Tobias Geerinckx-Rice <m...@tobias.gr> writes: > Hej Marius, > > [I see this is being CC'd to @libreboot.org. I'm answering only as a GNU > Guix user and contributor, and assume people who live and breathe this > stuff will find plenty of holes in my opinion. Which this is.] > > Marius Bakke wrote on 08/01/18 at 19:26: >> In my opinion, CPU microcode falls under "non-functional data", as >> expressly permitted by the GNU FSDG. > > I'm not sure how tongue-in-cheek this is, so I'm not sure how to > respond. I hope nobody on the Internet is wrong^Wseriously suggesting > that microcode or any other firmware isn't machine code and — > unfortunately for everyone everywhere — very (dis)functional indeed. > > (Don't get me wrong: I wish it weren't so, or that there were some sort > of commonly-agreed-upon wink-nudge fiction that it wasn't. If there is, > then Debian isn't playing along: microcode blobs are ‘non-free’[0].) > > I think the real and thornier question for GuixSD is: if the recent CPU > vulnerabilities require a microcode update to fully mitigate, then how > do we square not recommending proprietary globs like this in official > channels with giving users all knowledge required to decide for themselves? > For this particular question, I think we can point users to this discussion thread in the news section for example. Then they can decide for themselves what to do. I think this is close to the best thing we can do now.
>> It is not required for the processor to function, it is merely *a >> posteriori* data that the CPU can use to fix erratic behaviour. > > AIUI, at least on x86 CPUs, the microcode *is* a large and/or functional > part of the processor. I suspect that's the case for most sufficiently > modern (complex) chips, but it's not my field. > Agree, in my assembly programming course, the lecturer mentioned that (if I recall correctly) a mircrocode update can bring new instruction set to a CPU, so it is a very programmable part of the CPU. > Kind regards, > > T G-R > > [0]: https://lists.debian.org/debian-devel/2012/11/msg00109.html, > https://packages.debian.org/search?keywords=microcode
