diff --git a/packages/linux/package.mk b/packages/linux/package.mk
index 0f8382e434..fd607610e0 100644
--- a/packages/linux/package.mk
+++ b/packages/linux/package.mk
@@ -6,31 +6,31 @@ PKG_NAME="linux"
 PKG_LICENSE="GPL"
 PKG_SITE="http://www.kernel.org"
 PKG_DEPENDS_HOST="ccache:host rsync:host openssl:host"
-PKG_DEPENDS_TARGET="toolchain linux:host kmod:host xz:host keyutils $KERNEL_EXTRA_DEPENDS_TARGET"
-PKG_NEED_UNPACK="$LINUX_DEPENDS $(get_pkg_directory initramfs) $(get_pkg_variable initramfs PKG_NEED_UNPACK)"
+PKG_DEPENDS_TARGET="toolchain linux:host kmod:host xz:host keyutils ${KERNEL_EXTRA_DEPENDS_TARGET}"
+PKG_NEED_UNPACK="${LINUX_DEPENDS} $(get_pkg_directory initramfs) $(get_pkg_variable initramfs PKG_NEED_UNPACK)"
 PKG_LONGDESC="This package contains a precompiled kernel image and the modules."
 PKG_IS_KERNEL_PKG="yes"
-PKG_STAMP="$KERNEL_TARGET $KERNEL_MAKE_EXTRACMD"
+PKG_STAMP="${KERNEL_TARGET} ${KERNEL_MAKE_EXTRACMD}"
 
-PKG_PATCH_DIRS="$LINUX"
+PKG_PATCH_DIRS="${LINUX}"
 
-case "$LINUX" in
+case "${LINUX}" in
   amlogic)
     PKG_VERSION="7c53f6b671f4aba70ff15e1b05148b10d58c2837" # 5.11-rc3
     PKG_SHA256="30206f178c9c151a0c387c7967800bc0bf89a893958241a3add0098d443f323a"
-    PKG_URL="https://github.com/torvalds/linux/archive/$PKG_VERSION.tar.gz"
-    PKG_SOURCE_NAME="linux-$LINUX-$PKG_VERSION.tar.gz"
+    PKG_URL="https://github.com/torvalds/linux/archive/${PKG_VERSION}.tar.gz"
+    PKG_SOURCE_NAME="linux-${LINUX}-${PKG_VERSION}.tar.gz"
     ;;
   raspberrypi)
     PKG_VERSION="e9505f4612646533f53813aabef5ca040b0ea49d" # 5.10.7
     PKG_SHA256="2d6e3637dbe328161161cbdede2902e0aaaa979bd0179a40e14d2960a61de593"
-    PKG_URL="https://github.com/raspberrypi/linux/archive/$PKG_VERSION.tar.gz"
-    PKG_SOURCE_NAME="linux-$LINUX-$PKG_VERSION.tar.gz"
+    PKG_URL="https://github.com/raspberrypi/linux/archive/${PKG_VERSION}.tar.gz"
+    PKG_SOURCE_NAME="linux-${LINUX}-${PKG_VERSION}.tar.gz"
     ;;
   *)
     PKG_VERSION="5.10.4"
     PKG_SHA256="904e396c26e9992a16cd1cc989460171536bed7739bf36049f6eb020ee5d56ec"
-    PKG_URL="https://www.kernel.org/pub/linux/kernel/v5.x/$PKG_NAME-$PKG_VERSION.tar.xz"
+    PKG_URL="https://www.kernel.org/pub/linux/kernel/v5.x/${PKG_NAME}-${PKG_VERSION}.tar.xz"
     PKG_PATCH_DIRS="default"
     ;;
 esac
@@ -41,26 +41,26 @@ if listcontains "${UBOOT_FIRMWARE}" "crust"; then
   PKG_PATCH_DIRS+=" crust"
 fi
 
-if [ -n "$KERNEL_TOOLCHAIN" ]; then
-  PKG_DEPENDS_HOST="$PKG_DEPENDS_HOST gcc-arm-$KERNEL_TOOLCHAIN:host"
-  PKG_DEPENDS_TARGET="$PKG_DEPENDS_TARGET gcc-arm-$KERNEL_TOOLCHAIN:host"
-  HEADERS_ARCH=$TARGET_ARCH
+if [ -n "${KERNEL_TOOLCHAIN}" ]; then
+  PKG_DEPENDS_HOST+=" gcc-arm-${KERNEL_TOOLCHAIN}:host"
+  PKG_DEPENDS_TARGET+=" gcc-arm-${KERNEL_TOOLCHAIN}:host"
+  HEADERS_ARCH=${TARGET_ARCH}
 fi
 
