# Maintainer: Donald Carr <sirspudd at gmail dot com>

#set -x

options=('!strip')
# The firmware the kernel produces blows: don't falsify this lightly
# "linux-firmware=20170309.695f2d6-1"
pkgrel=1
pkgver=5.12.rc6.384.gfa3865905822
pkgdesc="Kernel build from head"
arch=("x86_64" "aarch64" "armv7h")
license=("GPL2.1")
log_path="${PWD}/$(date +"%Y-%m-%d-%H%M").log"
_kernel_src_dir=/opt/src/OSS/linux
_config_preset=""
_pi_ver="${LOCAL_PI_VER:-}"

pkgbase() {
    oldpath=${PWD}
    cd $_kernel_src_dir
    postfix="spudd-$(git branch --show-current)"
    if [[ -f testing ]]; then
        postfix=${postfix}-testing
    fi
    pkgbase=linux-${postfix}
    cd ${oldpath}
}
pkgbase

if [ -z "${_pi_ver}" ]; then
    install=spudd.install
fi

prepare() {
    cp ${startdir}/_spudd.install ${startdir}/spudd.install
    sed -i "s/spudd/${postfix}/g" ${startdir}/spudd.install
}

pkgver() {
  cd $_kernel_src_dir
  git describe --tags | sed -e "s/^v//" | tr '-' '.'
}

build() {
  set -o nounset
  set -o pipefail
  set -o errexit
  #set -o xtrace

  cd $_kernel_src_dir && git clean -xdf

  if [[ -n ${_config_preset} ]]; then
    echo ${_make_cmd} ${_config_preset}
    ${_make_cmd} ${_config_preset}
  elif [[ -n ${_config_file} ]]; then
    cp ${_config_file} ${_kernel_src_dir}/.config
  else
    echo "Kernel not configured; bailing"
    exit 1
  fi

  ${_make_cmd} all 2>&1 | tee ${log_path}

  if [ -n "${_pi_ver}" ]; then
    ${_make_cmd} dtbs 2>&1 | tee -a ${log_path}
  fi

  set +o nounset
  set +o pipefail
  set +o errexit
}

_package-headers() {
    pkgdesc="Headers and scripts for building modules for the $pkgdesc kernel"

    cd $_kernel_src_dir
    local builddir="$pkgdir/usr/lib/modules/$(<version)/build"

    echo "Installing build files..."
    install -Dt "$builddir" -m644 .config Makefile System.map \
        vmlinux
    install -Dt "$builddir/kernel" -m644 kernel/Makefile
    install -Dt "$builddir/arch/x86" -m644 arch/x86/Makefile
    cp -t "$builddir" -a scripts

    # add objtool for external module building and enabled VALIDATION_STACK option
    install -Dt "$builddir/tools/objtool" tools/objtool/objtool

    # add xfs and shmem for aufs building
    mkdir -p "$builddir"/{fs/xfs,mm}

    echo "Installing headers..."
    cp -t "$builddir" -a include
    cp -t "$builddir/arch/x86" -a arch/x86/include
    install -Dt "$builddir/arch/x86/kernel" -m644 arch/x86/kernel/asm-offsets.s

    install -Dt "$builddir/drivers/md" -m644 drivers/md/*.h
    install -Dt "$builddir/net/mac80211" -m644 net/mac80211/*.h

    # http://bugs.archlinux.org/task/13146
    install -Dt "$builddir/drivers/media/i2c" -m644 drivers/media/i2c/msp3400-driver.h

    # http://bugs.archlinux.org/task/20402
    install -Dt "$builddir/drivers/media/usb/dvb-usb" -m644 drivers/media/usb/dvb-usb/*.h
    install -Dt "$builddir/drivers/media/dvb-frontends" -m644 drivers/media/dvb-frontends/*.h
    install -Dt "$builddir/drivers/media/tuners" -m644 drivers/media/tuners/*.h

    echo "Installing KConfig files..."
    find . -name 'Kconfig*' -exec install -Dm644 {} "$builddir/{}" \;

    echo "Removing unneeded architectures..."
    local arch
    for arch in "$builddir"/arch/*/; do
        [[ $arch = */x86/ ]] && continue
        echo "Removing $(basename "$arch")"
        rm -r "$arch"
    done

    echo "Removing documentation..."
    rm -r "$builddir/Documentation"

    echo "Removing broken symlinks..."
    find -L "$builddir" -type l -printf 'Removing %P\n' -delete

