Insert SD card to your system.

sudo fdisk -l
sudo fdisk /dev/sdX

Create partitions.

• Clear partitions (o)
• Create boot partition (n, p, 1, enter, +500M, t, c)
• Create system partition (n, p, 2, enter, enter)
• Write partitions (w)

sudo mkfs.vfat /dev/sdX1
sudo mkfs.ext4 /dev/sdX2

Mount new partitions.

sudo mkdir /mnt/boot/
sudo mkdir /mnt/root/

sudo mount /dev/sdx1 /mnt/boot/
sudo mount /dev/sdx2 /mnt/root/

Download and install Arch Linux ARM.

wget http://os.archlinuxarm.org/os/ArchLinuxARM-rpi-aarch64-latest.tar.gz
sudo su
tar zxvf ArchLinuxARM-rpi-aarch64-latest.tar.gz -C /mnt/root
mv /mnt/root/boot/* /mnt/boot
sync
umount /mnt/boot/
umount /mnt/root/

Remove SD card, insert it into Raspberry PI and boot it to complete the installation.

pacman-key --init
pacman-key --populate archlinuxarm
pacman -Syu