Arria 10 :HPS booting using DDR3


I am using a custom board which took design reference from Arria 10.We did changes in debug port and configured as UART1 , also included sd card booting and replaced DDR4 memory with DDR3 memory. I have generated a new project from Quartus tool with all the pin muxing done . Also updated the pin planner configuration and with help of bsp-editor generated a uboot binary image which was loaded into sd card.But the uboot is not loaded in serial port.
In socfpga_arria10.h file , i did change console to ttyS1 for uart 1 and updated the core.rbf file but the uboot is still not working.

I am unsure what additional changes i need to do for booting OS . Also i have replaced DDR4 with DDR3 , so what configuration changes are required to be done.