Load winpe over pxe with grub

[Seidel, Michael]

Hello,

I am trying to load winpe over the network (UEFI).
I set up a dnsmasq as dhcp server and enabled tftp.

I send over the grubx64.efi file and give it the tftp folder in the 
dnsmasq.conf.

Put the grubx64.efi into the tftp folder and then I created /grub/grub.cfg.

menuentry 'winpe' {
               insmod chain
               insmod net
               set root=(tftp)
               chainloader /?

What would I need to chainload to get it to work, I already tried numerous 
things

  *   the complete winpe.iso,
  *   setting up foldertrees with assorted files
  *   bootx64.efi
  *   boot.wim
  *   bootmgr/ bootmgr.efi

Most of the time it tries to load but I get left with a black screen and no 
error message.

My understanding is that I have to also set root to the mod memdisk to be able 
to use the winpe.iso.
But I also have to have tftp set as root to be able to load it over the network.

Thank you for any pointers in advance.