UEFI bootx64.efi doesn't work from harddrive on IdeaPad S210 - NetBSD 8.1

[nome%nutilius.eu@localhost]

Hi everybody
I try to install NetBSD on Lenovo IdeaPad S210 with UEFI enabled. I have
used UEFI USB installation image and it boots correctly, recognize the GPT
partitioning and install NetBSD on selected partition.
Because there is Windows installed I did some steps on existing EFS
partiton:
- in EFI partition I created dedicated subdirectory (in /EFI) named NetBSD
- copy there bootx64.efi from USB stick 
- made label for partition with NetBSD using gpt tool (label is NetBSD)
- created simple boot.cfg :

  banner=Menu
  menu=Boot normally: boot NAME=NetBSD:netbsd

After this I used debian linux to add entry in NVRAM:

  efibootmgr -d /dev/sda -p 2 -l \\EFI\\NetBSD\\bootx64.efi 
       
After reboot when I select NetBSD EFI entry from hardisk, system
shows black screen and not blinking cursor in upper left corner -
nothing more. No menu, no prompt, no any other message.

The GRUB from from EFI harddisk works, the bootx64.efi from EFI
install USB works, windows boot works.

Currently I boot NetBSD from GRUB.

How I can diagnose this - any boot options, some debug options. 
Or maybe some suggestions how to fix it.

Kind regards

Piotr