ATF
From Rockchip open source Document
git clone https://github.com/ARM-software/arm-trusted-firmware.git
sudo apt-get install gcc-arm-none-eabi
$ cat mk-atf.sh #!/bin/bash make realclean CFLAGS='-gdwarf-2' \ CROSS_COMPILE=aarch64-linux-gnu- \ make PLAT=rk3399 DEBUG=1 ERROR_DEPRECATED=1 bl31