Zero the beginning of the SD card:

dd if=/dev/zero of=/dev/sdx bs=1M count=16

Start fdisk to partition the micro SD card:

fdisk /dev/sdx

1. type o.
2. type p.
3. type n, then p for primary, 1 for first partition on the drive, 32768 for the first sector.
4. type w.

Create the ext4 filesystem:

mkfs.ext4 /dev/sdx1

Mount the filesystem:

mkdir root
mount /dev/sdx1 root

Download and extract the root filesystem (as root, not via sudo):

wget http://os.archlinuxarm.org/os/ArchLinuxARM-aarch64-latest.tar.gz
bsdtar -xpf ArchLinuxARM-aarch64-latest.tar.gz -C root

extract r2s kernel images.

bsdtar -xpf kernel-r2s.tar.xz -C root

Unmount the partition:

umount root

Write bootloader.

Prebuilt binaries are in bootloader directory.

dd if=idbloader.bin of=/dev/sdx seek=64 conv=notrunc
dd if=uboot.img of=/dev/sdx seek=16384 conv=notrunc
dd if=trust.bin of=/dev/sdx seek=24576 conv=notrunc

These files are built from armbian sources.

Use the serial console or SSH to the IP address given to the board by your router.

• Login as the default user alarm with the password alarm.
• The fault root password is root.

Make sshd_config to PermitRootLogin yes for root login from ssh.

Remove useless kernel.

Don't pacman -Syu before replace linux-aarch64.

pacman -R linux-aarch64

Replace kernel to packaged version. Prebuilt packages from https://github.com/sakapoko/linux-r2s/releases

pacman -U linux-r2s-5.11.1.arch1-2-aarch64.pkg.tar.xz --overwrite '/usr/lib/modules/*','/boot/*'
pacman -U linux-r2s-5.11.1.arch1-2-aarch64.pkg.tar.xz

Edit extlinux.conf

Edit /boot/extlinux/extlinux.conf Change fdt and root partition if you need.

R2S or Neo3

label linux
   kernel /boot/Image
   initrd /boot/initramfs-linux.img
   fdt /boot/dtbs/rockchip/rk3328-nanopi-r2-rev02.dtb
   append console=ttyS2,1500000 earlycon=uart8250,mmio32,0xff130000 rw root=/dev/mmcblk0p1 rootwait rootfstype=ext4 coherent_pool=1M ethaddr=${ethaddr} serial=${serial#}

R4S

label linux
    kernel /boot/Image
    initrd /boot/initramfs-linux.img
   fdt /boot/dtbs/rockchip/rk3399-nanopi-r4s.dtb
   append console=ttyS2,1500000 earlycon=uart8250,mmio32,0xff1a0000 rw root=/dev/mmcblk1p1 rootwait rootfstype=ext4 coherent_pool=1M

MAC Address cannot be specified from uboot on R4S.

Initialize the pacman keyring and populate the Arch Linux ARM package signing keys:

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

system up to date

pacman -Syu

Configuration OS settings.

localegen, localtime and so on.