build_kernel_deb.sh: Make shellcheck happy

We switch to bash so we can use shell arrays.

build/build_kernel_deb.sh

-#!/bin/sh
+#!/bin/bash
 #
 # Copyright (C) 2017 Purism SPC
 #
@@ -6,7 +6,7 @@
 #
 
 # Passed in via the environment
-MAKE_OPTS="${MAKE_OPTS}"
+read -r -a MAKE_OPTS <<< "${MAKE_OPTS}"
 
 set -u
 set -e
@@ -15,25 +15,25 @@ CROSS_COMPILER=aarch64-linux-gnu-
 ARCH=arm64
 COMPILER_ARCH="${ARCH}"
 KERNEL_OUTPUT=../../files
-CWD=`pwd`
+CWD=$(pwd)
 pureos_board=imx6
 DTS_FILE=
 RSI_VER=RS9116.NB0.NL.LNX.PURISM_FW_UPGRADE.1.0.5
 
 
 build_redpine () {
-    tar -xf files/${RSI_VER}.tgz
+    tar -xf "files/${RSI_VER}.tgz"
 
-    RSI_BUILD_PATH=${RSI_VER}/rsi/
+    RSI_BUILD_PATH="${RSI_VER}/rsi/"
     ESCAPED_KERNEL_DIR=$(echo "${LINUX_DIR}" | sed 's/\//\\\//g')
 
-    sed "s/KERNELDIR=.*/KERNELDIR=${ESCAPED_KERNEL_DIR}/" -i ${RSI_BUILD_PATH}/Makefile
+    sed "s/KERNELDIR=.*/KERNELDIR=${ESCAPED_KERNEL_DIR}/" -i "${RSI_BUILD_PATH}/Makefile"
 
     cd ${RSI_BUILD_PATH}
-    make ${MAKE_OPTS} ARCH=${ARCH} CROSS_COMPILE=${CROSS_COMPILER} -C ${CWD}/${LINUX_DIR} M=$PWD modules
-    cd ${CWD}/${RSI_BUILD_PATH} && tar -cf ${CWD}/../files/rsi_upgrade.tar *.ko
-    cd ${CWD}/${RSI_VER}/Firmware && tar -cf ${CWD}/../files/rsi_firmware.tar *
-    cd ${CWD}
+    make "${MAKE_OPTS[@]}" ARCH="${ARCH}" CROSS_COMPILE="${CROSS_COMPILER}" -C "${CWD}/${LINUX_DIR}" M="$PWD" modules
+    cd "${CWD}/${RSI_BUILD_PATH}" && tar -cf "${CWD}/../files/rsi_upgrade.tar" ./*.ko
+    cd "${CWD}/${RSI_VER}/Firmware" && tar -cf "${CWD}/../files/rsi_firmware.tar" ./*
+    cd "${CWD}"
 }
 
 
@@ -46,15 +46,15 @@ usage() {
 while getopts ":hb:" opt; do
   case ${opt} in
     b)
-      pureos_board=$OPTARG
+      pureos_board="$OPTARG"
       ;;
     \?)
       echo "Invalid Option: -$OPTARG" 1>&2
-      usage $0
+      usage "$0"
       exit 0
       ;;
     h )
-      usage $0
+      usage "$0"
       exit 0
       ;;
   esac
@@ -62,7 +62,7 @@ done
 
 LINUX_DIR="linux-${pureos_board}"
 
