I'm pretty sure I've seen what you're talking about while I've been looking through the SRD, so it should be in Pathfinder.
EDIT: Could you be thinking of the Chain Fighter Half-Orc Alternate Racial Trait?
Chain Fighter: Some half-orcs have escaped from slavery and reforged the chains of their imprisonment into deadly weapons. Half-orcs with this racial trait are proficient with flails and heavy flails, and treat dire flails and spiked chains as martial weapons. This racial trait replaces weapon familiarity.
i think i read some where that you can craft a chain weapon from your slave chains or shackles. if there isn't then i must have seen it in some D&D stuff.
I couldn't find a feat or trait that was flavored like that, but the half-orc has an alternate racial feature called "Chain Fighter" that might be what you're looking for.
Chain Fighter: Some half-orcs have escaped from slavery and reforged the chains of their imprisonment into deadly weapons. Half-orcs with this racial trait are proficient with flails and heavy flails, and treat dire flails and spiked chains as martial weapons. This racial trait replaces weapon familiarity.
do you think that that trait would work with the meteor hammer which is two flail heads attached together by a chain?
Nah, sorry. That lists the specific weapons it works with. There's no reason you can't simply flavour your character's background the way you want, though.
Meteor Hammer is a cool weapon though; fun choice!