# SPDX-License-Identifier: GPL-2.0-or-later
# Copyright (C) 2009-2016 Stephan Raue (stephan@openelec.tv)
# Copyright (C) 2017-present Team LibreELEC (https://libreelec.tv)

PKG_NAME="linux"
PKG_LICENSE="GPL"
PKG_SITE="http://www.kernel.org"
PKG_DEPENDS_HOST="ccache:host openssl:host"
PKG_DEPENDS_TARGET="toolchain linux:host cpio:host kmod:host xz:host wireless-regdb keyutils $KERNEL_EXTRA_DEPENDS_TARGET"
PKG_DEPENDS_INIT="toolchain"
PKG_NEED_UNPACK="$LINUX_DEPENDS"
PKG_LONGDESC="This package contains a precompiled kernel image and the modules."
PKG_IS_KERNEL_PKG="yes"
PKG_STAMP="$KERNEL_TARGET $KERNEL_MAKE_EXTRACMD"

PKG_PATCH_DIRS="$LINUX"

case "$LINUX" in
  rockchip-4.4)
    PKG_VERSION="aa8bacf821e5c8ae6dd8cae8d64011c741659945"
    PKG_SHA256="a2760fe89a15aa7be142fd25fb08ebd357c5d855c41f1612cf47c6e89de39bb3"
    PKG_URL="https://github.com/rockchip-linux/kernel/archive/$PKG_VERSION.tar.gz"
    PKG_SOURCE_NAME="linux-$LINUX-$PKG_VERSION.tar.gz"
    ;;
  raspberrypi)
    PKG_VERSION="a831d7ceefd10b78f17d3fa0cc625d2dfd8ca00e" # 5.1.15
    PKG_SHA256="c498c0003c0078e7fbc4980f1fc577d3edd864b1b611d15b25fbe924b68ccf55"
    PKG_URL="https://github.com/raspberrypi/linux/archive/$PKG_VERSION.tar.gz"
    PKG_SOURCE_NAME="linux-$LINUX-$PKG_VERSION.tar.gz"
    ;;
  *)
    PKG_VERSION="5.1.15"
    PKG_SHA256="e8a128702680cea9f37c44bbeb456ea1c2ef1ae1eba0e05dcfc11d7d6cdc1399"
    PKG_URL="https://www.kernel.org/pub/linux/kernel/v5.x/$PKG_NAME-$PKG_VERSION.tar.xz"
    PKG_PATCH_DIRS="default"
    ;;
esac

PKG_KERNEL_CFG_FILE=$(kernel_config_path) || die

if [ -n "$KERNEL_TOOLCHAIN" ]; then
  PKG_DEPENDS_HOST="$PKG_DEPENDS_HOST gcc-arm-$KERNEL_TOOLCHAIN:host"
  PKG_DEPENDS_TARGET="$PKG_DEPENDS_TARGET gcc-arm-$KERNEL_TOOLCHAIN:host"
  HEADERS_ARCH=$TARGET_ARCH
fi

if [ "$PKG_BUILD_PERF" != "no" ] && grep -q ^CONFIG_PERF_EVENTS= $PKG_KERNEL_CFG_FILE ; then
  PKG_BUILD_PERF="yes"
  PKG_DEPENDS_TARGET="$PKG_DEPENDS_TARGET binutils elfutils libunwind zlib openssl"
fi

if [ "$TARGET_ARCH" = "x86_64" ]; then
  PKG_DEPENDS_TARGET="$PKG_DEPENDS_TARGET intel-ucode:host kernel-firmware elfutils:host pciutils"
fi

if [[ "$KERNEL_TARGET" = uImage* ]]; then
  PKG_DEPENDS_TARGET="$PKG_DEPENDS_TARGET u-boot-tools:host"
fi

post_patch() {
  cp $PKG_KERNEL_CFG_FILE $PKG_BUILD/.config

  sed -i -e "s|^CONFIG_INITRAMFS_SOURCE=.*$|CONFIG_INITRAMFS_SOURCE=\"$BUILD/image/initramfs.cpio\"|" $PKG_BUILD/.config
  sed -i -e '/^CONFIG_INITRAMFS_SOURCE=*./ a CONFIG_INITRAMFS_ROOT_UID=0\nCONFIG_INITRAMFS_ROOT_GID=0' $PKG_BUILD/.config

