Here is the step-by-step to boot U-Boot on rv1108 evb.


Compile  U-Boot
===========================
  > make CROSS_COMPILE=arm-linux-gnueabihf- evb-rv1108_defconfig  all
  > ./tools/mkimage  -n rv1108 -T rksd -d ./out/u-boot-spl.bin spl.bin
  You can also use the ddr bin from rockchip official release [0] instead of u-boot-spl:
  > ./tools/mkimage  -n rv1108 -T rksd -d ../rkbin/rv1x/rv1108ddr_v1.00.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/rv1108usbboot_v1.00.bin
  > rkdeveloptool wl 0x40 u-boot.img
  > rkdeveloptool RD


You should be able to get U-Boot log message from boot console with baudrate 1500000:

U-Boot SPL board initReturning to boot ROM...


U-Boot 2017.09-01119-gc3ef4c0-dirty (Feb 06 2018 - 10:04:12 +0800)

Model: Rockchip RV1108 Evaluation board
DRAM:  256 MiB
APLL: 400000000 DPLL:798000000 GPLL:384000000
MMC:
Using default environment

In:    serial@10210000
Out:   serial@10210000
Err:   serial@10210000
Model: Rockchip RV1108 Evaluation board
Net:   No ethernet found.
Hit any key to stop autoboot:  0
=>



[0] git clone  https://github.com/rockchip-linux/rkbin.git