[U-Boot] Nios II 10m50 is not working

U-boot for Nios II on the 10m50 dev board is not functioning. The serial terminal prints nothing upon booting up. The u-boot image is loaded via GDB/JTAG to the FPGA on-chip RAM.

Bisect activities were carried and discovered that the change from using dm_scan_fdt_node to dm_scan_fdt_dev in the simple_bus.c. This leads to suspecting the 10m50_devboard.dts need update to include "u-boot,dm-pre-reloc".

However, changing the 10m50_devboard.dts still does not solve the problem. Any idea? Sorry if missing out any info and I will glad to supply. Thanks.