#!/usr/bin/env bash
# Copyright (c) 2000-2020 Synology Inc. All rights reserved.

# shellcheck source=/dev/null
source "SynoBuildConf/_env"
source "SynoBuildConf/_kconfig"


case ${MakeClean:-} in
    [Yy][Ee][Ss])
        make distclean
        ;;
esac

case ${CleanOnly:-} in
    [Yy][Ee][Ss])
        return
        ;;
esac

build_public_key()
{
    # shellcheck disable=SC2154
    # lnxscripts/include/applyEnv: SysRootInclude="${ToolChainSysRoot}/usr/include"
    # lnxscripts/include/platforms: KernelDir="/source/${SYNO_KERNEL_SOURCE_DIR}"
    if [ "$PLATFORM_FAMILY" = "SYNOPLAT_F_X86_64" ]; then
        ln -fsv "$SysRootInclude/hydrogen/hydrogen.h" "$KernelDir/include/crypto/hydrogen.h"
        ln -fsv "$SysRootInclude/hydrogen/hydrogen.c" "$KernelDir/crypto/hydrogen/hydrogen.c"
        ln -fsv "$SysRootInclude/hydrogen/impl" "$KernelDir/crypto/hydrogen/impl"
        sed -i "s/__RAMDISK_SIGN_PUBLIC_KEY__/$(cat < "$ScriptsDir/config/rd_sign.pub" | xxd -i -c 32)/" \
               "$KernelDir/init/initramfs.c"
    fi
}

build_certification()
{
    ln -fsv "$ScriptsDir/config/signing_key.pem" "$KernelDir/synology/certs/signing_key.pem"
    ln -fsv "$ScriptsDir/config/trusted_certificates.pem" "$KernelDir/synology/certs/trusted_certificates.pem"
}

build_seed()
{
    # shellcheck disable=SC2154
    # lnxscripts/include/platforms: KernelDir="/source/${SYNO_KERNEL_SOURCE_DIR}"
    if [ "$PLATFORM_FAMILY" = "SYNOPLAT_F_X86_64" ]; then
        DECOMPRESSION_TYPE=$(shuf -i 1001-2147483647 -n 1)
        sed -i "s/__DECOMPRESSION_TYPE__/${DECOMPRESSION_TYPE}/" \
            "${KernelDir}/arch/x86/boot/compressed/head_64.S"
        sed -i "s/__DECOMPRESSION_TYPE__/${DECOMPRESSION_TYPE}/" \
            "${KernelDir}/lib/synolib/syno_kexec_test.c"
    fi
}

build_version()
{
    local _protect_ver _dsm_ver

    if [ -f "${VERSION_FILE:-/source/synoversion/VERSION}" ]; then
        # originally ".version" is updated by scripts/link-vmlinux.sh
        # we forcely overwrite it with DSM build number at every build.
        echo $(($(GetDSMBuildNumber) - 1)) > ".version"
    fi

    [ -f ".debug" ] || return

    _protect_ver="$(dpkg -l | grep "synoprotection-$PLATFORM_ABBR-" | awk '{print $3}' | cut -d'-' -f2 | head -n1)"
    _dsm_ver="$(GetDSMBuildNumber)"
    if [ -z "$_protect_ver" ]; then
        ERROR "Unable to detect dpkg 'synoprotection'"
        exit 1
    fi
    if [ "$_dsm_ver" != "$_protect_ver" ]; then
        ERROR "buildnumber in synoversion/VERSION doesn't match dpkg 'synoprotection'"
        exit 1
    fi

}

# shellcheck disable=SC2086
build_kernel()
{
    [ -f ".config" ] || return 1

    make prepare $MAKE_FLAGS
    make vmlinux $MAKE_FLAGS
    make modules $MAKE_FLAGS
    make "$(platform_target)" $MAKE_FLAGS

}

# shellcheck disable=SC2086
build_device_tree()
{
    # Usually only arm platform needs this action
    if [ "$BUILD_TARGET" = "REALTEK_RTD1619B" ]; then
        make $MAKE_FLAGS dtbs
    fi
}


INFO "Generate .config for architecture $ARCH platform $PLATFORM_ABBR"
kconfig_generate

# INFO "Copying signing_key and certification from build system"
# build_certification

# build_public_key
# build_seed
build_version

INFO "Build Synology linux kernel $(make -s kernelversion)"
build_kernel

INFO "Build device tree"
build_device_tree

INFO "Compare kernel config with re-generated one"
kconfig_check_diff

INFO "Check Synology kernel configs"
kconfig_check_syno_macro
kconfig_check_rule