Boot-looping or hanging Debian 11 FAI UEFI PXE - GRUB issue

[Thomas Lange]

Th variable ${kernelname} was added in FAI 6.0. If you are using the
config space from 5.10 this variable is not defined and not used
(which is defined in DEBIAN.var).

Concerning GRUB, please check if the class GRUB_EFI is defined and the
script GRUB_EFI/10-setup is executed without errors. The package
efibootmgr is needed in the nfsroot and the newer script
scripts/GRUB_EFI/10-setup prints the settings of the UEFI entries at
the end of the installation. This was not done in FAI 5.10.

regards Thomas