diff --git a/scripts/mkimage b/scripts/mkimage
index ed420bb896..0162506322 100755
--- a/scripts/mkimage
+++ b/scripts/mkimage
@@ -11,14 +11,14 @@
 
 # set variables
 LE_TMP=$(mktemp -d)
-SAVE_ERROR="$LE_TMP/save_error"
+SAVE_ERROR="${LE_TMP}/save_error"
 
-if [ -z "$SYSTEM_SIZE" -o -z "$SYSTEM_PART_START" ]; then
+if [ -z "${SYSTEM_SIZE}" -o -z "${SYSTEM_PART_START}" ]; then
   echo "mkimage: SYSTEM_SIZE and SYSTEM_PART_START must be configured!"
   exit 1
 fi
 
-if [ "$BOOTLOADER" = "syslinux" ]; then
+if [ "${BOOTLOADER}" = "syslinux" ]; then
   DISK_LABEL=gpt
 else
   DISK_LABEL=msdos
@@ -26,27 +26,24 @@ fi
 
 STORAGE_SIZE=32 # STORAGE_SIZE must be >= 32 !
 
-DISK_START_PADDING=$(( ($SYSTEM_PART_START + 2048 - 1) / 2048 ))
+DISK_START_PADDING=$(( (${SYSTEM_PART_START} + 2048 - 1) / 2048 ))
 DISK_GPT_PADDING=1
-DISK_SIZE=$(( $DISK_START_PADDING + $SYSTEM_SIZE + $STORAGE_SIZE + $DISK_GPT_PADDING ))
-DISK_BASENAME="$TARGET_IMG/$IMAGE_NAME"
+DISK_SIZE=$(( ${DISK_START_PADDING} + ${SYSTEM_SIZE} + ${STORAGE_SIZE} + ${DISK_GPT_PADDING} ))
+DISK_BASENAME="${TARGET_IMG}/${IMAGE_NAME}"
 DISK="${DISK_BASENAME}.img"
 
 # functions
 cleanup() {
-  echo "image: cleanup..."
-  rm -rf "$LE_TMP"
-  echo
-  exit
+  echo -e "image: cleanup...\n"
+  rm -rf "${LE_TMP}"
 }
 
 show_error() {
-  echo "image: error happen..."
-  echo
-  cat "$SAVE_ERROR"
+  echo -e "image: error happen...\n"
+  cat "${SAVE_ERROR}"
   echo
   cleanup
-  exit
+  exit 1
 }
 
 trap cleanup SIGINT
@@ -58,280 +55,281 @@ FAT_SERIAL_NUMBER="${UUID_1}${UUID_2}"
 UUID_SYSTEM="${UUID_1}-${UUID_2}"
 
 # create an image
-echo
-echo "image: creating file $(basename $DISK)..."
-dd if=/dev/zero of="$DISK" bs=1M count="$DISK_SIZE" conv=fsync >"$SAVE_ERROR" 2>&1 || show_error
+echo -e "\nimage: creating file $(basename ${DISK})..."
+dd if=/dev/zero of="${DISK}" bs=1M count="${DISK_SIZE}" conv=fsync >"${SAVE_ERROR}" 2>&1 || show_error
 
 # write a disklabel
-echo "image: creating $DISK_LABEL partition table..."
-parted -s "$DISK" mklabel $DISK_LABEL
+echo "image: creating ${DISK_LABEL} partition table..."
+parted -s "${DISK}" mklabel ${DISK_LABEL}
 sync
 
