How did someone figure out how to code homebrew?

I am curious to know how anyone figured out how to write homebrew applications for the Wii or any other console.
The only thing I can think of is that someone that works on an authentic Wii games developed DevkitPro to help aspiring game creators.

Anyone can write a full fledged SDK once they can write and test code on the hardware. Its not easy, but certainly more than possible. Tons of people have contributed to devkitPRO.

People like Team Twiizers (and others) did loads of l337 haxx0ring and made it.

They reverse engineered the Wii and worked out how things were done, then wrote their own code to do it. No official SDK was involved, nor anyone who has seen the offical SDK. That would be illegal, because it is copyrighted code.

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SifJar
People like Team Twiizers (and others) did loads of l337 haxx0ring and made it.

They reverse engineered the Wii and worked out how things were done, then wrote their own code to do it. No official SDK was involved, nor anyone who has seen the offical SDK. That would be illegal, because it is copyrighted code.

Just coz you could see the code doesnt make it illegal to reimplement it into homebrew, as long as you dont copy the code exactly i cant see what nintendo would do as i am sure that the code used to calculate playtimes is very similar to the ones used in disc games

I'm pretty sure that if you have access to the official SDK and then develop homebrew, you can compromise the legality of whatever homebrew stuff you work on. At least, it said that on the GC Linux wiki, maybe they were just making sure that they were covered legally.