# Maintainer:  Joakim Hernberg <jbh@alchemy.lu>
# Contributor: David Runge <dave@sleepmap.de>
# Contributor: Ray Rashif <schiv@archlinux.org>
# Contributor: timbosa <tinny_tim@dodo.com.au>
# Contributor: Jan Alexander Steffens (heftig) <jan.steffens@gmail.com>
# Contributor: Tobias Powalowski <tpowa@archlinux.org>
# Contributor: Thomas Baechler <thomas@archlinux.org>

#pkgbase=linux               # Build stock -ARCH kernel
pkgbase=linux-rt-lts       # Build kernel with a different name
_pkgver=4.19.72
_rtpatchver=rt25
pkgver=${_pkgver}_${_rtpatchver}
pkgrel=1
arch=('x86_64')
url="https://wiki.linuxfoundation.org/realtime/start"
license=('GPL2')
makedepends=('bc' 'git' 'inetutils' 'kmod' 'libelf' 'xmlto')
options=('!strip')
_srcname=linux-${_pkgver}
source=(
  "https://www.kernel.org/pub/linux/kernel/v4.x/linux-${_pkgver}.tar.xz"
  "https://www.kernel.org/pub/linux/kernel/v4.x/linux-${_pkgver}.tar.sign"
  "https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patch-${_pkgver}-${_rtpatchver}.patch.xz"
  "https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patch-${_pkgver}-${_rtpatchver}.patch.sign"
  0001-add-sysctl-to-disallow-unprivileged-CLONE_NEWUSER-by.patch
  0002-ZEN-Add-CONFIG-for-unprivileged_userns_clone.patch
  config         # the main kernel config file
  60-${pkgbase}.hook  # pacman hook for depmod
  90-${pkgbase}.hook  # pacman hook for initramfs regeneration
  ${pkgbase}.preset   # standard config files for mkinitcpio ramdisk
)
validpgpkeys=(
  'ABAF11C65A2970B130ABE3C479BE3E4300411886'  # Linus Torvalds
  '647F28654894E3BD457199BE38DBBDC86092693E'  # Greg Kroah-Hartman
  '8218F88849AAC522E94CF470A5E9288C4FA415FA'  # Jan Alexander Steffens (heftig)
  '64254695FFF0AA4466CC19E67B96E8162A8CF5D1'  # Sebastian Andrzej Siewior
  '5ED9A48FC54C0A22D1D0804CEBC26CDB5A56DE73'  # Steven Rostedt
  'E644E2F1D45FA0B2EAA02F33109F098506FF0B14'  # Thomas Gleixner
)
sha256sums=('f9fcb6b3bd29115ac55fc154e300c3dce2044502732f6842ad6c25e6f9f51f6d'
            'SKIP'
            'ef5150a4c30c0342bf5e21e3ed8832a688ee6d871e1017ff43f46eb51aaa9453'
            'SKIP'
            '75aa8dd708ca5a0137fbf7cddc9cafefe6aac6b8e0638c06c156d412d05af4bc'
            '67aed9742e4281df6f0bd18dc936ae79319fee3763737f158c0e87a6948d100d'
            'e5a6ac3346c359353b3a7491bb77637870328a4bf3f3d57bf434a29b72632600'
            'ae2e95db94ef7176207c690224169594d49445e04249d2499e9d2fbc117a0b21'
            '75f99f5239e03238f88d1a834c50043ec32b1dc568f2cc291b07d04718483919'
            'ad6344badc91ad0630caacde83f7f9b97276f80d26a20619a87952be65492c65')

_kernelname=${pkgbase#linux}
: ${_kernelname:=-ARCH}

prepare() {
  cd $_srcname

  # apply realtime patch
  msg "applying patch-${_pkgver}-${_rtpatchver}.patch"
  patch -Np1 -i ../patch-${_pkgver}-${_rtpatchver}.patch

  msg2 "Setting version..."
  scripts/setlocalversion --save-scmversion
  echo "-$pkgrel" > localversion.10-pkgrel
  echo "$_kernelname" > localversion.20-pkgname

  local src
  for src in "${source[@]}"; do
    src="${src%%::*}"
    src="${src##*/}"
    [[ $src = *.patch ]] || continue
    msg2 "Applying patch $src..."
    patch -Np1 < "../$src"
  done

  msg2 "Setting config..."
  cp ../config .config
  make olddefconfig
#  make menuconfig # CLI menu for configuration

  make -s kernelrelease > ../version
  msg2 "Prepared %s version %s" "$pkgbase" "$(<../version)"
}

build() {
  cd $_srcname
  make bzImage modules
}

_package() {
  pkgdesc="The ${pkgbase/linux/Linux} kernel and modules"
  [[ $pkgbase = linux ]] && groups=(base)
  depends=(coreutils linux-firmware kmod mkinitcpio)
  optdepends=('crda: to set the correct wireless channels of your country')
  backup=("etc/mkinitcpio.d/$pkgbase.preset")
  install=${pkgbase}.install

