# Maintainer: Leonidas Spyropoulos <artafinde AT gmail DOT com>
# Credit to graysky for shamelessly copying PKGBUILD from linux-ck

### BUILD OPTIONS
# Set these variables to ANYTHING that is not null to enable them

# Tweak kernel options prior to a build via nconfig
_makenconfig=

# Compile ONLY used modules to VASTLYreduce the number of modules built
# and the build time.
#
# To keep track of which modules are needed for your specific system/hardware,
# give module_db script a try: https://aur.archlinux.org/packages/modprobed-db
# This PKGBUILD read the database kept if it exists
#
# More at this wiki page ---> https://wiki.archlinux.org/index.php/Modprobed-db
_localmodcfg=

### IMPORTANT: Do no edit below this line unless you know what you're doing

pkgbase=linux-gc
pkgver=5.6.4
pkgrel=1
pkgdesc='Linux'
url="https://cchalpha.blogspot.co.uk/"
arch=(x86_64)
license=(GPL2)
makedepends=(
  bc kmod libelf
  xmlto python-sphinx python-sphinx_rtd_theme graphviz imagemagick
  git
)
options=('!strip')
_srcname=linux-${pkgver}
_bmqversion=5.6-r2
_bmq_patch="bmq_v${_bmqversion}.patch"
_gcc_more_v='20191217'
source=(
  "https://www.kernel.org/pub/linux/kernel/v5.x/linux-$pkgver.tar".{xz,sign}
  config         # the main kernel config file
  "${_bmq_patch}::https://gitlab.com/alfredchen/bmq/raw/master/${_bmqversion%-*}/${_bmq_patch}"
  "enable_additional_cpu_optimizations-${_gcc_more_v}.tar.gz::https://github.com/graysky2/kernel_gcc_patch/archive/${_gcc_more_v}.tar.gz"
  "0001-ZEN-Add-sysctl-and-CONFIG-to-disallow-unprivileged-C.patch::https://github.com/archlinux/linux/commit/cdc8cdae459c2ca60fd4d3ddf78e4568bb741d2d.patch"
  "0002-ALSA-hda-Fix-potential-access-overflow-in-beep-helpe.patch::https://github.com/archlinux/linux/commit/080da567cf3c1935204c2a88b580ce5f85a622a2.patch"
)
validpgpkeys=(
  'ABAF11C65A2970B130ABE3C479BE3E4300411886'  # Linus Torvalds
  '647F28654894E3BD457199BE38DBBDC86092693E'  # Greg Kroah-Hartman
  '8218F88849AAC522E94CF470A5E9288C4FA415FA'  # Jan Alexander Steffens (heftig)
)
sha256sums=('5df1741e550cb6fa7471530f42da98bac5093e693e2c4f3aef4393d8135b9d91'
            'SKIP'
            '27b84575ea6b1050951906e0b595351fe3f8e39fab9d2ed05e32cb6eaddca08f'
            '0e1b569bf16a6c514710715eff06df04447378d1c067b853db0c454ac3c5e463'
            '7a4a209de815f4bae49c7c577c0584c77257e3953ac4324d2aa425859ba657f5'
            'da555d4f3ecd3511b5dbe4063262c9f0b350d0256e43735bd753dfc0bd1b3a2c'
            '20631caf830d12e401608ba2dee9408b256b255b732a980fd46fba87e5c1cf54')

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

prepare() {
  cd $_srcname

  echo "Setting version..."
  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 = 0*.patch ]] || continue
    echo "Applying patch $src..."
    patch -Np1 < "../$src"
  done

  echo "Applying patch ${_bmq_patch}..."
  patch -Np1 -i "$srcdir/${_bmq_patch}"


  echo "Setting config..."
  cp ../config .config

  # https://github.com/graysky2/kernel_gcc_patch
  echo "Applying enable_additional_cpu_optimizations-${_gcc_more_v}..."
  patch -Np1 -i "$srcdir/kernel_gcc_patch-$_gcc_more_v/enable_additional_cpu_optimizations_for_gcc_v9.1+_kernel_v5.5+.patch"

  make prepare

  ### Optionally load needed modules for the make localmodconfig
  # See https://aur.archlinux.org/packages/modprobed-db
  if [ -n "$_localmodcfg" ]; then
    if [ -f $HOME/.config/modprobed.db ]; then
      echo "Running Steven Rostedt's make localmodconfig now"
      make LSMOD=$HOME/.config/modprobed.db localmodconfig
    else
      echo "No modprobed.db data found"
      exit
    fi
  fi

  # do not run `make olddefconfig` as it sets default options
  yes "" | make config >/dev/null

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

  [[ -z "$_makenconfig" ]] || make nconfig

  # save configuration for later reuse
  cat .config > "${startdir}/config.last"
}

build() {
  cd $_srcname
  make all
}

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

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

  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..."
  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 $pkgdesc kernel"
  depends=('linux-gc')
  provides=("linux-gc-headers=${pkgver}" "linux-headers=${pkgver}")

  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: