The SFC blog post doesn't mention any specific program but, in the article in The Register, the SFC director is quoted talking about Linux in particular. But Linux is just GPLv2, so doesn't have an anti-Tivoisation [1] clause. In other words, you're free to put it on hardware in binary form (even after modifying it) and sell that hardware, and you're under no obligation to give away the source code to it or any of your own software.
On the other hand, I'm sure the director of the SFC knows a lot more about this situation than I do, so I'm sure that there's something I'm missing.
However, with both GPLv2 and GPLv3, a vendor of an aggregation of copyleft and proprietary software can legally cause the the proprietary software to stop working when the copyleft software is modified. I think this hasn't been tested in court though, but the license as they are written both allow this. This would essentially brick your car/tractor until you rewrote that proprietary software from scratch.
The SFC blog post doesn't mention any specific program but, in the article in The Register, the SFC director is quoted talking about Linux in particular. But Linux is just GPLv2, so doesn't have an anti-Tivoisation [1] clause. In other words, you're free to put it on hardware in binary form (even after modifying it) and sell that hardware, and you're under no obligation to give away the source code to it or any of your own software.
On the other hand, I'm sure the director of the SFC knows a lot more about this situation than I do, so I'm sure that there's something I'm missing.
[1] https://en.wikipedia.org/wiki/Tivoization