diff --git a/packages/tools/amlogic-boot-fip/package.mk b/packages/tools/amlogic-boot-fip/package.mk
index 9e3728d604..5cfc465bd2 100644
--- a/packages/tools/amlogic-boot-fip/package.mk
+++ b/packages/tools/amlogic-boot-fip/package.mk
@@ -9,4 +9,4 @@ PKG_SITE="https://github.com/LibreELEC/amlogic-boot-fip"
 PKG_URL="https://github.com/LibreELEC/amlogic-boot-fip/archive/${PKG_VERSION}.tar.gz"
 PKG_LONGDESC="Firmware Image Package (FIP) sources used to sign Amlogic u-boot binaries in LibreELEC images"
 PKG_TOOLCHAIN="manual"
-PKG_STAMP="$UBOOT_SYSTEM"
+PKG_STAMP="${UBOOT_SYSTEM}"
diff --git a/packages/tools/atf/package.mk b/packages/tools/atf/package.mk
index c0414c73b5..3774afde4a 100644
--- a/packages/tools/atf/package.mk
+++ b/packages/tools/atf/package.mk
@@ -7,18 +7,18 @@ PKG_SHA256="4bfda9fdbe5022f2e88ad3344165f7d38a8ae4a0e2d91d44d9a1603425cc642d"
 PKG_ARCH="arm aarch64"
 PKG_LICENSE="BSD-3c"
 PKG_SITE="https://github.com/ARM-software/arm-trusted-firmware"
-PKG_URL="https://github.com/ARM-software/arm-trusted-firmware/archive/v$PKG_VERSION.tar.gz"
+PKG_URL="https://github.com/ARM-software/arm-trusted-firmware/archive/v${PKG_VERSION}.tar.gz"
 PKG_DEPENDS_TARGET="toolchain"
 PKG_LONGDESC="ARM Trusted Firmware is a reference implementation of secure world software, including a Secure Monitor executing at Exception Level 3 and various Arm interface standards."
 PKG_TOOLCHAIN="manual"
 
-[ -n "$KERNEL_TOOLCHAIN" ] && PKG_DEPENDS_TARGET+=" gcc-arm-$KERNEL_TOOLCHAIN:host"
+[ -n "${KERNEL_TOOLCHAIN}" ] && PKG_DEPENDS_TARGET+=" gcc-arm-${KERNEL_TOOLCHAIN}:host"
 
 make_target() {
-  CROSS_COMPILE="$TARGET_KERNEL_PREFIX" LDFLAGS="" CFLAGS="" make PLAT=$ATF_PLATFORM bl31
+  CROSS_COMPILE="${TARGET_KERNEL_PREFIX}" LDFLAGS="" CFLAGS="" make PLAT=${ATF_PLATFORM} bl31
 }
 
 makeinstall_target() {
-  mkdir -p $INSTALL/usr/share/bootloader
-  cp -a build/$ATF_PLATFORM/release/bl31.bin $INSTALL/usr/share/bootloader
+  mkdir -p ${INSTALL}/usr/share/bootloader
+  cp -a build/${ATF_PLATFORM}/release/bl31.bin ${INSTALL}/usr/share/bootloader
 }
diff --git a/packages/tools/bcm2835-bootloader/package.mk b/packages/tools/bcm2835-bootloader/package.mk
index 2c1f0c751c..683b7c11fb 100644
--- a/packages/tools/bcm2835-bootloader/package.mk
+++ b/packages/tools/bcm2835-bootloader/package.mk
@@ -8,26 +8,26 @@ PKG_SHA256="29ac3bf2be7be35512f8fa99cce2a8d0a305de085a96b5facd81258d63020c0c"
 PKG_ARCH="arm"
 PKG_LICENSE="nonfree"
 PKG_SITE="http://www.broadcom.com"
-PKG_URL="$DISTRO_SRC/$PKG_NAME-$PKG_VERSION.tar.xz"
+PKG_URL="${DISTRO_SRC}/${PKG_NAME}-${PKG_VERSION}.tar.xz"
 PKG_DEPENDS_TARGET="toolchain linux bcmstat"
 PKG_LONGDESC="bcm2835-bootloader: Tool to create a bootable kernel for RaspberryPi"
 PKG_TOOLCHAIN="manual"
 
 makeinstall_target() {
-  mkdir -p $INSTALL/usr/share/bootloader
-    cp -PRv LICENCE* $INSTALL/usr/share/bootloader
-    cp -PRv bootcode.bin $INSTALL/usr/share/bootloader
-    if [ "$DEVICE" = "RPi4" ]; then
-      cp -PRv fixup4x.dat $INSTALL/usr/share/bootloader/fixup.dat
-      cp -PRv start4x.elf $INSTALL/usr/share/bootloader/start.elf
+  mkdir -p ${INSTALL}/usr/share/bootloader
+    cp -PRv LICENCE* ${INSTALL}/usr/share/bootloader
+    cp -PRv bootcode.bin ${INSTALL}/usr/share/bootloader
+    if [ "${DEVICE}" = "RPi4" ]; then
+      cp -PRv fixup4x.dat ${INSTALL}/usr/share/bootloader/fixup.dat
+      cp -PRv start4x.elf ${INSTALL}/usr/share/bootloader/start.elf
     else
-      cp -PRv fixup_x.dat $INSTALL/usr/share/bootloader/fixup.dat
-      cp -PRv start_x.elf $INSTALL/usr/share/bootloader/start.elf
+      cp -PRv fixup_x.dat ${INSTALL}/usr/share/bootloader/fixup.dat
+      cp -PRv start_x.elf ${INSTALL}/usr/share/bootloader/start.elf
     fi
 
-    find_file_path bootloader/update.sh $PKG_DIR/files/update.sh && cp -PRv $FOUND_PATH $INSTALL/usr/share/bootloader
-    find_file_path bootloader/canupdate.sh && cp -PRv $FOUND_PATH $INSTALL/usr/share/bootloader
+    find_file_path bootloader/update.sh ${PKG_DIR}/files/update.sh && cp -PRv ${FOUND_PATH} ${INSTALL}/usr/share/bootloader
+    find_file_path bootloader/canupdate.sh && cp -PRv ${FOUND_PATH} ${INSTALL}/usr/share/bootloader
 
