-boot_part=$(awk '$2 == "/boot" {print $1}' /etc/mtab)
-boot_dev=${boot_part%[0-9]*}
-# from partition.DEFAULT
-new_boot_part=${boot_dev}4
-mount -o subvol=debianbuster_bootstrap $new_boot_part /mnt
+boot_part=$(awk '$2 == "/" {print $1}' /etc/mtab)
+mount -o subvol=boot_trisquelnabia $boot_part /mnt/boot