“This is a walkthrough for flashing custom ARM Trusted Firmware, OP-TEE, and the ARM UEFI Platform code on the Hikey board. Custom means code we’ve built it on our development machine, we’re not making any changes to these reference implementations just yet.[…]”
https://prosauce.org/blog/2016/11/25/hands-on-introduction-to-arm-firmware-using-the-hikey