看了acrn内部的磁盘制作、扩容脚本，学习一下

#!/bin/bash
# Copyright (C) 2020-2022 Intel Corporation.
# SPDX-License-Identifier: BSD-3-Clausebuild_dir="$PWD/build"
cloud_image="${build_dir}/focal-server-cloudimg-amd64.img"
cloud_image_url=https://cloud-images.ubuntu.com/focal/current/focal-server-cloudimg-amd64.img
hmi_vm_image="${build_dir}/hmi_vm.img"
rt_vm_image="${build_dir}/rt_vm.img"
rt_kernel=(linux-libc linux-headers linux-image)vm_type=$1
if [[ ${vm_type} != "rt-vm" ]] && [[ ${vm_type} != "hmi-vm" ]]; thencat <<EOT
Usage: $0 <vm_type>
This script creates VM images based on Ubuntu cloud images.VM type options:hmi-vm        create a VM with GNOME desktoprt-vm         create a VM with a preempt-RT-patched kernel and real-time test utilities
EOTexit 1
fi########################################
# Environment checks
########################################if [[ ! -d /etc/schroot/chroot.d ]]; thenecho "Package schroot is not installed."exit 1
fiif [[ ! -d $(dirname $PWD)/build ]]; thenmake -C $(dirname $PWD)
fiarr=("$PWD/mnt" "$PWD/build")
for dir in "${arr[@]}"; doif [[ ! -d "$dir" ]]; thenmkdir $dirfi
done########################################
# Helper functions
########################################source logger.sh########################################
# Actions defined as functions
########################################function copy_rt_kernel() {for file in ~/acrn-work/*rtvm*.debdoif [[ ${file} != *"dbg"* ]