How can I use grub-mkconfig for linux kernel/initramfs on tftp?

[Jeffrey Aylesworth]

I am trying to use Grub (x86_64-efi via PXE) to boot Void Linux. I
have the distribution installed and booting correctly, however I could
only make it work using a manual grub.cfg. I would like to use
grub-mkconfig to generate a config file that will download the kernel
and initramfs via tftp. I am using Grub 2.04. I have looked at
documentation for various other distributions and the Grub manual, but
they all end with a manual configuration.

I have tried running grub-mkconfig in a chroot with / mounted as an
NFS share, which I hoped would generate a configuration where
kernel/initramfs are read from a tftp server at the same address, but
I get the error

    /usr/bin/grub-probe: error: failed to get canonical path of
`192.168.3.2:/opt/nfsroot'.

I then tried to use a device map to reroute it to tftp,

    (tftp) 192.168.3.2:/opt/nfsroot

But mkconfig still fails with the same error.

I suppose what I want is some way to manually override how paths on
the linux filesystem are translated into paths on the grub filesystem.
Is such a thing possible with mkconfig?

Thank you,

- Jeffrey