-    find_file_path config/distroconfig.txt $PKG_DIR/files/distroconfig.txt && cp -PRv ${FOUND_PATH} $INSTALL/usr/share/bootloader
-    find_file_path config/config.txt $PKG_DIR/files/config.txt && cp -PRv ${FOUND_PATH} $INSTALL/usr/share/bootloader
+    find_file_path config/distroconfig.txt ${PKG_DIR}/files/distroconfig.txt && cp -PRv ${FOUND_PATH} ${INSTALL}/usr/share/bootloader
+    find_file_path config/config.txt ${PKG_DIR}/files/config.txt && cp -PRv ${FOUND_PATH} ${INSTALL}/usr/share/bootloader
 }
diff --git a/packages/tools/bcmstat/package.mk b/packages/tools/bcmstat/package.mk
index e7bdd8b9f1..3065f5e652 100644
--- a/packages/tools/bcmstat/package.mk
+++ b/packages/tools/bcmstat/package.mk
@@ -6,12 +6,12 @@ PKG_VERSION="0.5.5"
 PKG_SHA256="faf21907c183ec45ca5a7737a220d3275d24a7d8a387344ed1562849b2d67f27"
 PKG_LICENSE="GPL"
 PKG_SITE="https://github.com/MilhouseVH/bcmstat"
-PKG_URL="https://github.com/MilhouseVH/$PKG_NAME/archive/$PKG_VERSION.tar.gz"
+PKG_URL="https://github.com/MilhouseVH/${PKG_NAME}/archive/${PKG_VERSION}.tar.gz"
 PKG_LONGDESC="Raspberry Pi monitoring script"
 PKG_TOOLCHAIN="manual"
 
 makeinstall_target() {
-  mkdir -p $INSTALL/usr/bin
-    cp -PRv bcmstat.sh $INSTALL/usr/bin
-    chmod +x $INSTALL/usr/bin/*
+  mkdir -p ${INSTALL}/usr/bin
+    cp -PRv bcmstat.sh ${INSTALL}/usr/bin
+    chmod +x ${INSTALL}/usr/bin/*
 }
diff --git a/packages/tools/crust/package.mk b/packages/tools/crust/package.mk
index 276afbfe2b..f15baaca0a 100644
--- a/packages/tools/crust/package.mk
+++ b/packages/tools/crust/package.mk
@@ -11,20 +11,20 @@ PKG_URL="https://github.com/crust-firmware/crust/archive/${PKG_VERSION}.tar.gz"
 PKG_DEPENDS_TARGET="gcc-or1k-linux:host"
 PKG_LONGDESC="Crust: Libre SCP firmware for Allwinner sunxi SoCs"
 PKG_TOOLCHAIN="manual"
-PKG_STAMP="$UBOOT_SYSTEM"
+PKG_STAMP="${UBOOT_SYSTEM}"
 
 pre_configure_target() {
-  export CROSS_COMPILE="$TOOLCHAIN/lib/gcc-or1k-linux/bin/or1k-linux-"
+  export CROSS_COMPILE="${TOOLCHAIN}/lib/gcc-or1k-linux/bin/or1k-linux-"
 }
 
 make_target() {
-  if [ -z "$UBOOT_SYSTEM" ]; then
+  if [ -z "${UBOOT_SYSTEM}" ]; then
     echo "crust is only built when building an image"
     exit 0
   fi
 
-  CRUST_CONFIG=$($ROOT/$SCRIPTS/uboot_helper $PROJECT $DEVICE $UBOOT_SYSTEM crust_config)
-  if [ -z "$CRUST_CONFIG" ]; then
+  CRUST_CONFIG=$(${ROOT}/${SCRIPTS}/uboot_helper ${PROJECT} ${DEVICE} ${UBOOT_SYSTEM} crust_config)
+  if [ -z "${CRUST_CONFIG}" ]; then
     echo "crust_config must be set to build crust firmware"
     echo "see './scripts/uboot_helper' for more information"
     exit 0
@@ -32,18 +32,18 @@ make_target() {
 
   make distclean
   if [ "${BUILD_WITH_DEBUG}" = "yes" ]; then
-    echo "CONFIG_DEBUG_LOG=y" >> configs/$CRUST_CONFIG
+    echo "CONFIG_DEBUG_LOG=y" >> configs/${CRUST_CONFIG}
   else
-    echo "CONFIG_SERIAL=n" >> configs/$CRUST_CONFIG
+    echo "CONFIG_SERIAL=n" >> configs/${CRUST_CONFIG}
   fi
   # Boards with a PMIC need to disable CONFIG_PMIC_SHUTDOWN to get CIR wakeup from suspend
-  echo "CONFIG_PMIC_SHUTDOWN=n" >> configs/$CRUST_CONFIG
-  echo "CONFIG_CIR=y" >> configs/$CRUST_CONFIG
-  make $CRUST_CONFIG
+  echo "CONFIG_PMIC_SHUTDOWN=n" >> configs/${CRUST_CONFIG}
+  echo "CONFIG_CIR=y" >> configs/${CRUST_CONFIG}
+  make ${CRUST_CONFIG}
   make scp
 }
 
 makeinstall_target() {
-  mkdir -p $INSTALL/usr/share/bootloader
-  cp -a build/scp/scp.bin $INSTALL/usr/share/bootloader
+  mkdir -p ${INSTALL}/usr/share/bootloader
+  cp -a build/scp/scp.bin ${INSTALL}/usr/share/bootloader
 }
diff --git a/packages/tools/dtc/package.mk b/packages/tools/dtc/package.mk
index a9c0a3a72f..b5d228bc40 100644
--- a/packages/tools/dtc/package.mk
+++ b/packages/tools/dtc/package.mk
@@ -7,7 +7,7 @@ PKG_VERSION="1.6.0"
 PKG_SHA256="af720893485b02441f8812773484b286f969d1b8c98769d435a75c6ad524104b"
 PKG_LICENSE="GPL"
 PKG_SITE="https://git.kernel.org/pub/scm/utils/dtc/dtc.git/"
-PKG_URL="https://git.kernel.org/pub/scm/utils/dtc/dtc.git/snapshot/$PKG_VERSION.tar.gz"
+PKG_URL="https://git.kernel.org/pub/scm/utils/dtc/dtc.git/snapshot/${PKG_VERSION}.tar.gz"
 PKG_DEPENDS_HOST="toolchain:host"
 PKG_DEPENDS_TARGET="toolchain"
 PKG_LONGDESC="The Device Tree Compiler"
@@ -16,15 +16,15 @@ PKG_MAKE_OPTS_TARGET="dtc fdtput fdtget libfdt"
 PKG_MAKE_OPTS_HOST="libfdt"
 
 makeinstall_host() {
-  mkdir -p $TOOLCHAIN/lib
-    cp -P $PKG_BUILD/libfdt/libfdt.so $TOOLCHAIN/lib
+  mkdir -p ${TOOLCHAIN}/lib
+    cp -P ${PKG_BUILD}/libfdt/libfdt.so ${TOOLCHAIN}/lib
 }
 
