创建 Ubuntu 根文件系统¶
准备工作¶
下载和解压 ubuntu-core¶
Ubuntu 根文件系统是基于 Ubuntu base 16.04 来创建的。用户可以到 ubuntu cdimg 下载，选择下载 ubuntu-base-16.04.1-base-arm64.tar.gz。
下载完之后，创建临时文件夹并解压根文件系统：
mkdir temp
sudo tar -xpf ubuntu-base-16.04.1-base-arm64.tar.gz -C temp
修改根文件系统¶
准备工作¶
准备网络：
sudo cp -b /etc/resolv.conf temp/etc/resolv.conf
准备 qemu：
sudo cp /usr/bin/qemu-aarch64-static temp/usr/bin/
进入根文件系统进行操作：
sudo chroot temp
更新及安装¶
更新：
apt update
apt upgrade
安装自己需要的功能
apt install vim git ....(根据自己需求添加)
安装 xubuntu：
apt-get install xubuntu-desktop
可能出现错误:
E: Unable to locate package xxxx
安装包的源没有添加到 /etc/apt/source.list 中,导致无法识别安装包,可以自行添加源，也可以使用下面给出的 source.list 覆盖原来的 /etc/apt/source.list 文件:
# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://ports.ubuntu.com/ubuntu-ports/ xenial main restricted
deb-src http://ports.ubuntu.com/ubuntu-ports/ xenial main restricted
## Major bug fix updates produced after the final release of the
## distribution.
deb http://ports.ubuntu.com/ubuntu-ports/ xenial-updates main restricted
deb-src http://ports.ubuntu.com/ubuntu-ports/ xenial-updates main restricted
## Uncomment the following two lines to add software from the 'universe'
## repository.
## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team. Also, please note that software in universe WILL NOT receive any
## review or updates from the Ubuntu security team.
deb http://ports.ubuntu.com/ubuntu-ports/ xenial universe
deb-src http://ports.ubuntu.com/ubuntu-ports/ xenial universe
deb http://ports.ubuntu.com/ubuntu-ports/ xenial-updates universe
deb-src http://ports.ubuntu.com/ubuntu-ports/ xenial-updates universe
## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
deb http://ports.ubuntu.com/ubuntu-ports/ xenial-backports main restricted
deb-src http://ports.ubuntu.com/ubuntu-ports/ xenial-backports main restricted
deb http://ports.ubuntu.com/ubuntu-ports/ xenial-security main restricted
deb-src http://ports.ubuntu.com/ubuntu-ports/ xenial-security main restricted
deb http://ports.ubuntu.com/ubuntu-ports/ xenial-security universe
deb-src http://ports.ubuntu.com/ubuntu-ports/ xenial-security universe
deb http://ports.ubuntu.com/ubuntu-ports/ xenial-security multiverse
deb-src http://ports.ubuntu.com/ubuntu-ports/ xenial-security multiverse
添加用户及设置密码¶
添加用户：
useradd -s '/bin/bash' -m -G adm,sudo firefly
给用户设置密码：
passwd firefly
给root用户设置密码：
passwd root
修改完自己的根文件系统就可以退出了。
exit
制作根文件系统¶
制作自己的根文件系统，大小依据自己的根文件系统而定，注意依据 temp 文件夹的大小来修改 count 值：
mkdir rootfs
dd if=/dev/zero of=linuxroot.img bs=1M count=4000
mkfs.ext4 linuxroot.img
sudo mount linuxroot.img rootfs/
sudo cp -rfp temp/* rootfs/
sudo umount rootfs/
e2fsck -p -f linuxroot.img
resize2fs -M linuxroot.img
这样 linuxroot.img 就是最终的根文件系统映像文件了。