# Maintainer: MischievousTomat <mischievoustomato at protonmail dot com>
# Contributor: Joan Figueras <ffigue at gmail dot com>
# Contributor: Torge Matthies <openglfreak at googlemail dot com>
# Contributor: Jan Alexander Steffens (heftig) <jan.steffens@gmail.com>
# Contributor: Yoshi2889 <rick.2889 at gmail dot com>
# Contributor: Tobias Powalowski <tpowa@archlinux.org>
# Contributor: Thomas Baechler <thomas@archlinux.org>

## Set 98 (Intel native) or 99 (AMD native)
if [ -z ${_microarchitecture+x} ]; then
  _microarchitecture=0
fi

## Disable NUMA since most users do not have multiple processors. Breaks CUDA/NvEnc.
## Archlinux and Xanmod enable it by default.
## Set variable "use_numa" to: n to disable (possibly increase performance)
##                             y to enable  (stock default)
if [ -z ${use_numa+x} ]; then
  use_numa=y
fi

## For performance you can disable FUNCTION_TRACER/GRAPH_TRACER. Limits debugging and analyzing of the kernel.
## Stock Archlinux and Xanmod have this enabled. 
## Set variable "use_tracers" to: n to disable (possibly increase performance)
##                                y to enable  (stock default)
if [ -z ${use_tracers+x} ]; then
  use_tracers=y
fi

## Choose between GCC and CLANG config (default is GCC)
if [ -z ${_compiler+x} ]; then
  _compiler=gcc
fi

# Compress modules with ZSTD (to save disk space)
if [ -z ${_compress_modules+x} ]; then
  _compress_modules=y
fi

pkgbase=linux-cpu-optimized
_major=5.14
_minor=14
pkgver=${_major}.${_minor}
_branch=5.x
pkgrel=1
pkgdesc='Linux with cpu optimizations'
url="https://kernel.org/"
arch=(x86_64)
license=(GPL2)
makedepends=(
  bc kmod libelf pahole cpio perl tar xz
  xmlto python-sphinx python-sphinx_rtd_theme graphviz imagemagick
  git
)
options=('!strip')
_srcname="linux-${pkgver}-cpu-optimized${pkgrel}"
source=(
  "https://cdn.kernel.org/pub/linux/kernel/v${_branch}/linux-${_major}.${_minor}.tar."{xz,sign}
  config         # the main kernel config file
  "https://raw.githubusercontent.com/graysky2/kernel_compiler_patch/master/more-uarches-for-kernel-5.8-5.14.patch"
  choose-gcc-optimization.sh
)
validpgpkeys=(
  'ABAF11C65A2970B130ABE3C479BE3E4300411886'  # Linus Torvalds
  '647F28654894E3BD457199BE38DBBDC86092693E'  # Greg Kroah-Hartman
  'A2FF3A36AAA56654109064AB19802F8B0D70FC30'  # Jan Alexander Steffens (heftig)
  'C7E7849466FE2358343588377258734B41C31549'  # David Runge <dvzrv@archlinux.org>
)

# Archlinux patches
#_commit="ec9e9a4219fe221dec93fa16fddbe44a34933d8d"
#_patches=()
#for _patch in ${_patches[@]}; do
    #source+=("${_patch}::https://git.archlinux.org/svntogit/packages.git/plain/trunk/${_patch}?h=packages/linux&id=${_commit}")
    #source+=("${_patch}::https://raw.gigthubusercontent.com/archlinux/svntogit-packages/${_commit}/trunk/${_patch}")
#done

sha256sums=('4dff4e96d4052195002538027f8a810411ba6116a41bff5575952702d509d06a'
            'SKIP'
            'be98ee1a3b9b4eaa547ca6d54692513d3073cdb776785c8608eb05afc259ac6d'
            '2f99d9e37f372925e054115bfead4723a328ffbdb7bf958753aab2ac48dc5673'
            '1ac18cad2578df4a70f9346f7c6fccbb62f042a0ee0594817fdef9f2704904ee')

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

prepare() {
  cd linux-${_major}.${_minor}

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

  # Patching
  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
  make olddefconfig
  diff -u ../config .config || :

  # CONFIG_STACK_VALIDATION gives better stack traces. Also is enabled in all official kernel packages by Archlinux team
  scripts/config --enable CONFIG_STACK_VALIDATION

  # Enable IKCONFIG following Arch's philosophy
  scripts/config --enable CONFIG_IKCONFIG \
                 --enable CONFIG_IKCONFIG_PROC

  # User set. See at the top of this file
  if [ "$use_tracers" = "n" ]; then
    msg2 "Disabling FUNCTION_TRACER/GRAPH_TRACER only if we are not compiling with clang..."
    if [ "${_compiler}" = "gcc" ]; then
      scripts/config --disable CONFIG_FUNCTION_TRACER \
                     --disable CONFIG_STACK_TRACER
    fi
  fi

  if [ "$use_numa" = "n" ]; then
    msg2 "Disabling NUMA..."
    scripts/config --disable CONFIG_NUMA
  fi

  # Compress modules by default (following Arch's kernel)
  if [ "$_compress_modules" = "y" ]; then
    scripts/config --enable CONFIG_MODULE_COMPRESS_ZSTD
  fi

  # Let's user choose microarchitecture optimization in GCC
  sh ${srcdir}/choose-gcc-optimization.sh $_microarchitecture

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

build() {
  cd linux-${_major}.${_minor}
  make all
  
}

_package() {
  pkgdesc="The linux-cpu-optimized 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')
  provides=(VIRTUALBOX-GUEST-MODULES WIREGUARD-MODULE)
  replaces=(virtualbox-guest-modules-arch wireguard-arch)

  cd linux-${_major}.${_minor}
  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" INSTALL_MOD_STRIP=1 modules_install

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

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

  cd linux-${_major}.${_minor}
  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

  # 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 "$(file -bi "$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 "Stripping vmlinux..."
  strip -v $STRIP_STATIC "$builddir/vmlinux"

  echo "Adding symlink..."
  mkdir -p "$pkgdir/usr/src"
  ln -sr "$builddir" "$pkgdir/usr/src/$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: