diff --git a/project/building.sh b/project/building.sh
index 6034bff..9829fc6 100755
--- a/project/building.sh
+++ b/project/building.sh
@@ -46,9 +46,6 @@ function download_extract() {
 
 function download_extract_all() {
   download_extract "${KERNEL_URL}" "${KERNEL_SHA256}" "${KERNEL_PATH}" || return $?
-  download_extract "${BUSYBOX_URL}" "${BUSYBOX_SHA256}" "${BUSYBOX_PATH}" || return $?
-  download_extract "${DROPBEAR_URL}" "${DROPBEAR_SHA256}" "${DROPBEAR_PATH}" || return $?
-  download_extract "${GESFTPSERVER_URL}" "${GESFTPSERVER_SHA256}" "${GESFTPSERVER_PATH}" || return $?
 }
 
 function cpu_count() {
@@ -72,53 +69,8 @@ function compile_kernel() {
   cp -pf "${KERNEL_IMAGE}" "${ARTIFACTS_PATH}/"
 }
 
-# compile busybox
-function compile_busybox() {
-  ln -sf "${BUSYBOX_CONFIG_PATH}" "${BUSYBOX_SOURCE_PATH}/.config"
-  echo "Compile busybox..."
-  time make -C "${BUSYBOX_SOURCE_PATH}" -j "$(cpu_count)" || return $?
-  echo "Copy busybox..."
-  cp -pf "${BUSYBOX_BIN}" "${ARTIFACTS_PATH}/"
-  echo "Copy libs and patch ld path..."
-  build_binary "${BUSYBOX_BIN}" || return $?
-}
-
-# compile dropbear
-function compile_dropbear() {
-  ln -sf "${DROPBEAR_CONFIG_PATH}" "${DROPBEAR_SOURCE_PATH}/options.h"
-  echo "Configure dropbear..."
-  cd "${DROPBEAR_SOURCE_PATH}" && CC=${CROSS_COMPILE}gcc LD=${CROSS_COMPILE}ld ./configure --host=aarch64-linux-gnu --disable-lastlog --disable-syslog --disable-wtmp --disable-wtmpx --disable-utmpx || return $?
-  echo "Compile dropbear..."
-  time make -C "${DROPBEAR_SOURCE_PATH}" -j "$(cpu_count)" PROGRAMS="dropbear dbclient dropbearkey dropbearconvert scp" MULTI=1 || return $?
-  echo "Copy dropbear..."
-  cp -pf "${DROPBEAR_BIN}" "${ARTIFACTS_PATH}/"
-  echo "Copy libs and patch ld path..."
-  build_binary "${DROPBEAR_BIN}" || return $?
-}
-
-# compile gesftpserver
-function compile_gesftpserver() {
-  echo "Configure gesftpserver..."
-  cd "${GESFTPSERVER_SOURCE_PATH}" && CC=${CROSS_COMPILE}gcc LD=${CROSS_COMPILE}ld CFLAGS=-pthread ./configure --host=aarch64-linux-gnu || return $?
-  echo "Compile gesftpserver..."
-  time make -C "${GESFTPSERVER_SOURCE_PATH}" -j "$(cpu_count)" gesftpserver || return $?
-  echo "Copy gesftpserver..."
-  cp -pf "${GESFTPSERVER_BIN}" "${ARTIFACTS_PATH}/"
-  echo "Copy libs and patch ld path..."
-  # TODO: ld.so with qemu-aarch64 does not work for gesftpserver
-  #build_binary "${GESFTPSERVER_BIN}"
-  patch_binary "${GESFTPSERVER_BIN}" || return $?
-  copy_libs 'libc.so.6' 'libpthread.so.0' || return $?
-}
-
-# compile sysinfo
-function compile_sysinfo() {
-  echo "Compile sysinfo..."
-  time CC=${CROSS_COMPILE}gcc LD=${CROSS_COMPILE}ld make -C "${SYSINFO_SOURCE_PATH}" -j "$(cpu_count)" || return $?
-  echo "Copy sysinfo..."
-  cp -pf "${SYSINFO_BIN}" "${ARTIFACTS_PATH}/"
-  echo "Copy libs and patch ld path..."
-  build_binary "${SYSINFO_BIN}" || return $?
+function find_modules() {
+  find "$MODULES_DIR" -mindepth 1 -maxdepth 1 -type d -not -name '_*' -print0
 }
 
 function compile_module() {
@@ -151,11 +103,7 @@ function modules_compile() {
 }
 
 function compile() {
-  compile_kernel || return $?
-  compile_busybox || return $?
-  compile_dropbear || return $?
-  compile_gesftpserver || return $?
-  compile_sysinfo || return $?
+  modules_compile || return $?
 }
 
 function get_binary_linker() {
@@ -163,188 +111,6 @@ function get_binary_linker() {
   file "$binary" | grep -o -E ', interpreter (.*\.so(\.[0-9]+)?)' | cut -d' ' -f3
 }
 