 makeinstall_target() {
-  mkdir -p $INSTALL/usr/bin
-    cp -P $PKG_BUILD/dtc $INSTALL/usr/bin
-    cp -P $PKG_BUILD/fdtput $INSTALL/usr/bin/
-    cp -P $PKG_BUILD/fdtget $INSTALL/usr/bin/
-  mkdir -p $INSTALL/usr/lib
-    cp -P $PKG_BUILD/libfdt/libfdt.so $INSTALL/usr/lib/
+  mkdir -p ${INSTALL}/usr/bin
+    cp -P ${PKG_BUILD}/dtc ${INSTALL}/usr/bin
+    cp -P ${PKG_BUILD}/fdtput ${INSTALL}/usr/bin/
+    cp -P ${PKG_BUILD}/fdtget ${INSTALL}/usr/bin/
+  mkdir -p ${INSTALL}/usr/lib
+    cp -P ${PKG_BUILD}/libfdt/libfdt.so ${INSTALL}/usr/lib/
 }
diff --git a/packages/tools/exynos-boot-fip/package.mk b/packages/tools/exynos-boot-fip/package.mk
index a080dcb32e..201654b8df 100644
--- a/packages/tools/exynos-boot-fip/package.mk
+++ b/packages/tools/exynos-boot-fip/package.mk
@@ -9,11 +9,11 @@ PKG_SITE="https://github.com/chewitt/exynos-boot-fip"
 PKG_URL="https://github.com/chewitt/exynos-boot-fip/archive/${PKG_VERSION}.tar.gz"
 PKG_LONGDESC="Firmware Image Package (FIP) sources used with Exynos u-boot binaries in LibreELEC images"
 PKG_TOOLCHAIN="manual"
-PKG_STAMP="$UBOOT_SYSTEM"
+PKG_STAMP="${UBOOT_SYSTEM}"
 
 makeinstall_target() {
-  mkdir -p $INSTALL/usr/boot
-    cp -P $PKG_BUILD/bl1.bin.hardkernel $INSTALL/usr/boot
-    cp -P $PKG_BUILD/bl2.bin.hardkernel.720k_uboot $INSTALL/usr/boot
-    cp -P $PKG_BUILD/tzsw.bin.hardkernel $INSTALL/usr/boot
+  mkdir -p ${INSTALL}/usr/boot
+    cp -P ${PKG_BUILD}/bl1.bin.hardkernel ${INSTALL}/usr/boot
+    cp -P ${PKG_BUILD}/bl2.bin.hardkernel.720k_uboot ${INSTALL}/usr/boot
+    cp -P ${PKG_BUILD}/tzsw.bin.hardkernel ${INSTALL}/usr/boot
 }
diff --git a/packages/tools/grub/package.mk b/packages/tools/grub/package.mk
index d949bd5953..3f45c2b515 100755
--- a/packages/tools/grub/package.mk
+++ b/packages/tools/grub/package.mk
@@ -7,7 +7,7 @@ PKG_SHA256="e099d18bdeef5312765f20c6de3384ca9ff03f776f1c7632b1e4bc4d1715a961"
 PKG_ARCH="x86_64"
 PKG_LICENSE="GPLv3"
 PKG_SITE="https://www.gnu.org/software/grub/index.html"
-PKG_URL="http://git.savannah.gnu.org/cgit/grub.git/snapshot/$PKG_NAME-$PKG_VERSION.tar.gz"
+PKG_URL="http://git.savannah.gnu.org/cgit/grub.git/snapshot/${PKG_NAME}-${PKG_VERSION}.tar.gz"
 PKG_DEPENDS_TARGET="toolchain flex freetype:host gettext:host"
 PKG_DEPENDS_UNPACK="gnulib"
 PKG_LONGDESC="GRUB is a Multiboot boot loader."
@@ -24,29 +24,29 @@ pre_configure_target() {
   unset LDFLAGS
   unset CPP
 
-  cd $PKG_BUILD
+  cd ${PKG_BUILD}
     # keep grub synced with gnulib
     ./bootstrap --gnulib-srcdir=$(get_build_dir gnulib) --copy --no-git --no-bootstrap-sync --skip-po
 }
 
 make_target() {
-  make CC=$CC \
-       AR=$AR \
-       RANLIB=$RANLIB \
-       CFLAGS="-I$SYSROOT_PREFIX/usr/include -fomit-frame-pointer -D_FILE_OFFSET_BITS=64" \
-       LDFLAGS="-L$SYSROOT_PREFIX/usr/lib"
+  make CC=${CC} \
+       AR=${AR} \
+       RANLIB=${RANLIB} \
+       CFLAGS="-I${SYSROOT_PREFIX}/usr/include -fomit-frame-pointer -D_FILE_OFFSET_BITS=64" \
+       LDFLAGS="-L${SYSROOT_PREFIX}/usr/lib"
 }
 
 makeinstall_target() {
-  cd $PKG_BUILD/grub-core
-     $PKG_BUILD/grub-mkimage -d . -o bootia32.efi -O i386-efi -p /EFI/BOOT \
+  cd ${PKG_BUILD}/grub-core
+     ${PKG_BUILD}/grub-mkimage -d . -o bootia32.efi -O i386-efi -p /EFI/BOOT \
                                 boot chain configfile ext2 fat linux search \
                                 efi_gop efi_uga part_gpt gzio \
                                 gettext loadenv loadbios memrw
 
-  mkdir -p $INSTALL/usr/share/grub
-     cp -P $PKG_BUILD/grub-core/bootia32.efi $INSTALL/usr/share/grub
+  mkdir -p ${INSTALL}/usr/share/grub
+     cp -P ${PKG_BUILD}/grub-core/bootia32.efi ${INSTALL}/usr/share/grub
 
-  mkdir -p $TOOLCHAIN/share/grub
-     cp -P $PKG_BUILD/grub-core/bootia32.efi $TOOLCHAIN/share/grub
+  mkdir -p ${TOOLCHAIN}/share/grub
+     cp -P ${PKG_BUILD}/grub-core/bootia32.efi ${TOOLCHAIN}/share/grub
 }
diff --git a/packages/tools/hdparm/package.mk b/packages/tools/hdparm/package.mk
index f5f2dbdf5d..bb4833ad0c 100644
--- a/packages/tools/hdparm/package.mk
+++ b/packages/tools/hdparm/package.mk
@@ -7,11 +7,11 @@ PKG_VERSION="9.60"
 PKG_SHA256="8397739c73e44d5ab96c4aef28fa9c0147276d53a1b5657ce04c4565cf6635cc"
 PKG_LICENSE="BSD"
 PKG_SITE="http://sourceforge.net/projects/hdparm/"
-PKG_URL="$SOURCEFORGE_SRC/$PKG_NAME/$PKG_NAME/$PKG_NAME-$PKG_VERSION.tar.gz"
+PKG_URL="${SOURCEFORGE_SRC}/${PKG_NAME}/${PKG_NAME}/${PKG_NAME}-${PKG_VERSION}.tar.gz"
 PKG_DEPENDS_TARGET="toolchain"
 PKG_LONGDESC="Shell utility to access/tune ioctl features of the Linux IDE driver and IDE drives."
 
