Follow:

 <https://wiki.NetBSD.org/ports/evbarm/allwinner/>

I.e.:

 - Download:
   <http://nycdn.netbsd.org/pub/NetBSD-daily/HEAD/201806071500Z/evbarm-aarch64/binary/gzimg/arm64.img.gz>
 - gunzip it:
    % gunzip arm64.img.gz
 - Write the image via:
    # dd if=arm64.img of=/dev/rsd0d bs=1m conv=sync
 - Write uboot via:
    # dd if=/usr/pkg/share/u-boot/pinebook/u-boot-sunxi-with-spl.bin of=/dev/rsd0d bs=1k seek=8

 - Set in rc.conf:
    resize_disklabel_part=d
 - Comment out all services in rc.conf
 - Create via disklabel partitions for /usr (f) and a cgd for home (g)
 # newfs /dev/rld0f
 # mount -o async /dev/rld0f /mnt
 # cp -a /usr/* /mnt
 # service cron stop
 # service syslogd stop
 # rm -rf /usr/*
 # umount /mnt
 # mount /dev/ld0f /usr
 [...add /usr entry in fstab...]
 [...add /usr in critical_filesystems_local in rc.conf...]

Create cgd /home:

 # cgdconfig -g -V disklabel -o /etc/cgd/ld0g aes-cbc 192
 # cgdconfig -V re-enter cgd0 /dev/ld0g
 # disklabel -Ii cgd0
 # newfs /dev/rcgd0a
 # mkdir /home
 [...add cgd0 as /home in fstab...]

XXXoutdated:
Then:

 - Boot via the uSD card
 - Wait for resize_disklabel and resize_root
 - Wait for the automatic reboot
 - Comment out most services in rc.conf

 - During the 3rd boot stopped via ^C
   * Resize the disklabel via:
      # disklabel -i ld0
      [...]
      partition>a
      Filesystem type [4.2BSD]:
      Start offset [...] [224c, 458752s, 224M]:
      Partition size [...] [60895c, 124712960s, 60895M]: 3G
       a:   6291456   458752    4.2BSD    0    0    0  # (Cyl. 224 -    3295)
      partition>W
      Label disk [n]?y
      Label written
      partition>^D
   * Uncomment all resize_root* lines in rc.conf