    echo "Removing loose objects..."
    find "$builddir" -type f -name '*.o' -printf 'Removing %P\n' -delete

    echo "Stripping build tools..."
    local file
    while read -rd '' file; do
        case "$(file -bi "$file")" in
            application/x-sharedlib\;*)      # Libraries (.so)
                strip -v $STRIP_SHARED "$file" ;;
            application/x-archive\;*)        # Libraries (.a)
                strip -v $STRIP_STATIC "$file" ;;
            application/x-executable\;*)     # Binaries
                strip -v $STRIP_BINARIES "$file" ;;
            application/x-pie-executable\;*) # Relocatable binaries
                strip -v $STRIP_SHARED "$file" ;;
        esac
    done < <(find "$builddir" -type f -perm -u+x ! -name vmlinux -print0)

    echo "Adding symlink..."
    mkdir -p "$pkgdir/usr/src"
    ln -sr "$builddir" "$pkgdir/usr/src/$pkgbase"
}

pkgname=("$pkgbase" "$pkgbase-headers")
for _p in "${pkgname[@]}"; do
  eval "package_$_p() {
    $(declare -f "_package${_p#$pkgbase}")
    _package${_p#$pkgbase}
  }"
done

_package() {
  prepare
  boot_dir="${pkgdir}/boot"
  dtb_dir="${boot_dir}/dtbs"
  usr_dir="${pkgdir}/usr"
  firmware_dir="${usr_dir}/lib/firmware"
  preset_dir=${pkgdir}/etc/mkinitcpio.d

  cd $_kernel_src_dir
  if [ -n "${_pi_ver}" ]; then
    INSTALL_DTBS_PATH=${dtb_dir} ${_make_cmd} dtbs_install
  fi

  mkdir -p ${boot_dir}
  if [ "${_pi_ver}" = "3" ] || [ "${_pi_ver}" = "4" ]; then
    cp arch/arm64/boot/Image ${boot_dir}/Image
    cp arch/arm64/boot/Image.gz ${boot_dir}/Image.gz
  elif [ "${_pi_ver}" = "2" ]; then
    cp arch/arm/boot/zImage ${boot_dir}/vmlinuz-${postfix}
  else
    cp arch/x86/boot/bzImage ${boot_dir}/vmlinuz-${postfix}
  fi

  mkdir -p ${preset_dir}
  cp ${startdir}/spudd.preset ${preset_dir}/${postfix}.preset
  sed -i "s/spudd/${postfix}/g" ${preset_dir}/${postfix}.preset

  rm -Rf ${startdir}/firmware
  if [[ -d ${firmware_dir} ]]; then
    mv ${firmware_dir} ${startdir}
  fi
}

if [ -n "${_pi_ver}" ]; then
    case ${_pi_ver} in
    2)
        echo "Compiling for the RPi 2 aarch32"
        _config_file="${startdir}/rpi2"
        _xcompile_args="ARCH=arm CROSS_COMPILE=/opt/armv7-rpi2-linux-gnueabihf/bin/armv7-rpi2-linux-gnueabihf-"
    ;;
    3)
        #symbols omitted by default wtf!
        #DTC_FLAGS=\"-@ -H epapr\"
        echo "Compiling for the RPi 3 aarch64"
        _config_file="${startdir}/rpi3"
        _xcompile_args="ARCH=arm64 CROSS_COMPILE=/opt/x-tools/aarch64-rpi3-linux-gnu/bin/aarch64-rpi3-linux-gnu-"
    ;;
   4)
        #symbols omitted by default wtf!
        #DTC_FLAGS=\"-@ -H epapr\"
        echo "Compiling for the RPi 4 aarch64"
        _config_preset="bcm2711_defconfig"
        _xcompile_args="ARCH=arm64 CROSS_COMPILE=${HOME}/x-tools/aarch64-spudd-linux-gnu/bin/aarch64-spudd-linux-gnu-"
    ;;
    *)
        echo "Only supports the rpi 4 at this point in time"
        exit 1
    ;;
    esac
else
    echo "Compiling for desktop"
    # wasted a lot of time manually tracking this shit down before finding this doc, like a muppet
    # Documentation/kbuild/llvm.rst
    _xcompile_args="LLVM=1 LLVM_IAS=1"
    #_xcompile_args=""
    _config_file="${startdir}/desktop"
    #_config_file="${_kernel_src_dir}/configs/desktop"
fi

_make_cmd="eval time make V=0 ${_xcompile_args}"