These are my script for NetBSD emulation on aarch64 (Pinebook and similar) 
using KVM acceleration 

Images are from http://www.invisible.ca/arm/ 

Below scripts are tested on a Debian9/Arch aarch64 Linux (Pinebook-Pro) 
Make sure you have a kernel with KVM enabled ( /dev/kvm) and a 
full aarch64 userspace (Manjaro Linux for Pinebook Pro)
https://osdn.net/projects/manjaro-arm/storage/pbpro/xfce/preview4/
 
- Place the desired aarch64 NetBSD img file in the working directory 

$ gunzip arm64.img.gz
$ qemu-img resize arm64.img 20g

- Then copy the qemu-ifup to /etc/ 
- As root execute the network.sh 

# ./networking.sh 

- Disable the small CPUs on the Pinebook as only the 2 BIG ones work with KVM 

# ./enable-cpu

- Run the simulator 

# ./run.sh