False premise: you often cannot blow away the firmware, because it is either hard-coded, or signed.
And even when said premise is correct for a device, there are cases where the firmware inherently requires copyrighted material (For instance, requiring a (copyrighted) poem in a handshake).
Do you want the state to use men with guns to force everything with a microcontroller in it to also come with an SDK? I'm basically a socialist, and even I think that's ridiculous overreach.
You could be held for circumvention of copy protection schemes.
http://arstechnica.com/tech-policy/2013/01/unlocking-new-cel...
No way! Copyright law does not prevent someone from creating a new work that is designed to be compatible with an old work. Likely outcomes are that the poem would not qualify for copyright protection for that usage (it's not a poem as much as a sequence of arbitrary bytes to be read only by a computer), or that a fair use finding would be made, perhaps on the grounds that the copy does not affect the market for the original work - i.e. nobody was paying for the poem. Most likely a judge would just throw out the entire case at the start as a waste of the court's time.