-if [ "$PKG_BUILD_PERF" != "no" ] && grep -q ^CONFIG_PERF_EVENTS= $PKG_KERNEL_CFG_FILE ; then
+if [ "${PKG_BUILD_PERF}" != "no" ] && grep -q ^CONFIG_PERF_EVENTS= ${PKG_KERNEL_CFG_FILE}; then
   PKG_BUILD_PERF="yes"
-  PKG_DEPENDS_TARGET="$PKG_DEPENDS_TARGET binutils elfutils libunwind zlib openssl"
+  PKG_DEPENDS_TARGET+=" binutils elfutils libunwind zlib openssl"
 fi
 
-if [ "$TARGET_ARCH" = "x86_64" ]; then
-  PKG_DEPENDS_TARGET="$PKG_DEPENDS_TARGET elfutils:host pciutils"
+if [ "${TARGET_ARCH}" = "x86_64" ]; then
+  PKG_DEPENDS_TARGET+=" elfutils:host pciutils"
   PKG_DEPENDS_UNPACK+=" intel-ucode kernel-firmware"
-elif [ "$TARGET_ARCH" = "arm" -a "$DEVICE" = "iMX6" ]; then
+elif [ "${TARGET_ARCH}" = "arm" -a "${DEVICE}" = "iMX6" ]; then
   PKG_DEPENDS_UNPACK+=" firmware-imx"
 fi
 
-if [[ "$KERNEL_TARGET" = uImage* ]]; then
-  PKG_DEPENDS_TARGET="$PKG_DEPENDS_TARGET u-boot-tools:host"
+if [[ "${KERNEL_TARGET}" = uImage* ]]; then
+  PKG_DEPENDS_TARGET+=" u-boot-tools:host"
 fi
 
 # Ensure that the dependencies of initramfs:target are built correctly, but
@@ -72,108 +72,108 @@ done
 
 post_patch() {
   # linux was already built and its build dir autoremoved - prepare it again for kernel packages
-  if [ -d $PKG_INSTALL/.image ]; then
-    cp -p $PKG_INSTALL/.image/.config $PKG_BUILD
-    kernel_make -C $PKG_BUILD prepare
+  if [ -d ${PKG_INSTALL}/.image ]; then
+    cp -p ${PKG_INSTALL}/.image/.config ${PKG_BUILD}
+    kernel_make -C ${PKG_BUILD} prepare
 
     # restore the required Module.symvers from an earlier build
-    cp -p $PKG_INSTALL/.image/Module.symvers $PKG_BUILD
+    cp -p ${PKG_INSTALL}/.image/Module.symvers ${PKG_BUILD}
   else
-    cp $PKG_KERNEL_CFG_FILE $PKG_BUILD/.config
+    cp ${PKG_KERNEL_CFG_FILE} ${PKG_BUILD}/.config
 
-    sed -i -e "s|@INITRAMFS_SOURCE@|$(kernel_initramfs_confs) $BUILD/initramfs|" $PKG_BUILD/.config
+    sed -i -e "s|@INITRAMFS_SOURCE@|$(kernel_initramfs_confs) ${BUILD}/initramfs|" ${PKG_BUILD}/.config
 
-    # set default hostname based on $DISTRONAME
-      sed -i -e "s|@DISTRONAME@|$DISTRONAME|g" $PKG_BUILD/.config
+    # set default hostname based on ${DISTRONAME}
+      sed -i -e "s|@DISTRONAME@|${DISTRONAME}|g" ${PKG_BUILD}/.config
 
     # disable swap support if not enabled
-    if [ ! "$SWAP_SUPPORT" = yes ]; then
-      sed -i -e "s|^CONFIG_SWAP=.*$|# CONFIG_SWAP is not set|" $PKG_BUILD/.config
+    if [ ! "${SWAP_SUPPORT}" = yes ]; then
+      sed -i -e "s|^CONFIG_SWAP=.*$|# CONFIG_SWAP is not set|" ${PKG_BUILD}/.config
     fi
 
