Seems to be working fine on the i9305, I just changed these lines
mount("ext4", "EMMC", "/dev/block/mmcblk0p9", "/system");
mount("ext4", "EMMC", "/dev/block/mmcblk0p8", "/cache");
mount("ext4", "EMMC", "/dev/block/mmcblk0p12", "/data");
For these
run_program("/sbin/busybox", "mount"...