diff --git a/arch/x86_64/src/intel64/intel64_cpupause.c b/arch/x86_64/src/intel64/intel64_cpupause.c
index 7f6891d24cabb..9d95e8f08dc47 100644
--- a/arch/x86_64/src/intel64/intel64_cpupause.c
+++ b/arch/x86_64/src/intel64/intel64_cpupause.c
@@ -286,9 +286,16 @@ int up_pause_handler(int irq, void *c, void *arg)
 
 int up_pause_async_handler(int irq, void *c, void *arg)
 {
+  struct tcb_s *tcb;
   int cpu = this_cpu();
 
+  tcb = current_task(cpu);
+  nxsched_suspend_scheduler(tcb);
+  x86_64_savestate(tcb->xcp.regs);
   nxsched_process_delivered(cpu);
+  tcb = current_task(cpu);
+  nxsched_resume_scheduler(tcb);
+  x86_64_restorestate(tcb->xcp.regs);
 
   return OK;
 }
diff --git a/boot.iso b/boot.iso
new file mode 100644
index 0000000000000..6cb15d3cfa992
Binary files /dev/null and b/boot.iso differ
diff --git a/tools/build.sh b/tools/build.sh
new file mode 100755
index 0000000000000..4b32fdc2ff232
--- /dev/null
+++ b/tools/build.sh
@@ -0,0 +1,529 @@
+#!/usr/bin/env bash
+# tools/build.sh
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+function cleanup()
+{
+  # keep the mapping but change to the link since:
+  # 1.root can't access mount point created by normal user
+  # 2.debugger could find the source code without manual setting
+  fusermount -u ${MOUNTDIR}
+  rmdir ${MOUNTDIR}
+  ln -s ${ROOTDIR} ${MOUNTDIR}
+}
+
+function mount_unionfs()
+{
+  echo -e "Mount command line:"
+  echo -e "  unionfs-fuse -o cow ${OUTDIR}=RW:${ROOTDIR}=RO ${MOUNTDIR}"
+
+  rm -f ${MOUNTDIR}
+  mkdir -p ${MOUNTDIR}
+  unionfs-fuse -o cow ${OUTDIR}=RW:${ROOTDIR}=RO ${MOUNTDIR}
+}
+
+function setup_environment()
+{
+  PACKAGES=( \
+      "autoconf" \
+      "automake" \
+      "bison" \
+      "build-essential" \
+      "dfu-util" \
+      "genromfs" \
+      "flex" \
+      "git" \
+      "gperf" \
+      "libncurses5" \
+      "lib32ncurses5-dev" \
+      "libc6-dev-i386" \
+      "libx11-dev" \
+      "libx11-dev:i386" \
+      "libxext-dev" \
+      "libxext-dev:i386" \
+      "net-tools" \
+      "pkgconf" \
+      "unionfs-fuse" \
+      "zlib1g-dev" \
+      "kconfig-frontends" \
+      "g++-11" \
+      "g++-11-multilib" \
+      "libpulse-dev:i386" \
+      "libasound2-dev:i386" \
+      "libasound2-plugins:i386" \
+      "libusb-1.0-0-dev" \
+      "libusb-1.0-0-dev:i386" \
+      "libv4l-dev" \
+      "libv4l-dev:i386" \
+      "libuv1-dev" \
+      "libmp3lame-dev:i386" \
+      "libmad0-dev:i386" \
+      "libv4l-dev:i386" \
+      "npm" \
+      "nodejs" \
+      "xxd" \
+      "qemu-system-arm" \
+      "qemu-efi-aarch64" \
+      "qemu-utils" \
+      "nasm" \
+      "yasm" \
+      "libdivsufsort-dev" \
