Installing Win 8.1 64 Bit via iPXE

[BenBach]

Hello,

I'm trying for days now to get my pxe boot environment working.

I have a dnsmasq server which pxe boots to a syslinux menu where you can select different images (working fine).

The menu calls the following:
KERNEL IPXE.KRN
APPEND dhcp && set image win81 && chain http://install.local/default.ipxe

To say it first the images / extracted files work fine if used on CD...

In the default.ipxe I tryed different configs:

set boot-url http://install.local/

:win81
sanboot --drive 0x81 --keep --no-describe ${boot-url}os/Win81.iso
--> Error /Boot/BCD is missing

:win81
sanboot --no-describe ${boot-url}os/Win81.iso
--> I/O error

:win81_org1
set dir ${osdir}Win81/
kernel ${boot-url}_boot/wimboot
initrd ${dir}bootmgr bootmgr
initrd ${dir}boot/bcd BCD

initrd ${boot-url}_boot/fonts/chs_boot.ttf fonts/chs_boot.ttf
initrd ${boot-url}_boot/fonts/cht_boot.ttf fonts/cht_boot.ttf
initrd ${boot-url}_boot/fonts/jpn_boot.ttf fonts/jpn_boot.ttf
initrd ${boot-url}_boot/fonts/kor_boot.ttf fonts/kor_boot.ttf
initrd ${boot-url}_boot/fonts/segmono_boot.ttf fonts/segmono_boot.ttf
initrd ${boot-url}_boot/fonts/segoe_slboot.ttf fonts/segoe_slboot.ttf
initrd ${boot-url}_boot/fonts/segoen_slboot.ttf fonts/segoen_slboot.ttf
initrd ${boot-url}_boot/fonts/wgl4_boot.ttf fonts/wgl4_boot.ttf

initrd ${boot-url}_boot/fonts/malgunn_boot.ttf fonts/malgunn_boot.ttf
initrd ${boot-url}_boot/fonts/meiryo_boot.ttf fonts/meiryo_boot.ttf
initrd ${boot-url}_boot/fonts/meiryon_boot.ttf fonts/meiryon_boot.ttf
initrd ${boot-url}_boot/fonts/msjh_boot.ttf fonts/msjh_boot.ttf
initrd ${boot-url}_boot/fonts/msjhn_boot.ttf fonts/msjhn_boot.ttf
initrd ${boot-url}_boot/fonts/msyh_boot.ttf fonts/msyh_boot.ttf
initrd ${boot-url}_boot/fonts/msyhn_boot.ttf fonts/msyhn_boot.ttf
initrd ${dir}boot/boot.sdi boot.sdi
initrd ${dir}sources/boot.wim boot.wim
imgstat
boot

--> This config works for the 32Bit version fine but for 64 Bit the Bootloader starts (Loading Files) and then stops with a black screen.

I have a bit of technical experience but I'm pretty new to the whole pxe booting topic.
I tried to get some kind of debug output but totaly failed as I'm not even sure where the setup failed.
What I already tried is to change the bootmgr and afterwards the whole boot folder from the working 32 Bit install -> no success...

I also managed to get the install.wim instead of the install.esd - I changed the files but no change / same behaviour.

I would be happy if somebody could point me in the right direction.

BTW I know that I can boot a Winpe image and start the install from there but that's not what I would like to have - I would like to directly boot to the setup as if the cd would be in the machine.

Thanks in advance for any help