Eri HaKawai is a new exploit for PAL Wiis, which work for all currently released System Menu versions (<= 4.3). It works by using a bug in the savegame loading code of Tales of Symphonia: Dawn of the New World, the sequel to the Gamecube game Tales of Symphonia.
I'm releasing it in a source format (no binary data.bin) under the GPLv2. You'll need a Broadway cross-compilation toolchain, as well as a checkout of Segher's Wii Git repository. Do whatever you want with it (as long as it is allowed by the license, of course!), I'm just too lazy to distribute binaries.
How to use (directly copied from the README file in the tarball):
Usage: - Compile it with ./make.sh - Copy the "private" folder to the root of your SD card. - Put the homebrew you want to load on the root of your SD card, named "boot.elf" - Start the game and load the first save - Press the PLUS button to enter the game menu - Scroll to the STATUS button and press A - Scroll to the monster named "Eri HaKawai" and press A - The boot.elf file should be loaded from your SD card.
That's it! Have fun with this new exploit, and don't forget to play the great game that Tales of Symphonia: Dawn of the New World is :-) .