I do not know if it is welcome here (please advise), but it appears there are knowledge here about the transition from NT3-5 "i386" scheme (with ntldr, setupldr, textmode etc.) toward the current scheme including bootmgr, wim etc.

I am not sure, but I think I read about experiments during Longhorn beta period about launching the XP/2003 kernel using the bootmgr, bcd and winload.exe infrastructure from 4xxx (or 5xxx?) betas.
I know about the /usenewloader switch to ntldr/boot.ini, and it is just the reverse way, I would like to use bootmgr and BCD/editbcd NOT ntldr and boot.ini!

Does anyone have pointers about this?

Installing BCD from a Win6.* disk or whatever will make it auto-detect XP (previous version of Windows) as long as you have added it to the boot list.
About XP WIMs: PantherXP. It packs XPs into install WIM-based disks. (it also installs Bootmgr, I think).
Winload is only needed for Win6.*. Bootmgr can load XP perfectly.

Yes, but if you have several entries in boot.ini then you have to go through the "previous versions" menu; either way bootmgr is really chainloading ntldr which in turn loads the XP kernel as it always did, just that if there is only one entry you'll not see it on screen. I want to bypass this ntldr step.

Thanks, I shall look at it. I was incorrectly thinking of PantherXP as the leaked "Panther SDK" from LH build 4074 , looks like this path was further enhanced, this is good...
Although what I am after is not setup-time use, rather everyday use... but you are right, looking closely at the internals of WIM setup booting is likely to give me the keys.

Well, I do not believe so... Bootmgr is only able to load so-called "boot applications", with a special subsystem indicator (16), starting at OslMain; winload or memtest are such applications, but ntoskrnl is not, it is a "native" (1) one, and the entry point protocol is different; plus you also should load the system hive and all the boot-time drivers.

Actually I succeeded in booting xp with bootmgr+winload.exe from vista beta1 to vista sp2.

The only thing you should do is put the winload.exe to system32 of winxp and create a vista boot item in bcd to load the winload.exe in xp's system32.

And you should disable the drive signature in F8 menu.

Well, i try boot xp kernel with winload from Vista beta 1 while My computer fix....It's probally work, i use vista beta 1 setup engine, and use longhorn 4074 setup quite functionnal. Vista Beta 1 is better why use WinPE 2005 and is more beautiful. I try test too with vista beta 2 setup engine smaller of build 5365, because not require digital signature of ntoskrnl and install perfectly.

BootMGR uses a program to boot.
NTLDR uses a directory to boot.
No, it won't work.

Actually, it could work if a certain variable was set in the LoaderBlock extension...

One could boot windows xp sp2 and 2003, from the bootmgr / winload.exe that was in longhorn 5112.

I know. I did this.

BootViaWinload

What should the BCD file look like in the BOOTICE program?


I need boot WinXP x64 with winload.exe from Vista Beta x64