+      "libc++-dev" \
+      "libc++abi-dev" \
+      "libprotobuf-dev" \
+      "protobuf-compiler" \
+      "protobuf-c-compiler" \
+      "gcc-multilib" \
+      "g++-multilib" \
+      "gettext" \
+      "mtools" \
+      )
+
+  for (( i = 0; i < ${#PACKAGES[*]}; i++)); do
+    dpkg -l ${PACKAGES[$i]} > /dev/null 2>&1
+    if [ $? -eq 1 ]; then
+      echo "WARNING: no packages found matching ${PACKAGES[$i]}"
+      INSTALLS[${#INSTALLS[@]}]=${PACKAGES[$i]}
+    fi
+  done
+
+  if [ ${#INSTALLS[*]} -eq 0 ]; then
+    return
+  fi
+
+  if [ ${#INSTALLS[*]} -eq 1 ] && [ "${INSTALLS[0]}" == "kconfig-frontends" ]; then
+    return
+  fi
+
+  echo "*************************************************************************************"
+  echo "The environment of Vela depends on above tools, Run the following command to install:"
+  echo ""
+  echo " sudo dpkg --add-architecture i386"
+
+  for (( i = 0; i < ${#INSTALLS[*]}; i++)); do
+    result=`apt-cache search ${INSTALLS[$i]}`
+    if [ "$result" == "" ]; then
+      if [ "${INSTALLS[$i]}" == "kconfig-frontends" ]; then
+        unset INSTALLS[$i]
+      fi
+    fi
+  done
+
+  echo " sudo apt-get install -y software-properties-common"
+  echo " sudo add-apt-repository ppa:ubuntu-toolchain-r/test"
+  echo " sudo apt-get update"
+  echo " sudo apt-get install -y ${INSTALLS[@]}"
+  echo ""
+  echo "*************************************************************************************"
+}
+
+function setup_toolchain()
+{
+  V='\033[0;97m'
+  E='\033[0;94m'
+  L='\033[0;96m'
+  A='\033[0;94m'
+  B='\033[0;34m'
+  N='\033[0m'
+  echo -e "${B}**""**""**""**""**""**""**""**""**""**""**""**""**""***${N}"
+  echo -e "${B}*${V} __      __   ${E}   ""${L}_ ${A}      "   " ${B}*${N}"
+  echo -e "${B}* ${V}\\ \\    / /${E}     ${L}| |${A}      "   " ${B}*${N}"
+  echo -e "${B}*  ${V}\\ \\  / /${E} ___  ${L}| |${A}  __ _"   " ${B}*${N}"
+  echo -e "${B}*   ${V}\\ \\/ /${E} / _ \\ ${L}| |${A} / _\` |" "${B}*${N}"
+  echo -e "${B}*    ${V}\\  / ${E}|  __/ ${L}| |${A}| (_| |"    "${B}*${N}"
+  echo -e "${B}*     ${V}\\/ ${E}  \\___| ${L}|_|${A} \\__,_|"  "${B}*${N}"
+  echo -e "${B}*           "                         "               *${N}"
+  echo -e "${B}**""**""**""**""**""**""**""**""**""**""**""**""**""***${N}"
+
+  SYSTEM=`uname | tr '[:upper:]' '[:lower:]'`
+  SYS_ARCH=`uname -m | sed 's/arm64/aarch64/'`
+
+  if [ ${SYSTEM} == "darwin" ]; then
+    export MACOSX_DEPLOYMENT_TARGET=11
+    BONJOUR=" Welcome, dear macOS user "
+    for ((i=0;i<${#BONJOUR};i++)); do
+      printf "\e[38;5;$(($RANDOM%213+19))m${BONJOUR:i:1}\e[0m"
+    done
+    echo #
+  fi
+
+  ARCH=(\