     # disable nfs support if not enabled
-    if [ ! "$NFS_SUPPORT" = yes ]; then
-      sed -i -e "s|^CONFIG_NFS_FS=.*$|# CONFIG_NFS_FS is not set|" $PKG_BUILD/.config
+    if [ ! "${NFS_SUPPORT}" = yes ]; then
+      sed -i -e "s|^CONFIG_NFS_FS=.*$|# CONFIG_NFS_FS is not set|" ${PKG_BUILD}/.config
     fi
 
     # disable cifs support if not enabled
-    if [ ! "$SAMBA_SUPPORT" = yes ]; then
-      sed -i -e "s|^CONFIG_CIFS=.*$|# CONFIG_CIFS is not set|" $PKG_BUILD/.config
+    if [ ! "${SAMBA_SUPPORT}" = yes ]; then
+      sed -i -e "s|^CONFIG_CIFS=.*$|# CONFIG_CIFS is not set|" ${PKG_BUILD}/.config
     fi
 
     # disable iscsi support if not enabled
-    if [ ! "$ISCSI_SUPPORT" = yes ]; then
-      sed -i -e "s|^CONFIG_SCSI_ISCSI_ATTRS=.*$|# CONFIG_SCSI_ISCSI_ATTRS is not set|" $PKG_BUILD/.config
-      sed -i -e "s|^CONFIG_ISCSI_TCP=.*$|# CONFIG_ISCSI_TCP is not set|" $PKG_BUILD/.config
-      sed -i -e "s|^CONFIG_ISCSI_BOOT_SYSFS=.*$|# CONFIG_ISCSI_BOOT_SYSFS is not set|" $PKG_BUILD/.config
-      sed -i -e "s|^CONFIG_ISCSI_IBFT_FIND=.*$|# CONFIG_ISCSI_IBFT_FIND is not set|" $PKG_BUILD/.config
-      sed -i -e "s|^CONFIG_ISCSI_IBFT=.*$|# CONFIG_ISCSI_IBFT is not set|" $PKG_BUILD/.config
+    if [ ! "${ISCSI_SUPPORT}" = yes ]; then
+      sed -i -e "s|^CONFIG_SCSI_ISCSI_ATTRS=.*$|# CONFIG_SCSI_ISCSI_ATTRS is not set|" ${PKG_BUILD}/.config
+      sed -i -e "s|^CONFIG_ISCSI_TCP=.*$|# CONFIG_ISCSI_TCP is not set|" ${PKG_BUILD}/.config
+      sed -i -e "s|^CONFIG_ISCSI_BOOT_SYSFS=.*$|# CONFIG_ISCSI_BOOT_SYSFS is not set|" ${PKG_BUILD}/.config
+      sed -i -e "s|^CONFIG_ISCSI_IBFT_FIND=.*$|# CONFIG_ISCSI_IBFT_FIND is not set|" ${PKG_BUILD}/.config
+      sed -i -e "s|^CONFIG_ISCSI_IBFT=.*$|# CONFIG_ISCSI_IBFT is not set|" ${PKG_BUILD}/.config
     fi
 
     # disable lima/panfrost if libmali is configured
-    if [ "$OPENGLES" = "libmali" ]; then
-      sed -e "s|^CONFIG_DRM_LIMA=.*$|# CONFIG_DRM_LIMA is not set|" -i $PKG_BUILD/.config
-      sed -e "s|^CONFIG_DRM_PANFROST=.*$|# CONFIG_DRM_PANFROST is not set|" -i $PKG_BUILD/.config
+    if [ "${OPENGLES}" = "libmali" ]; then
+      sed -e "s|^CONFIG_DRM_LIMA=.*$|# CONFIG_DRM_LIMA is not set|" -i ${PKG_BUILD}/.config
+      sed -e "s|^CONFIG_DRM_PANFROST=.*$|# CONFIG_DRM_PANFROST is not set|" -i ${PKG_BUILD}/.config
     fi
 
