diff --git a/pkg/de-p1st-installer/de-p1st-installer.sh b/pkg/de-p1st-installer/de-p1st-installer.sh
index da8ea9e..49514fe 100755
--- a/pkg/de-p1st-installer/de-p1st-installer.sh
+++ b/pkg/de-p1st-installer/de-p1st-installer.sh
@@ -32,7 +32,7 @@ function increase_cow_space() {
 }
 
 function get_user_input() {
-  # return: the following variables:
+  # @post
   #   BIOS_TYPE (uefi or bios)
   #   KERNEL    (linux or linux-lts)
   #   FS        (BTRFS, EXT4, F2FS)
@@ -74,7 +74,7 @@ function get_user_input() {
 }
 
 function get_cpu_vendor() {
-  # return: the following variables:
+  # @post
   #   CPU_VENDOR ("amd", "intel", "none")
 
   if [ -z "${CPU_VENDOR}" ]; then
@@ -95,7 +95,9 @@ function get_cpu_vendor() {
 }
 
 function get_default_mount_options() {
-  # return: the following variables:
+  # @pre
+  #   FS
+  # @post
   #   FS_DEFAULT_MOUNT_OPTIONS (array)
 
   FS_DEFAULT_MOUNT_OPTIONS=()
@@ -124,7 +126,9 @@ function get_default_mount_options() {
 }
 
 function choose_mount_options() {
-  # return: the following variables:
+  # @pre
+  #   FS
+  # @post
   #   FS_CHOSEN_MOUNT_OPTIONS (array)
 
   case "${FS}" in
@@ -153,6 +157,11 @@ function choose_mount_options() {
 }
 
 function run_pacstrap() {
+  # @pre
+  #   BIOS_TYPE
+  #   KERNEL
+  #   CPU_VENDOR
+
   # TODO: intel/amd/none CPU_VENDOR
 
   case "${BIOS_TYPE}" in
@@ -171,6 +180,9 @@ function run_pacstrap() {
 }
 
 function run_genfstab() {
+  # @pre
+  #   FS
+
   local fstab
   fstab="$(genfstab -U /mnt)"
 
@@ -200,15 +212,30 @@ function run_genfstab() {
 }
 
 function main() {
-  check_network             || return $?
-  get_user_input            || return $?
-  get_cpu_vendor            || return $?
+  # @pre
+  #   bash libraries imported
+  # @post
+  #   installation finished
 
+  check_network  || return $?
+  # out: BIOS_TYPE, KERNEL, FS, HOSTNAME, USERNAME, USER_PWD, LUKS_PWD
+  get_user_input || return $?
+  # out: CPU_VENDOR
+  get_cpu_vendor || return $?
+
+  # in: FS
+  # out: FS_DEFAULT_MOUNT_OPTIONS
   get_default_mount_options || return $?
+  # in: FS
+  # out: FS_CHOSEN_MOUNT_OPTIONS
   choose_mount_options      || return $?
 
-  partition "${TARGET_BLOCK_DEVICE}" "$BIOS_TYPE" || return $?
-  format "$BIOS_TYPE" "${BOOT_PART}" "${LUKS_PART}" "${LUKS_PWD}" "${FS}" DATA_PART || return $?
+  # in: TARGET_BLOCK_DEVICE, BIOS_TYPE
+  # out: BOOT_PART, LUKS_PART
+  partition || return $?
+  # in: BIOS_TYPE, BOOT_PART, LUKS_PART, LUKS_PWD, FS
+  # out: DATA_PART
+  format    || return $?
 