+      "xtensa" \
+      "arm" \
+      "arm64" \
+      "risc-v" \
+      "tc32" )
+
+  TOOLCHAIN=(\
+            "gcc" \
+            "clang" )
+
+  if [ "$XTENSAD_LICENSE_FILE" == "" ]; then
+    export XTENSAD_LICENSE_FILE=28000@10.38.168.2
+  fi
+  export WASI_SDK_PATH=${ROOTDIR}/prebuilts/clang/${SYSTEM}/wasm
+  export PATH=${WASI_SDK_PATH}:$PATH
+  export PYTHONPATH=${PYTHONPATH}:${ROOTDIR}/prebuilts/tools/python/dist-packages/pyelftools
+  export PYTHONPATH=${PYTHONPATH}:${ROOTDIR}/prebuilts/tools/python/dist-packages/cxxfilt
+  export PYTHONPATH=${PYTHONPATH}:${ROOTDIR}/prebuilts/tools/python/dist-packages/Mako
+  export PYTHONPATH=${PYTHONPATH}:${ROOTDIR}/prebuilts/tools/python/dist-packages/ply
+  export PYTHONPATH=${PYTHONPATH}:${ROOTDIR}/prebuilts/tools/python/dist-packages/jsonpath
+  export PYTHONPATH=${PYTHONPATH}:${ROOTDIR}/prebuilts/tools/python/dist-packages/kconfiglib
+  export PYTHONPATH=${PYTHONPATH}:${ROOTDIR}/prebuilts/tools/python/dist-packages/construct
+
+  # Recommended to use kconfiglib instead of kconfig-frontends
+  export PATH=${ROOTDIR}/prebuilts/tools/python/bin:$PATH
+
+  for (( i = 0; i < ${#ARCH[*]}; i++)); do
+    for (( j = 0; j < ${#TOOLCHAIN[*]}; j++)); do
+      if [ -d ${ROOTDIR}/prebuilts/${TOOLCHAIN[$j]}/${SYSTEM}-${SYS_ARCH}/${ARCH[$i]}/bin ]; then
+        export PATH=${ROOTDIR}/prebuilts/${TOOLCHAIN[$j]}/${SYSTEM}-${SYS_ARCH}/${ARCH[$i]}/bin:$PATH
+      elif [ -d ${ROOTDIR}/prebuilts/${TOOLCHAIN[$j]}/${SYSTEM}/${ARCH[$i]}/bin ]; then
+        export PATH=${ROOTDIR}/prebuilts/${TOOLCHAIN[$j]}/${SYSTEM}/${ARCH[$i]}/bin:$PATH
+      fi
+    done
+  done
+
+  # Arm Compiler
+  export PATH=${ROOTDIR}/prebuilts/clang/${SYSTEM}/armclang/bin:$PATH
+
+  if [ ! -n "${ARM_PRODUCT_DEF}" ]; then
+    export ARM_PRODUCT_DEF=${ROOTDIR}/prebuilts/clang/${SYSTEM}/armclang/mappings/eval.elmap
+  fi
+  if [ ! -n "${LM_LICENSE_FILE}" ]; then
+    export LM_LICENSE_FILE=${HOME}/.arm/ds/licenses/DS000-EV-31030.lic
+  fi
+  if [ ! -n "${ARMLMD_LICENSE_FILE}" ]; then
+    export ARMLMD_LICENSE_FILE=${HOME}/.arm/ds/licenses/DS000-EV-31030.lic
+  fi
+
+  # Generate compile database file compile_commands.json
+  if type bear >/dev/null 2>&1; then
+    # get version of bear
+    BEAR_VERSION=$(bear --version | awk '{print $2}' | awk -F. '{printf("%d%03d%03d ", $1,$2,$3)}')
+
+    # judge version of bear
+    if [ $BEAR_VERSION -ge 3000000 ]; then
+        # BEAR="bear --append --output compile_commands.json -- "
+        echo -e "Note: currently not support bear 3.0.0+ for some prebuilt toolchain limited."
+    else
+        echo -e "Note: bear 2.4.3 in Ubuntu 20.04 works out of box."