     # disable wireguard support if not enabled
-    if [ ! "$WIREGUARD_SUPPORT" = yes ]; then
-      sed -e "s|^CONFIG_WIREGUARD=.*$|# CONFIG_WIREGUARD is not set|" -i $PKG_BUILD/.config
+    if [ ! "${WIREGUARD_SUPPORT}" = yes ]; then
+      sed -e "s|^CONFIG_WIREGUARD=.*$|# CONFIG_WIREGUARD is not set|" -i ${PKG_BUILD}/.config
     fi
   fi
 }
 
 make_host() {
   make \
-    ARCH=${HEADERS_ARCH:-$TARGET_KERNEL_ARCH} \
-    HOSTCC="$TOOLCHAIN/bin/host-gcc" \
-    HOSTCXX="$TOOLCHAIN/bin/host-g++" \
-    HOSTCFLAGS="$HOST_CFLAGS" \
-    HOSTCXXFLAGS="$HOST_CXXFLAGS" \
-    HOSTLDFLAGS="$HOST_LDFLAGS" \
+    ARCH=${HEADERS_ARCH:-${TARGET_KERNEL_ARCH}} \
+    HOSTCC="${TOOLCHAIN}/bin/host-gcc" \
+    HOSTCXX="${TOOLCHAIN}/bin/host-g++" \
+    HOSTCFLAGS="${HOST_CFLAGS}" \
+    HOSTCXXFLAGS="${HOST_CXXFLAGS}" \
+    HOSTLDFLAGS="${HOST_LDFLAGS}" \
     headers_check
 }
 
 makeinstall_host() {
   make \
-    ARCH=${HEADERS_ARCH:-$TARGET_KERNEL_ARCH} \
-    HOSTCC="$TOOLCHAIN/bin/host-gcc" \
-    HOSTCXX="$TOOLCHAIN/bin/host-g++" \
-    HOSTCFLAGS="$HOST_CFLAGS" \
-    HOSTCXXFLAGS="$HOST_CXXFLAGS" \
-    HOSTLDFLAGS="$HOST_LDFLAGS" \
+    ARCH=${HEADERS_ARCH:-${TARGET_KERNEL_ARCH}} \
+    HOSTCC="${TOOLCHAIN}/bin/host-gcc" \
+    HOSTCXX="${TOOLCHAIN}/bin/host-g++" \
+    HOSTCFLAGS="${HOST_CFLAGS}" \
+    HOSTCXXFLAGS="${HOST_CXXFLAGS}" \
+    HOSTLDFLAGS="${HOST_LDFLAGS}" \
     INSTALL_HDR_PATH=dest \
     headers_install
-  mkdir -p $SYSROOT_PREFIX/usr/include
-    cp -R dest/include/* $SYSROOT_PREFIX/usr/include
+  mkdir -p ${SYSROOT_PREFIX}/usr/include
+    cp -R dest/include/* ${SYSROOT_PREFIX}/usr/include
 }
 
 pre_make_target() {
-  ( cd $ROOT
-    rm -rf $BUILD/initramfs
+  ( cd ${ROOT}
+    rm -rf ${BUILD}/initramfs
     rm -f ${STAMPS_INSTALL}/initramfs/install_target ${STAMPS_INSTALL}/*/install_init
-    $SCRIPTS/install initramfs
+    ${SCRIPTS}/install initramfs
   )
   pkg_lock_status "ACTIVE" "linux:target" "build"
 
-  if [ "$TARGET_ARCH" = "x86_64" ]; then
+  if [ "${TARGET_ARCH}" = "x86_64" ]; then
     # copy some extra firmware to linux tree
-    mkdir -p $PKG_BUILD/external-firmware
-      cp -a $(get_build_dir kernel-firmware)/.copied-firmware/{amdgpu,amd-ucode,i915,radeon,e100,rtl_nic} $PKG_BUILD/external-firmware
+    mkdir -p ${PKG_BUILD}/external-firmware
+      cp -a $(get_build_dir kernel-firmware)/.copied-firmware/{amdgpu,amd-ucode,i915,radeon,e100,rtl_nic} ${PKG_BUILD}/external-firmware
 
-    cp -a $(get_build_dir intel-ucode)/intel-ucode $PKG_BUILD/external-firmware
+    cp -a $(get_build_dir intel-ucode)/intel-ucode ${PKG_BUILD}/external-firmware
 
-    FW_LIST="$(find $PKG_BUILD/external-firmware \( -type f -o -type l \) \( -iname '*.bin' -o -iname '*.fw' -o -path '*/intel-ucode/*' \) | sed 's|.*external-firmware/||' | sort | xargs)"
-    sed -i "s|CONFIG_EXTRA_FIRMWARE=.*|CONFIG_EXTRA_FIRMWARE=\"${FW_LIST}\"|" $PKG_BUILD/.config
+    FW_LIST="$(find ${PKG_BUILD}/external-firmware \( -type f -o -type l \) \( -iname '*.bin' -o -iname '*.fw' -o -path '*/intel-ucode/*' \) | sed 's|.*external-firmware/||' | sort | xargs)"
+    sed -i "s|CONFIG_EXTRA_FIRMWARE=.*|CONFIG_EXTRA_FIRMWARE=\"${FW_LIST}\"|" ${PKG_BUILD}/.config
 
