获取Ubuntu

http://cdimage.ubuntu.com/ubuntu-base/releases/
#解压系统包
tar -xvf ubuntu-base-18.04.5-base-armhf.tar.gz

安装qemu

sudo apt-get install qemu-user-static
# 将安装的 qemu-user-static 拷贝到解压出来的 ubuntu-base中的/usr/bin 目录下
cp /usr/bin/qemu-arm-static xxx/usr/bin

添加软件源

cp /etc/apt/source.list etc/apt/source.list
# 追加软件源
vi etc/apt/source.list 

#中科大源
deb http://mirrors.ustc.edu.cn/ubuntu-ports/ xenial main multiverse restricted universe
deb http://mirrors.ustc.edu.cn/ubuntu-ports/ xenial-backports main multiverse restricted universe
deb http://mirrors.ustc.edu.cn/ubuntu-ports/ xenial-proposed main multiverse restricted universe
deb http://mirrors.ustc.edu.cn/ubuntu-ports/ xenial-security main multiverse restricted universe
deb http://mirrors.ustc.edu.cn/ubuntu-ports/ xenial-updates main multiverse restricted universe
deb-src http://mirrors.ustc.edu.cn/ubuntu-ports/ xenial main multiverse restricted universe
deb-src http://mirrors.ustc.edu.cn/ubuntu-ports/ xenial-backports main multiverse restricted universe
deb-src http://mirrors.ustc.edu.cn/ubuntu-ports/ xenial-proposed main multiverse restricted universe
deb-src http://mirrors.ustc.edu.cn/ubuntu-ports/ xenial-security main multiverse restricted universe
deb-src http://mirrors.ustc.edu.cn/ubuntu-ports/ xenial-updates main multiverse restricted universe

配置DNS

cp /etc/resolv.conf etc/resolv.conf
vi etc/resolv.conf

nameserver 114.114.114.114
nameserver 8.8.8.8 

主机上挂载根文件系统

创建挂载脚本mount.sh

#!/bin/bash
echo "MOUNTING"
sudo mount -t proc /proc /home/xxx/rootfs/proc
sudo mount -t sysfs /sys /home/xxx/rootfs/sys
sudo mount -o bind /dev /home/xxx/rootfs/dev
sudo mount -o bind /dev/pts /home/xxx/rootfs/dev/pts
sudo chroot /home/xxx/rootfs

创建卸载脚本umount.sh

#!/bin/bash
echo "UMOUNTING"
sudo umount /home/xxx/rootfs/proc
sudo umount /home/xxx/rootfs/sys
sudo umount /home/xxx/rootfs/dev
sudo umount /home/xxx/rootfs/dev/pts

安装常用命令和工具

chmod 777 /tmp
apt update
apt install vim
apt install net-tools
apt install iputils-ping