Simple initramfs generator tool for mounting multiple devices BTRFS root filesystems.
Depends on statically linked busybox and btrfs-register.
Assumes that the initrd image is put in /boot/initramfs.img, that the initrd root is in /usr/local/src/initramfs, and that the BTRFS root partition is spread among any of the partitions /dev/sda2, /dev/sdb2, /dev/sdc2, /dev/sdd2, /dev/sde2, /dev/sdf2.
There's no user configuration, and if the above conditions are not satisfied it will not work.