 # create part1
 echo "image: creating part1..."
-SYSTEM_PART_END=$(( $SYSTEM_PART_START + ($SYSTEM_SIZE * 1024 * 1024 / 512) - 1 ))
-if [ "$DISK_LABEL" = "gpt" ]; then
-  parted -s "$DISK" -a min unit s mkpart system fat32 $SYSTEM_PART_START $SYSTEM_PART_END
-  parted -s "$DISK" set 1 legacy_boot on
+SYSTEM_PART_END=$(( ${SYSTEM_PART_START} + (${SYSTEM_SIZE} * 1024 * 1024 / 512) - 1 ))
+if [ "${DISK_LABEL}" = "gpt" ]; then
+  parted -s "${DISK}" -a min unit s mkpart system fat32 ${SYSTEM_PART_START} ${SYSTEM_PART_END}
+  parted -s "${DISK}" set 1 legacy_boot on
 else
-  parted -s "$DISK" -a min unit s mkpart primary fat32 $SYSTEM_PART_START $SYSTEM_PART_END
-  parted -s "$DISK" set 1 boot on
+  parted -s "${DISK}" -a min unit s mkpart primary fat32 ${SYSTEM_PART_START} ${SYSTEM_PART_END}
+  parted -s "${DISK}" set 1 boot on
 fi
 sync
 
 # create part2
 echo "image: creating part2..."
-STORAGE_PART_START=$(( $SYSTEM_PART_END + 1 ))
-STORAGE_PART_END=$(( $STORAGE_PART_START + ($STORAGE_SIZE * 1024 * 1024 / 512) - 1 ))
-if [ "$DISK_LABEL" = "gpt" ]; then
-  parted -s "$DISK" -a min unit s mkpart storage ext4 $STORAGE_PART_START $STORAGE_PART_END
+STORAGE_PART_START=$(( ${SYSTEM_PART_END} + 1 ))
+STORAGE_PART_END=$(( ${STORAGE_PART_START} + (${STORAGE_SIZE} * 1024 * 1024 / 512) - 1 ))
+if [ "${DISK_LABEL}" = "gpt" ]; then
+  parted -s "${DISK}" -a min unit s mkpart storage ext4 ${STORAGE_PART_START} ${STORAGE_PART_END}
 else
-  parted -s "$DISK" -a min unit s mkpart primary ext4 $STORAGE_PART_START $STORAGE_PART_END
+  parted -s "${DISK}" -a min unit s mkpart primary ext4 ${STORAGE_PART_START} ${STORAGE_PART_END}
 fi
 sync
 
-if [ "$BOOTLOADER" = "syslinux" ]; then
+if [ "${BOOTLOADER}" = "syslinux" ]; then
   # write mbr
   echo "image: writing mbr..."
-  MBR="$TOOLCHAIN/share/syslinux/gptmbr.bin"
-  if [ -n "$MBR" ]; then
-    dd bs=440 count=1 conv=fsync,notrunc if="$MBR" of="$DISK" >"$SAVE_ERROR" 2>&1 || show_error
+  MBR="${TOOLCHAIN}/share/syslinux/gptmbr.bin"
+  if [ -n "${MBR}" ]; then
+    dd bs=440 count=1 conv=fsync,notrunc if="${MBR}" of="${DISK}" >"${SAVE_ERROR}" 2>&1 || show_error
   fi
 fi
 
 # create filesystem on part1
 echo "image: creating filesystem on part1..."
-OFFSET=$(( $SYSTEM_PART_START * 512 ))
+OFFSET=$(( ${SYSTEM_PART_START} * 512 ))
 HEADS=4
 TRACKS=32
-SECTORS=$(( $SYSTEM_SIZE * 1024 * 1024 / 512 / $HEADS / $TRACKS ))
+SECTORS=$(( ${SYSTEM_SIZE} * 1024 * 1024 / 512 / ${HEADS} / ${TRACKS} ))
 
 shopt -s expand_aliases  # enables alias expansion in script
-alias mformat="mformat -i $DISK@@$OFFSET -h $HEADS -t $TRACKS -s $SECTORS"
-alias mcopy="mcopy -i $DISK@@$OFFSET"
-alias mmd="mmd -i $DISK@@$OFFSET"
+alias mformat="mformat -i ${DISK}@@${OFFSET} -h ${HEADS} -t ${TRACKS} -s ${SECTORS}"
+alias mcopy="mcopy -i ${DISK}@@${OFFSET}"
+alias mmd="mmd -i ${DISK}@@${OFFSET}"
 
