diff --git a/setup.sh b/setup.sh
index 69ee073..6fe77e6 100644
--- a/setup.sh
+++ b/setup.sh
@@ -36,6 +36,38 @@ trap '[ "$?" -ne 77 ] || exit 77' ERR
 
 declare zpool_drive efi_drive boot_drive part_schema
 
+function arg_parse () {
+    [[ "${1}" ]] && while :; do
+        case "${1}" in
+            -[[:alnum:]]*)
+                >&3 printf -- '%s\n' \
+                    'Short options '"'${1}'"' detected. Only known option is' \
+                    'literal string '"'"'setup'"'"'. No idea what '"'${1}'"' is.' \
+                    'Exiting ...'
+                    exit 77
+                ;;
+            --*)
+                >&3 printf -- '%s\n' \
+                    'Long-form option '"'${1}'"' detected. Only known option is' \
+                    'literal string '"'"'setup'"'"'. No idea what '"'${1}'"' is.' \
+                    'Exiting ...'
+                    exit 77
+                ;;
+            setup)
+                setup_env_vars
+                return
+                ;;
+            *)
+                >&3 printf -- '%s\n' \
+                    'Argument '"'${1}'"' detected. Only known option is literal' \
+                    'string '"'"'setup'"'"'. No idea what '"'${1}'"' is.' \
+                    'Exiting ...'
+                    exit 77
+                ;;
+            esac
+    done
+}
+
 function we_are_changerooted () {
     if [ "$(stat -c '%d:%i' '/')" != "$(stat -c '%d:%i' '/proc/1/root/.')" ]; then
         return 0
@@ -1137,6 +1169,9 @@ function finalize_os_setup () {
 }
 
 function main () {
+    if [[ "${#@}" -gt '0' ]]; then
+        arg_parse "${@}"
+    fi
     if we_are_changerooted; then
         install_os_in_chroot                    #2.2
     else
@@ -1164,4 +1199,4 @@ function main () {
     fi
 }
 
-main
+main "${@}"