-  elif [ "$TARGET_ARCH" = "arm" -a "$DEVICE" = "iMX6" ]; then
-    mkdir -p $PKG_BUILD/external-firmware/imx/sdma
-      cp -a $(get_build_dir firmware-imx)/firmware/sdma/*imx6*.bin $PKG_BUILD/external-firmware/imx/sdma
-      cp -a $(get_build_dir firmware-imx)/firmware/vpu/*imx6*.bin $PKG_BUILD/external-firmware
+  elif [ "${TARGET_ARCH}" = "arm" -a "${DEVICE}" = "iMX6" ]; then
+    mkdir -p ${PKG_BUILD}/external-firmware/imx/sdma
+      cp -a $(get_build_dir firmware-imx)/firmware/sdma/*imx6*.bin ${PKG_BUILD}/external-firmware/imx/sdma
+      cp -a $(get_build_dir firmware-imx)/firmware/vpu/*imx6*.bin ${PKG_BUILD}/external-firmware
 
-    FW_LIST="$(find $PKG_BUILD/external-firmware -type f | sed 's|.*external-firmware/||' | sort | xargs)"
-    sed -i -e "s|^CONFIG_EXTRA_FIRMWARE=.*$|CONFIG_EXTRA_FIRMWARE=\"${FW_LIST}\"|" $PKG_BUILD/.config
-    sed -i -e "/CONFIG_EXTRA_FIRMWARE_DIR/d" -e "/CONFIG_EXTRA_FIRMWARE=.../a CONFIG_EXTRA_FIRMWARE_DIR=\"external-firmware\"" $PKG_BUILD/.config
+    FW_LIST="$(find ${PKG_BUILD}/external-firmware -type f | sed 's|.*external-firmware/||' | sort | xargs)"
+    sed -i -e "s|^CONFIG_EXTRA_FIRMWARE=.*$|CONFIG_EXTRA_FIRMWARE=\"${FW_LIST}\"|" ${PKG_BUILD}/.config
+    sed -i -e "/CONFIG_EXTRA_FIRMWARE_DIR/d" -e "/CONFIG_EXTRA_FIRMWARE=.../a CONFIG_EXTRA_FIRMWARE_DIR=\"external-firmware\"" ${PKG_BUILD}/.config
   fi
 
   kernel_make oldconfig
@@ -182,21 +182,21 @@ pre_make_target() {
 make_target() {
   # arm64 target does not support creating uImage.
   # Build Image first, then wrap it using u-boot's mkimage.
-  if [[ "$TARGET_KERNEL_ARCH" = "arm64" && "$KERNEL_TARGET" = uImage* ]]; then
-    if [ -z "$KERNEL_UIMAGE_LOADADDR" -o -z "$KERNEL_UIMAGE_ENTRYADDR" ]; then
+  if [[ "${TARGET_KERNEL_ARCH}" = "arm64" && "${KERNEL_TARGET}" = uImage* ]]; then
+    if [ -z "${KERNEL_UIMAGE_LOADADDR}" -o -z "${KERNEL_UIMAGE_ENTRYADDR}" ]; then
       die "ERROR: KERNEL_UIMAGE_LOADADDR and KERNEL_UIMAGE_ENTRYADDR have to be set to build uImage - aborting"
     fi
-    KERNEL_UIMAGE_TARGET="$KERNEL_TARGET"
+    KERNEL_UIMAGE_TARGET="${KERNEL_TARGET}"
     KERNEL_TARGET="${KERNEL_TARGET/uImage/Image}"
   fi
 
-  kernel_make $KERNEL_TARGET $KERNEL_MAKE_EXTRACMD modules
+  kernel_make ${KERNEL_TARGET} ${KERNEL_MAKE_EXTRACMD} modules
 
-  if [ "$PKG_BUILD_PERF" = "yes" ] ; then
+  if [ "${PKG_BUILD_PERF}" = "yes" ]; then
     ( cd tools/perf
 
