On Fri, Jan 12, 2018 at 09:48:11AM -0800, Paul Rogers wrote: > This morning I was referred to this site with microcode updates: > https://downloadcenter.intel.com/download/27431/Linux-Processor-Microcode-Data-File > > But it claims to have microcode updates going back to the venerable "P54" > Pentium-90 and "P55" Pentium-233 MMX. I'm confused. We're not told these > i586 CPUs, which don't do speculative execution, are susceptible to SPECTRE. > I don't recall reading microcode *could* be updated on them! I was afraid > microcode for the Pentium-3 family, a few of which I *can* still run, would > be neglected, but I don't know what to make of all this. Making sense of > Intel's file names as relates to particular hardware is also obscure to me. >
Not all the microcode is to fix Spectre! My experience is that intel microcode for older processors does not get changed, but they copy it into the latest tarball. When I looked at debian last week, the documentation suggested that old microcode sometimes got removed, probably as a cleanup of the site. I'm not sure if that still happens. And no, I also don't think CPUs before the Pentium4 can have microcode updated at runtime. But the P3 is apparently used in embedded products, perhaps manufacturers can use the microcode to refresh their bios. If you get microcode for an old Intel CPU, and load it, you should be able to see in dmesg the before/after versions, and the date. Alternatively, your motherboard may already be using that version. For matching filenames to hardware, I guess you mean the family - - model - stepping part : I don't know of any way to convert that to particular CPUs, but if you read the current svn version of the BLFS book it should tell you how to translate the values for your current CPU. http://www.linuxfromscratch.org/blfs/view/svn/postlfs/firmware.html If you still have a problem, please ask. I _think_ I got the Intel part (including the late and early examples) consistent when I updated it, but it's a very long and complicated page, things might still be unclear to people who have never updated microcode before. One further comment: although the debian microcode that I posted about last week does work as a (large) initrd to cover multiple machines (in early loading), I have no idea how to generate such a multi-machine initrd. That is why near the top of the page I wrote: "Preparing firmware for multiple different machines, as a distro would do, is outside the scope of this book." ĸen -- Truth, in front of her huge walk-in wardrobe, selected black leather boots with stiletto heels for such a barefaced truth. - Unseen Academicals -- http://lists.linuxfromscratch.org/listinfo/lfs-support FAQ: http://www.linuxfromscratch.org/blfs/faq.html Unsubscribe: See the above information page Do not top post on this list. A: Because it messes up the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail? http://en.wikipedia.org/wiki/Posting_style
