Introduction
============

RK3399 key features we might use in U-Boot:
* CPU: ARMv8 64bit Big-Little architecture,
*      Big: dual-core Cortex-A72
*      Little: quad-core Cortex-A53
* IRAM: 200KB
* DRAM: 4GB-128MB dual-channel
* eMMC: support eMMC 5.0/5.1, suport HS400, HS200, DDR50
* SD/MMC: support SD 3.0, MMC 4.51
* USB: USB3.0 typc-C port *2 with dwc3 controller
*      USB2.0 EHCI host port *2
* Display: RGB/HDMI/DP/MIPI/EDP

evb key features:
* regulator: pwm regulator for CPU B/L
* PMIC: rk808
* debug console: UART2

In order to support Arm Trust Firmware(ATF), we need to use the
miniloader from rockchip which:
* do DRAM init
* load and verify ATF image
* load and verify U-Boot image

Here is the step-by-step to boot to U-Boot on rk3399.

Get the Source and prebuild binary
==================================

  > mkdir ~/evb_rk3399
  > cd ~/evb_rk3399
  > git clone https://github.com/ARM-software/arm-trusted-firmware.git
  > git clone https://github.com/rockchip-linux/rkbin
  > git clone https://github.com/rockchip-linux/rkflashtool

Compile the ATF
===============

  > cd arm-trusted-firmware
  > make realclean
  > make CROSS_COMPILE=aarch64-linux-gnu- PLAT=rk3399 bl31

Compile the U-Boot
==================

  > cd ../u-boot
  > make CROSS_COMPILE=aarch64-linux-gnu- evb-rk3399_defconfig all

Compile the rkflashtool
=======================

  > cd ../rkflashtool
  > make

Package the image for miniloader
================================
  > cd ..
  > cp arm-trusted-firmware/build/rk3399/release/bl31.bin rkbin/rk33
  > ./rkbin/tools/trust_merger rkbin/tools/RK3399TRUST.ini
  > ./rkbin/tools/loaderimage --pack --uboot u-boot/u-boot-dtb.bin uboot.img
  > mkdir image
  > mv trust.img ./image/
  > mv uboot.img ./image/rk3399evb-uboot.bin

Flash the image
===============
Power on(or reset with RESET KEY) with MASKROM KEY preesed, and then:

  > ./rkflashtool/rkflashloader rk3399evb

You should be able to get U-Boot log message in console/UART2 now.