-function copy_lib() {
-  cp -pf "$1" "${ARTIFACTS_PATH}/lib/" || return $?
-}
-
-# copy binary libs
-function copy_binary_libs() {
-  local -r binary="$1"
-
-  echo "Copy libs for '$binary'..."
-  mkdir -p "${ARTIFACTS_PATH}/lib"
-
-  local -r linker="$(get_binary_linker "$binary")"
-  local -r libs="$(qemu-aarch64 "$linker" --list "$binary" | sed -e 's/[^\t].* => //' | sed -e 's/^\s//' | cut -d' ' -f1)"
-
-  while read -r lib; do
-    copy_lib "$lib" || return $?
-  done <<< "$libs"
-}
-
-# copy libs
-function copy_libs() {
-  echo "Copy libs..."
-  mkdir -p "${ARTIFACTS_PATH}/lib"
-  for lib in "$@"; do
-    copy_lib "$(${CROSS_COMPILE}gcc "-print-file-name=$lib")" || return $?
-  done
-}
-
-# patch lib paths
-function patch_binary() {
-  local -r binary="$1"
-  echo "Patching lib paths for '$binary'..."
-  local -r linker="$(basename "$(get_binary_linker "$binary")")"
-  patchelf --set-interpreter "/lib/$linker" --set-rpath '/lib' "$binary" || return $?
-}
-
-# do magic for binaries
-function build_binary(){
-  local -r binary="$1"
-  local -r binary_dst="${ARTIFACTS_PATH}/${2}$(basename "$binary")"
-  patch_binary "$binary_dst" || return $?
-  copy_binary_libs "$binary" || return $?
-}
-
-# copy drobear libs
-function copy_dropbear_libs() {
-  local -r libs=(libnss_compat.so.2 libnss_files.so.2)
-  copy_libs "${libs[@]}" || return $?
-}
-
-# create dropbear rsa key
-function build_dropbear_rsa_key() {
-  local -r priv_key="${ARTIFACTS_PATH}/${1:-id_dropbear}"
-  local -r priv_key_openssh="${2}"
-  local -r pub_key="${priv_key}.pub"
-
-  # create private key
-  if [ ! -f "${priv_key}" ]; then
-    echo "Create dropbear private key..."
-    qemu-aarch64 "${DROPBEAR_BIN}" dropbearkey -t rsa -s 4096 -f "${priv_key}" || return $?
-    rm -f "${pub_key}"
-  fi
-
-  # convert private key to openssh
-  if [ ! -z "$priv_key_openssh" ] && [ ! -f "${priv_key_openssh}" ]; then
-    qemu-aarch64 "${DROPBEAR_BIN}" dropbearconvert dropbear openssh "${priv_key}" "${priv_key_openssh}" || return $?
-  fi
-
-
-  # create public key
-  if [ ! -f "${pub_key}" ]; then
-    echo "Extract dropbear public key..."
-    qemu-aarch64 "${DROPBEAR_BIN}" dropbearkey -f "${priv_key}" -y | tail -n 2 | head -n 1 > "${pub_key}" || return $?
-  fi
-}
-
-# build dropbear files
-function build_dropbear() {
-  copy_dropbear_libs || return $?
-  build_dropbear_rsa_key id_dropbear "${SSH_KEY}" || return $?
-  build_dropbear_rsa_key dropbear_rsa_host_key || return $?
-
-  update_known_hosts || return $?
-}
-
-# build initrd
-function build_initrd() {
-  local -r name="${1:-initrd}"
-  local -r root="${SCRIPT_DIR}/${name}"
-  local -r output="${ARTIFACTS_PATH}/${name}.cpio"
-
-  echo "Update libs in initrd..."
-  rm -Rf "${root:?}/lib/"
-  mkdir -p "${root}/lib/"
-  while IFS= read -r -d '' lib; do
-    ln -s "$lib" "${root}/lib/" || return $?
-  done < <(find "${ARTIFACTS_PATH}/lib/" -type f -print0)
-  
-  echo "Build initrd..."
-  cd "${root}" && find . -not -name '.keep' | cpio -L -v -o -H newc > "${output}" || return $?
-}
-
-# compile
-function build() {
-  build_dropbear || return $?
-  build_initrd initrd || return $?
-}
-
-# run qemu
-function run_qemu() {
-  local -r initrd="${ARTIFACTS_PATH}/${1:-initrd.cpio}"
-  local -r init="${2:-/init}"