   # Combine default and chosen mount options
   TMP1=("${FS_DEFAULT_MOUNT_OPTIONS[@]}" "${FS_CHOSEN_MOUNT_OPTIONS[@]}") || return $?
@@ -224,6 +251,7 @@ function main() {
 
   run_pacstrap || return $?
   run_genfstab || return $?
+
   echo "${HOSTNAME}" >/mnt/etc/hostname || return $?
 }
 
diff --git a/pkg/de-p1st-installer/installer.cfg b/pkg/de-p1st-installer/installer.cfg
index e089042..f70b824 100644
--- a/pkg/de-p1st-installer/installer.cfg
+++ b/pkg/de-p1st-installer/installer.cfg
@@ -3,6 +3,8 @@
 
 HOSTNAME=yodaTest
 USERNAME=arch
+
+# one should rather enter these interactively than saving in this cfg
 USER_PWD=test
 LUKS_PWD=test
 
diff --git a/pkg/de-p1st-installer/lib/block-device.sh b/pkg/de-p1st-installer/lib/block-device.sh
index c021f74..e1f6435 100644
--- a/pkg/de-p1st-installer/lib/block-device.sh
+++ b/pkg/de-p1st-installer/lib/block-device.sh
@@ -8,8 +8,8 @@
 # -x, --sort column
 
 function get_partitions(){
-  # $1 block-device
-  # return: the following variables:
+  # arg $1: block-device
+  # @post
   #   PARTITIONS (array with one partition per entry)
 
   # Remove first line of output (which is just the block device $1 itself)
@@ -20,7 +20,7 @@ function get_partitions(){
 }
 
 function get_block_devices() {
-  # return: the following variables:
+  # @post
   #   BLOCK_DEVICES (array with one entry for each block device)
 
   # Get list of devices, one per line
@@ -30,7 +30,7 @@ function get_block_devices() {
 }
 
 function get_block_devices_with_size() {
-  # return: the following variables:
+  # @post
   #   BLOCK_DEVICE_SIZES (array with two entries for each block device: device path and device size)
 
   # Get list of devices and their sizes, one pair per line
@@ -43,18 +43,12 @@ function get_block_devices_with_size() {
 
 
 function partition() {
-  # $1: target block device
-  # $2: uefi or bios
-  if [ "$#" -ne 2 ]; then
-    echo "partition requires two args!";
-    return 1
-  fi
-  for i in "$@"; do
-    if [ -z "$i" ]; then
-      echo "partition: all given args must not be empty";
-      return 1;
-    fi
-  done
+  # @pre
+  #   TARGET_BLOCK_DEVICE
+  #   BIOS_TYPE
+  # @post
+  #   BOOT_PART
+  #   LUKS_PART
 
   # if BOOT_PART_SIZE not given, set to default value
   BOOT_PART_SIZE="${BOOT_PART_SIZE:='261'}"
@@ -66,20 +60,20 @@ function partition() {
 
   # As our data partition is encrypted,
   # we need a separate boot partition!
-  case "$2" in
+  case "${BIOS_TYPE}" in
 	uefi)
 	  # EFI boot partition
     #
     # Create a partition with fat32 as the file system type and set the
     # esp flag on it.
-    parted --script "$1" -- mklabel gpt \
+    parted --script "${TARGET_BLOCK_DEVICE}" -- mklabel gpt \
       mkpart ESP fat32 2Mib "${BOOT_PART_SIZE}MiB" \
       set 1 esp on \
       mkpart primary "${BOOT_PART_SIZE}MiB" 100% || return $?
 
-      get_partitions "$1" || return $?
-      BOOT_PART="${PARTITIONS[0]}"
-      LUKS_PART="${PARTITIONS[1]}"
+    get_partitions "${TARGET_BLOCK_DEVICE}" || return $?
+    BOOT_PART="${PARTITIONS[0]}"
+    LUKS_PART="${PARTITIONS[1]}"
 		;;
 	bios)
 	  # > On a BIOS/GPT configuration, a BIOS boot partition is required. GRUB embeds its `core.img`
@@ -88,18 +82,18 @@ function partition() {
 	  #
 	  # archwiki -> GRUB#GUID_Partition_Table_(GPT)_specific_instructions
 	  # https://www.gnu.org/software/grub/manual/grub/html_node/BIOS-installation.html#BIOS-installation
-	  parted --script "$1" -- mklabel gpt \
+	  parted --script "${TARGET_BLOCK_DEVICE}" -- mklabel gpt \
       mkpart primary 1MiB 2MiB \
       set 1 bios_grub on \
       mkpart primary 2MiB "${BOOT_PART_SIZE}MiB" \
       mkpart primary "${BOOT_PART_SIZE}MiB" 100% || return $?
 
