arm64_download script waits for VM to boot before finishing.

platform_tools/barelinux/bin/arm64_download

 #!/bin/sh
 
 # Copyright 2014 Google Inc.
 #
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 
 usage() {
     cat >&2 <<EOF
@@ skipping 100 matching lines @@
 
     DISPLAY='' nohup \
     "$foundation" \
         --image="${firmware}" \
         --cores=4 \
         --block-device="${rootfs}" \
         --network="nat" \
         --network-nat-subnet="192.168.31.0/24" \
         --network-nat-ports="8022=22" \
         > /dev/null 2>&1 &
+    echo 'Waiting for foundation model to boot...'
+    while ! ssh -i "${working_dir}/key" \
+        -o NoHostAuthenticationForLocalhost=yes \
+        -p 8022 user@localhost true 2> /dev/null; do
+        sleep 5
+    done
     echo 'Listening to SSH on port 8022.'
 }
 
 arm64_download() {
     local working_directory="$1"
     try mkdir -p "$working_directory" || return
 
     try download_necessary_software_to_dir "$working_directory" || return
 
     try install_compiler "$working_directory" || return
 
     try install_runtime "$working_directory" || return
 
     try start_arm64_image "$working_directory" || return
 
     try start_arm64_image \
         "$working_directory" \
         || return
 }
 
 for command in gsutil xz tar md5sum gunzip; do
     try command -v "$command" > /dev/null || usage || exit
 done
 
 if [ -z "$1" ] ; then
     usage || exit
 fi
 try arm64_download "$1"