From gonna to finna?

Factual Questions
1

Over lunch I overheard a term I have long wondered about.

"I ain’t finna mess with that."

In my experience, the term finna (sp?) is been used exclusively by black people. I also understand it to be synonymous with “going to.” But for the life of me, I cannot figure out the etiology of “finna.”

Any ideas?

2

Damn - I’m a fucking idiot!
(Is it okay to call yourself names in GQ?)
Derived from “fixing to.”

Google first, then post…

3

fixing > fixin’ > fi’in’

to > ta > 'a

fixing to > fi’in’a