Hi,
I was trying to enable Ocarina for debugging. I found out that if you disable the codes and just use the hook, the game won't load. Just leave the codes enabled, even if there isn't a gct for it to point to.
Also, you can make it generic by changing the following line to match up. It will automatically calculate the appropriate gct file name. Also don't forget to get rid of the id game tag.
<memory valuefile="/CODES/{$__gameid}{$__region}{$__maker}.gct" offset="0x800028E8" />
cheers,
dcx2