 makeinstall_target() {
-  mkdir -p $INSTALL/usr/sbin
-    cp -a $PKG_BUILD/hdparm $INSTALL/usr/sbin
+  mkdir -p ${INSTALL}/usr/sbin
+    cp -a ${PKG_BUILD}/hdparm ${INSTALL}/usr/sbin
 }
diff --git a/packages/tools/installer/package.mk b/packages/tools/installer/package.mk
index 6125d76624..dc0516be08 100644
--- a/packages/tools/installer/package.mk
+++ b/packages/tools/installer/package.mk
@@ -11,18 +11,18 @@ PKG_LONGDESC="LibreELEC.tv Install manager to install the system on any disk"
 PKG_TOOLCHAIN="manual"
 
 post_install() {
-  mkdir -p $INSTALL/usr/bin
-    cp $PKG_DIR/scripts/installer $INSTALL/usr/bin
-    sed -e "s/@DISTRONAME@/$DISTRONAME/g" \
-        -i  $INSTALL/usr/bin/installer
+  mkdir -p ${INSTALL}/usr/bin
+    cp ${PKG_DIR}/scripts/installer ${INSTALL}/usr/bin
+    sed -e "s/@DISTRONAME@/${DISTRONAME}/g" \
+        -i  ${INSTALL}/usr/bin/installer
 
-  mkdir -p $INSTALL/etc
+  mkdir -p ${INSTALL}/etc
     find_file_path config/installer.conf
-    cp ${FOUND_PATH} $INSTALL/etc
-    sed -e "s/@SYSTEM_SIZE@/$SYSTEM_SIZE/g" \
-        -e "s/@SYSTEM_PART_START@/$SYSTEM_PART_START/g" \
-        -e "s/@SYSLINUX_PARAMETERS@/$SYSLINUX_PARAMETERS/g" \
-        -i $INSTALL/etc/installer.conf
+    cp ${FOUND_PATH} ${INSTALL}/etc
+    sed -e "s/@SYSTEM_SIZE@/${SYSTEM_SIZE}/g" \
+        -e "s/@SYSTEM_PART_START@/${SYSTEM_PART_START}/g" \
+        -e "s/@SYSLINUX_PARAMETERS@/${SYSLINUX_PARAMETERS}/g" \
+        -i ${INSTALL}/etc/installer.conf
 
   enable_service installer.service
 }
diff --git a/packages/tools/mkbootimg/package.mk b/packages/tools/mkbootimg/package.mk
index a3b0ca02c0..ce2cf2511e 100644
--- a/packages/tools/mkbootimg/package.mk
+++ b/packages/tools/mkbootimg/package.mk
@@ -7,11 +7,11 @@ PKG_VERSION="6668fc24a3130ab003aae9fda95bcd4110617de9"
 PKG_SHA256="d84870e055414d638a3e7eb4b7a3ebf415899841218f24cb3647d06ecf6ddb17"
 PKG_LICENSE="GPL"
 PKG_SITE="https://android.googlesource.com/platform/system/core/+/master/mkbootimg/"
-PKG_URL="https://github.com/codesnake/mkbootimg/archive/$PKG_VERSION.tar.gz"
+PKG_URL="https://github.com/codesnake/mkbootimg/archive/${PKG_VERSION}.tar.gz"
 PKG_DEPENDS_HOST="toolchain:host"
 PKG_LONGDESC="mkbootimg: Creates kernel boot images for Android"
 
 makeinstall_host() {
-  mkdir -p $SYSROOT_PREFIX/usr/include
-  cp mkbootimg $TOOLCHAIN/bin/
+  mkdir -p ${SYSROOT_PREFIX}/usr/include
+  cp mkbootimg ${TOOLCHAIN}/bin/
 }
diff --git a/packages/tools/mtools/package.mk b/packages/tools/mtools/package.mk
index e48b5c3eb3..c62c6e12a8 100644
--- a/packages/tools/mtools/package.mk
+++ b/packages/tools/mtools/package.mk
@@ -7,7 +7,7 @@ PKG_VERSION="4.0.26"
 PKG_SHA256="539f1c8b476a16e198d8bcb10a5799e22e69de49d854f7dbd85b64c2a45dea1a"
 PKG_LICENSE="GPL"
 PKG_SITE="http://www.gnu.org/software/mtools/"
-PKG_URL="http://ftpmirror.gnu.org/$PKG_NAME/$PKG_NAME-$PKG_VERSION.tar.bz2"
+PKG_URL="http://ftpmirror.gnu.org/${PKG_NAME}/${PKG_NAME}-${PKG_VERSION}.tar.bz2"
 PKG_DEPENDS_HOST="toolchain:host"
 PKG_LONGDESC="mtools: A collection of utilities to access MS-DOS disks"
 PKG_TOOLCHAIN="autotools"
diff --git a/packages/tools/newt/package.mk b/packages/tools/newt/package.mk
index 6eaece09e2..f39c336d5e 100644
--- a/packages/tools/newt/package.mk
+++ b/packages/tools/newt/package.mk
@@ -6,7 +6,7 @@ PKG_VERSION="0.52.21"
 PKG_SHA256="265eb46b55d7eaeb887fca7a1d51fe115658882dfe148164b6c49fccac5abb31"
 PKG_LICENSE="GPL"
 PKG_SITE="https://pagure.io/newt"
-PKG_URL="https://releases.pagure.org/newt/$PKG_NAME-$PKG_VERSION.tar.gz"
+PKG_URL="https://releases.pagure.org/newt/${PKG_NAME}-${PKG_VERSION}.tar.gz"
 PKG_DEPENDS_TARGET="toolchain slang popt"
 PKG_LONGDESC="Newt is a programming library for color text mode, widget based user interfaces."
 PKG_TOOLCHAIN="autotools"
@@ -17,12 +17,12 @@ PKG_CONFIGURE_OPTS_TARGET="--disable-nls \
 
 pre_configure_target() {
  # newt fails to build in subdirs
- cd $PKG_BUILD
- rm -rf .$TARGET_NAME
+ cd ${PKG_BUILD}
+ rm -rf .${TARGET_NAME}
 }
 
 pre_configure_host() {
  # newt fails to build in subdirs
- cd $PKG_BUILD
- rm -rf .$HOST_NAME
+ cd ${PKG_BUILD}
+ rm -rf .${HOST_NAME}
 }
diff --git a/packages/tools/plymouth-lite/package.mk b/packages/tools/plymouth-lite/package.mk
index 59f39a7283..f3cad5bef1 100644
--- a/packages/tools/plymouth-lite/package.mk
+++ b/packages/tools/plymouth-lite/package.mk
@@ -6,21 +6,21 @@ PKG_VERSION="0.6.0"
 PKG_SHA256="fa7b581bdd38c5751668243ff9d2ebaee7c45753358cbb310fb50cfcd3a8081b"
 PKG_LICENSE="GPL"
 PKG_SITE="http://www.meego.com"
-PKG_URL="$DISTRO_SRC/$PKG_NAME-$PKG_VERSION.tar.bz2"
+PKG_URL="${DISTRO_SRC}/${PKG_NAME}-${PKG_VERSION}.tar.bz2"
 PKG_DEPENDS_INIT="toolchain gcc:init libpng"
 PKG_LONGDESC="Boot splash screen based on Fedora's Plymouth code"
 
 pre_configure_init() {
   # plymouth-lite dont support to build in subdirs
-  cd $PKG_BUILD
-    rm -rf .$TARGET_NAME-init
+  cd ${PKG_BUILD}
+    rm -rf .${TARGET_NAME}-init
 }
 
 makeinstall_init() {
-  mkdir -p $INSTALL/usr/bin
-    cp ply-image $INSTALL/usr/bin
+  mkdir -p ${INSTALL}/usr/bin
+    cp ply-image ${INSTALL}/usr/bin
 
