@lxo @jas >on them work exactly like Tivo-supplied binaries and signatures (by a Tivo-controlled secret key):
I don't know if confident if Tivo ever setup such a scheme - do you have a link to exactly what Tivo did for a specific Tive model?

It's not Tivotization, as if it was tivotized, the unsigned binary would still run, but other parts of the system would cease to function.

It's a case of digital handcuffs - the software won't run without a signature and you don't have the key and how the source code that probably mostly, but not completely corresponds, happens to be free software doesn't change anything - as the software is only practically useful to run on certain model DSPs.