I'm using mx6 and I'm using nfs in uboot. Uboot was built and built at https://github.com/varigit/uboot-imx.git-b imx_v2018.03_4.14.78_ga_var01, but the Internet was not connected. But our board is using SMSC Lan8720, which supports RMII. I want to modify the SMSC Lan8720 to operate on RMII in the above link uboot code. What do you do? Or can you get an uboot that supports RMII with SMSC Lan8720?