1Here is the step-by-step to boot U-Boot on rv1108 evb.
2
3Get ddr init binary
4==============================================================================
5  > git clone  https://github.com/rockchip-linux/rkbin.git
6
7Compile  U-Boot
8===========================
9  > make CROSS_COMPILE=arm-linux-gnueabi- evb-rv1108_defconfig  all
10  > ./tools/mkimage  -n rv1108 -T rksd -d ../rkbin/rv1x/rv1108ddr_v1.00.bin spl.bin
11  > cat spl.bin u-boot.bin > u-boot.img
12
13Flash the image by rkdeveloptool
14================================
15rkdeveloptool can get from https://github.com/rockchip-linux/rkdeveloptool.git
16
17Power on(or reset with RESET KEY) with MASKROM KEY preesed, and then:
18  > rkdeveloptool db ./rkbin/rv1x/rv1108usbboot_v1.00.bin
19  > rkdeveloptool wl 0x40 u-boot.img
20  > rkdeveloptool RD
21
22You should be able to get U-Boot log message from boot console:
23
24DDR Version V1.02 20170220
25In
26400MHz
27DDR3
28Bus Width=16 Col=10 Bank=8 Row=15 CS=1 Die Bus-Width=16 Size=512MB
29mach:2
30OUT
31
32
33U-Boot 2017.05-00693-g3a5b171 (Jun 01 2017 - 17:37:53 +0800)
34
35Model: Rockchip RV1108 Evaluation board
36DRAM:  128 MiB
37APLL: 600000000 DPLL:792000000 GPLL:384000000
38MMC:
39Using default environment
40
41In:    serial@10210000
42Out:   serial@10210000
43Err:   serial@10210000
44Net:   No ethernet found.
45Hit any key to stop autoboot:  0
46=>
47