-  shift 1 && shift 1
-  echo "Run qemu..."
-  qemu-system-aarch64 -nographic -m 64 -M virt -cpu cortex-a53 -kernel "${KERNEL_IMAGE}" -initrd "${initrd}" -append "console=ttyAMA0,115200 loglevel=9 earlyprintk init=${init} $*" -device "virtio-net-pci,netdev=net0" -netdev "user,id=net0,net=10.4.0.0/24,dhcpstart=10.4.0.100,hostfwd=tcp::${SSH_PORT}-:22" || return $?
-}
-
-# update ssh known_hosts
-function update_known_hosts() {
-  echo "Update public key in known_hosts..."
-  mkdir -p "${HOME}/.ssh"
-  ssh-keygen -R "[${SSH_HOST}]:${SSH_PORT}"
-  echo "[${SSH_HOST}]:${SSH_PORT} $(cat "${ARTIFACTS_PATH}/dropbear_rsa_host_key.pub")" >> ~/.ssh/known_hosts
-}
-
-# ssh connect
-function ssh_connect() {
-  local -r user="${1:-root}"
-  shift 1
-  echo "Connect with ssh to qemu..." >&2
-  # shellcheck disable=SC2029
-  ssh -p "${SSH_PORT}" -l "${user}" -i "${SSH_KEY}" "${SSH_HOST}" "$@" || return $?
-}
-
-# ssh cmd
-function ssh_cmd() {
-  echo "Running '$*' over ssh..." >&2
-  ssh_connect root -n . /etc/profile\; "$@" || return $?
-}
-
-# scp copy
-function scp_copy() {
-  local -r user=root
-  local -r dst="$1"
-  shift 1
-  echo "Copying '$*' over scp to '$dst'..."
-  scp -P "${SSH_PORT}" -i "${SSH_KEY}" "$@" "root@${SSH_HOST}:${dst}" || return $?
-}
-
-function find_modules() {
-  find "$MODULES_DIR" -mindepth 1 -maxdepth 1 -type d -not -name '_*' -print0
-}
-
-function modules_copy() {
-  echo "Copying modules and module tests..."
-  scp_copy "/lib/modules/$(ssh_cmd uname -r)/" "$MODULES_DST_DIR/"*.ko || return $?
-  scp_copy "/tmp/" "$MODULES_DST_DIR/"*.ko.test || return $?
-}
-function modules_load() {
-  echo "Load modules..."
-  ssh_cmd depmod || return $?
-
-  while IFS= read -r -d '' module_dir; do
-    ssh_cmd modprobe "$(basename "$module_dir")" || return 1
-  done < <(find_modules)
-}
-function modules_test() {
-  local module
-  echo "Test modules..."
-  while IFS= read -r -d '' module_dir; do
-    module="$(basename "$module_dir")"
-    echo "Running test for kernel module '$module'"
-    ssh_cmd "/tmp/${module}.ko.test" || return 1
-  done < <(find_modules)
-}
-function modules_unload() {
-  echo "Unload modules..."
-
-  while IFS= read -r -d '' module_dir; do
-    ssh_cmd rmmod -w "$(basename "$module_dir")" || return 1
-  done < <(find_modules)
-}
 
 # clean untracked git files
 function clean() {
@@ -359,8 +125,7 @@ function main() {
   case "$cmd" in
     all )
       download_extract_all &&
-      compile &&
-      build ;;
+      compile ;;
 
     download )
       download_extract_all ;;
@@ -368,24 +133,8 @@ function main() {
     compile )
       compile ;;
 
-    build )
-      build ;;
-
-    qemu )
-      run_qemu initrd.cpio /init "$@" ;;
-
-    ssh )
-      ssh_connect "$@" ;;
-
-    ssh_cmd )
-      ssh_cmd "$@" ;;
-
     modules )
-      modules_compile &&
-      modules_copy &&
-      modules_load &&
-      modules_test &&
-      modules_unload ;;
+      modules_compile ;;
 
     modules_build )
       modules_compile ;;
@@ -393,15 +142,6 @@ function main() {
     modules_copy )
       modules_copy ;;
 
-    modules_load )
-      modules_load ;;
-
-    modules_test )
-      modules_test ;;
-
-    modules_unload )
-      modules_unload ;;
-
     clean )
       clean ;;