-if [ "$BOOTLOADER" = "syslinux" -o "$BOOTLOADER" = "bcm2835-bootloader" -o "$BOOTLOADER" = "u-boot" ]; then
-  mformat -v "$DISTRO_BOOTLABEL" -N "$FAT_SERIAL_NUMBER" ::
+if [ "${BOOTLOADER}" = "syslinux" -o "${BOOTLOADER}" = "bcm2835-bootloader" -o "${BOOTLOADER}" = "u-boot" ]; then
+  mformat -v "${DISTRO_BOOTLABEL}" -N "${FAT_SERIAL_NUMBER}" ::
 fi
 sync
 
-if [ "$BOOTLOADER" = "syslinux" ]; then
+if [ "${BOOTLOADER}" = "syslinux" ]; then
   # create bootloader configuration
   echo "image: creating bootloader configuration..."
-  cat << EOF > "$LE_TMP"/syslinux.cfg
+  cat << EOF > "${LE_TMP}/syslinux.cfg"
 SAY Wait for installer to start or press <TAB> for more options (live, run)
 DEFAULT installer
 TIMEOUT 50
 PROMPT 1
 
 LABEL installer
-  KERNEL /$KERNEL_NAME
-  APPEND boot=UUID=$UUID_SYSTEM installer quiet tty vga=current
+  KERNEL /${KERNEL_NAME}
+  APPEND boot=UUID=${UUID_SYSTEM} installer quiet tty vga=current
 
 LABEL live
-  KERNEL /$KERNEL_NAME
-  APPEND boot=UUID=$UUID_SYSTEM live quiet tty vga=current
+  KERNEL /${KERNEL_NAME}
+  APPEND boot=UUID=${UUID_SYSTEM} live quiet tty vga=current
 
 LABEL run
-  KERNEL /$KERNEL_NAME
-  APPEND boot=UUID=$UUID_SYSTEM disk=UUID=$UUID_STORAGE tty portable quiet
+  KERNEL /${KERNEL_NAME}
+  APPEND boot=UUID=${UUID_SYSTEM} disk=UUID=${UUID_STORAGE} tty portable quiet
 EOF
 
-  cat << EOF > "$LE_TMP"/grub.cfg
+  cat << EOF > "${LE_TMP}/grub.cfg"
 set timeout="25"
 set default="Installer"
 menuentry "Installer" {
 	search --set -f /KERNEL
-	linux /KERNEL boot=UUID=$UUID_SYSTEM installer quiet tty vga=current
+	linux /KERNEL boot=UUID=${UUID_SYSTEM} installer quiet tty vga=current
 }
 menuentry "Live" {
 	search --set -f /KERNEL
-	linux /KERNEL boot=UUID=$UUID_SYSTEM grub_live quiet tty vga=current
+	linux /KERNEL boot=UUID=${UUID_SYSTEM} grub_live quiet tty vga=current
 }
 menuentry "Run" {
 	search --set -f /KERNEL
-	linux /KERNEL boot=UUID=$UUID_SYSTEM disk=UUID=$UUID_STORAGE tty grub_portable quiet
+	linux /KERNEL boot=UUID=${UUID_SYSTEM} disk=UUID=${UUID_STORAGE} tty grub_portable quiet
 }
 EOF
 
-  mcopy "$LE_TMP/syslinux.cfg" ::
+  mcopy "${LE_TMP}/syslinux.cfg" ::
 
   # install syslinux
   echo "image: installing syslinux to part1..."
-  syslinux.mtools --offset "$OFFSET" -i "$DISK"
+  syslinux.mtools --offset "${OFFSET}" -i "${DISK}"
 