  # set default hostname based on $DISTRONAME
    sed -i -e "s|@DISTRONAME@|$DISTRONAME|g" $PKG_BUILD/.config

  # disable swap support if not enabled
  if [ ! "$SWAP_SUPPORT" = yes ]; then
    sed -i -e "s|^CONFIG_SWAP=.*$|# CONFIG_SWAP is not set|" $PKG_BUILD/.config
  fi

  # disable nfs support if not enabled
  if [ ! "$NFS_SUPPORT" = yes ]; then
    sed -i -e "s|^CONFIG_NFS_FS=.*$|# CONFIG_NFS_FS is not set|" $PKG_BUILD/.config
  fi

  # disable cifs support if not enabled
  if [ ! "$SAMBA_SUPPORT" = yes ]; then
    sed -i -e "s|^CONFIG_CIFS=.*$|# CONFIG_CIFS is not set|" $PKG_BUILD/.config
  fi

  # disable iscsi support if not enabled
  if [ ! "$ISCSI_SUPPORT" = yes ]; then
    sed -i -e "s|^CONFIG_SCSI_ISCSI_ATTRS=.*$|# CONFIG_SCSI_ISCSI_ATTRS is not set|" $PKG_BUILD/.config
    sed -i -e "s|^CONFIG_ISCSI_TCP=.*$|# CONFIG_ISCSI_TCP is not set|" $PKG_BUILD/.config
    sed -i -e "s|^CONFIG_ISCSI_BOOT_SYSFS=.*$|# CONFIG_ISCSI_BOOT_SYSFS is not set|" $PKG_BUILD/.config
    sed -i -e "s|^CONFIG_ISCSI_IBFT_FIND=.*$|# CONFIG_ISCSI_IBFT_FIND is not set|" $PKG_BUILD/.config
    sed -i -e "s|^CONFIG_ISCSI_IBFT=.*$|# CONFIG_ISCSI_IBFT is not set|" $PKG_BUILD/.config
  fi

  # disable lima/panfrost if libmali is configured
  if [ "$OPENGLES" = "libmali" ]; then
    sed -e "s|^CONFIG_DRM_LIMA=.*$|# CONFIG_DRM_LIMA is not set|" -i $PKG_BUILD/.config
    sed -e "s|^CONFIG_DRM_PANFROST=.*$|# CONFIG_DRM_PANFROST is not set|" -i $PKG_BUILD/.config
  fi
}

make_host() {
  make \
    ARCH=${HEADERS_ARCH:-$TARGET_KERNEL_ARCH} \
    HOSTCC="$TOOLCHAIN/bin/host-gcc" \
    HOSTCXX="$TOOLCHAIN/bin/host-g++" \
    HOSTCFLAGS="$HOST_CFLAGS" \
    HOSTCXXFLAGS="$HOST_CXXFLAGS" \
    HOSTLDFLAGS="$HOST_LDFLAGS" \
    headers_check
}

makeinstall_host() {
  make \
    ARCH=${HEADERS_ARCH:-$TARGET_KERNEL_ARCH} \
    HOSTCC="$TOOLCHAIN/bin/host-gcc" \
    HOSTCXX="$TOOLCHAIN/bin/host-g++" \
    HOSTCFLAGS="$HOST_CFLAGS" \
    HOSTCXXFLAGS="$HOST_CXXFLAGS" \
    HOSTLDFLAGS="$HOST_LDFLAGS" \
    INSTALL_HDR_PATH=dest \
    headers_install
  mkdir -p $SYSROOT_PREFIX/usr/include
    cp -R dest/include/* $SYSROOT_PREFIX/usr/include
}

pre_make_target() {
  ( cd $ROOT
    rm -rf $BUILD/initramfs
    $SCRIPTS/install initramfs
  )

  if [ "$TARGET_ARCH" = "x86_64" ]; then
    # copy some extra firmware to linux tree
    mkdir -p $PKG_BUILD/external-firmware
      cp -a $(get_build_dir kernel-firmware)/{amdgpu,amd-ucode,i915,radeon,e100,rtl_nic} $PKG_BUILD/external-firmware

    cp -a $(get_build_dir intel-ucode)/intel-ucode $PKG_BUILD/external-firmware

    FW_LIST="$(find $PKG_BUILD/external-firmware \( -type f -o -type l \) \( -iname '*.bin' -o -iname '*.fw' -o -path '*/intel-ucode/*' \) | sed 's|.*external-firmware/||' | sort | xargs)"
    sed -i "s|CONFIG_EXTRA_FIRMWARE=.*|CONFIG_EXTRA_FIRMWARE=\"${FW_LIST}\"|" $PKG_BUILD/.config
  fi

  kernel_make oldconfig

  # regdb (backward compatability with pre-4.15 kernels)
  if grep -q ^CONFIG_CFG80211_INTERNAL_REGDB= $PKG_BUILD/.config ; then
    cp $(get_build_dir wireless-regdb)/db.txt $PKG_BUILD/net/wireless/db.txt
  fi
}

make_target() {
  # arm64 target does not support creating uImage.
  # Build Image first, then wrap it using u-boot's mkimage.
  if [[ "$TARGET_KERNEL_ARCH" = "arm64" && "$KERNEL_TARGET" = uImage* ]]; then
    if [ -z "$KERNEL_UIMAGE_LOADADDR" -o -z "$KERNEL_UIMAGE_ENTRYADDR" ]; then
      die "ERROR: KERNEL_UIMAGE_LOADADDR and KERNEL_UIMAGE_ENTRYADDR have to be set to build uImage - aborting"
    fi
    KERNEL_UIMAGE_TARGET="$KERNEL_TARGET"
    KERNEL_TARGET="${KERNEL_TARGET/uImage/Image}"
  fi

  kernel_make $KERNEL_TARGET $KERNEL_MAKE_EXTRACMD modules

  if [ "$PKG_BUILD_PERF" = "yes" ] ; then
    ( cd tools/perf

      # arch specific perf build args
      case "$TARGET_ARCH" in
        x86_64)
          PERF_BUILD_ARGS="ARCH=x86"
          ;;
        aarch64)
          PERF_BUILD_ARGS="ARCH=arm64"
          ;;
        *)
          PERF_BUILD_ARGS="ARCH=$TARGET_ARCH"
          ;;
      esac

      WERROR=0 \
      NO_LIBPERL=1 \
      NO_LIBPYTHON=1 \
      NO_SLANG=1 \
      NO_GTK2=1 \
      NO_LIBNUMA=1 \
      NO_LIBAUDIT=1 \
      NO_LZMA=1 \
      NO_SDT=1 \
      CROSS_COMPILE="$TARGET_PREFIX" \
      JOBS="$CONCURRENCY_MAKE_LEVEL" \
        make $PERF_BUILD_ARGS
      mkdir -p $INSTALL/usr/bin
        cp perf $INSTALL/usr/bin
    )
  fi

  if [ -n "$KERNEL_UIMAGE_TARGET" ] ; then
    # determine compression used for kernel image
    KERNEL_UIMAGE_COMP=${KERNEL_UIMAGE_TARGET:7}
    KERNEL_UIMAGE_COMP=$(echo ${KERNEL_UIMAGE_COMP:-none} | sed 's/gz/gzip/; s/bz2/bzip2/')

    # calculate new load address to make kernel Image unpack to memory area after compressed image
    if [ "$KERNEL_UIMAGE_COMP" != "none" ] ; then
      COMPRESSED_SIZE=$(stat -t "arch/$TARGET_KERNEL_ARCH/boot/$KERNEL_TARGET" | awk '{print $2}')
      # align to 1 MiB
      COMPRESSED_SIZE=$(( (($COMPRESSED_SIZE - 1 >> 20) + 1) << 20 ))
      PKG_KERNEL_UIMAGE_LOADADDR=$(printf '%X' "$(( $KERNEL_UIMAGE_LOADADDR + $COMPRESSED_SIZE ))")
      PKG_KERNEL_UIMAGE_ENTRYADDR=$(printf '%X' "$(( $KERNEL_UIMAGE_ENTRYADDR + $COMPRESSED_SIZE ))")
    else
      PKG_KERNEL_UIMAGE_LOADADDR=${KERNEL_UIMAGE_LOADADDR}
      PKG_KERNEL_UIMAGE_ENTRYADDR=${KERNEL_UIMAGE_ENTRYADDR}
    fi

    mkimage -A $TARGET_KERNEL_ARCH \
            -O linux \
            -T kernel \
            -C $KERNEL_UIMAGE_COMP \
            -a $PKG_KERNEL_UIMAGE_LOADADDR \
            -e $PKG_KERNEL_UIMAGE_ENTRYADDR \
            -d arch/$TARGET_KERNEL_ARCH/boot/$KERNEL_TARGET \
               arch/$TARGET_KERNEL_ARCH/boot/$KERNEL_UIMAGE_TARGET

    KERNEL_TARGET="${KERNEL_UIMAGE_TARGET}"
  fi
}

makeinstall_target() {
  kernel_make INSTALL_MOD_PATH=$INSTALL/$(get_kernel_overlay_dir) modules_install
  rm -f $INSTALL/$(get_kernel_overlay_dir)/lib/modules/*/build
  rm -f $INSTALL/$(get_kernel_overlay_dir)/lib/modules/*/source

  if [ "$BOOTLOADER" = "u-boot" ]; then
    mkdir -p $INSTALL/usr/share/bootloader
    for dtb in arch/$TARGET_KERNEL_ARCH/boot/dts/*.dtb arch/$TARGET_KERNEL_ARCH/boot/dts/*/*.dtb; do
      if [ -f $dtb ]; then
        cp -v $dtb $INSTALL/usr/share/bootloader
      fi
    done
  elif [ "$BOOTLOADER" = "bcm2835-bootloader" ]; then
    mkdir -p $INSTALL/usr/share/bootloader/overlays

    # install platform dtbs, but remove upstream kernel dtbs (i.e. without downstream
    # drivers and decent USB support) as these are not required by LibreELEC
    cp -p arch/$TARGET_KERNEL_ARCH/boot/dts/*.dtb $INSTALL/usr/share/bootloader
    rm -f $INSTALL/usr/share/bootloader/bcm283*.dtb

    # install overlay dtbs
    for dtb in arch/$TARGET_KERNEL_ARCH/boot/dts/overlays/*.dtbo; do
      cp $dtb $INSTALL/usr/share/bootloader/overlays 2>/dev/null || :
    done
    cp -p arch/$TARGET_KERNEL_ARCH/boot/dts/overlays/README $INSTALL/usr/share/bootloader/overlays
  fi
}

post_install() {
  mkdir -p $INSTALL/$(get_full_firmware_dir)/

  # regdb and signature is now loaded as firmware by 4.15+
    if grep -q ^CONFIG_CFG80211_REQUIRE_SIGNED_REGDB= $PKG_BUILD/.config; then
      cp $(get_build_dir wireless-regdb)/regulatory.db{,.p7s} $INSTALL/$(get_full_firmware_dir)
    fi
}