Reproducibility and microcode updates

[Bernhard M. Wiedemann]

On 22/06/2021 12.50, Dan Shearer wrote:
> https://travisdowns.github.io/blog/2021/06/17/rip-zero-opt.html . We
> capture as much as we can about the build/test environment, but of
> course not the microcode version :-)

It says it ran on Ubuntu and that has
https://packages.ubuntu.com/search?suite=default&section=all&arch=any&keywords=intel-microcode&searchon=names

On openSUSE, the package is called ucode-intel.

So you just need to keep track of what packages are installed in which
version and that is a smart thing to do anyway.
The part you miss is which microcode version is running at that point
and that you could get from
cat /sys/devices/system/cpu/cpu*/microcode/version

I also remember a bug when after resume from s2ram, only 3 of 4 CPU
cores would have their microcode version restored and that caused
trouble when software detected available features on one core and then
tried to use it on another core that had this feature disabled.
https://bugzilla.opensuse.org/show_bug.cgi?id=903874


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