ubuntu编译openwrt环境搭建:
1.sudo apt-get install gcc  g++ binutils patch bzip2 flex bison make autocnf gettext texinfo unzip sharutils subversion libncurses5-dev ncurses-term zlib1g-dev subversion git-cor gaw asciido libz-dev
当然安装之前最好先更新下组件包：
sudo apt-get update

下载编译：
1. git clone https://github.com/link4all/20170920openwrt
2. cd 20170920openwrt
3. ./scripts/feeds update -a && ./scripts/feeds install -a
4. cp 7628.config .config
5. make V=s