git clone https://github.com/enki/libev.git
cd libev
./configure --host=arm-linux-gnueabi
DESTDIR=/tmp/rtty_install make install

git clone --recursive https://github.com/zhaojh329/rtty.git
cd rtty
cmake . -DCMAKE_C_COMPILER=arm-linux-gnueabi-gcc -DCMAKE_FIND_ROOT_PATH=/tmp/rtty_install
DESTDIR=/tmp/rtty_install make install

/tmp/rtty_install/
└── usr
    └── local
        ├── bin
        │   └── rtty
        └── lib
            ├── libev.so -> libev.so.4.0.0
            ├── libev.so.4 -> libev.so.4.0.0
            ├── libev.so.4.0.0