Raspberry pi kernel build script

build-kernel.sh

#!/bin/bash

# https://forums.raspberrypi.com/viewtopic.php?t=330358

trap '{ stty sane; echo ""; errexit "Aborted"; }' SIGINT SIGTERM

CONFIG1="Raspberry Pi 1, Zero and Zero W, and Raspberry Pi Compute Module 1 (32-bit)"
CONFIG2="Raspberry Pi 2, 3, 3+ and Zero 2 W, and Raspberry Pi Compute Modules 3 and 3+ (32-bit)"
CONFIG3="Raspberry Pi 4 and 400, and Raspberry Pi Compute Module 4 (32-bit)"
CONFIG4="Raspberry Pi 3, 3+, 4, 400 and Zero 2 W, and Raspberry Pi Compute Modules 3, 3+ and 4 (64-bit)"

errexit() {
  echo ""
  echo "$1"
  echo ""
  exit 1
}

instpkgs() {
  local i
  local PKGS

  PKGS=("$@")
  for i in ${!PKGS[@]}; do
    dpkg -s "${PKGS[i]}" &>/dev/null
    if [ $? -eq 0 ]; then
      unset PKGS[i]
    fi
  done
  if [ ${#PKGS[@]} -ne 0 ]; then
    echo ""
    apt -y update
    apt -y install "${PKGS[@]}"
  fi
}

usage() {
  echo ""
  echo -e "Usage: $0 [options]\n\
-b,--branch       Branch to use\n\
-c,--config       Configuration to build:\n\
   1 = ${CONFIG1}\n\
   2 = ${CONFIG2}\n\
   3 = ${CONFIG3}\n\
   4 = ${CONFIG4}\n\
-d,--delete       Delete existing source files\n\
-h,--help         This usage description\n\
-k,--keep         Keep old kernel as .bak\n\
-m,--menuconfig   Run menuconfig\n\
-p,--purge        Purge source files upon completion\n\
-r,--reboot       Reboot upon completion\n\
-s,--suffix       Append modules suffix\n\
-u,--unattended   Unattended operation, defaults:\n\
   Branch = default\n\
   Config = ${CONFIG4}\n\
   Delete = auto\n\
   Keep = no\n\
   Menuconfig = no\n\
   Purge = no\n\
   Reboot = no\n\
   Suffix = none\n"
}

if [ $(id -u) -ne 0 ]; then
  errexit "Must be run as root user: sudo $0"
fi
PGMNAME="$(basename $0)"
for PID in $(pidof -x -o %PPID "${PGMNAME}"); do
  if [ ${PID} -ne $$ ]; then
    errexit "${PGMNAME} is already running"
  fi
done
BRANCH=""
CONFIG=""
DELETE=false
KEEP=false
MNUCFG=false
PURGE=false
REBOOT=false
SUFFIX=""
UNATND=false
while [ $# -gt 0 ]; do
  case "$1" in

  -b | --branch)
    BRANCH="$2"
    shift 2
    ;;

  -c | --config)
    CONFIG="$2"
    shift 2
    ;;

  -d | --delete)
    DELETE=true
    shift
    ;;

  -h | --help)
    usage
    exit
    ;;

  -k | --keep)
    KEEP=true
    shift
    ;;

  -m | --menuconfig)
    MNUCFG=true
    shift
    ;;

  -p | --purge)
    PURGE=true
    shift
    ;;

  -r | --reboot)
    REBOOT=true
    shift
    ;;

  -s | --suffix)
    SUFFIX="$2"
    shift 2
    ;;

  -u | --unattended)
    UNATND=true
    shift
    ;;

  -* | --*)
    errexit "Unrecognized option"
    ;;

  *)
    errexit "Unrecognized parameter"
    ;;

  esac
done
if [[ "${UNATND}" = "false" && "${CONFIG}" = "" ]]; then
  echo ""
  echo -e -n "\
1) ${CONFIG1}\n\
2) ${CONFIG2}\n\
3) ${CONFIG3}\n\
4) ${CONFIG4}\n\
Configuration: "
  while read -r -n 1 -s answer; do
    if [[ ${answer} = [1234] ]]; then
      echo "${answer}"
      CONFIG="${answer}"
      break
    fi
  done
fi
if [ "${CONFIG}" = "" ]; then
  CONFIG=4
fi
case "${CONFIG}" in

