How I fix this problem ? please help! Thank you!

Helo,

First of all I recommend you check our rocketboards.org for tutorials here, from task 1 to task 10, select Cyclone V SoC and the version you are working on and the task:

https://rocketboards.org/foswiki/Main/GettingStarted

If you are sorta new to Cyclone V SoC on how it boots, you may want to check on task 10 which is to boot using our prebuilt SD card image, to see how it actually boot up.

Once you are familiar, if you are opt for a little advance technique, you can check out here which demo on how to build the bootloader using the latest version 20.1 Quartus and SoC EDS, using Linux enviroment, https://rocketboards.org/foswiki/Documentation/BuildingBootloader#Cyclone_V_SoC_45_Boot_from_SD_Card