The emulator doesn't come with a standard bios, every game has to be decrypted with a key that matches the game and region so the emulator can read the game data. A user will have to source a set of up to date keys which are a key.txt file.
Some arguments below i found
--- Launch options ---
-g Path of game
-f Launch in fullscreen mode
-ud Render output upside-down
--- Extractor tool ---
-e Path to WUD or WUX file for extraction
-p Path of file to extract (for example meta/meta.xml)
-o Output path for extracted file.
Just figuring out the default key.txt location so i can run a game and then work out how to get the keys stored under /BIOS/wiiu and have the emulator automatically see them in the location.