1.修改LibreELEC系统镜像
LibreELEC系统镜像为只读，无法创建opt文件夹。
mac系统下安装brew，然后brew install squashfs
插入SD卡在终端中输入如下：
cd /Volumes/LIBREELEC
mkdir -p new/opt
mksquashfs new SYSTEM -all-root
rm -rf new
现在LibreELEC系统镜像就会生成一个opt文件夹，每次LibreELEC升级都需要重新创建这个opt文件夹。
2.启动LIbreELEC系统并登入SSH
在LibreELEC的系统设置中开启ssh，然后在终端中输入ssh root@LibreELEC.local
输入密码后登入LibreELEC
3.安装Entware
尽管/根目录还是只读，但是/storage是可读写的，所以先创建/storage/opt，然后把/opt挂载到/storage/opt，然后安装opkg，在终端中输入如下：
mkdir -p /storage/opt
mount -o bind /storage/opt /opt
wget -O - http://bin.entware.net/armv7sf-k3.2/installer/generic.sh | sh
export PATH=$PATH:/opt/bin:/opt/sbin
opkg update
opkg install coreutils-expr
这里面的安装脚本需要根据你的设备来修改
可以到http://bin.entware.net/来查看支持的设备类型
可以选择的有
[aarch64-k3.10/](http://bin.entware.net/aarch64-k3.10/)
[armv5sf-k3.2/](http://bin.entware.net/armv5sf-k3.2/)
[armv7sf-k2.6/](http://bin.entware.net/armv7sf-k2.6/)
[armv7sf-k3.2/](http://bin.entware.net/armv7sf-k3.2/)
[mipselsf-k3.4/](http://bin.entware.net/mipselsf-k3.4/)
[mipssf-k3.4/](http://bin.entware.net/mipssf-k3.4/)
[x64-k3.2/](http://bin.entware.net/x64-k3.2/)
修改启动项，LibreELEC启动自动挂载/opt到/storage/opt
输入nano -w /storage/.config/system.d/opt.mount
[Unit]
DefaultDependencies=no
Conflicts=umount.target
Before=local-fs.target umount.target
[Mount]
What=/storage/opt
Where=/opt
Type=none
Options=bind
[Install]
WantedBy=local-fs.target
启动开机自动挂载
systemctl enable opt.mount
添加环境变量nano /storage/.profile
export LC_ALL=en_US.UTF-8
export LANG=en_US.UTF-8
export LANGUAGE=en_US.UTF-8
export PATH=$PATH:/opt/bin:/opt/sbin
重启系统，ssh登入，检查/opt是否挂载ls /opt看是否有相应文件夹
输入opkg list检测环境变量是否设置成功
4.设置Entware启动项
输入nano -w /storage/.config/system.d/entware.service
[Unit]
Requires=network-online.service
[Service]
Type=oneshot
ExecStart=/opt/etc/init.d/rc.unslung start
ExecStop=/opt/etc/init.d/rc.unslung stop
RemainAfterExit=yes
[Install]
WantedBy=multi-user.target
开机自启动systemctl enable entware.service
启动服务systemctl start entware.service
5.安装Entware应用
opkg list
opkg list | grep package
opkg install package
opkg uninstall package