       # arch specific perf build args
-      case "$TARGET_ARCH" in
+      case "${TARGET_ARCH}" in
         x86_64)
           PERF_BUILD_ARGS="ARCH=x86"
           ;;
@@ -204,7 +204,7 @@ make_target() {
           PERF_BUILD_ARGS="ARCH=arm64"
           ;;
         *)
-          PERF_BUILD_ARGS="ARCH=$TARGET_ARCH"
+          PERF_BUILD_ARGS="ARCH=${TARGET_ARCH}"
           ;;
       esac
 
@@ -217,72 +217,72 @@ make_target() {
       NO_LIBAUDIT=1 \
       NO_LZMA=1 \
       NO_SDT=1 \
-      CROSS_COMPILE="$TARGET_PREFIX" \
-      JOBS="$CONCURRENCY_MAKE_LEVEL" \
-        make $PERF_BUILD_ARGS
-      mkdir -p $INSTALL/usr/bin
-        cp perf $INSTALL/usr/bin
+      CROSS_COMPILE="${TARGET_PREFIX}" \
+      JOBS="${CONCURRENCY_MAKE_LEVEL}" \
+        make ${PERF_BUILD_ARGS}
+      mkdir -p ${INSTALL}/usr/bin
+        cp perf ${INSTALL}/usr/bin
     )
   fi
 
-  if [ -n "$KERNEL_UIMAGE_TARGET" ] ; then
+  if [ -n "${KERNEL_UIMAGE_TARGET}" ]; then
     # determine compression used for kernel image
     KERNEL_UIMAGE_COMP=${KERNEL_UIMAGE_TARGET:7}
     KERNEL_UIMAGE_COMP=$(echo ${KERNEL_UIMAGE_COMP:-none} | sed 's/gz/gzip/; s/bz2/bzip2/')
 
     # calculate new load address to make kernel Image unpack to memory area after compressed image
-    if [ "$KERNEL_UIMAGE_COMP" != "none" ] ; then
-      COMPRESSED_SIZE=$(stat -t "arch/$TARGET_KERNEL_ARCH/boot/$KERNEL_TARGET" | awk '{print $2}')
+    if [ "${KERNEL_UIMAGE_COMP}" != "none" ]; then
+      COMPRESSED_SIZE=$(stat -t "arch/${TARGET_KERNEL_ARCH}/boot/${KERNEL_TARGET}" | awk '{print $2}')
       # align to 1 MiB
-      COMPRESSED_SIZE=$(( (($COMPRESSED_SIZE - 1 >> 20) + 1) << 20 ))
-      PKG_KERNEL_UIMAGE_LOADADDR=$(printf '%X' "$(( $KERNEL_UIMAGE_LOADADDR + $COMPRESSED_SIZE ))")
-      PKG_KERNEL_UIMAGE_ENTRYADDR=$(printf '%X' "$(( $KERNEL_UIMAGE_ENTRYADDR + $COMPRESSED_SIZE ))")
+      COMPRESSED_SIZE=$(( ((${COMPRESSED_SIZE} - 1 >> 20) + 1) << 20 ))
+      PKG_KERNEL_UIMAGE_LOADADDR=$(printf '%X' "$(( ${KERNEL_UIMAGE_LOADADDR} + ${COMPRESSED_SIZE} ))")
+      PKG_KERNEL_UIMAGE_ENTRYADDR=$(printf '%X' "$(( ${KERNEL_UIMAGE_ENTRYADDR} + ${COMPRESSED_SIZE} ))")
     else
       PKG_KERNEL_UIMAGE_LOADADDR=${KERNEL_UIMAGE_LOADADDR}
       PKG_KERNEL_UIMAGE_ENTRYADDR=${KERNEL_UIMAGE_ENTRYADDR}
     fi
 
-    mkimage -A $TARGET_KERNEL_ARCH \
+    mkimage -A ${TARGET_KERNEL_ARCH} \
             -O linux \
             -T kernel \
-            -C $KERNEL_UIMAGE_COMP \
-            -a $PKG_KERNEL_UIMAGE_LOADADDR \
-            -e $PKG_KERNEL_UIMAGE_ENTRYADDR \
-            -d arch/$TARGET_KERNEL_ARCH/boot/$KERNEL_TARGET \
-               arch/$TARGET_KERNEL_ARCH/boot/$KERNEL_UIMAGE_TARGET
+            -C ${KERNEL_UIMAGE_COMP} \
+            -a ${PKG_KERNEL_UIMAGE_LOADADDR} \
+            -e ${PKG_KERNEL_UIMAGE_ENTRYADDR} \
+            -d arch/${TARGET_KERNEL_ARCH}/boot/${KERNEL_TARGET} \
+               arch/${TARGET_KERNEL_ARCH}/boot/${KERNEL_UIMAGE_TARGET}
 