-  mkdir -p $INSTALL/splash
-    find_file_path splash/splash.conf && cp ${FOUND_PATH} $INSTALL/splash
-    find_file_path "splash/splash-*.png" && cp ${FOUND_PATH} $INSTALL/splash
+  mkdir -p ${INSTALL}/splash
+    find_file_path splash/splash.conf && cp ${FOUND_PATH} ${INSTALL}/splash
+    find_file_path "splash/splash-*.png" && cp ${FOUND_PATH} ${INSTALL}/splash
 }
diff --git a/packages/tools/populatefs/package.mk b/packages/tools/populatefs/package.mk
index 196dca1cbb..e94a1f9160 100644
--- a/packages/tools/populatefs/package.mk
+++ b/packages/tools/populatefs/package.mk
@@ -6,7 +6,7 @@ PKG_VERSION="1.0"
 PKG_SHA256="e5845404188b5da3afb11229ecb38646cc1562b61400035774dbc237c3b706d2"
 PKG_LICENSE="GPL"
 PKG_SITE="https://github.com/lipnitsk/populatefs"
-PKG_URL="https://github.com/lipnitsk/$PKG_NAME/archive/v${PKG_VERSION}.tar.gz"
+PKG_URL="https://github.com/lipnitsk/${PKG_NAME}/archive/v${PKG_VERSION}.tar.gz"
 PKG_DEPENDS_HOST="e2fsprogs:host"
 PKG_LONGDESC="populatefs: Tool for replacing genext2fs when creating ext4 images"
 PKG_BUILD_FLAGS="+pic:host"
@@ -16,8 +16,8 @@ make_host() {
 }
 
 makeinstall_host() {
-  $STRIP src/populatefs
+  ${STRIP} src/populatefs
 
-  mkdir -p $TOOLCHAIN/sbin
-  cp src/populatefs $TOOLCHAIN/sbin
+  mkdir -p ${TOOLCHAIN}/sbin
+  cp src/populatefs ${TOOLCHAIN}/sbin
 }
diff --git a/packages/tools/procps-ng/package.mk b/packages/tools/procps-ng/package.mk
index 2a6c522b07..77d593f5d0 100644
--- a/packages/tools/procps-ng/package.mk
+++ b/packages/tools/procps-ng/package.mk
@@ -23,9 +23,9 @@ PKG_MAKE_OPTS_TARGET="free top/top proc/libprocps.la proc/libprocps.pc"
 PKG_MAKEINSTALL_OPTS_TARGET="install-libLTLIBRARIES install-pkgconfigDATA"
 
 makeinstall_target() {
-  mkdir -p $INSTALL/usr/bin
-    cp -P $PKG_BUILD/.$TARGET_NAME/free $INSTALL/usr/bin
-    cp -P $PKG_BUILD/.$TARGET_NAME/top/top $INSTALL/usr/bin
+  mkdir -p ${INSTALL}/usr/bin
+    cp -P ${PKG_BUILD}/.${TARGET_NAME}/free ${INSTALL}/usr/bin
+    cp -P ${PKG_BUILD}/.${TARGET_NAME}/top/top ${INSTALL}/usr/bin
 
-  make DESTDIR=$SYSROOT_PREFIX -j1 $PKG_MAKEINSTALL_OPTS_TARGET
+  make DESTDIR=${SYSROOT_PREFIX} -j1 ${PKG_MAKEINSTALL_OPTS_TARGET}
 }
diff --git a/packages/tools/qemu/package.mk b/packages/tools/qemu/package.mk
index 5f30788e64..e4f787fd60 100644
--- a/packages/tools/qemu/package.mk
+++ b/packages/tools/qemu/package.mk
@@ -6,20 +6,20 @@ PKG_VERSION="4.0.0"
 PKG_SHA256="13a93dfe75b86734326f8d5b475fde82ec692d5b5a338b4262aeeb6b0fa4e469"
 PKG_LICENSE="GPL"
 PKG_SITE="http://wiki.qemu.org"
-PKG_URL="https://download.qemu.org/qemu-$PKG_VERSION.tar.xz"
+PKG_URL="https://download.qemu.org/qemu-${PKG_VERSION}.tar.xz"
 PKG_DEPENDS_HOST="toolchain:host glib:host pixman:host Python3:host zlib:host"
 PKG_LONGDESC="QEMU is a generic and open source machine emulator and virtualizer."
 
 pre_configure_host() {
-  HOST_CONFIGURE_OPTS="--bindir=$TOOLCHAIN/bin \
-                       --extra-cflags=-I$TOOLCHAIN/include \
-                       --extra-ldflags=-L$TOOLCHAIN/lib \
-                       --libexecdir=$TOOLCHAIN/lib \
-                       --localstatedir=$TOOLCHAIN/var \
-                       --prefix=$TOOLCHAIN \
-                       --sbindir=$TOOLCHAIN/sbin \
+  HOST_CONFIGURE_OPTS="--bindir=${TOOLCHAIN}/bin \
+                       --extra-cflags=-I${TOOLCHAIN}/include \
+                       --extra-ldflags=-L${TOOLCHAIN}/lib \
+                       --libexecdir=${TOOLCHAIN}/lib \
+                       --localstatedir=${TOOLCHAIN}/var \
+                       --prefix=${TOOLCHAIN} \
+                       --sbindir=${TOOLCHAIN}/sbin \
                        --static \
-                       --sysconfdir=$TOOLCHAIN/etc \
+                       --sysconfdir=${TOOLCHAIN}/etc \
                        --disable-blobs \
                        --disable-docs \
                        --disable-gcrypt \
diff --git a/packages/tools/rkbin/package.mk b/packages/tools/rkbin/package.mk
index e37a1cf1fb..38dde0b931 100644
--- a/packages/tools/rkbin/package.mk
+++ b/packages/tools/rkbin/package.mk
@@ -8,6 +8,6 @@ PKG_SHA256="0b3479117700bce9afea2110c1f027b626c76d99045802218b35a53606547d60"
 PKG_ARCH="arm aarch64"
 PKG_LICENSE="nonfree"
 PKG_SITE="https://github.com/rockchip-linux/rkbin"
-PKG_URL="https://github.com/rockchip-linux/rkbin/archive/$PKG_VERSION.tar.gz"
+PKG_URL="https://github.com/rockchip-linux/rkbin/archive/${PKG_VERSION}.tar.gz"
 PKG_LONGDESC="rkbin: Rockchip Firmware and Tool Binaries"
 PKG_TOOLCHAIN="manual"
diff --git a/packages/tools/rpi-eeprom/package.mk b/packages/tools/rpi-eeprom/package.mk
index f06db0d790..abfc6969a2 100644
--- a/packages/tools/rpi-eeprom/package.mk
+++ b/packages/tools/rpi-eeprom/package.mk
@@ -17,7 +17,7 @@ makeinstall_target() {
 
