build-rpi3-kernel

#!/usr/bin/env bash
set -x -e

export LINUX_SRC_DIR=${LINUX_SRC_DIR:-${WORKDIR}/linux}

# Use -j<nproc> as default if MAKEFLAGS is not set
if [[ -z "${MAKEFLAGS}" ]]; then
  export MAKEFLAGS="-j$(nproc)"
fi

# Start building the kernel
patch_dir_array=( "${PATCH_DIRS}" )

for patch_dir in "${patch_dir_array[@]}"
do
  # Apply patches if `patch_dir` exists
  if [ -d "${patch_dir}" ]; then
    echo "Applying patches from ${patch_dir}"
    for patch in "${patch_dir}/"*.patch; do
      echo "Applying patch ${patch}"
      patch -p1 < "${patch}"
    done
  fi
done

# Configure kernel
if [[ -v "${ALLCONFIG}" ]]; then
  make KCONFIG_ALLCONFIG="${KCONFIG_ALLCONFIG:-arch/arm/configs/bcm2709_defconfig}" ${ALLCONFIG}
else
  make "${DEFCONFIG:-bcm2709_defconfig}"
fi

# Store and print kernelrease
make kernelrelease
KERNEL_VERSION=$(make kernelrelease | grep "^[45].")
echo "Building kernel ${KERNEL_VERSION}"

# Build everything
make "${MAKEFLAGS}" zImage modules dtbs

# Package for each platform
for platform in $(cd platform && \ls -1d *)
do
    # Copy to tmp destination
    export TMP_DEST="/tmp/build.${platform}"
    INSTALL_MOD_PATH="${TMP_DEST}" make modules_install

    mkdir -p "${TMP_DEST}/boot/overlays"
    cp arch/arm/boot/zImage "${TMP_DEST}/boot/kernel-${KERNEL_VERSION}.img"
    cp arch/arm/boot/dts/*.dtb "${TMP_DEST}"/boot/
    cp arch/arm/boot/dts/overlays/*.dtb* "${TMP_DEST}"/boot/overlays/
    cp arch/arm/boot/dts/overlays/README "${TMP_DEST}"/boot/overlays/

    # Copy config.txt to /boot if it exists
    if [ -f platform/"${platform}"/config.txt ] ; then
        cp platform/"${platform}"/config.txt "${TMP_DEST}"/boot/
        # Add kernel version to config.txt
        echo -e "\nkernel=kernel-${KERNEL_VERSION}.img" >> "${TMP_DEST}"/boot/config.txt
    fi

    # Copy cmdline.txt to /boot if it exists
    if [ -f platform/"${platform}"/cmdline.txt ] ; then
        cp platform/"${platform}"/cmdline.txt "${TMP_DEST}"/boot/
    fi

    # Compile and copy dt-blob.dts to /boot/dt-blob.bin if it exists
    if [ -f dt-blob.dts ] ; then
        ./scripts/dtc/dtc -I dts -O dtb -o "${TMP_DEST}"/boot/dt-blob.bin dt-blob.dts
    fi

    # Create tar file of everything
    mkdir -p "${BUILD_DEST}"
    tar -cvzf "${BUILD_DEST}/kernel-${KERNEL_VERSION}-${platform}.tar.gz" -C $TMP_DEST .
    sha256sum "${BUILD_DEST}/kernel-${KERNEL_VERSION}-${platform}.tar.gz" > "${BUILD_DEST}/kernel-${KERNEL_VERSION}-${platform}.sha256"
done