I tried booting with the uEnv.txt settings as explained by you
bootfile=xinu.boot boot_mmc=fatload mmc 0 0x80200000 ${bootfile}; bootm uenvcmd=run boot_mmc
how ever the value needs to be slightly adjusted to
bootfile=xinu.boot boot_mmc=fatload mmc 0 0x82000000 ${bootfile}; bootm uenvcmd=run boot_mmc
The 80200000 needs to be changed to 82000000 on the README.md
That load value can actually change. If you see check other guides you will see different load addresses for different people. I suspect it got to do with the version of uboot in use.
I tried booting with the uEnv.txt settings as explained by you
bootfile=xinu.boot boot_mmc=fatload mmc 0 0x80200000 ${bootfile}; bootm uenvcmd=run boot_mmc
how ever the value needs to be slightly adjusted to
bootfile=xinu.boot boot_mmc=fatload mmc 0 0x82000000 ${bootfile}; bootm uenvcmd=run boot_mmc
The 80200000 needs to be changed to 82000000 on the README.md