Hello 晓 刘,
Please refer to the section "8.1 U-Boot debug" in CW4NET_v2018.01\CW_ARMv8\ARMv8\Help\PDF\ARMv8_Targeting_Manual.pdf to download u-boot image to DDR to do debugging.
Have a great day,
TIC
-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------