Expanding DS Wi-Fi support

[asiekierka]

Supporting local multiplayer between consoles has been a long-requested feature. At the same time, new research has been done on how local communication and multiboot is expected to operate:

• GBAtek received DS Wi-Fi related updates in 2021,
• The GBAtek addendum documents antenna power saving registers,
• A post from Arisotura documents some additional hardware details not present in GBAtek.
• Additional research from Arisotura is available in this thread.

I'm not sure what direction to take this in, but I'm keeping this issue open as a reminder, as well as a collection of useful notes scattered across the Internet.

Prior art

Most of these don't use proper hardware-accelerated "Ni-Fi"/"multiplay"; rather, they use something more akin to sending raw Wi-Fi frames.

• CTurt's dsgmDSWIFI "local multiplayer" patch
• CTurt's NiFiCapture
• cotodevel's NiFi

[AntonioND]

CTurt's dsgmDSWIFI "local multiplayer" patch

I've cleaned that patch from built artifacts and pushed it to a branch here: https://github.com/blocksds/dswifi/tree/nifi