Discovered another huge amount of I/O ports in the DSi's wifi unit (the Atheros chip on the wifi daughterboard). The thing is accessed via SDIO (arm7 port 4004A00h..4004BFFh), my current impression is that it's a whole new wifi unit (not just a replacement for the older/slower BB/RF chip, ie. also a complete replacement for the wifi packet transfers via NDS port 480xxxxh) (the Atheros datasheets are a bit unclear about if or how the Atheros chips can do anything like transferring packets, or...
DSi wifi hardware discovered
DSi wifi hardware discovered