1)
  MAKCFG=bcmrpi_defconfig
  KERNEL=kernel
  ;;

2)
  MAKCFG=bcm2709_defconfig
  KERNEL=kernel7
  ;;

3)
  MAKCFG=bcm2711_defconfig
  KERNEL=kernel7l
  ;;

4)
  MAKCFG=bcm2711_defconfig
  KERNEL=kernel8
  ;;

*)
  errexit "Invalid configuration"
  ;;

esac
if [[ "${UNATND}" = "false" && "${BRANCH}" = "" ]]; then
  echo ""
  echo -n "Branch (blank = default): "
  read -r BRANCH
fi
BRANCH="$(sed -e 's/^[[:space:]]*//' -e 's/[[:space:]]*$//' <<<"${BRANCH}")"
if [[ "${BRANCH}" != "" && "${BRANCH}" != "$(git ls-remote --symref https://github.com/raspberrypi/linux | sed -n "s|^\S\+\s\+refs/heads/\(${BRANCH}\)$|\1|p")" ]]; then
  errexit "Branch '${BRANCH}' does not exist"
fi
if [[ "${UNATND}" = "false" && "${SUFFIX}" = "" ]]; then
  echo ""
  echo -n "Suffix (blank = none): "
  read -r SUFFIX
fi
SUFFIX="$(sed -e 's/^[[:space:]]*//' -e 's/[[:space:]]*$//' <<<"${SUFFIX}")"
SUFFIX="$(tr [[:blank:]] _ <<<"${SUFFIX}")"
if [[ "${UNATND}" = "false" && "${MNUCFG}" = "false" ]]; then
  echo ""
  echo -n "Run menuconfig (y/n)? "
  while read -r -n 1 -s answer; do
    if [[ ${answer} = [yYnN] ]]; then
      echo "${answer}"
      if [[ ${answer} = [yY] ]]; then
        MNUCFG=true
      fi
      break
    fi
  done
fi
if [[ "${UNATND}" = "false" && "${KEEP}" = "false" ]]; then
  echo ""
  echo -n "Keep old kernel as .bak (y/n)? "
  while read -r -n 1 -s answer; do
    if [[ ${answer} = [yYnN] ]]; then
      echo "${answer}"
      if [[ ${answer} = [yY] ]]; then
        KEEP=true
      fi
      break
    fi
  done
fi
if [[ "${UNATND}" = "false" && "${PURGE}" = "false" ]]; then
  echo ""
  echo -n "Purge source files upon completion (y/n)? "
  while read -r -n 1 -s answer; do
    if [[ ${answer} = [yYnN] ]]; then
      echo "${answer}"
      if [[ ${answer} = [yY] ]]; then
        PURGE=true
      fi
      break
    fi
  done
fi
if [[ "${UNATND}" = "false" && "${REBOOT}" = "false" ]]; then
  echo ""
  echo -n "Reboot upon completion (y/n)? "
  while read -r -n 1 -s answer; do
    if [[ ${answer} = [yYnN] ]]; then
      echo "${answer}"
      if [[ ${answer} = [yY] ]]; then
        REBOOT=true
      fi
      break
    fi
  done
fi
echo ""
echo -n "Configuration: "
case "${KERNEL}" in
kernel)
  echo "${CONFIG1}"
  ;;

kernel7)
  echo "${CONFIG2}"
  ;;

kernel7l)
  echo "${CONFIG3}"
  ;;