   mkdir -p ${DESTDIR}
     _dirs="critical stable"
-    [ "$LIBREELEC_VERSION" = "devel" ] && _dirs+=" beta"
+    [ "${LIBREELEC_VERSION}" = "devel" ] && _dirs+=" beta"
 
     for _maindir in ${_dirs}; do
       for _dir in ${PKG_BUILD}/firmware/${_maindir} ${PKG_BUILD}/firmware/{_maindir}-*; do
diff --git a/packages/tools/syslinux/package.mk b/packages/tools/syslinux/package.mk
index f47bcee789..bc4d037aa1 100644
--- a/packages/tools/syslinux/package.mk
+++ b/packages/tools/syslinux/package.mk
@@ -8,13 +8,13 @@ PKG_SHA256="26d3986d2bea109d5dc0e4f8c4822a459276cf021125e8c9f23c3cca5d8c850e"
 PKG_ARCH="x86_64"
 PKG_LICENSE="GPL"
 PKG_SITE="http://syslinux.zytor.com/"
-PKG_URL="http://www.kernel.org/pub/linux/utils/boot/$PKG_NAME/$PKG_NAME-$PKG_VERSION.tar.xz"
+PKG_URL="http://www.kernel.org/pub/linux/utils/boot/${PKG_NAME}/${PKG_NAME}-${PKG_VERSION}.tar.xz"
 PKG_DEPENDS_HOST="util-linux:host"
 PKG_DEPENDS_TARGET="toolchain util-linux e2fsprogs syslinux:host"
 PKG_LONGDESC="The SYSLINUX project covers lightweight linux bootloaders."
 
 pre_configure_target() {
-  PKG_MAKE_OPTS_TARGET="CC=$CC AR=$AR RANLIB=$RANLIB installer"
+  PKG_MAKE_OPTS_TARGET="CC=${CC} AR=${AR} RANLIB=${RANLIB} installer"
 
 # Unset all compiler FLAGS
   unset CFLAGS
@@ -24,53 +24,53 @@ pre_configure_target() {
 }
 
 pre_build_target() {
-  mkdir -p $PKG_BUILD/.$TARGET_NAME
-  cp -RP $PKG_BUILD/* $PKG_BUILD/.$TARGET_NAME
+  mkdir -p ${PKG_BUILD}/.${TARGET_NAME}
+  cp -RP ${PKG_BUILD}/* ${PKG_BUILD}/.${TARGET_NAME}
 }
 
 pre_build_host() {
-  mkdir -p $PKG_BUILD/.$HOST_NAME
-  cp -RP $PKG_BUILD/* $PKG_BUILD/.$HOST_NAME
+  mkdir -p ${PKG_BUILD}/.${HOST_NAME}
+  cp -RP ${PKG_BUILD}/* ${PKG_BUILD}/.${HOST_NAME}
 }
 
 pre_make_target() {
-  cd .$TARGET_NAME
+  cd .${TARGET_NAME}
 }
 
 pre_make_host() {
-  cd .$HOST_NAME
+  cd .${HOST_NAME}
 }
 
 make_host() {
-  make CC=$CC \
-       AR=$AR \
-       RANLIB=$RANLIB \
-       CFLAGS="-I$TOOLCHAIN/include -I$PKG_BUILD/libinstaller -I$PKG_BUILD/libfat -I$PKG_BUILD/bios -I$PKG_BUILD/utils -fomit-frame-pointer -D_FILE_OFFSET_BITS=64" \
-       LDFLAGS="-L$TOOLCHAIN/lib" \
+  make CC=${CC} \
+       AR=${AR} \
+       RANLIB=${RANLIB} \
+       CFLAGS="-I${TOOLCHAIN}/include -I${PKG_BUILD}/libinstaller -I${PKG_BUILD}/libfat -I${PKG_BUILD}/bios -I${PKG_BUILD}/utils -fomit-frame-pointer -D_FILE_OFFSET_BITS=64" \
+       LDFLAGS="-L${TOOLCHAIN}/lib" \
        installer
 }
 
 makeinstall_host() {
-  mkdir -p $TOOLCHAIN/bin
-    cp bios/linux/syslinux $TOOLCHAIN/bin
-    cp bios/mtools/syslinux $TOOLCHAIN/bin/syslinux.mtools
+  mkdir -p ${TOOLCHAIN}/bin
+    cp bios/linux/syslinux ${TOOLCHAIN}/bin
+    cp bios/mtools/syslinux ${TOOLCHAIN}/bin/syslinux.mtools
 
-  mkdir -p $TOOLCHAIN/share/syslinux
-    cp bios/mbr/mbr.bin $TOOLCHAIN/share/syslinux
-    cp bios/mbr/gptmbr.bin $TOOLCHAIN/share/syslinux
-    cp efi64/efi/syslinux.efi $TOOLCHAIN/share/syslinux/bootx64.efi
-    cp efi64/com32/elflink/ldlinux/ldlinux.e64  $TOOLCHAIN/share/syslinux
+  mkdir -p ${TOOLCHAIN}/share/syslinux
+    cp bios/mbr/mbr.bin ${TOOLCHAIN}/share/syslinux
+    cp bios/mbr/gptmbr.bin ${TOOLCHAIN}/share/syslinux
+    cp efi64/efi/syslinux.efi ${TOOLCHAIN}/share/syslinux/bootx64.efi
+    cp efi64/com32/elflink/ldlinux/ldlinux.e64  ${TOOLCHAIN}/share/syslinux
 }
 
 makeinstall_target() {
-  mkdir -p $INSTALL/usr/bin
-    cp bios/linux/syslinux $INSTALL/usr/bin
+  mkdir -p ${INSTALL}/usr/bin
+    cp bios/linux/syslinux ${INSTALL}/usr/bin
 