-      get_partitions "$1" || return $?
-      BOOT_PART="${PARTITIONS[2]}"
-      LUKS_PART="${PARTITIONS[3]}"
+    get_partitions "${TARGET_BLOCK_DEVICE}" || return $?
+    BOOT_PART="${PARTITIONS[2]}"
+    LUKS_PART="${PARTITIONS[3]}"
 		;;
 	*)
-		echo "Expected uefi or bios but got $2 instead!"
+		echo "Expected uefi or bios but got ${BIOS_TYPE} instead!"
 		return 1
 		;;
   esac
@@ -109,54 +103,53 @@ function partition() {
 }
 
 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 $6 assigned to path to data partition
+  # @pre
+  #   BIOS_TYPE
+  #   BOOT_PART
+  #   LUKS_PART
+  #   LUKS_PWD
+  #   FS
+  # @post
+  #   DATA_PART (variable set with value /dev/mapper/$(basename "${LUKS_PART}")
+  #   boot partition formatted
+  #   luks partition formatted and opened at DATA_PART
 
   echo "Wiping old signatures from partitions ..."
-  wipefs "${2}" || return $?
-  wipefs "${3}" || return $?
+  wipefs "${BOOT_PART}" || return $?
+  wipefs "${LUKS_PART}" || return $?
 
-  echo "Formatting boot partition $2 ..."
-  mkfs.fat -F32 "$2" || return $?
+  echo "Formatting boot partition ${BOOT_PART} ..."
+  mkfs.fat -F32 "${BOOT_PART}" || return $?
 
-  echo "Creating encrypted luks partition $3 ..."
-  printf "%s" "$4" | cryptsetup luksFormat --type luks1 \
+  echo "Creating encrypted luks partition ${LUKS_PART} ..."
+  printf "%s" "${LUKS_PWD}" | cryptsetup luksFormat --type luks1 \
     --cipher aes-xts-plain64 --key-size 512 --hash sha512 \
-    --iter-time 3500 --use-random "$3" || return $?
+    --iter-time 10000 --use-random "${LUKS_PART}" || return $?
 
   local luks_name
-  luks_name=$(basename "$3")
-  local -n data_part=$6 || return $?
-  data_part="/dev/mapper/${luks_name}"
+  luks_name=$(basename "${LUKS_PART}")
+  DATA_PART="/dev/mapper/${luks_name}"
 
   # open luks partition
-  printf "%s" "$4" | cryptsetup luksOpen "$3" "${luks_name}" || return $?
+  printf "%s" "${LUKS_PWD}" | cryptsetup luksOpen "${LUKS_PART}" "${luks_name}" || return $?
 