kernel8)
  echo "${CONFIG4}"
  ;;
esac
echo -n "Branch: "
if [ "${BRANCH}" = "" ]; then
  echo "default"
else
  echo "${BRANCH}"
fi
echo -n "Suffix: "
if [ "${SUFFIX}" = "" ]; then
  echo "none"
else
  echo "${SUFFIX}"
fi
echo -n "Run menuconfig: "
if [ "${MNUCFG}" = "true" ]; then
  echo "Yes"
else
  echo "No"
fi
echo -n "Keep old kernel as .bak: "
if [ "${KEEP}" = "true" ]; then
  echo "Yes"
else
  echo "No"
fi
echo -n "Purge source files upon completion: "
if [ "${PURGE}" = "true" ]; then
  echo "Yes"
else
  echo "No"
fi
echo -n "Reboot upon completion: "
if [ "${REBOOT}" = "true" ]; then
  echo "Yes"
else
  echo "No"
fi
if [ "${UNATND}" = "false" ]; then
  echo ""
  echo -n "Build kernel (y/n)? "
  while read -r -n 1 -s answer; do
    if [[ ${answer} = [yYnN] ]]; then
      echo "${answer}"
      if [[ ${answer} = [nN] ]]; then
        errexit "Aborted"
      fi
      break
    fi
  done
fi
instpkgs bc bison flex git libssl-dev make
if [ -e /usr/src/linux ]; then
  SOURCE="$(sed -n 's|^\[branch "\(.*\)"\]|\1|p' /usr/src/linux/.git/config)"
  TARGET="${BRANCH}"
  if [ "${TARGET}" = "" ]; then
    TARGET="$(git ls-remote --symref https://github.com/raspberrypi/linux | head -n 1 | sed -n 's|^ref:\s\+refs/heads/\(.*\)\s\+HEAD$|\1|p')"
  fi
  if [ "${TARGET}" != "${SOURCE}" ]; then
    DELETE=true
  fi
  if [[ "${UNATND}" = "false" && "${DELETE}" = "false" ]]; then
    echo ""
    echo -n "Delete existing source files [Source/Target branch = ${SOURCE}] (y/n)? "
    while read -r -n 1 -s answer; do
      if [[ ${answer} = [yYnN] ]]; then
        echo "${answer}"
        if [[ ${answer} = [yY] ]]; then
          DELETE=true
        fi
        break
      fi
    done
  fi
  if [ "${DELETE}" = "true" ]; then
    echo ""
    echo "Deleting existing source files"
    rm -r /usr/src/linux
  fi
fi
if [ ! -e /usr/src/linux ]; then
  cd /usr/src
  echo ""
  if [ "${BRANCH}" = "" ]; then
    git clone --depth=1 https://github.com/raspberrypi/linux
  else
    git clone --depth=1 --branch "${BRANCH}" https://github.com/raspberrypi/linux
  fi
fi
cd /usr/src/linux
echo ""
make -j$(nproc) "${MAKCFG}"
if [ "${SUFFIX}" != "" ]; then
  sed -i "s|^\(CONFIG_LOCALVERSION=\".*\)\"$|\1-${SUFFIX}\"|" .config
fi
if [ "${MNUCFG}" = "true" ]; then
  instpkgs libncurses5-dev
  make -j$(nproc) menuconfig
fi
echo ""
if [ "${KERNEL}" = "kernel8" ]; then
  make -j$(nproc) Image modules dtbs
  make modules_install
  cp arch/arm64/boot/dts/broadcom/*.dtb /boot/
  cp arch/arm64/boot/dts/overlays/*.dtb* /boot/overlays/
  cp arch/arm64/boot/dts/overlays/README /boot/overlays/
  if [ "${KEEP}" = "true" ]; then
    mv /boot/${KERNEL}.img /boot/${KERNEL}.img.bak
  fi
  cp arch/arm64/boot/Image /boot/${KERNEL}.img
  gzip --best /boot/${KERNEL}.img
  mv /boot/${KERNEL}.img.gz /boot/${KERNEL}.img
else
  make -j$(nproc) zImage modules dtbs
  make modules_install
  cp arch/arm/boot/dts/*.dtb /boot/
  cp arch/arm/boot/dts/overlays/*.dtb* /boot/overlays/
  cp arch/arm/boot/dts/overlays/README /boot/overlays/
  if [ "${KEEP}" = "true" ]; then
    mv /boot/${KERNEL}.img /boot/${KERNEL}.img.bak
  fi
  cp arch/arm/boot/zImage /boot/${KERNEL}.img
fi
echo ""
echo "Kernel successfully built"
if [ "${PURGE}" = "true" ]; then
  echo ""
  echo "Purging source files"
  rm -r /usr/src/linux
fi
echo ""
if [ "${REBOOT}" = "true" ]; then
  echo "Rebooting"
  echo ""
  shutdown -r now
else
  echo "Reboot required to use new kernel"
  echo ""
fi