Here is the step-by-step to boot U-Boot on rv1108 evb. Get ddr init binary ============================================================================== > git clone https://github.com/rockchip-linux/rkbin.git > dd if=./rkbin/rv1x/rv1108ddr.bin of=ddr.bin bs=4 skip=1 Compile U-Boot =========================== > make CROSS_COMPILE=arm-linux-gnueabi- evb-rv1108_defconfig all > ./tools/mkimage -n rv1108 -T rksd -d ddr.bin spl.bin > cat spl.bin u-boot.bin > u-boot.img Flash the image by rkdeveloptool ================================ rkdeveloptool can get from https://github.com/rockchip-linux/rkdeveloptool.git Power on(or reset with RESET KEY) with MASKROM KEY preesed, and then: > rkdeveloptool db ./rkbin/rv1x/RV1108_usb_boot.bin > rkdeveloptool wl 0x40 u-boot.img > rkdeveloptool RD You should be able to get U-Boot log message from boot console: DDR Version V1.02 20170220 In 400MHz DDR3 Bus Width=16 Col=10 Bank=8 Row=15 CS=1 Die Bus-Width=16 Size=512MB mach:2 OUT U-Boot 2017.05-00693-g3a5b171 (Jun 01 2017 - 17:37:53 +0800) Model: Rockchip RV1108 Evaluation board DRAM: 128 MiB APLL: 600000000 DPLL:792000000 GPLL:384000000 MMC: Using default environment In: serial@10210000 Out: serial@10210000 Err: serial@10210000 Net: No ethernet found. Hit any key to stop autoboot: 0 =>