This documentation will introduce how to upgrade U-Boot manually.
Copy the U-Boot debian package to your board and install it directly.
The U-Boot debian package is linux-u-boot-vim3-vendor_xxxx-2015.01_arm64.deb,
xxxx is the version number, e.g. 1.0.11.
$ sudo dpkg -i linux-u-boot-vim3-vendor_xxxx-2015.01_arm64.deb $ sync $ sudo reboot