I noticed that Linux 5.12 has a new config option regarding "Processor family". The default choice, Pentium-Pro (M686), is highlighted in this quote:
------ Processor family 1. 486SX (M486SX) (NEW) 2. 486DX (M486) (NEW) 3. 586/K5/5x86/6x86/6x86MX (M586) (NEW) 4. Pentium-Classic (M586TSC) (NEW) 5. Pentium-MMX (M586MMX) (NEW) > 6. Pentium-Pro (M686) (NEW) 7. Pentium-II/Celeron(pre-Coppermine) (MPENTIUMII) (NEW) 8. Pentium-III/Celeron(Coppermine)/Pentium-III Xeon (MPENTIUMIII) (NEW) 9. Pentium M (MPENTIUMM) (NEW) 10. Pentium-4/Celeron(P4-based)/Pentium-4 M/older Xeon (MPENTIUM4) (NEW) 11. K6/K6-II/K6-III (MK6) (NEW) 12. Athlon/Duron/K7 (MK7) (NEW) 13. Opteron/Athlon64/Hammer/K8 (MK8) 14. Crusoe (MCRUSOE) (NEW) 15. Efficeon (MEFFICEON) (NEW) 16. Winchip-C6 (MWINCHIPC6) (NEW) 17. Winchip-2/Winchip-2A/Winchip-3 (MWINCHIP3D) (NEW) 18. AMD Elan (MELAN) (NEW) 19. GeodeGX1 (MGEODEGX1) (NEW) 20. Geode GX/LX (MGEODE_LX) (NEW) 21. CyrixIII/VIA-C3 (MCYRIXIII) (NEW) 22. VIA C3-2 (Nehemiah) (MVIAC3_2) (NEW) 23. VIA C7 (MVIAC7) (NEW) 24. Core 2/newer Xeon (MCORE2) 25. Intel Atom (MATOM) ------ info: https://cateee.net/lkddb/web-lkddb/M686.html I know that, in the past, we have been careful to not require certain processor features on i686, such as SSE [0]. I would appreciate some guidance, both about this kernel configuration option, and what we have historically considered to be the "minimum requirements" for i686 hardware. I will put that information the manual so that it doesn't get lost. Leo [0] https://lists.gnu.org/archive/html/guix-devel/2016-07/msg01534.html