Help understanding Ocarina source please

Hi
I'm trying to get my head round the source code for applying Ocarina codes. I can read the appropriate GCT file from SD using the game id but what happens next? When the contents of the GCT file are copied into memory at 0x800027E8 is that how the game code is patched or is it placed there temporarily before the game gets patched (I read that this area of memory is commonly used as temporary storage)? If it's the latter, what code performs the patching?

Thanks for reading...

According to WiiBrew: 0x80001800 (size:0x1800) is an unused Exception Vector area often used for loader stubs and reloaders as this area is never cleared or used.

In other words: it is a save place for code that is called by ocarina's hooks.

Thanks for saying "hooks" - that triggered me to look in the right places - it was the bit where the kenobiwii stuff is placed at 0x80001800 that sets the whole thing up.