# This is the source.sh script. It is executed by BPM in a temporary directory when compiling a source package
# BPM Expects the source code to be extracted into the automatically created 'source' directory which can be accessed using $BPM_SOURCE
# BPM Expects the output files to be present in the automatically created 'output' directory which can be accessed using $BPM_OUTPUT

# The prepare function is executed in the root of the temp directory
# This function is used for putting downloaded files to the correct location or applying patches
prepare() {
  cd "$BPM_SOURCE"

  make mrproper
  cp ../config .config
}

# The build function is executed in the source directory
# This function is used to compile the source code
build() {
  make LLVM=1 olddefconfig
  make LLVM=1
  make -C tools/bpf/bpftool vmlinux.h feature-clang-bpf-co-re=1
}

# The package function is executed in the source directory
# This function is used to move the compiled files into the output directory
package_linux-lts() {
  # Install kernel modules
  make INSTALL_MOD_PATH="$BPM_OUTPUT"/usr INSTALL_MOD_STRIP=1 modules_install

  # Install kernel image and config
  install -Dm644 arch/x86/boot/bzImage "$BPM_OUTPUT"/boot/vmlinuz-linux-lts
  install -Dm644 .config "$BPM_OUTPUT"/boot/config-linux-lts

  # Remove build link
  rm "$BPM_OUTPUT"/usr/lib/modules/$(make -s kernelrelease)/build

  # Install package licenses
  install -d "$BPM_OUTPUT"/usr/share/licenses
  cp -r LICENSES "$BPM_OUTPUT"/usr/share/licenses/linux-lts
}

package_linux-lts-headers() {
  local builddir="$BPM_OUTPUT"/usr/lib/modules/$(make -s kernelrelease)/build

  local karch
  case $CARCH in
    x86_64) karch=x86 ;;
    *) echo "Unknown CARCH $CARCH"; exit 1 ;;
  esac


  echo "Installing build files..."
  install -Dt "$builddir" -m644 .config Makefile Module.symvers System.map vmlinux tools/bpf/bpftool/vmlinux.h
  install -Dt "$builddir/kernel" -m644 kernel/Makefile
  install -Dt "$builddir/arch/$karch" -m644 arch/$karch/Makefile
  cp -t "$builddir" -a scripts
  ln -srt "$builddir" "$builddir/scripts/gdb/vmlinux-gdb.py"

  if [[ $(scripts/config -s CONFIG_HAVE_STACK_VALIDATION) = y ]]; then
    install -Dt "$builddir/tools/objtool" tools/objtool/objtool
  fi

  if [[ $(scripts/config -s CONFIG_DEBUG_INFO_BTF_MODULES) = y ]]; then
    install -Dt "$builddir/tools/bpf/resolve_btfids" tools/bpf/resolve_btfids/resolve_btfids
  fi

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

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

  install -Dt "$builddir/drivers/media/i2c" -m644 drivers/media/i2c/msp3400-driver.h

  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

  install -Dt "$builddir/drivers/iio/common/hid-sensors" -m644 drivers/iio/common/hid-sensors/*.h

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

  echo "Installing Rust files..."
  if [[ $(scripts/config -s CONFIG_RUST) = y ]]; then
    install -Dt "$builddir/rust" -m644 rust/*.rmeta
    install -Dt "$builddir/rust" rust/*.so
  fi

  echo "Installing unstripped VDSO..."
  make INSTALL_MOD_PATH="$BPM_OUTPUT"/usr vdso_install \
    link=  # Suppress build-id symlinks

  echo "Removing unneeded architectures..."
  local arch
  for arch in "$builddir"/arch/*/; do
    [[ $arch = */$karch/ ]] && 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 "$(file -Sib "$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 "Stripping vmlinux..."
  strip -v $STRIP_STATIC "$builddir/vmlinux"

  echo "Adding symlink..."
  mkdir -p "$BPM_OUTPUT"/usr/src
  ln -sr "$builddir" "$BPM_OUTPUT"/usr/src/linux-lts
}

package_linux-lts-docs() {
  # Install documentation
  install -d "$BPM_OUTPUT"/usr/share/doc/
  cp -r Documentation "$BPM_OUTPUT"/usr/share/doc/linux-lts

  # Install package licenses
  install -d "$BPM_OUTPUT"/usr/share/licenses
  ln -sf linux-lts "$BPM_OUTPUT"/usr/share/licenses/linux-lts-docs
}