   # copy files
   echo "image: copying files to part1..."
-  mcopy $TARGET_IMG/$IMAGE_NAME.kernel "::/$KERNEL_NAME"
-  mcopy $TARGET_IMG/$IMAGE_NAME.system ::/SYSTEM
-  mcopy $RELEASE_DIR/target/KERNEL.md5 "::/$KERNEL_NAME.md5"
-  mcopy $RELEASE_DIR/target/SYSTEM.md5 ::/SYSTEM.md5
+  mcopy "${TARGET_IMG}/${IMAGE_NAME}.kernel" "::/${KERNEL_NAME}"
+  mcopy "${TARGET_IMG}/${IMAGE_NAME}.system" ::/SYSTEM
+  mcopy "${RELEASE_DIR}/target/KERNEL.md5" "::/${KERNEL_NAME}.md5"
+  mcopy "${RELEASE_DIR}/target/SYSTEM.md5" ::/SYSTEM.md5
 
   mmd EFI EFI/BOOT
-  mcopy $TOOLCHAIN/share/syslinux/bootx64.efi ::/EFI/BOOT
-  mcopy $TOOLCHAIN/share/syslinux/ldlinux.e64 ::/EFI/BOOT
-  mcopy $TOOLCHAIN/share/grub/bootia32.efi ::/EFI/BOOT
-  mcopy "$LE_TMP"/grub.cfg ::/EFI/BOOT
+  mcopy "${TOOLCHAIN}/share/syslinux/bootx64.efi" ::/EFI/BOOT
+  mcopy "${TOOLCHAIN}/share/syslinux/ldlinux.e64" ::/EFI/BOOT
+  mcopy "${TOOLCHAIN}/share/grub/bootia32.efi" ::/EFI/BOOT
+  mcopy "${LE_TMP}/grub.cfg" ::/EFI/BOOT
 
-elif [ "$BOOTLOADER" = "bcm2835-bootloader" ]; then
+elif [ "${BOOTLOADER}" = "bcm2835-bootloader" ]; then
   # create bootloader configuration
   echo "image: creating bootloader configuration..."
-  cat << EOF > "$LE_TMP"/cmdline.txt
-boot=UUID=$UUID_SYSTEM disk=UUID=$UUID_STORAGE quiet $EXTRA_CMDLINE
+  cat << EOF > "${LE_TMP}/cmdline.txt"
+boot=UUID=${UUID_SYSTEM} disk=UUID=${UUID_STORAGE} quiet ${EXTRA_CMDLINE}
 EOF
 
-  mcopy "$LE_TMP/cmdline.txt" ::
+  mcopy "${LE_TMP}/cmdline.txt" ::
 
   # copy files
   echo "image: copying files to part1..."
-  mcopy $TARGET_IMG/$IMAGE_NAME.kernel "::/$KERNEL_NAME"
-  mcopy $TARGET_IMG/$IMAGE_NAME.system ::/SYSTEM
-  mcopy $RELEASE_DIR/target/KERNEL.md5 "::/$KERNEL_NAME.md5"
-  mcopy $RELEASE_DIR/target/SYSTEM.md5 ::/SYSTEM.md5
+  mcopy "${TARGET_IMG}/${IMAGE_NAME}.kernel" "::/${KERNEL_NAME}"
+  mcopy "${TARGET_IMG}/${IMAGE_NAME}.system" ::/SYSTEM
+  mcopy "${RELEASE_DIR}/target/KERNEL.md5" "::/${KERNEL_NAME}.md5"
+  mcopy "${RELEASE_DIR}/target/SYSTEM.md5" ::/SYSTEM.md5
 
-  mcopy $RELEASE_DIR/3rdparty/bootloader/bootcode.bin ::
-  mcopy $RELEASE_DIR/3rdparty/bootloader/fixup.dat ::
-  mcopy $RELEASE_DIR/3rdparty/bootloader/start.elf ::
-  mcopy $RELEASE_DIR/3rdparty/bootloader/config.txt ::
-  mcopy $RELEASE_DIR/3rdparty/bootloader/distroconfig.txt ::
+  mcopy "${RELEASE_DIR}/3rdparty/bootloader/bootcode.bin" ::
+  mcopy "${RELEASE_DIR}/3rdparty/bootloader/fixup.dat" ::
+  mcopy "${RELEASE_DIR}/3rdparty/bootloader/start.elf" ::
+  mcopy "${RELEASE_DIR}/3rdparty/bootloader/config.txt" ::
+  mcopy "${RELEASE_DIR}/3rdparty/bootloader/distroconfig.txt" ::
 