-  echo "Formatting the data partition ${data_part} ..."
-  case "$5" in
+  echo "Formatting the data partition ${DATA_PART} ..."
+  case "${FS}" in
 	BTRFS)
-      mkfs.btrfs "${data_part}" || return $?
+      mkfs.btrfs "${DATA_PART}" || return $?
 		;;
 	EXT4)
 	    # archwiki -> Ext4#Enabling_metadata_checksums
-      mkfs.ext4 -O metadata_csum "${data_part}" || return $?
+      mkfs.ext4 -O metadata_csum "${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 $?
+      mkfs.f2fs -O extra_attr,inode_checksum,sb_checksum,compression "${DATA_PART}" || return $?
 		;;
 	*)
-		echo "Filesystem $5 is not yet supported!"
+		echo "Filesystem ${FS} is not yet supported!"
 		return 1
 		;;
   esac
diff --git a/pkg/de-p1st-installer/lib/user-input.sh b/pkg/de-p1st-installer/lib/user-input.sh
index c07d83e..6c64557 100644
--- a/pkg/de-p1st-installer/lib/user-input.sh
+++ b/pkg/de-p1st-installer/lib/user-input.sh
@@ -3,8 +3,8 @@ function get_text_input {
   # Only one line user input is allowed.
   # User input must not be empty.
   #
-  # $1: name of variable to store user input
-  # $2: text to display (e.g. "Enter hostname:")
+  # arg $1: name of variable to store user input
+  # arg $2: text to display (e.g. "Enter hostname:")
   if [ "$#" -ne 2 ]; then
     echo "get_text_input requires two args!";
     return 1
@@ -33,9 +33,9 @@ function get_text_input {
 function get_single_choice {
   # If variable with name $1 is zero, then ask user to select one option.
   #
-  # $1: name of variable to store the selected option
-  # $2: text to display
-  # $3: name of variable with array of options to display (for each option there must be two entries in the array: Item and description)
+  # arg $1: name of variable to store the selected option
+  # arg $2: text to display
+  # arg $3: name of variable with array of options to display (for each option there must be two entries in the array: Item and description)
   if [ "$#" -ne 3 ]; then
     echo "get_single_choice requires three args!";
     return 1
@@ -64,9 +64,9 @@ function get_single_choice {
 function get_multi_choice {
   # If variable with name $1 is zero, then ask user to select one ore more options.
   #
-  # $1: name of variable to store array of selected options
-  # $2: text to display
-  # $3: name of variable with array of options to display (for each option there must be three entries in the array: Item, description, on/off)
+  # arg $1: name of variable to store array of selected options
+  # arg $2: text to display
+  # arg $3: name of variable with array of options to display (for each option there must be three entries in the array: Item, description, on/off)
     if [ "$#" -ne 3 ]; then
     echo "get_multi_choice requires three args!";
     return 1
diff --git a/pkg/de-p1st-installer/lib/util.sh b/pkg/de-p1st-installer/lib/util.sh
index 9feefeb..0f18a98 100644
--- a/pkg/de-p1st-installer/lib/util.sh
+++ b/pkg/de-p1st-installer/lib/util.sh
@@ -1,8 +1,9 @@
 function join_by() {
   # Join array elements with character $1
-  # $1: delimiter
-  # $2: name of source array
-  # $3: variable name to store result
+  #
+  # arg $1: delimiter
+  # arg $2: name of source array
+  # arg $3: variable name to store result
 
   local -n ptr=$2  || return $?
   local -n ptr2=$3 || return $?
@@ -12,7 +13,8 @@ function join_by() {
 
 function newline_to_space() {
   # Replaces all newlines with spaces
-  # $1: name of variable
+  #
+  # arg $1: name of variable
 
   local -n ptr=$1 || return $?
   # Replace newlines with spaces
@@ -27,8 +29,8 @@ function newline_separated_to_array() {
   # Watch out for tailing newlines as these will get an empty array entry at the end.
   # $1 and $2 can be equal (if the result shall be written to the input variable)
   #
-  # $1: name of variable with newline separated list
-  # $2: name of array to store values into
+  # arg $1: name of variable with newline separated list
+  # arg $2: name of array to store values into
 
   local -n ptr=$1  || return $?
   local -n ptr2=$2 || return $?
@@ -38,8 +40,8 @@ function newline_separated_to_array() {
 }
 
 function space_separated_to_array() {
-  # $1: name of variable with space separated list
-  # $2: name of array to store values into
+  # arg $1: name of variable with space separated list
+  # arg $2: name of array to store values into
 
   local -n ptr=$1  || return $?
   local -n ptr2=$2 || return $?