There are all kinds of different tablets, with different price ranges...
Tablets are essentially, smartphones, without the "phone" part, for the cheap
models. And, I guess, small computers, of a type similar to "netbooks" and
notebooks, for the expensive ones. (But, with touch screens, instead of
keyboards.)
I don't know anything about any firmwares (or even a BIOS, for the cheap
models) besides the firmware blobs that come embedded in the non-free OSs
(Android versions) that come pre-installed on the tablets - and, that you can
get rid of, when you install Debian, for example.
(But, I haven't tried them myself, yet. So, I'm not sure about this...)
Concerning the hardware,
Since the Allwinner SOCs and the motherboards are not "Free Hardware"... We
can't know how they work, inside.
And, although I seriously doubt that someone would bother spending costly
resources putting "spychip" components inside such cheap models, of the type
that interest me (in order to create parallel circuits to access the
Internet, or the 3G network, without my knowledge)... I can never be sure of
that.
Anyway, that's one of the reasons why I ordered a Chinese model... So that,
if it's possible (which I very much doubt that it is) it should be only the
Chinese Big Brother that is capable of such. :)
(Through the Western telecoms?!... :) ehehe)