-  if [ -f $RELEASE_DIR/3rdparty/bootloader/dt-blob.bin ]; then
-    mcopy $RELEASE_DIR/3rdparty/bootloader/dt-blob.bin ::
+  if [ -f "${RELEASE_DIR}/3rdparty/bootloader/dt-blob.bin" ]; then
+    mcopy "${RELEASE_DIR}/3rdparty/bootloader/dt-blob.bin" ::
   fi
 
-  for dtb in $RELEASE_DIR/3rdparty/bootloader/*.dtb ; do
-    if [ -f $dtb ] ; then
-      mcopy "$dtb" ::/$(basename "$dtb")
+  for dtb in "${RELEASE_DIR}/3rdparty/bootloader/"*.dtb ; do
+    if [ -f "${dtb}" ]; then
+      mcopy "${dtb}" ::/$(basename "${dtb}")
     fi
   done
 
-  if [ -d $RELEASE_DIR/3rdparty/bootloader/overlays ]; then
-    mcopy -s $RELEASE_DIR/3rdparty/bootloader/overlays ::
+  if [ -d "${RELEASE_DIR}/3rdparty/bootloader/overlays" ]; then
+    mcopy -s "${RELEASE_DIR}/3rdparty/bootloader/overlays" ::
   fi
 
-elif [ "$BOOTLOADER" = "u-boot" -a \( -n "$UBOOT_SYSTEM" -o "$UBOOT_VERSION" = "vendor" \) ]; then
+elif [ "${BOOTLOADER}" = "u-boot" -a \( -n "${UBOOT_SYSTEM}" -o "${UBOOT_VERSION}" = "vendor" \) ]; then
   # create bootloader configuration
   echo "image: creating bootloader configuration..."
 
-  if [ "$UBOOT_VERSION" != "vendor" ]; then
-    DTB="$($SCRIPTS/uboot_helper $PROJECT $DEVICE $UBOOT_SYSTEM dtb)"
+  if [ "${UBOOT_VERSION}" != "vendor" ]; then
+    DTB="$(${SCRIPTS}/uboot_helper ${PROJECT} ${DEVICE} ${UBOOT_SYSTEM} dtb)"
 
-    if [ -f "$RELEASE_DIR/3rdparty/bootloader/$DTB" ]; then
-      mcopy $RELEASE_DIR/3rdparty/bootloader/$DTB ::
+    if [ -f "${RELEASE_DIR}/3rdparty/bootloader/${DTB}" ]; then
+      mcopy "${RELEASE_DIR}/3rdparty/bootloader/${DTB}" ::
     fi
 
-    mkdir -p "$LE_TMP"/extlinux
+    mkdir -p "${LE_TMP}/extlinux"
 
-    cat << EOF > "$LE_TMP"/extlinux/extlinux.conf
-LABEL $DISTRO
-  LINUX /$KERNEL_NAME
-  FDT /$DTB
-  APPEND boot=UUID=$UUID_SYSTEM disk=UUID=$UUID_STORAGE quiet $EXTRA_CMDLINE
+    cat << EOF > "${LE_TMP}/extlinux/extlinux.conf"
+LABEL ${DISTRO}
+  LINUX /${KERNEL_NAME}
+  FDT /${DTB}
+  APPEND boot=UUID=${UUID_SYSTEM} disk=UUID=${UUID_STORAGE} quiet ${EXTRA_CMDLINE}
 EOF
 