+        COMPILE_COMMANDS_DB_PATH="${ROOTDIR}/compile_commands"
+        if [ ! -d "$COMPILE_COMMANDS_DB_PATH" ]; then
+            mkdir -p $COMPILE_COMMANDS_DB_PATH
+        fi
+
+        COMPILE_COMMANDS=${ROOTDIR}/compile_commands.json
+        COMPILE_COMMANDS_BACKUP=${COMPILE_COMMANDS_DB_PATH}/compile_commands_${1//\//_}_$(date "+%Y-%m-%d-%H-%M-%S").json
+        BEAR="bear -a -o ${COMPILE_COMMANDS} "
+    fi
+  fi
+
+  # Add prebuilt tool
+  TOOLS_DIR=${ROOTDIR}/prebuilts/tools/${SYSTEM}/${SYS_ARCH}
+  export PATH="${TOOLS_DIR}:$PATH"
+
+  # Additional prebuilt GNU tools
+  if [ ${SYSTEM} == "darwin" ]; then
+    export PATH=${ROOTDIR}/prebuilts/tools/gnu/${SYSTEM}/${SYS_ARCH}:$PATH
+    export PATH=${ROOTDIR}/prebuilts/tools/gnu/${SYSTEM}/universal:$PATH
+  fi
+}
+
+function build_board()
+{
+  echo -e "Build command line:"
+  echo -e "  ${TOOLSDIR}/configure.sh -e $1"
+  echo -e "  make -C ${NUTTXDIR} EXTRAFLAGS="$EXTRA_FLAGS" ${@:2}"
+  echo -e "  make -C ${NUTTXDIR} savedefconfig"
+
+  KCONFIG_ARGS="--enable-mconf --disable-nconf --disable-gconf --disable-qconf"
+  if [ `uname` == "Darwin" ]; then
+    KCONFIG_ARGS+=" --disable-shared --enable-static"
+  fi
+
+  if [ ! -f "${ROOTDIR}/prebuilts/kconfig-frontends/bin/kconfig-conf" ] &&
+     [ ! -x "$(command -v kconfig-conf)" ]; then
+    pushd ${ROOTDIR}/prebuilts/kconfig-frontends
+    ./configure --prefix=${ROOTDIR}/prebuilts/kconfig-frontends ${KCONFIG_ARGS} 1>/dev/null
+    touch aclocal.m4 Makefile.in
+    make install 1>/dev/null
+    popd
+  fi
+  export PATH=${ROOTDIR}/prebuilts/kconfig-frontends/bin:$PATH
+
+  setup_toolchain $1
+
+  if ! ${TOOLSDIR}/configure.sh -e $1; then
+    echo "Error: ############# config ${1} fail ##############"
+    exit 1
+  fi
+
+  GHS_OPTS_STRING="CONFIG_ARCH_TOOLCHAIN_GHS=y"
+  if grep -q "^${GHS_OPTS_STRING}$" "${NUTTXDIR}/.config"; then
+    echo "EXTRA_FLAGS are required to update the when using the GHS toolchain."
+    EXTRA_FLAGS=$(echo "$EXTRA_FLAGS" | sed 's/-Wno-cpp//' | xargs)
+  fi
+
+  if ! ${BEAR} make -C ${NUTTXDIR} EXTRAFLAGS="$EXTRA_FLAGS" ${@:2}; then
+    echo "Error: ############# build ${1} fail ##############"
+    exit 2
+  else
+    if [ -f "${COMPILE_COMMANDS}" ]; then
+      cp ${COMPILE_COMMANDS} ${COMPILE_COMMANDS_BACKUP}
+    fi
+  fi
+
+  if [ "${2}" == "distclean" ]; then
+    if [ -f "${COMPILE_COMMANDS}" ]; then
+      rm -rf ${COMPILE_COMMANDS}
+    fi
+    return;
+  fi
+
+   if ! make -C ${NUTTXDIR} savedefconfig; then
+    echo "Error: ############# save ${1} fail ##############"
+    exit 3
+  fi
+  if [ ! -d $1 ]; then
+    cp ${NUTTXDIR}/defconfig ${ROOTDIR}/nuttx/boards/*/*/${1/[:|\/]//configs/}
+  else
+    cp ${NUTTXDIR}/defconfig $1
