Set usb drive within interactive installer

src/freedombone-config

@@ -82,6 +82,7 @@ MICROBLOG_DOMAIN_NAME=
 MICROBLOG_CODE=
 GIT_DOMAIN_NAME=
 GIT_CODE=
+USB_DRIVE=/dev/sdb1
 
 CONFIGURATION_FILE=
 
@@ -149,6 +150,7 @@ function save_configuration_file {
   fi
   echo "SYSTEM_TYPE=$SYSTEM_TYPE" >> $CONFIGURATION_FILE
   echo "INSTALLING_ON_BBB=$INSTALLING_ON_BBB" >> $CONFIGURATION_FILE
+  echo "USB_DRIVE=$USB_DRIVE" >> $CONFIGURATION_FILE
   echo "DDNS_PROVIDER=$DDNS_PROVIDER" >> $CONFIGURATION_FILE
   echo "DDNS_USERNAME=$DDNS_USERNAME" >> $CONFIGURATION_FILE
   echo "DDNS_PASSWORD=$DDNS_PASSWORD" >> $CONFIGURATION_FILE
@@ -306,6 +308,9 @@ function interactive_configuration {
       1) INSTALLING_ON_BBB="no";;
       255) exit 0;;
   esac
+  if [[ $INSTALLING_ON_BBB == "yes" ]]; then
+      USB_DRIVE=/dev/sdb1
+  fi
   save_configuration_file
 
   data=$(tempfile 2>/dev/null)
@@ -1085,6 +1090,9 @@ function read_configuration {
       if grep -q "INSTALLING_ON_BBB" $CONFIGURATION_FILE; then
           INSTALLING_ON_BBB=$(grep "INSTALLING_ON_BBB" $CONFIGURATION_FILE | awk -F '=' '{print $2}')
       fi
+      if grep -q "USB_DRIVE" $CONFIGURATION_FILE; then
+          USB_DRIVE=$(grep "USB_DRIVE" $CONFIGURATION_FILE | awk -F '=' '{print $2}')
+      fi
       if grep -q "PUBLIC_MAILING_LIST" $CONFIGURATION_FILE; then
           PUBLIC_MAILING_LIST=$(grep "PUBLIC_MAILING_LIST" $CONFIGURATION_FILE | awk -F '=' '{print $2}')
       fi