Hmm... I was hoping for a serial shell or something... Is there USB network support (like the ethernet gadget linux module)
Rockbox doesn't have a shell or network stack, so no.
or USB host support?
Not yet, though someday we'd like to get it.
(I'm not experienced at all in C or such... I'm just a Python programmer, keep it simple
)
So you picked one of the most complicated possible things to work on?