-  $STRIP $INSTALL/usr/bin/syslinux
+  ${STRIP} ${INSTALL}/usr/bin/syslinux
 
-  mkdir -p $INSTALL/usr/share/syslinux
-    cp bios/mbr/mbr.bin $INSTALL/usr/share/syslinux
-    cp bios/mbr/gptmbr.bin $INSTALL/usr/share/syslinux
-    cp efi64/efi/syslinux.efi $INSTALL/usr/share/syslinux/bootx64.efi
-    cp efi64/com32/elflink/ldlinux/ldlinux.e64  $INSTALL/usr/share/syslinux
+  mkdir -p ${INSTALL}/usr/share/syslinux
+    cp bios/mbr/mbr.bin ${INSTALL}/usr/share/syslinux
+    cp bios/mbr/gptmbr.bin ${INSTALL}/usr/share/syslinux
+    cp efi64/efi/syslinux.efi ${INSTALL}/usr/share/syslinux/bootx64.efi
+    cp efi64/com32/elflink/ldlinux/ldlinux.e64  ${INSTALL}/usr/share/syslinux
 }
diff --git a/packages/tools/texturecache.py/package.mk b/packages/tools/texturecache.py/package.mk
index b12eb442d4..802f7b4537 100644
--- a/packages/tools/texturecache.py/package.mk
+++ b/packages/tools/texturecache.py/package.mk
@@ -6,13 +6,13 @@ PKG_VERSION="2.5.4"
 PKG_SHA256="0717c2e62dc3f809e8754be2c83d2c7d0f92188741eb425d5377c1d326d25276"
 PKG_LICENSE="GPL"
 PKG_SITE="https://github.com/MilhouseVH/texturecache.py"
-PKG_URL="https://github.com/MilhouseVH/$PKG_NAME/archive/$PKG_VERSION.tar.gz"
+PKG_URL="https://github.com/MilhouseVH/${PKG_NAME}/archive/${PKG_VERSION}.tar.gz"
 PKG_LONGDESC="The Swiss Army knife for Kodi"
 PKG_TOOLCHAIN="manual"
 
 makeinstall_target() {
-  mkdir -p $INSTALL/usr/bin
-    cp -PRv texturecache.py $INSTALL/usr/bin
-    cp -PRv tools/mklocal.py $INSTALL/usr/bin
-    chmod +x $INSTALL/usr/bin/*
+  mkdir -p ${INSTALL}/usr/bin
+    cp -PRv texturecache.py ${INSTALL}/usr/bin
+    cp -PRv tools/mklocal.py ${INSTALL}/usr/bin
+    chmod +x ${INSTALL}/usr/bin/*
 }
diff --git a/packages/tools/u-boot-script/package.mk b/packages/tools/u-boot-script/package.mk
index 808cb5f499..3ada32eeca 100644
--- a/packages/tools/u-boot-script/package.mk
+++ b/packages/tools/u-boot-script/package.mk
@@ -8,18 +8,18 @@ PKG_DEPENDS_TARGET="u-boot-tools:host"
 PKG_TOOLCHAIN="manual"
 PKG_LONGDESC="Compile scripts for u-boot environment."
 
-PKG_NEED_UNPACK="$PROJECT_DIR/$PROJECT/bootloader"
-[ -n "$DEVICE" ] && PKG_NEED_UNPACK+=" $PROJECT_DIR/$PROJECT/devices/$DEVICE/bootloader"
+PKG_NEED_UNPACK="${PROJECT_DIR}/${PROJECT}/bootloader"
+[ -n "${DEVICE}" ] && PKG_NEED_UNPACK+=" ${PROJECT_DIR}/${PROJECT}/devices/${DEVICE}/bootloader"
 
 make_target() {
-  if find_dir_path bootloader/scripts ; then
-    for src in $FOUND_PATH/*.src ; do
-      mkimage -A $TARGET_KERNEL_ARCH -O linux -T script -C none -d "$src" "$(basename $src .src)"
+  if find_dir_path bootloader/scripts; then
+    for src in ${FOUND_PATH}/*.src; do
+      mkimage -A ${TARGET_KERNEL_ARCH} -O linux -T script -C none -d "${src}" "$(basename ${src} .src)"
     done
   fi
 }
 
 makeinstall_target() {
-  mkdir -p $INSTALL/usr/share/bootloader
-    cp -a $PKG_BUILD/* $INSTALL/usr/share/bootloader/
+  mkdir -p ${INSTALL}/usr/share/bootloader
+    cp -a ${PKG_BUILD}/* ${INSTALL}/usr/share/bootloader/
 }
diff --git a/packages/tools/u-boot-tools/package.mk b/packages/tools/u-boot-tools/package.mk
index 60d7f0c864..1fa15b30d8 100644
--- a/packages/tools/u-boot-tools/package.mk
+++ b/packages/tools/u-boot-tools/package.mk
@@ -6,7 +6,7 @@ PKG_VERSION="2021.01"
 PKG_SHA256="b407e1510a74e863b8b5cb42a24625344f0e0c2fc7582d8c866bd899367d0454"
 PKG_LICENSE="GPL"
 PKG_SITE="https://www.denx.de/wiki/U-Boot"
-PKG_URL="http://ftp.denx.de/pub/u-boot/u-boot-$PKG_VERSION.tar.bz2"
+PKG_URL="http://ftp.denx.de/pub/u-boot/u-boot-${PKG_VERSION}.tar.bz2"
 PKG_DEPENDS_HOST="ccache:host bison:host flex:host"
 PKG_LONGDESC="Das U-Boot is a cross-platform bootloader for embedded systems."
 
@@ -20,6 +20,6 @@ make_target() {
 }
 
 makeinstall_host() {
-  mkdir -p $TOOLCHAIN/bin
-    cp tools/mkimage $TOOLCHAIN/bin
+  mkdir -p ${TOOLCHAIN}/bin
+    cp tools/mkimage ${TOOLCHAIN}/bin
 }
diff --git a/packages/tools/u-boot/package.mk b/packages/tools/u-boot/package.mk
index af8550034c..eed24ae828 100644
--- a/packages/tools/u-boot/package.mk
+++ b/packages/tools/u-boot/package.mk
@@ -9,69 +9,69 @@ PKG_SITE="https://www.denx.de/wiki/U-Boot"
 PKG_DEPENDS_TARGET="toolchain Python3:host swig:host"
 PKG_LONGDESC="Das U-Boot is a cross-platform bootloader for embedded systems."
 
