GRUB2 PXE chainloading and EFI handles

[kitzman]

Dear all,

I'm here to ask for some help - I'm not an EFI expert so brace 
yourselves.

I have the following situation: I PXE boot EFI GRUB2, which has menu 
entries for some operating systems.
One of the operating systems requires chainloading - only the loaded 
bootloader knows how to load the kernel
and the configuration (9front).

My problem is that: once GRUB2 chainloads, and the second bootloader is 
running, some EFI handles
are not there. The second bootloader, on startup, checks if it 
should/can PXE, ISO or local disk boot.
The PXE check is done by looking up some EFI handles for the PXE 
protocol, and such handles also allow
it to use the network - but they are not found, and it falls back to 
local disk boot.

Is there a way to leave the handles there? Maybe it's not GRUB2 deciding 
if those handles
should be there anymore? Maybe I'm assuming that's the problem? I don't 
know.

Kind regards,
kitzman