Allwinner requires registration to get access to their version of the
required software for more recent chips, aka SDK. CNX software has run
through the SDK dance with allwinner for the D1 RISC-V SoC . The
article shows a disclaimer  that needs to be clicked through to get
access to the SDK. It reads:
"This deliverable may not be altered, copied, reversed, sold,
distributed, or otherwise engaged in commercial activities without prior
written permission of the company."
Which, to my knowledge, is at odds with the GPL.
Thanks to our great community, we have the SDK mirrored. A new manifest
still needs to be provided, and the process still needs to be documented
on our wiki.