+  fi
+}
+
+function build_board_cmake()
+{
+  # first check if the command target is `distclean`
+  # cmake is built for out-of-tree, so delete the CMAKE_BINARY_DIR directory directly
+  if echo "${@:2}" | grep -q "distclean"; then
+    echo -e "Build target distclean:"
+    echo -e "  there is no need to distclean in cmake, delete '${CMAKE_BINARY_DIR}' directly"
+    if [ -d "${CMAKE_BINARY_DIR}" ]; then
+      rm -rf $CMAKE_BINARY_DIR
+    fi
+    return 0
+  fi
+  # check parallelism
+  j_arg=$(echo ${@:2} |grep -oP '\-j[0-9]+')
+  # import environmeni
+  setup_toolchain $1
+  # cmake verbose
+  v_arg=""
+  # check if cmake configuration is required
+  if [ ! -d "${CMAKE_BINARY_DIR}" ]; then
+    echo -e "Build CMake configuration:"
+    echo -e "  cmake -B ${CMAKE_BINARY_DIR} -S ${NUTTXDIR} -DBOARD_CONFIG=$1 -DEXTRA_FLAGS=\"${EXTRA_FLAGS}\" ${CMAKE_GENERATOR}"
+    if ! cmake -B ${CMAKE_BINARY_DIR} -S ${NUTTXDIR} -DBOARD_CONFIG=$1 -DEXTRA_FLAGS="${EXTRA_FLAGS}" ${CMAKE_GENERATOR}; then
+      echo "Error: ############# config ${1} fail ##############"
+      exit 1
+    fi
+  fi
+  # check if the command target is `Xconfig`
+  for arg in "${@:2}"
+  do
+    if [[ $arg == *config ]]; then
+      echo -e "  cmake --build ${CMAKE_BINARY_DIR} -t $arg"
+      if ! cmake --build ${CMAKE_BINARY_DIR} -t $arg; then
+        echo "Error: ############# CMake -t $arg fail ##############"
+        exit 2
+      else
+        return 0
+      fi
+    fi
+    if [[ "$arg" =~ ^V=1$ ]]; then
+      v_arg+="-v"
+    fi
+  done
+  # do cmake build
+  echo -e "  cmake --build ${CMAKE_BINARY_DIR} $j_arg $v_arg"
+  if ! ${BEAR} cmake --build ${CMAKE_BINARY_DIR} $j_arg $v_arg; then
+    echo "Error: ############# build ${1} fail ##############"
+    exit 2
+  else
+    if [ -f "${COMPILE_COMMANDS}" ]; then
+      cp ${COMPILE_COMMANDS} ${COMPILE_COMMANDS_BACKUP}
+    fi
+  fi
+}
+
+function pack_sdk()
+{
+  VENDOR=(\
+      "realtek" \
+      "bes" )
+  BOARDS=(\
+      "
+      amebaZ
+      " \
+      "
+      best2001_ep
+      " \
+      )
+
+  if [ "${2}" != "export" ]; then
+    exit 0
+  fi
+
+  if [ ! -f $OUTDIR/nuttx/.version ]; then
+    exit 1
+  fi
+
+  source $OUTDIR/nuttx/.version
+
+  local exportzip=$OUTDIR/nuttx/nuttx-export-$CONFIG_VERSION_STRING.zip
+
+  echo $exportzip
+  if [ ! -f $exportzip ]; then
+    exit 1
+  fi
+
+  local version=$CONFIG_VERSION_STRING.$CONFIG_VERSION_BUILD
+  local board=`echo $1 | awk -F '/' '{print $4}'`
+  local packname=`echo nuttx-sdk-$board-$version.zip`
+  local vendor=
+
+  for (( i = 0; i < ${#BOARDS[*]}; i++)); do
+    if [ $board == ${BOARDS[$i]} ]; then
+      vendor=vendor/${VENDOR[$i]}
+      break
+    fi
+  done
+
+  cp $exportzip .