-PKG_STAMP="$UBOOT_SYSTEM $UBOOT_TARGET"
+PKG_STAMP="${UBOOT_SYSTEM} ${UBOOT_TARGET}"
 
-[ -n "$KERNEL_TOOLCHAIN" ] && PKG_DEPENDS_TARGET+=" gcc-arm-$KERNEL_TOOLCHAIN:host"
+[ -n "${KERNEL_TOOLCHAIN}" ] && PKG_DEPENDS_TARGET+=" gcc-arm-${KERNEL_TOOLCHAIN}:host"
 
-if [ -n "$UBOOT_FIRMWARE" ]; then
-  PKG_DEPENDS_TARGET+=" $UBOOT_FIRMWARE"
-  PKG_DEPENDS_UNPACK+=" $UBOOT_FIRMWARE"
+if [ -n "${UBOOT_FIRMWARE}" ]; then
+  PKG_DEPENDS_TARGET+=" ${UBOOT_FIRMWARE}"
+  PKG_DEPENDS_UNPACK+=" ${UBOOT_FIRMWARE}"
 fi
 
-PKG_NEED_UNPACK="$PROJECT_DIR/$PROJECT/bootloader"
-[ -n "$DEVICE" ] && PKG_NEED_UNPACK+=" $PROJECT_DIR/$PROJECT/devices/$DEVICE/bootloader"
+PKG_NEED_UNPACK="${PROJECT_DIR}/${PROJECT}/bootloader"
+[ -n "${DEVICE}" ] && PKG_NEED_UNPACK+=" ${PROJECT_DIR}/${PROJECT}/devices/${DEVICE}/bootloader"
 
-case "$PROJECT" in
+case "${PROJECT}" in
   Rockchip)
     PKG_VERSION="8659d08d2b589693d121c1298484e861b7dafc4f"
     PKG_SHA256="3f9f2bbd0c28be6d7d6eb909823fee5728da023aca0ce37aef3c8f67d1179ec1"
-    PKG_URL="https://github.com/rockchip-linux/u-boot/archive/$PKG_VERSION.tar.gz"
+    PKG_URL="https://github.com/rockchip-linux/u-boot/archive/${PKG_VERSION}.tar.gz"
     PKG_PATCH_DIRS="rockchip"
     ;;
   *)
     PKG_VERSION="2021.01"
     PKG_SHA256="b407e1510a74e863b8b5cb42a24625344f0e0c2fc7582d8c866bd899367d0454"
-    PKG_URL="http://ftp.denx.de/pub/u-boot/$PKG_NAME-$PKG_VERSION.tar.bz2"
+    PKG_URL="http://ftp.denx.de/pub/u-boot/${PKG_NAME}-${PKG_VERSION}.tar.bz2"
     ;;
 esac
 
 post_patch() {
-  if [ -n "$UBOOT_SYSTEM" ] && find_file_path bootloader/config; then
-    PKG_CONFIG_FILE="$PKG_BUILD/configs/$($ROOT/$SCRIPTS/uboot_helper $PROJECT $DEVICE $UBOOT_SYSTEM config)"
-    if [ -f "$PKG_CONFIG_FILE" ]; then
-      cat $FOUND_PATH >> "$PKG_CONFIG_FILE"
+  if [ -n "${UBOOT_SYSTEM}" ] && find_file_path bootloader/config; then
+    PKG_CONFIG_FILE="${PKG_BUILD}/configs/$(${ROOT}/${SCRIPTS}/uboot_helper ${PROJECT} ${DEVICE} ${UBOOT_SYSTEM} config)"
+    if [ -f "${PKG_CONFIG_FILE}" ]; then
+      cat ${FOUND_PATH} >> "${PKG_CONFIG_FILE}"
     fi
   fi
 }
 
 make_target() {
-  if [ -z "$UBOOT_SYSTEM" ]; then
+  if [ -z "${UBOOT_SYSTEM}" ]; then
     echo "UBOOT_SYSTEM must be set to build an image"
     echo "see './scripts/uboot_helper' for more information"
   else
     [ "${BUILD_WITH_DEBUG}" = "yes" ] && PKG_DEBUG=1 || PKG_DEBUG=0
-    DEBUG=${PKG_DEBUG} CROSS_COMPILE="$TARGET_KERNEL_PREFIX" LDFLAGS="" ARCH=arm make mrproper
-    [ -n "$UBOOT_FIRMWARE" ] && find_file_path bootloader/firmware && . ${FOUND_PATH}
-    DEBUG=${PKG_DEBUG} CROSS_COMPILE="$TARGET_KERNEL_PREFIX" LDFLAGS="" ARCH=arm make $($ROOT/$SCRIPTS/uboot_helper $PROJECT $DEVICE $UBOOT_SYSTEM config)
-    DEBUG=${PKG_DEBUG} CROSS_COMPILE="$TARGET_KERNEL_PREFIX" LDFLAGS="" ARCH=arm _python_sysroot="$TOOLCHAIN" _python_prefix=/ _python_exec_prefix=/ make $UBOOT_TARGET HOSTCC="$HOST_CC" HOSTLDFLAGS="-L$TOOLCHAIN/lib" HOSTSTRIP="true" CONFIG_MKIMAGE_DTC_PATH="scripts/dtc/dtc"
+    DEBUG=${PKG_DEBUG} CROSS_COMPILE="${TARGET_KERNEL_PREFIX}" LDFLAGS="" ARCH=arm make mrproper
+    [ -n "${UBOOT_FIRMWARE}" ] && find_file_path bootloader/firmware && . ${FOUND_PATH}
+    DEBUG=${PKG_DEBUG} CROSS_COMPILE="${TARGET_KERNEL_PREFIX}" LDFLAGS="" ARCH=arm make $(${ROOT}/${SCRIPTS}/uboot_helper ${PROJECT} ${DEVICE} ${UBOOT_SYSTEM} config)
+    DEBUG=${PKG_DEBUG} CROSS_COMPILE="${TARGET_KERNEL_PREFIX}" LDFLAGS="" ARCH=arm _python_sysroot="${TOOLCHAIN}" _python_prefix=/ _python_exec_prefix=/ make ${UBOOT_TARGET} HOSTCC="${HOST_CC}" HOSTLDFLAGS="-L${TOOLCHAIN}/lib" HOSTSTRIP="true" CONFIG_MKIMAGE_DTC_PATH="scripts/dtc/dtc"
   fi
 }
 
 makeinstall_target() {
-  mkdir -p $INSTALL/usr/share/bootloader
+  mkdir -p ${INSTALL}/usr/share/bootloader
 
     # Only install u-boot.img et al when building a board specific image
-    if [ -n "$UBOOT_SYSTEM" ]; then
+    if [ -n "${UBOOT_SYSTEM}" ]; then
       find_file_path bootloader/install && . ${FOUND_PATH}
     fi
 
     # Always install the update script
-    find_file_path bootloader/update.sh && cp -av ${FOUND_PATH} $INSTALL/usr/share/bootloader
+    find_file_path bootloader/update.sh && cp -av ${FOUND_PATH} ${INSTALL}/usr/share/bootloader
 
     # Always install the canupdate script
     if find_file_path bootloader/canupdate.sh; then
-      cp -av ${FOUND_PATH} $INSTALL/usr/share/bootloader
-      sed -e "s/@PROJECT@/${DEVICE:-$PROJECT}/g" \
-          -i $INSTALL/usr/share/bootloader/canupdate.sh
+      cp -av ${FOUND_PATH} ${INSTALL}/usr/share/bootloader
+      sed -e "s/@PROJECT@/${DEVICE:-${PROJECT}}/g" \
+          -i ${INSTALL}/usr/share/bootloader/canupdate.sh
     fi
 }