# Maintainer: Josip Ponjavic <josipponjavic at gmail dot com>
# Contributor:

### BUILD OPTIONS
# Set the next two variables to ANYTHING that is not null to enable them

# Tweak kernel options prior to a build via nconfig
: "${_makenconfig:=""}"

# Only compile active modules to VASTLY reduce 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 a try: https://aur.archlinux.org/packages/modprobed-db
# This PKGBUILD reads the database kept if it exists
#
# More at this wiki page ---> https://wiki.archlinux.org/index.php/Modprobed-db
: "${_localmodcfg:=""}"

# Optionally select a sub architecture by number or leave blank which will
# require user interaction during the build. Note that the generic (default)
# option is 40.
#
#  1. AMD Opteron/Athlon64/Hammer/K8 (MK8)
#  2. AMD Opteron/Athlon64/Hammer/K8 with SSE3 (MK8SSE3)
#  3. AMD 61xx/7x50/PhenomX3/X4/II/K10 (MK10)
#  4. AMD Barcelona (MBARCELONA)
#  5. AMD Bobcat (MBOBCAT)
#  6. AMD Jaguar (MJAGUAR)
#  7. AMD Bulldozer (MBULLDOZER)
#  8. AMD Piledriver (MPILEDRIVER)
#  9. AMD Steamroller (MSTEAMROLLER)
#  10. AMD Excavator (MEXCAVATOR)
#  11. AMD Zen (MZEN)
#  12. AMD Zen 2 (MZEN2)
#  13. AMD Zen 3 (MZEN3)
#  14. AMD Zen 4 (MZEN4)
#  15. Intel P4 / older Netburst based Xeon (MPSC)
#  16. Intel Core 2 (MCORE2)
#  17. Intel Atom (MATOM)
#  18. Intel Nehalem (MNEHALEM)
#  19. Intel Westmere (MWESTMERE)
#  20. Intel Silvermont (MSILVERMONT)
#  21. Intel Goldmont (MGOLDMONT)
#  22. Intel Goldmont Plus (MGOLDMONTPLUS)
#  23. Intel Sandy Bridge (MSANDYBRIDGE)
#  24. Intel Ivy Bridge (MIVYBRIDGE)
#  25. Intel Haswell (MHASWELL)
#  26. Intel Broadwell (MBROADWELL)
#  27. Intel Skylake (MSKYLAKE)
#  28. Intel Skylake X (MSKYLAKEX)
#  29. Intel Cannon Lake (MCANNONLAKE)
#  30. Intel Ice Lake (MICELAKE)
#  31. Intel Cascade Lake (MCASCADELAKE)
#  32. Intel Cooper Lake (MCOOPERLAKE)
#  33. Intel Tiger Lake (MTIGERLAKE)
#  34. Intel Sapphire Rapids (MSAPPHIRERAPIDS)
#  35. Intel Rocket Lake (MROCKETLAKE)
#  36. Intel Alder Lake (MALDERLAKE)
#  37. Intel Raptor Lake (MRAPTORLAKE)
#  38. Intel Meteor Lake (MMETEORLAKE)
#  39. Intel Emerald Rapids (MEMERALDRAPIDS)
#  40. Generic-x86-64 (GENERIC_CPU)
#  41. Generic-x86-64-v2 (GENERIC_CPU2)
#  42. Generic-x86-64-v3 (GENERIC_CPU3)
#  43. Generic-x86-64-v4 (GENERIC_CPU4)
#  44. Intel-Native optimizations autodetected by the compiler (MNATIVE_INTEL)
#  45. AMD-Native optimizations autodetected by the compiler (MNATIVE_AMD)
_subarch=40
: "${_subarch:=""}"

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

_major=6.1
_minor=46
_rtpatchver=13
_clr=${_major}.38-105
_gcc_more_v='20230105'
_srcname=linux-${_major}.${_minor}
pkgbase=linux-clear-preempt-rt
pkgver=${_major}.${_minor}
pkgrel=1
pkgdesc='Clear Linux Preempt-RT'
arch=('x86_64')
url="https://github.com/clearlinux-pkgs/linux-preempt-rt"
license=('GPL2')
makedepends=('bc' 'cpio' 'git' 'libelf' 'pahole' 'xmlto')
options=('!strip')
source=(
  "https://cdn.kernel.org/pub/linux/kernel/v6.x/linux-${_major}.${_minor}.tar.xz"
  "https://cdn.kernel.org/pub/linux/kernel/v6.x/linux-${_major}.${_minor}.tar.sign"
  "https://cdn.kernel.org/pub/linux/kernel/projects/rt/${_major}/patch-${_major}.46-rt${_rtpatchver}.patch.xz"
  "$pkgbase::git+https://github.com/clearlinux-pkgs/linux-preempt-rt.git#tag=${_clr}"
  "more-uarches-$_gcc_more_v.tar.gz::https://github.com/graysky2/kernel_compiler_patch/archive/$_gcc_more_v.tar.gz"
)

