diff --git a/pkg/de-p1st-installer/de-p1st-installer.sh b/pkg/de-p1st-installer/de-p1st-installer.sh
index 71b11e6..64f8580 100755
--- a/pkg/de-p1st-installer/de-p1st-installer.sh
+++ b/pkg/de-p1st-installer/de-p1st-installer.sh
@@ -160,8 +160,12 @@ function main() {
   get_default_mount_options || return $?
   choose_mount_options      || return $?
 
-  partition "${TARGET_BLOCK_DEVICE}" "$BIOS_TYPE"
+  partition "${TARGET_BLOCK_DEVICE}" "$BIOS_TYPE" || return $?
+  format "$BIOS_TYPE" "${BOOT_PART}" "${LUKS_PART}" "${LUKS_PWD}" "${FS}" DATA_PART || return $?
+
   # TODO: use FS_DEFAULT_MOUNT_OPTIONS and FS_MOUNT_OPTIONS in combination
+  mount "$DATA_PART" /mnt || return $?
+  mkdir /mnt/boot && mount "$BOOT_PART" /mnt/boot || return $?
 }
 
 main "$@"
diff --git a/pkg/de-p1st-installer/lib/block-device.sh b/pkg/de-p1st-installer/lib/block-device.sh
index c72f7fa..c021f74 100644
--- a/pkg/de-p1st-installer/lib/block-device.sh
+++ b/pkg/de-p1st-installer/lib/block-device.sh
@@ -104,6 +104,60 @@ function partition() {
 		;;
   esac
 
-  echo "boot partition: $BOOT_PART"
-  echo "luks partition: $LUKS_PART"
+  echo "boot partition: ${BOOT_PART}"
+  echo "luks partition: ${LUKS_PART}"
+}
+
+function format() {
+  # $1: uefi or bios
+  # $2: boot partition
+  # $3: luks partition
+  # $4: luks passphrase
+  # $5: FS for data partition (opened luks partition): BTRFS, EXT4 or F2FS
+  # $6: name of variable to store path to data partition (/dev/mapper/$(basename "$3"))
+  # return:
+  #  -> boot partition formatted
+  #  -> luks partition formatted and opened at /dev/mapper/$(basename "$3")
+  #  -> variable with name $6 assigned to path to data partition
+
+  echo "Wiping old signatures from partitions ..."
+  wipefs "${2}" || return $?
+  wipefs "${3}" || return $?
+
+  echo "Formatting boot partition $2 ..."
+  mkfs.fat -F32 "$2" || return $?
+
+  echo "Creating encrypted luks partition $3 ..."
+  printf "%s" "$4" | cryptsetup luksFormat --type luks1 \
+    --cipher aes-xts-plain64 --key-size 512 --hash sha512 \
+    --iter-time 3500 --use-random "$3" || return $?
+
+  local luks_name
+  luks_name=$(basename "$3")
+  local -n data_part=$6 || return $?
+  data_part="/dev/mapper/${luks_name}"
+
+  # open luks partition
+  printf "%s" "$4" | cryptsetup luksOpen "$3" "${luks_name}" || return $?
+
+  echo "Formatting the data partition ${data_part} ..."
+  case "$5" in
+	BTRFS)
+      mkfs.btrfs "${data_part}" || return $?
+		;;
+	EXT4)
+	    # archwiki -> Ext4#Enabling_metadata_checksums
+      mkfs.ext4 -O metadata_csum "${data_part}" || return $?
+		;;
+	F2FS)
+      # archwiki -> F2FS#Creating_a_F2FS_file_system
+      # - requires f2fs-tools
+      # - compression: "-O compression" and when mounting the filesystem, specify compress_algorithm=(lzo|lz4|zstd|lzo-rle)
+      mkfs.f2fs -O extra_attr,inode_checksum,sb_checksum,compression "${data_part}" || return $?
+		;;
+	*)
+		echo "Filesystem $5 is not yet supported!"
+		return 1
+		;;
+  esac
 }