+  zip -r $packname sdk $vendor `basename $exportzip` -x "sdk/.git*" 1>/dev/null 2>&1
+
+  if [ $? -eq 0 ]; then
+    echo "############## Export SDK Success: $packname ##############"
+  fi
+
+  rm `basename $exportzip`
+}
+
+function setup_cmake_binary_dir()
+{
+  local boardconfig=$1
+  if [ -d ${ROOTDIR}/${boardconfig} ]; then
+    # parse path config
+    config_name=$(basename "$boardconfig")
+    board_name=$(basename $(dirname $(dirname "$boardconfig")))
+  else
+    # parse nuttx config pair
+    config_name=`echo ${boardconfig} | cut -s -d':' -f2`
+    if [ -z "${config_name}" ]; then
+      board_name=`echo ${boardconfig} | cut -d'/' -f1`
+      config_name=`echo ${boardconfig} | cut -d'/' -f2`
+    else
+      board_name=`echo ${boardconfig} | cut -d':' -f1`
+    fi
+  fi
+  CMAKE_BINARY_DIR+="/${board_name}_${config_name}"
+}
+
+if [ $# == 0 ]; then
+  echo "Usage: $0 [-m] <board-name>:<config-name> [-e <extraflags>] [--cmake] [-b <cmake_binary_dir>] [--dis-ninja] [make options]"
+  echo ""
+  echo "Where:"
+  echo "  -m: out of tree build. Or default in tree build without it."
+  echo "  -e: pass extra c/c++ flags such as -Werror via make command line"
+  echo "  --cmake: switch the build mode to CMake compilation."
+  echo "  -b: set custom binary directory for CMake."
+  echo "  --dis-ninja: disable CMake Ninja generator fo default."
+  exit 1
+fi
+
+ROOTDIR=$(dirname $(readlink -f ${0}))
+ROOTDIR=$(realpath ${ROOTDIR}/../..)
+
+setup_environment
+
+CONFIGPATH=$2
+
+if [ $1 == "-m" ]; then
+  # out of tree build
+  confparams=(${CONFIGPATH//:/ })
+  configdir=${confparams[1]}
+
+  if [ -z "${configdir}" ]; then
+    # handle cases where the end is a "/"
+    if [ "${CONFIGPATH:(-1)}" = "/" ]; then
+      CONFIGPATH=${CONFIGPATH:0:-1}
+    fi
+    boarddir=`echo ${CONFIGPATH} | rev | cut -d'/' -f3 | rev`
+    configdir=`echo ${CONFIGPATH} | rev | cut -d'/' -f1 | rev`
+  else
+    boarddir=${confparams[0]}
+  fi
+
+  OUTDIR=${ROOTDIR}/out/${boarddir}/${configdir}
+  MOUNTDIR=${OUTDIR}/.unionfs
+  NUTTXDIR=${MOUNTDIR}/nuttx
+
+  trap cleanup EXIT
+  mount_unionfs
+  shift
+else
+  # in tree build
+  OUTDIR=${ROOTDIR}
+  NUTTXDIR=${ROOTDIR}/nuttx
+fi
+
+TOOLSDIR=${NUTTXDIR}/tools
+board_config=$1
+shift
+
+EXTRA_FLAGS="-Wno-cpp"
+while [[ "$1" == "-e" ]]; do
+  shift
+  EXTRA_FLAGS+=" $1"
+  echo "extraflags: $EXTRA_FLAGS"
+  shift
+done
+
+if [ "$1" == "--cmake" ]; then
+  CMAKE_BINARY_DIR="cmake_out"
+  CMAKE_GENERATOR="-GNinja"
+  CMAKE_BUILD="cmake"
+  setup_cmake_binary_dir $board_config
+  shift
+fi
+
+if [ "$1" == "-b" ]; then
+  shift
+  CMAKE_BINARY_DIR="$1"
+  echo "custom CMake binary dir: $CMAKE_BINARY_DIR"
+  shift
+fi
+
+if [ "$1" == "--dis-ninja" ]; then
+  CMAKE_GENERATOR=""
+  shift
+fi
+
+if [ -d ${ROOTDIR}/${board_config} ]; then
+  if [ -z "$CMAKE_BUILD" ]; then
+    build_board ${ROOTDIR}/${board_config} $*
+  else
+    build_board_cmake ../${board_config} $*
+  fi
+else
+  if [ -z "$CMAKE_BUILD" ]; then
+    build_board ${board_config} $*
+  else
+    build_board_cmake ${board_config} $*
+  fi
+fi
+
+pack_sdk ${board_config} $*