-    mcopy -s "$LE_TMP"/extlinux ::
+    mcopy -s "${LE_TMP}/extlinux" ::
   fi
 
-  if [ -f $PROJECT_DIR/$PROJECT/devices/$DEVICE/bootloader/mkimage ]; then
-    . $PROJECT_DIR/$PROJECT/devices/$DEVICE/bootloader/mkimage
-  elif [ -f $PROJECT_DIR/$PROJECT/bootloader/mkimage ]; then
-    . $PROJECT_DIR/$PROJECT/bootloader/mkimage
+  if [ -f "${PROJECT_DIR}/${PROJECT}/devices/${DEVICE}/bootloader/mkimage" ]; then
+    . "${PROJECT_DIR}/${PROJECT}/devices/${DEVICE}/bootloader/mkimage"
+  elif [ -f "${PROJECT_DIR}/${PROJECT}/bootloader/mkimage" ]; then
+    . "${PROJECT_DIR}/${PROJECT}/bootloader/mkimage"
   else
     echo "image: skipping u-boot. no mkimage script found"
   fi
 
   echo "image: copying files to part1..."
-  mcopy $TARGET_IMG/$IMAGE_NAME.kernel "::/$KERNEL_NAME"
-  mcopy $TARGET_IMG/$IMAGE_NAME.system ::/SYSTEM
-  mcopy $RELEASE_DIR/target/KERNEL.md5 "::/$KERNEL_NAME.md5"
-  mcopy $RELEASE_DIR/target/SYSTEM.md5 ::/SYSTEM.md5
+  mcopy "${TARGET_IMG}/${IMAGE_NAME}.kernel" "::/${KERNEL_NAME}"
+  mcopy "${TARGET_IMG}/${IMAGE_NAME}.system" ::/SYSTEM
+  mcopy "${RELEASE_DIR}/target/KERNEL.md5" "::/${KERNEL_NAME}.md5"
+  mcopy "${RELEASE_DIR}/target/SYSTEM.md5" ::/SYSTEM.md5
 
-elif [ "$BOOTLOADER" = "u-boot" ]; then
+elif [ "${BOOTLOADER}" = "u-boot" ]; then
   echo "to make an image using u-boot UBOOT_SYSTEM must be set"
   cleanup
+  exit
 fi # bootloader
 
 # extract part2 from image to format and copy files
 echo "image: extracting part2 from image..."
-STORAGE_PART_COUNT=$(( $STORAGE_PART_END - $STORAGE_PART_START + 1 ))
+STORAGE_PART_COUNT=$(( ${STORAGE_PART_END} - ${STORAGE_PART_START} + 1 ))
 sync
-dd if="$DISK" of="$LE_TMP/part2.ext4" bs=512 skip="$STORAGE_PART_START" count="$STORAGE_PART_COUNT" conv=fsync >"$SAVE_ERROR" 2>&1 || show_error
+dd if="${DISK}" of="${LE_TMP}/part2.ext4" bs=512 skip="${STORAGE_PART_START}" count="${STORAGE_PART_COUNT}" conv=fsync >"${SAVE_ERROR}" 2>&1 || show_error
 
 # create filesystem on part2
 echo "image: creating filesystem on part2..."
-mke2fs -F -q -t ext4 -m 0 "$LE_TMP/part2.ext4"
-tune2fs -L "$DISTRO_DISKLABEL" -U $UUID_STORAGE "$LE_TMP/part2.ext4" >"$SAVE_ERROR" 2>&1 || show_error
-e2fsck -n "$LE_TMP/part2.ext4" >"$SAVE_ERROR" 2>&1 || show_error
+mke2fs -F -q -t ext4 -m 0 "${LE_TMP}/part2.ext4"
+tune2fs -L "${DISTRO_DISKLABEL}" -U ${UUID_STORAGE} "${LE_TMP}/part2.ext4" >"${SAVE_ERROR}" 2>&1 || show_error
+e2fsck -n "${LE_TMP}/part2.ext4" >"${SAVE_ERROR}" 2>&1 || show_error
 sync
 