     KERNEL_TARGET="${KERNEL_UIMAGE_TARGET}"
   fi
 }
 
 makeinstall_target() {
-  mkdir -p $INSTALL/.image
-  cp -p arch/${TARGET_KERNEL_ARCH}/boot/${KERNEL_TARGET} System.map .config Module.symvers $INSTALL/.image/
+  mkdir -p ${INSTALL}/.image
+  cp -p arch/${TARGET_KERNEL_ARCH}/boot/${KERNEL_TARGET} System.map .config Module.symvers ${INSTALL}/.image/
 
-  kernel_make INSTALL_MOD_PATH=$INSTALL/$(get_kernel_overlay_dir) modules_install
-  rm -f $INSTALL/$(get_kernel_overlay_dir)/lib/modules/*/build
-  rm -f $INSTALL/$(get_kernel_overlay_dir)/lib/modules/*/source
+  kernel_make INSTALL_MOD_PATH=${INSTALL}/$(get_kernel_overlay_dir) modules_install
+  rm -f ${INSTALL}/$(get_kernel_overlay_dir)/lib/modules/*/build
+  rm -f ${INSTALL}/$(get_kernel_overlay_dir)/lib/modules/*/source
 
-  if [ "$BOOTLOADER" = "u-boot" ]; then
-    mkdir -p $INSTALL/usr/share/bootloader
-    for dtb in arch/$TARGET_KERNEL_ARCH/boot/dts/*.dtb arch/$TARGET_KERNEL_ARCH/boot/dts/*/*.dtb; do
-      if [ -f $dtb ]; then
-        cp -v $dtb $INSTALL/usr/share/bootloader
+  if [ "${BOOTLOADER}" = "u-boot" ]; then
+    mkdir -p ${INSTALL}/usr/share/bootloader
+    for dtb in arch/${TARGET_KERNEL_ARCH}/boot/dts/*.dtb arch/${TARGET_KERNEL_ARCH}/boot/dts/*/*.dtb; do
+      if [ -f ${dtb} ]; then
+        cp -v ${dtb} ${INSTALL}/usr/share/bootloader
       fi
     done
-  elif [ "$BOOTLOADER" = "bcm2835-bootloader" ]; then
-    mkdir -p $INSTALL/usr/share/bootloader/overlays
+  elif [ "${BOOTLOADER}" = "bcm2835-bootloader" ]; then
+    mkdir -p ${INSTALL}/usr/share/bootloader/overlays
 
     # install platform dtbs, but remove upstream kernel dtbs (i.e. without downstream
     # drivers and decent USB support) as these are not required by LibreELEC
-    cp -p arch/$TARGET_KERNEL_ARCH/boot/dts/*.dtb $INSTALL/usr/share/bootloader
-    rm -f $INSTALL/usr/share/bootloader/bcm283*.dtb
+    cp -p arch/${TARGET_KERNEL_ARCH}/boot/dts/*.dtb ${INSTALL}/usr/share/bootloader
+    rm -f ${INSTALL}/usr/share/bootloader/bcm283*.dtb
 
     # install overlay dtbs
-    for dtb in arch/$TARGET_KERNEL_ARCH/boot/dts/overlays/*.dtb \
-               arch/$TARGET_KERNEL_ARCH/boot/dts/overlays/*.dtbo; do
-      cp $dtb $INSTALL/usr/share/bootloader/overlays 2>/dev/null || :
+    for dtb in arch/${TARGET_KERNEL_ARCH}/boot/dts/overlays/*.dtb \
+               arch/${TARGET_KERNEL_ARCH}/boot/dts/overlays/*.dtbo; do
+      cp ${dtb} ${INSTALL}/usr/share/bootloader/overlays 2>/dev/null || :
     done
-    cp -p arch/$TARGET_KERNEL_ARCH/boot/dts/overlays/README $INSTALL/usr/share/bootloader/overlays
+    cp -p arch/${TARGET_KERNEL_ARCH}/boot/dts/overlays/README ${INSTALL}/usr/share/bootloader/overlays
   fi
 }