You need a gamecube homebrew compatible cMIOS. The recommend cMIOS for NeoGamma should do it fine. Then you need a way to boot GC.dols with that cMIOS.
I received the SD Media Launcher complete kit with adaptor for read sd card on PC, the boot DVD-ROM and the Media Launcher for Gamecube. The shipping is fast, I'm glad with the purchase. Wii Key - Gamecube SD Gecko PS2 HDAdvance/HDloader Guide PS2 Hard Drive Guide is in the second Reply below. A more convenient way to play your games, Homebrews and EMUs using other forms of Media.
![Nook color sd boot Nook color sd boot](/uploads/1/2/5/6/125626739/731903790.jpg)
NeoGamma in GC mode external, the SD-Boot.dol as sd/NeoGamma/GC.dol on a sd card in the wii's sd card slot, and a retail GC disc in the drive should do it. Or just use some GC homebrew launcher, which still requires the cMIOS, but might be easier to use. Also with a GC homebrew launcher it should work with a retail wii disc in the drive too.
But don't ask me about the.iso format you need, or if the.isos need to be defragmented.