 # add resize mark
-mkdir "$LE_TMP/part2.fs"
-touch "$LE_TMP/part2.fs/.please_resize_me"
+mkdir "${LE_TMP}/part2.fs"
+touch "${LE_TMP}/part2.fs/.please_resize_me"
 echo "image: populating filesystem on part2..."
-populatefs -U -d "$LE_TMP/part2.fs" "$LE_TMP/part2.ext4" >"$SAVE_ERROR" 2>&1 || show_error
+populatefs -U -d "${LE_TMP}/part2.fs" "${LE_TMP}/part2.ext4" >"${SAVE_ERROR}" 2>&1 || show_error
 sync
-e2fsck -n "$LE_TMP/part2.ext4" >"$SAVE_ERROR" 2>&1 || show_error
+e2fsck -n "${LE_TMP}/part2.ext4" >"${SAVE_ERROR}" 2>&1 || show_error
 
 # merge part2 back to disk image
 echo "image: merging part2 back to image..."
-dd if="$LE_TMP/part2.ext4" of="$DISK" bs=512 seek="$STORAGE_PART_START" conv=fsync,notrunc >"$SAVE_ERROR" 2>&1 || show_error
+dd if="${LE_TMP}/part2.ext4" of="${DISK}" bs=512 seek="${STORAGE_PART_START}" conv=fsync,notrunc >"${SAVE_ERROR}" 2>&1 || show_error
 
 # extract part1 from image to run fsck
 echo "image: extracting part1 from image..."
-SYSTEM_PART_COUNT=$(( $SYSTEM_PART_END - $SYSTEM_PART_START + 1 ))
+SYSTEM_PART_COUNT=$(( ${SYSTEM_PART_END} - ${SYSTEM_PART_START} + 1 ))
 sync
-dd if="$DISK" of="$LE_TMP/part1.fat" bs=512 skip="$SYSTEM_PART_START" count="$SYSTEM_PART_COUNT" conv=fsync >"$SAVE_ERROR" 2>&1 || show_error
+dd if="${DISK}" of="${LE_TMP}/part1.fat" bs=512 skip="${SYSTEM_PART_START}" count="${SYSTEM_PART_COUNT}" conv=fsync >"${SAVE_ERROR}" 2>&1 || show_error
 echo "image: checking filesystem on part1..."
-fsck -n $LE_TMP/part1.fat >"$SAVE_ERROR" 2>&1 || show_error
+fsck -n "${LE_TMP}/part1.fat" >"${SAVE_ERROR}" 2>&1 || show_error
 
