# Maintainer: Jan Alexander Steffens (heftig) <heftig@archlinux.org>
pkgbase=linux-custom-ultimate
pkgver=6.12.1.arch1
pkgrel=1
pkgdesc='Linux'
arch=(x86_64)
license=(GPL-2.0-only)
makedepends=(
  bc
  cpio
  gettext
  libelf
  pahole
  perl
  python
  tar
  xz

  # htmldocs
  graphviz
  imagemagick
  python-sphinx
  python-yaml
  texlive-latexextra
)
options=(
  !debug
  !strip
)
_srcname=linux-${pkgver%.*}
_srctag=v${pkgver%.*}-${pkgver##*.}
source=(
  https://cdn.kernel.org/pub/linux/kernel/v${pkgver%%.*}.x/${_srcname}.tar.xz
  config  # the main kernel config file
  defaultmaxASLR.patch
)
# https://www.kernel.org/pub/linux/kernel/v6.x/sha256sums.asc
md5sums=('f541bbef36e51ba1e7165137fe1186db'
         '4884706db6e5843370de9362e1742ee9'
         '7c0ac5bcdae16821cc24be558f18d144')
sha1sums=('3cb9a1a5d0c53d6a5fc5cd9438a36330151b4e5f'
          '26552825e6ee5c65244e63560c0a2b43ece6f392'
          'cd8e93c882a6a52e87a4c47caeaabd1261dc3a62')
sha256sums=('0193b1d86dd372ec891bae799f6da20deef16fc199f30080a4ea9de8cef0c619'
            '92164a6674440aa761aef94a429a55909162ee4806937544549590b67312ac55'
            '9f29efd7acf37d8e3015029216865fb590362d9589feb91dc84e68fee6dabff0')
b2sums=('de3f4dec2fc7e36711c68683d6564d0c3ce6fe728ffa6a629604e2fa9e489dbab45fd6676343f6e68bafbd202a3e814e82a1448b46844e34046b9f82f819b8f4'
        '47c8b74829e086d080c0dd0d9a033dd4894ee1d7473acb6fe254a6b5b3d0cf4e01ce3967eaca843d126f1ce54fade4f3ae64f2df29719cff88702d5e4cd2ca4f'
        '30f9ecc8011b67e89166a01cf15c6994ba72cb7277cf8cce3461db66c3f0dfa77f396976dc82b6b78c723845282ea721a07a8fb1f3baff43dbf46bee10940b1a')
export KBUILD_BUILD_HOST=archlinux
export KBUILD_BUILD_USER=$pkgbase
export KBUILD_BUILD_TIMESTAMP="$(date -Ru${SOURCE_DATE_EPOCH:+d @$SOURCE_DATE_EPOCH})"

prepare() {
  cd $_srcname

  echo "Setting version..."
  echo "-$pkgrel" > localversion.10-pkgrel
  echo "${pkgbase#linux}" > localversion.20-pkgname

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

  echo "Setting config..."
  cp ../config .config
  make oldconfig

  diff -u ../config .config || :

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

build() {
  cd $_srcname
  make all
  make -C tools/bpf/bpftool vmlinux.h feature-clang-bpf-co-re=1
}

_package() {
  pkgdesc="The $pkgdesc kernel and modules"
  depends=(
    coreutils
    initramfs
    kmod
  )
  optdepends=(
    'wireless-regdb: to set the correct wireless channels of your country'
    'linux-firmware: firmware images needed for some devices'
  )
  provides=(
    KSMBD-MODULE
    VIRTUALBOX-GUEST-MODULES
    WIREGUARD-MODULE
  )
  replaces=(
    virtualbox-guest-modules-arch
    wireguard-arch
  )

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

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

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

  echo "Installing modules..."
  ZSTD_CLEVEL=19 make INSTALL_MOD_PATH="$pkgdir/usr" INSTALL_MOD_STRIP=1 \
    DEPMOD=/doesnt/exist modules_install  # Suppress depmod

  # remove build link
  rm "$modulesdir"/build
}

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

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

  echo "Installing build files..."
  install -Dt "$builddir" -m644 .config Makefile Module.symvers System.map \
    localversion.* version vmlinux tools/bpf/bpftool/vmlinux.h
  install -Dt "$builddir/kernel" -m644 kernel/Makefile
  install -Dt "$builddir/arch/x86" -m644 arch/x86/Makefile
  cp -t "$builddir" -a scripts

  # required when STACK_VALIDATION is enabled
  install -Dt "$builddir/tools/objtool" tools/objtool/objtool

  # required when DEBUG_INFO_BTF_MODULES is enabled
  install -Dt "$builddir/tools/bpf/resolve_btfids" tools/bpf/resolve_btfids/resolve_btfids

  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

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

  # https://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

  # https://bugs.archlinux.org/task/71392
  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 "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 "$(file -Sib "$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 "$pkgdir/usr/src"
  ln -sr "$builddir" "$pkgdir/usr/src/$pkgbase"
}

_package-docs() {
  pkgdesc="Documentation for the $pkgdesc kernel"

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

  echo "Installing documentation..."
  local src dst
  while read -rd '' src; do
    dst="${src#Documentation/}"
    dst="$builddir/Documentation/${dst#output/}"
    install -Dm644 "$src" "$dst"
  done < <(find Documentation -name '.*' -prune -o ! -type d -print0)

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

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: