios. And I use the normal (unmodded) ntldr_dbg and the unmodded kdcom.dll. And voila: First starts the Boot debugger Windbg BD and then continues with the kdcom.dll file Windbg. Waooh, this means, that the connection to the Serial Port on the PCIe card Lindy is only lost at the beginning of the second part of booting XP SP3 Dietmar Microsoft (R) Windows Debugger Version 6.12.0002.633 X86 Copyright (c) Microsoft Corporation. All rights reserved. Opened \\.\com1 Waiting to reconnect... BD: Boot Debugger Initialized BD: osloader.exe base address 00400000 Connected to Windows Boot Debugger 2600 x86 compatible target at (Sun Feb 6 20:07:42.109 2022 (UTC + 1:00)), ptr64 FALSE Kernel Debugger connection established. Symbol search path is: C:\symbols;C:\symbolss;C:\symbolsss Executable search path is: C:\Symbols Module List address is NULL - debugger not initialized properly. WARNING: .reload failed, module list may be incomplete KdDebuggerData.KernBase < SystemRangeStart Windows Boot Debugger Kernel Version 2600 UP Checked x86 compatible Machine Name: Primary image base = 0x00000000 Loaded module list = 0x00000000 System Uptime: not available BD: \WINDOWS\system32\ntoskrnl.exe base address 804DC000 BD: \WINDOWS\system32\hal.dll base address 80705000 BD: \WINDOWS\system32\KDCOM.DLL base address 80726000 BD: \WINDOWS\system32\BOOTVID.dll base address 80010000 BD: \WINDOWS\system32\DRIVERS\ACPI.sys base address 80364000 BD: \WINDOWS\system32\DRIVERS\WMILIB.SYS base address 80004000 BD: \WINDOWS\system32\DRIVERS\pci.sys base address 80062000 BD: \WINDOWS\system32\DRIVERS\isapnp.sys base address 80006000 BD: \WINDOWS\System32\Drivers\MountMgr.sys base address 80013000 BD: \WINDOWS\system32\DRIVERS\ftdisk.sys base address 80394000 BD: \WINDOWS\System32\drivers\dmload.sys base address 8001E000 BD: \WINDOWS\System32\drivers\dmio.sys base address 803B3000 BD: \WINDOWS\System32\Drivers\PartMgr.sys base address 803D9000 BD: \WINDOWS\System32\Drivers\VolSnap.sys base address 803DE000 BD: \WINDOWS\system32\DRIVERS\storahci.sys base address 803EC000 BD: \WINDOWS\system32\DRIVERS\storpor8.sys base address 80728000 BD: \WINDOWS\system32\DRIVERS\storport.sys base address 8072D000 BD: \WINDOWS\system32\DRIVERS\ntoskrn8.sys base address 80776000 BD: \WINDOWS\system32\DRIVERS\disk.sys base address 80799000 BD: \WINDOWS\system32\DRIVERS\CLASSPNP.SYS base address 807A2000 BD: \WINDOWS\system32\DRIVERS\fltMgr.sys base address 807AF000 BD: \WINDOWS\system32\DRIVERS\sr.sys base address 807CF000 BD: \WINDOWS\System32\Drivers\KSecDD.sys base address 807E1000 BD: \WINDOWS\System32\Drivers\Ntfs.sys base address 80A02000 BD: \WINDOWS\System32\Drivers\NDIS.sys base address 80A8F000 BD: \WINDOWS\System32\Drivers\Mup.sys base address 80ABC000 Shutdown occurred at (Sun Feb 6 20:07:53.890 2022 (UTC + 1:00))...unloading all symbol tables. Waiting to reconnect... Connected to Windows XP 2600 x86 compatible target at (Sun Feb 6 20:07:54.593 2022 (UTC + 1:00)), ptr64 FALSE Kernel Debugger connection established. Symbol search path is: C:\symbols;C:\symbolss;C:\symbolsss;E:\binaries.x86fre\Symbols;https://msdl.microsoft.com/download/symbols;srv* Executable search path is: C:\Symbols Windows XP Kernel Version 2600 MP (1 procs) Free x86 compatible Built by: 2600.xpsp.080413-2111 Machine Name: Kernel base = 0x804dc000 PsLoadedModuleList = 0x805684c0 System Uptime: not available Break instruction exception - code 80000003 (first chance) ******************************************************************************* * * * You are seeing this message because you pressed either * * CTRL+C (if you run kd.exe) or, * * CTRL+BREAK (if you run WinDBG), * * on your debugger machine's keyboard. * * * * THIS IS NOT A BUG OR A SYSTEM CRASH * * * * If you did not intend to break into the debugger, press the "g" key, then * * press the "Enter" key now. This message might immediately reappear. If it * * does, press "g" and "Enter" again. * * * ******************************************************************************* nt!RtlpBreakWithStatusInstruction: 804e7a42 cc int 3 0: kd> lm start end module name 7c910000 7c9c6000 ntdll (pdb symbols) c:\symbols\ntdll.pdb\1751003260CA42598C0FB326585000ED2\ntdll.pdb 804dc000 80705000 nt (pdb symbols) c:\symbols\ntkrnlmp.pdb\FB6BF595C0344379B369466C1ED25FCB2\ntkrnlmp.pdb 80705000 80725d00 hal (deferred)

@Gelip DOS works for this card, Serial Mouse works for this card, Windbg not works Dietmar

@Gelip I make a brandnew XP SP3 installation without any modded files, same result Dietmar

@Gelip I did all exact as you describe. Did not work on the Asrock z370 gaming k6 board. Thanks for help Dietmar

@Gelip Now I have the same PCIe card as you. lspci -s ... shows as input port D000 and also(?) D020. But Windbg does not work with 03F8 => D000 on kdcom.dll on the Asrock z370 k6 board Dietmar PS: Modded kdcom.dll with 03F8 => D020 also not works.

@Gelip Please make simple test via DOS on your working PCIe card: debug -d 0040:0000 And write me your results Dietmar

@Gelip The card works in DOS, I tested in Win-Raid forum. But I can do what I want, I just make new try, no Serial PCIe card works for the Asrock z370 Fatalty gaming k6 board Dietmar

Looks, like Gigabyte enables full CSM support on this board Gigabyte Z690 UD DDR4 (rev. 1.0) with Bios F5. "Add Legacy Game Compatibility Mode option" I will test this board with 12900k cpu in next days for XP SP3 boot Dietmar

@Gelip I make a try with reactos freeldr.sys on a Fat32 partition with XP SP3 on the Asrock z370 gaming k6 board. With onboard COM port, windbg starts at once, with Com port on Serial card not Dietmar

@Gelip Before I get nuts, I go back to my Asrock z370 Fatalty gaming K6 board. Oh..what a nice board. At once normal Windbg works through its internal COM1 port. Tomorrow I try your methode on this board with one after the other of all my PCIe serial slot cards. By the way, I just ordered your Card PCIe Sunix SER5427A also Dietmar

@Gelip Crazy, I even cant get the onboard serial COM port for to work with Windbg on the Biostar z690A board under XP SP3 Dietmar

@Gelip Waaaoohh:)))))))!!!!!!!! I tried such a lot with Windbg and did not reach this. And the Admins from Microsoft wrote in a Blog, that it is impossible! For me is still unclear, what you make other than me before. Have you tested, that it really depends only on the different Baud rates on both compis? This for Windbg working card is the card with the bridge, right? I try in the afternoon also, have a nice day Dietmar

@George King I have only the 64 bit timer modded Hal.dll for XP. You can compare it with original file and so you find the differences. The hack for the intelppm.sys is much more complex. Only @Mov AX, 0xDEAD can help with this Dietmar https://ufile.io/z0be2cez

@Gelip The pci bus depth for the Lindy card is exact as it is for your working PCIeExpress card. No extra bridge chip on Lindy card. I found this: "The upper two slots (from CPU) will run in PCIe Gen 5.0 mode, and the lower full-length PCIe slot (from PCH) is Gen 4.0." No difference in XP device manager, if I put the Lindy Serial card in Slot2 (direct connected to cpu) or in Slot3 (via chipset) Dietmar

@Gelip I did this already in Pic in Post here up "This card Lindy 2S 16C950 is also connected via PCI bridge" Dietmar

@Gelip Not easy to understand, how they managed the PCIe lines on the Biostar z690A board. Because all USB is direct connected to the PCI Bus (without any bridge) via Device Manager, but when you look at this layout, all USB goes through the z690 chipset. The same is true for the Sata connector: On top of my device manager pic you can see, that it is direct connected to the PCI bus. But again on this z690 diagramm you can see, that all Sata goes through the z690 chipset. And maybe, that XP does not list correct in Device Manager, which device is connected via Pci-to-Pci bridge and what not. Hm, is there a test for Pci-to-Pci bridge or direct connected to PCI bus? And if yes, what is the difference, Busmaster?! Dietmar

@Gelip For me the same. So, PCI Express Root is just another name for pci-to-pci bridge Dietmar

The timertest still shows negativ values after few sec on the Biostar z690A board. This means, that the timer problem still exists on Alderlake, brrr.. and needs halplusintelppm hack Dietmar PS: With this files the timerproblem is gone https://ufile.io/sky3nbcm

@Gelip What driver has your PCI Express Root Dietmar

@Gelip Without graphikcard this board does not boot, even you can see the Bios and change all there. The graphikcard GT730 is also connected over pci-to-pci bridge. The same for the Lindy card. Driver for this pci-to-pci bridge is pci.sys . The onboard COM port is connected via ISA-PCI bridge. Only the Sata is direct connected to Pci, no bridge Dietmar