Archlinuxarm Raspberry Pi3 B+ btrfs root subvolume


Archlinuxarm ARMv8 (AArch64) uses uboot to boot the system
You have to modify /boot/boot.txt with your rootflags
mine look like this:

setenv bootargs console=ttyS1,115200 console=tty0 root=PARTUUID=${uuid} rootflags=subvol=root,compress rw rootwait smsc95xx.macaddr="${usbethaddr}"

So you have to insert “rootflags=subvol=root,compress” to boot from your btrfs subvolume!
After editing the text file you have to run

cd /boot/

This will recreate your boot.scr

Have fun!