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

  cd $_srcname

  msg2 "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"
  install -Dm644 "$modulesdir/vmlinuz" "$pkgdir/boot/vmlinuz-$pkgbase"

  msg2 "Installing modules..."
  make INSTALL_MOD_PATH="$pkgdir/usr" modules_install

  # a place for external modules,
  # with version file for building modules and running depmod from hook
  local extramodules="extramodules$_kernelname"
  local extradir="$pkgdir/usr/lib/modules/$extramodules"
  install -Dt "$extradir" -m644 ../version
  ln -sr "$extradir" "$modulesdir/extramodules"

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

  msg2 "Installing hooks..."
  # sed expression for following substitutions
  local subst="
    s|%PKGBASE%|$pkgbase|g
    s|%KERNVER%|$kernver|g
    s|%EXTRAMODULES%|$extramodules|g
  "

  # hack to allow specifying an initially nonexisting install file
  sed "$subst" "$startdir/$install" > "$startdir/$install.pkg"
  true && install=$install.pkg

  # fill in mkinitcpio preset and pacman hooks
  sed "$subst" ../${pkgbase}.preset | install -Dm644 /dev/stdin \
    "$pkgdir/etc/mkinitcpio.d/$pkgbase.preset"
  sed "$subst" ../60-${pkgbase}.hook | install -Dm644 /dev/stdin \
    "$pkgdir/usr/share/libalpm/hooks/60-$pkgbase.hook"
  sed "$subst" ../90-${pkgbase}.hook | install -Dm644 /dev/stdin \
    "$pkgdir/usr/share/libalpm/hooks/90-$pkgbase.hook"

  msg2 "Fixing permissions..."
  chmod -Rc u=rwX,go=rX "$pkgdir"
}

_package-headers() {
  pkgdesc="Header files and scripts for building modules for ${pkgbase/linux/Linux} kernel"

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

  cd $_srcname

  msg2 "Installing build files..."
  install -Dt "$builddir" -m644 Makefile .config Module.symvers System.map vmlinux
  install -Dt "$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}

  # ???
  mkdir "$builddir/.tmp_versions"

  msg2 "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

  msg2 "Installing KConfig files..."
  find . -name 'Kconfig*' -exec install -Dm644 {} "$builddir/{}" \;

  msg2 "Removing unneeded architectures..."
  local arch
  for arch in "$builddir"/arch/*/; do
    [[ $arch = */x86/ ]] && continue
    echo "Removing $(basename "$arch")"
    rm -r "$arch"
  done

  msg2 "Removing documentation..."
  rm -r "$builddir/Documentation"

  msg2 "Removing broken symlinks..."
  find -L "$builddir" -type l -printf 'Removing %P\n' -delete

  msg2 "Removing loose objects..."
  find "$builddir" -type f -name '*.o' -printf 'Removing %P\n' -delete

  msg2 "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)

  msg2 "Adding symlink..."
  mkdir -p "$pkgdir/usr/src"
  ln -sr "$builddir" "$pkgdir/usr/src/$pkgbase-$pkgver"

  msg2 "Fixing permissions..."
  chmod -Rc u=rwX,go=rX "$pkgdir"
}

_package-docs() {
  pkgdesc="Kernel hackers manual - HTML documentation that comes with the ${pkgbase/linux/Linux} kernel"

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

  cd $_srcname

  msg2 "Installing documentation..."
  mkdir -p "$builddir"
  cp -t "$builddir" -a Documentation

  msg2 "Adding symlink..."
  mkdir -p "$pkgdir/usr/share/doc"
  ln -sr "$builddir/Documentation" "$pkgdir/usr/share/doc/$pkgbase"

  msg2 "Fixing permissions..."
  chmod -Rc u=rwX,go=rX "$pkgdir"
}

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

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