| Introduction | 
 | ============ | 
 |  | 
 | RK3328 key features we might use in U-Boot: | 
 | * CPU: ARMv8 64bit quad-core Cortex-A53 | 
 | * IRAM: 36KB | 
 | * DRAM: 4GB-16MB dual-channel | 
 | * eMMC: support eMMC 5.0/5.1, suport HS400, HS200, DDR50 | 
 | * SD/MMC: support SD 3.0, MMC 4.51 | 
 | * USB: 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 rk3328. | 
 |  | 
 | Get the Source and prebuild binary | 
 | ================================== | 
 |  | 
 |   > mkdir ~/evb_rk3328 | 
 |   > cd ~/evb_rk3328 | 
 |   > 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 ATF | 
 | =============== | 
 |  | 
 |   > cd arm-trusted-firmware | 
 |   > make realclean | 
 |   > make CROSS_COMPILE=aarch64-linux-gnu- PLAT=rk3328 bl31 | 
 |  | 
 | Compile U-Boot | 
 | ================== | 
 |  | 
 |   > cd ../u-boot | 
 |   > make CROSS_COMPILE=aarch64-linux-gnu- evb-rk3328_defconfig all | 
 |  | 
 | Compile rkflashtool | 
 | ======================= | 
 |  | 
 |   > cd ../rkflashtool | 
 |   > make | 
 |  | 
 | Package image for miniloader | 
 | ================================ | 
 |   > cd .. | 
 |   > cp arm-trusted-firmware/build/rk3328/release/bl31.bin rkbin/rk33 | 
 |   > ./rkbin/tools/trust_merger rkbin/tools/RK3328TRUST.ini | 
 |   > ./rkbin/tools/loaderimage --pack --uboot u-boot/u-boot-dtb.bin uboot.img | 
 |   > mkdir image | 
 |   > mv trust.img ./image/ | 
 |   > mv uboot.img ./image/rk3328evb-uboot.bin | 
 |  | 
 | Flash image | 
 | =============== | 
 | Power on(or reset with RESET KEY) with MASKROM KEY preesed, and then: | 
 |  | 
 |   > ./rkflashtool/rkflashloader rk3328evb | 
 |  | 
 | You should be able to get U-Boot log message in console/UART2 now. |