sudo apt-get update
sudo apt-get install git-core build-essential libssl-dev libncurses5-dev unzip gawk zlib1g-dev

sudo apt-get install subversion mercurial

git clone https://github.com/openwrt/openwrt.git

cd openwrt
./scripts/feeds update -a
./scripts/feeds install -a

make menuconfig 
make defconfig
make prereq
原文
https://wiki.openwrt.org/doc/howto/buildroot.exigence