This page leads you to upgrade Linux Kernel manually.
Copy the kernel, dtb and header - these debian packages to your board and install them directly.
The Linux debian packages as below:
xxxx is version number, e.g. 1.0.11.
$ sudo dpkg -i linux-dtb-amlogic-5.4_xxxx_arm64.deb $ sudo dpkg -i linux-image-amlogic-5.4_xxxx_arm64.deb $ sudo dpkg -i linux-headers-amlogic-5.4_xxx_arm64.deb $ sync $ sudo reboot