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}

    ### Add upstream patches
    echo "Add upstream patches"
    patch -Np1 -i ../patch-${_major}.46-rt${_rtpatchver}.patch

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

    ### Add Clearlinux patches
    for i in $(grep '^Patch' ${srcdir}/$pkgbase/linux-preempt-rt.spec |\
        grep -Ev '^Patch0000|^Patch0110|^Patch0112|^Patch0114|^Patch0123|^Patch0127' | sed -n 's/.*: //p'); do
        echo "Applying patch ${i}..."
        patch -Np1 -i "$srcdir/$pkgbase/${i}"
    done

    ### Setting config
    echo "Setting config..."
    cp -Tf $srcdir/$pkgbase/config ./.config

    ### Enable extra stuff from arch kernel
    echo "Enable extra stuff from arch kernel..."

    # General setup
    scripts/config --set-str DEFAULT_HOSTNAME archlinux \
                   --enable IKCONFIG \
                   --enable IKCONFIG_PROC

    # Power management and ACPI options
    scripts/config --enable ACPI_REV_OVERRIDE_POSSIBLE \
                   --enable ACPI_TABLE_UPGRADE

    # General architecture-dependent options
    scripts/config --enable KPROBES

    # Enable loadable module support
    scripts/config --undefine MODULE_SIG_FORCE \
                   --undefine MODULE_COMPRESS_NONE \
                   --enable MODULE_COMPRESS_ZSTD

    # Networking support
    scripts/config --enable NETFILTER_INGRESS \
                   --module NET_SCH_CAKE

    # Device Drivers
    scripts/config --enable FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER \
                   --enable DELL_SMBIOS_SMM \
                   --module PATA_JMICRON \
                   --enable-after SOUND SOUND_OSS_CORE \
                   --enable SND_OSSEMUL \
                   --module-after SND_OSSEMUL SND_MIXER_OSS \
                   --module-after SND_MIXER_OSS SND_PCM_OSS \
                   --enable-after SND_PCM_OSS SND_PCM_OSS_PLUGINS \
                   --enable FW_LOADER_COMPRESS

    # Kernel hacking -> Compile-time checks and compiler options -> Make section mismatch errors non-fatal
    scripts/config --enable SECTION_MISMATCH_WARN_ONLY

    # Security options
    scripts/config --enable SECURITY_SELINUX \
                   --enable SECURITY_SELINUX_BOOTPARAM \
                   --enable SECURITY_SMACK \
                   --enable SECURITY_SMACK_BRINGUP \
                   --enable SECURITY_SMACK_NETFILTER \
                   --enable SECURITY_SMACK_APPEND_SIGNALS \
                   --enable SECURITY_TOMOYO \
                   --enable SECURITY_APPARMOR \
                   --enable SECURITY_YAMA

    # Library routines
    scripts/config --enable FONT_TER16x32

    make olddefconfig
    diff -u $srcdir/$pkgbase/config .config || :

    # https://github.com/graysky2/kernel_compiler_patch
    # make sure to apply after olddefconfig to allow the next section
    echo "Patching to enable GCC optimization for other uarchs..."
    patch -Np1 -i "$srcdir/kernel_compiler_patch-$_gcc_more_v/more-uarches-for-kernel-5.17+.patch"

    if [ -n "$_subarch" ]; then
        # user wants a subarch so apply choice defined above interactively via 'yes'
        yes "$_subarch" | make oldconfig
    else
        # no subarch defined so allow user to pick one
        make oldconfig
    fi

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

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

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

    ### Save configuration for later reuse
    cp -Tf ./.config "${startdir}/config-${pkgver}-${pkgrel}${pkgbase#linux}"
}

build() {
    cd ${_srcname}
    make all
}

_package() {
    pkgdesc="The $pkgdesc kernel and modules"
    depends=('coreutils' 'kmod' 'initramfs')
    optdepends=('wireless-regdb: to set the correct wireless channels of your country'
                'linux-firmware: firmware images needed for some devices'
                'modprobed-db: Keeps track of EVERY kernel module that has ever been probed - useful for those of us who make localmodconfig')
    provides=(VIRTUALBOX-GUEST-MODULES WIREGUARD-MODULE)
    install=linux.install

    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 ${BUILD_FLAGS[*]} INSTALL_MOD_PATH="$pkgdir/usr" INSTALL_MOD_STRIP=1 \
        DEPMOD=/doesnt/exist modules_install  # Suppress depmod

    # remove build and source links
    rm "$modulesdir"/{source,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 "$builddir" -m644 .config Makefile Module.symvers System.map \
        localversion.* version vmlinux
    install -Dt "$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 "$(file -Sib "$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"
}

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

sha256sums=('f5f67bcfccd47f8d9db2d5ba24e33af7778f40a777577d1fba424f4a1712a296'
            'SKIP'
            'df29cf27bb7ef0b7750f541d959b791905a5d41a322896f9a4bb57b5ab00f202'
            'SKIP'
            '802946f623c69ae1a636b63697c23ca48af31a099415ed837d2c1e168a272d23')

validpgpkeys=(
  'ABAF11C65A2970B130ABE3C479BE3E4300411886'  # Linus Torvalds
  '647F28654894E3BD457199BE38DBBDC86092693E'  # Greg Kroah-Hartman
)