# Maintainer: Maximilian Luz <luzmaximilian@gmail.com>
# Maintainer: Andreas Radke <andyrtr@archlinux.org>

pkgbase=linux-lts
pkgver=5.4.20
pkgrel=1
pkgdesc='LTS Linux'
url="https://www.kernel.org/"
arch=(x86_64)
license=(GPL2)
makedepends=(
  bc kmod libelf
)
options=('!strip')
_srcname=linux-$pkgver
source=(
  https://www.kernel.org/pub/linux/kernel/v${pkgver%%.*}.x/${_srcname}.tar.{xz,sign}
  config         # the main kernel config file

  surface.config
  0001-surface3-power.patch
  0002-surface3-spi.patch
  0003-surface3-oemb.patch
  0004-surface-sam.patch
  0005-surface-lte.patch
  0006-wifi.patch
  0007-ipts.patch
)
validpgpkeys=(
  'ABAF11C65A2970B130ABE3C479BE3E4300411886'  # Linus Torvalds
  '647F28654894E3BD457199BE38DBBDC86092693E'  # Greg Kroah-Hartman
)
# https://www.kernel.org/pub/linux/kernel/v5.x/sha256sums.asc
sha256sums=('793f6dcd9a7074dc61bbb092b40b3ce9567f776f21589ecd09f07bc9ed5c67bb'
            'SKIP'
            'f410ce12cf83e1642ac02e23689112d7a6027da79bec358ec9bf93e7e301cacc'

            'b6a2604183b5061a58025b309f1b7ad8af209a55a1534ea7b5325ca90aefcc34' # 0001-surface3-power.patch
            'c2d9f4058e772ebe2918e59f16d03e94173a694dc1dc9bec3e55a82d0b7e2949' # 0002-surface3-spi.patch
            '8ebec0cfb32e4c5364093186c58a2f8f6a02bfa17d6a9950257b9cc1b19fe70b' # 0003-surface3-oemb.patch
            '000fd10046d462627e41175608865642e39eddf6e300353017f8f21fcb0e4224' # 0004-ioremap_uc.patch
            '641ea3a9c4a6cc4754e34c7f635aa5dfe6741f108333d70326370129c1b25055' # 0005-surface-sam.patch
            '03b7c1ac1d5ee144e03d645eb88736a4812e362646c093bfd523a30655289400' # 0006-surface-lte.patch
            '1350f40163f3a2f91fccb0e87a3f93e4ee47f1c431714e64cbaf49ae1ae689c8' # 0007-wifi.patch
)

export KBUILD_BUILD_HOST=archlinux
export KBUILD_BUILD_USER=$pkgbase
export KBUILD_BUILD_TIMESTAMP="$(date -Ru${SOURCE_DATE_EPOCH:+d @$SOURCE_DATE_EPOCH})"

# optional certificate and key for secure boot signing
_mok_crt="$PWD/MOK.crt"
_mok_key="$PWD/MOK.key"

prepare() {
  cd $_srcname

  echo "Setting version..."
  scripts/setlocalversion --save-scmversion
  echo "-$pkgrel" > localversion.10-pkgrel
  echo "${pkgbase#linux}" > localversion.20-pkgname

  local src
  for src in "${source[@]}"; do
    src="${src%%::*}"
    src="${src##*/}"
    [[ $src = *.patch ]] || continue
    echo "Applying patch $src..."
    patch -Np1 < "../$src"
  done

  echo "Setting config..."
  # cp ../config .config
  # merge the two configs together
  ./scripts/kconfig/merge_config.sh -m ../config ../surface.config
  make olddefconfig

  make -s kernelrelease > version
  echo "Prepared $pkgbase version $(<version)"
}

build() {
  cd $_srcname
  make bzImage modules
}

_package() {
  pkgdesc="The $pkgdesc kernel and modules"
  depends=(coreutils kmod initramfs)
  optdepends=('crda: to set the correct wireless channels of your country'
              'linux-firmware: firmware images needed for some devices')

  cd $_srcname
  local kernver="$(<version)"
  local modulesdir="$pkgdir/usr/lib/modules/$kernver"
  local image_name="$(make -s image_name)"

  # sign boot image if the prequisites are available
  if [[ -f "$_mok_crt" ]] && [[ -f "$_mok_key" ]] && [[ -x "$(command -v sbsign)" ]]; then
    echo "Signing boot image..."
    sbsign --key "$_mok_key" --cert "$_mok_crt" --output "$image_name" "$image_name"
  fi

  echo "Installing boot image..."
  # systemd expects to find the kernel here to allow hibernation
  # https://github.com/systemd/systemd/commit/edda44605f06a41fb86b7ab8128dcf99161d2344
  install -Dm644 "$image_name" "$modulesdir/vmlinuz"

  # Used by mkinitcpio to name the kernel
  echo "$pkgbase" | install -Dm644 /dev/stdin "$modulesdir/pkgbase"

  echo "Installing modules..."
  make INSTALL_MOD_PATH="$pkgdir/usr" modules_install

  # remove build and source links
  rm "$modulesdir"/{source,build}

  echo "Fixing permissions..."
  chmod -Rc u=rwX,go=rX "$pkgdir"
}

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

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

  echo "Installing build files..."
  install -Dt "$builddir" -m644 .config Makefile Module.symvers System.map \
    localversion.* version vmlinux
  install -Dt "$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"

  echo "Fixing permissions..."
  chmod -Rc u=rwX,go=rX "$pkgdir"
}

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

# vim:set ts=8 sts=2 sw=2 et: