debian-installer preparation for NanoPi M3 (arm64) please help

[Rafal]

I'm trying to prepare Debian installer for NanoPi M3 board. This is an 
arm64 device. I have a custom kernel package (which contains drivers 
specific to the board) and I'm trying to build network debian-installer 
(netboot) with a few additional local udeb's whose will install the 
custom kernel on target system and make the system bootable.But I can 
not cope with a few problems.

The first problem is that anna complains about missing kernel modules. 
The complain is completely unnecessary but I don't know how to avoid it. 
Is possible to disable the complain somehow?

Second problem I have with bootstrap-base package, It installs also 
kernel. It picks some kernel from Debian repository, but this kernel 
will not work. Is possible to avoid kernel installation by the 
bootstrap-base package?


Rafal