-case ${pureos_board} in 
+case "${pureos_board}" in 
   imx6)
     KERNEL_BRANCH=purism-nitrogen6_4.16.x
     KERNEL_REPO=https://source.puri.sm/Librem5/linux-nitrogen6.git
@@ -70,25 +70,25 @@ case ${pureos_board} in
     CROSS_COMPILER=arm-linux-gnueabihf-
     ARCH=arm
     COMPILER_ARCH=armhf
-    GIT_OPTS="--depth 1"
+    GIT_OPTS=(--depth 1)
     ;;
   imx8)
     KERNEL_BRANCH=imx8-4.21-evk
     KERNEL_REPO=https://source.puri.sm/Librem5/linux-next.git
     DOT_CONFIG=imx8mq-evk_defconfig
-    GIT_OPTS="--depth 1"
+    GIT_OPTS=(--depth 1)
     ;;
   ec-som)
     KERNEL_BRANCH=imx8-4.18-wip
     KERNEL_REPO=https://source.puri.sm/Librem5/linux-emcraft.git
     DOT_CONFIG=emcraft-som-imx8_defconfig
-    GIT_OPTS="--depth 1"
+    GIT_OPTS=(--depth 1)
     ;;
   devkit)
     KERNEL_BRANCH=imx8-4.18-wip
     KERNEL_REPO=https://source.puri.sm/Librem5/linux-emcraft.git
     DOT_CONFIG=librem5-evk_defconfig
-    GIT_OPTS="--depth 1"
+    GIT_OPTS=(--depth 1)
     ;;
   \?)
     echo "unrecognized board type ${pureos_board}"
@@ -96,39 +96,39 @@ case ${pureos_board} in
     ;;
 esac
 
-if [ ! -e ${LINUX_DIR} ]; then
+if [ ! -e "${LINUX_DIR}" ]; then
   echo "Cloning kernel"
-  git clone ${GIT_OPTS} -b ${KERNEL_BRANCH} ${KERNEL_REPO} ${LINUX_DIR}
-  cd ${LINUX_DIR}
+  git clone "${GIT_OPTS[@]}" -b "${KERNEL_BRANCH}" "${KERNEL_REPO}" "${LINUX_DIR}"
+  cd "${LINUX_DIR}"
 else
-  cd ${LINUX_DIR}
+  cd "${LINUX_DIR}"
   echo "Updating kernel"
-  git pull ${GIT_OPTS} ${KERNEL_REPO} ${KERNEL_BRANCH}
-  git checkout ${KERNEL_BRANCH}
+  git pull "${GIT_OPTS[@]}" "${KERNEL_REPO}" "${KERNEL_BRANCH}"
+  git checkout "${KERNEL_BRANCH}"
 fi
 
 if [ ! -e .config ]; then
   echo "Configuring kernel"
-  if [ -e arch/${ARCH}/configs/${DOT_CONFIG} ]; then
-    cp arch/${ARCH}/configs/${DOT_CONFIG} .config
+  if [ -e "arch/${ARCH}/configs/${DOT_CONFIG}" ]; then
+    cp "arch/${ARCH}/configs/${DOT_CONFIG}" .config
   else
-    cp ../${DOT_CONFIG} .config
+    cp "../${DOT_CONFIG}" .config
   fi
 fi
 
 if [ -n "${DTS_FILE}" ]; then
   echo "Adding device tree file"
-  cp ../${DTS_FILE} arch/${ARCH}/boot/dts/
+  cp "../${DTS_FILE}" "arch/${ARCH}/boot/dts/"
 fi
 
 echo "Building kernel"
-make ${MAKE_OPTS} ARCH=${ARCH} CROSS_COMPILE=${CROSS_COMPILER} bindeb-pkg
+make "${MAKE_OPTS[@]}" ARCH="${ARCH}" CROSS_COMPILE="${CROSS_COMPILER}" bindeb-pkg
 
 echo "Copying kernel"
-mkdir -p ${KERNEL_OUTPUT}
-cp ../*${COMPILER_ARCH}.deb ${KERNEL_OUTPUT}
+mkdir -p "${KERNEL_OUTPUT}"
+cp ../*${COMPILER_ARCH}.deb "${KERNEL_OUTPUT}"
 
-cd ${CWD}
+cd "${CWD}"
 
 case "${pureos_board}" in
     devkit)
@@ -138,7 +138,7 @@ case "${pureos_board}" in
     ;;
 esac
 
-echo ${KERNEL_REPO} > kernel-git-${ARCH}.txt
-git log | head -n 1 | awk '{ print $2 };' >> kernel-git-${ARCH}.txt
+echo "${KERNEL_REPO}" > "kernel-git-${ARCH}.txt"
+git log | head -n 1 | awk '{ print $2 };' >> "kernel-git-${ARCH}.txt"
 
-cp kernel-git-${ARCH}.txt ../files/kernel-git-${ARCH}.txt
+cp "kernel-git-${ARCH}.txt" "../files/kernel-git-${ARCH}.txt"