 # create virtual image
-if [ "$PROJECT" = "Generic" ]; then
+if [ "${PROJECT}" = "Generic" ]; then
   echo "image: creating open virtual appliance..."
   # duplicate $DISK so anything we do to it directly doesn't effect original
-  dd if="$DISK" of="${DISK_BASENAME}.tmp" bs=1M >"$SAVE_ERROR" 2>&1 || show_error
+  dd if="${DISK}" of="${DISK_BASENAME}.tmp" bs=1M >"${SAVE_ERROR}" 2>&1 || show_error
   # change syslinux default to 'run'
   echo "image: modifying fs on part1 for open virtual appliance..."
-  sed -i "/DEFAULT/ s/installer/run/" "$LE_TMP"/syslinux.cfg
-  sed -i "/set default=/s/\"Installer\"/\"Run\"/" "$LE_TMP"/grub.cfg
+  sed -e "/DEFAULT/ s/installer/run/" -i "${LE_TMP}/syslinux.cfg"
+  sed -e "/set default=/s/\"Installer\"/\"Run\"/" -i "${LE_TMP}/grub.cfg"
   # FIXME: an unalias should work here, but it does not; call mcopy directly
-  $TOOLCHAIN/bin/mcopy -i $LE_TMP/part1.fat -o "$LE_TMP"/syslinux.cfg ::
-  $TOOLCHAIN/bin/mcopy -i $LE_TMP/part1.fat -o "$LE_TMP"/grub.cfg ::/EFI/BOOT
+  "${TOOLCHAIN}"/bin/mcopy -i "${LE_TMP}/part1.fat" -o "${LE_TMP}/syslinux.cfg" ::
+  "${TOOLCHAIN}"/bin/mcopy -i "${LE_TMP}/part1.fat" -o "${LE_TMP}/grub.cfg" ::/EFI/BOOT
   sync
   # merge modified part1 back to tmp disk image
   echo "image: merging part1 back to open virtual appliance..."
-  dd if="$LE_TMP/part1.fat" of="${DISK_BASENAME}.tmp" bs=512 seek="$SYSTEM_PART_START" conv=fsync,notrunc >"$SAVE_ERROR" 2>&1 || show_error
+  dd if="${LE_TMP}/part1.fat" of="${DISK_BASENAME}.tmp" bs=512 seek="${SYSTEM_PART_START}" conv=fsync,notrunc >"${SAVE_ERROR}" 2>&1 || show_error
   # create vmdk from tmp $DISK
   qemu-img convert -O vmdk -o subformat=streamOptimized "${DISK_BASENAME}.tmp" "${DISK_BASENAME}.vmdk"
   # generate ovf from template
-  sed -e "s,@DISTRO@,$DISTRO,g" -e "s,@DISK@,${IMAGE_NAME},g" \
-      -e "s,@DISK_SIZE@,$(($DISK_SIZE*1024*1024)),g" \
-      $PROJECT_DIR/$PROJECT/config/ovf.template > ${DISK_BASENAME}.ovf
+  sed -e "s,@DISTRO@,${DISTRO},g" -e "s,@DISK@,${IMAGE_NAME},g" \
+      -e "s,@DISK_SIZE@,$((${DISK_SIZE}*1024*1024)),g" \
+      "${PROJECT_DIR}/${PROJECT}/config/ovf.template" > "${DISK_BASENAME}.ovf"
   # combine ovf and vmdk into official ova
-  tar -C $TARGET_IMG -cf ${DISK_BASENAME}.ova ${IMAGE_NAME}.ovf ${IMAGE_NAME}.vmdk
+  tar -C "${TARGET_IMG}" -cf "${DISK_BASENAME}.ova" "${IMAGE_NAME}.ovf" "${IMAGE_NAME}.vmdk"
   # create sha256 checksum of ova image
-  ( cd $TARGET_IMG
-    sha256sum ${IMAGE_NAME}.ova > ${IMAGE_NAME}.ova.sha256
+  ( cd "${TARGET_IMG}"
+    sha256sum "${IMAGE_NAME}.ova" > "${IMAGE_NAME}.ova.sha256"
   )
   echo "image: cleaning up..."
   # remove tmp $DISK, vmdk and ovf
-  rm ${DISK_BASENAME}.tmp ${DISK_BASENAME}.vmdk ${DISK_BASENAME}.ovf
+  rm "${DISK_BASENAME}.tmp" "${DISK_BASENAME}.vmdk" "${DISK_BASENAME}.ovf"
   # set owner
-  [ -n "$SUDO_USER" ] && chown $SUDO_USER: ${DISK_BASENAME}.ova
+  [ -n "${SUDO_USER}" ] && chown "${SUDO_USER}:" "${DISK_BASENAME}.ova"
 fi
 
 # gzip
 echo "image: compressing..."
-gzip $DISK
+gzip "${DISK}"
 
 # set owner
-if [ -n "$SUDO_USER" ] ; then
-  chown $SUDO_USER: $DISK.gz
+if [ -n "${SUDO_USER}" ]; then
+  chown "${SUDO_USER}:" "${DISK}.gz"
 fi
 # create sha256 checksum of image
-( cd $TARGET_IMG
-  sha256sum $(basename $DISK).gz > $(basename $DISK).gz.sha256
+( cd "${TARGET_IMG}"
+  sha256sum $(basename "${DISK}").gz > $(basename "${DISK}").gz.sha256
 )
 
 # cleanup
 cleanup
+exit