As a follow-up to the news first-covered on Phoronix earlier this month about Linux 7.1 expected to begin removing i486 CPU support: it indeed happened. Linus Torvalds took the initial removal bits today without any fuss today for beginning the phase out of M486 / M486SX / ELAN kernel support.
As explained in the prior article, the initial removal is getting rid of the kernel configuration (Kconfig) options for building M486 / M486SX / ELAN CPU support. With that Kconfig code now removed, building a Linux 7.1+ kernel with that Intel 486 support isn’t possible and specifically affects AMD/Cyrix/IBM/Intel SL/SLC/SLC2/SLC3/SX/SX2 and UMC U5S. The M486 Kconfig option is for 486-class CPUs such as the AMD/Cyrix/IBM/Intel 486DX/DX2/DX4 and UMC U5D.
Assuming no one complains or raises legitimate reasons for keeping the support around, in Linux 7.2 or later more of the actual 486 code removal can easily happy for those i486-only code paths. If you still are miraculously using a i486 CPU with modern Linux kernel versions, you can keep using the likes of Linux 6.18 LTS for having maintained kernel support for the next few years. 32-bit CPUs past the i486 are still maintained albeit don’t look for any exciting advancements out of the modern kernel versions. It’s also with Linux 7.1 there is a change that may negatively impact 32-bit Linux users.
It’s this merge specifically of x86/platform material a short time ago that took that first step for i486 removal. No i486 nostalgia or other reasons kept Linus from beginning the removal process from the mainline kernel. Also in that pull for newer AMD CPUs is also a useful addition of finally printing the AMD AGESA version to the Linux kernel log when detected for easier debugging and diagnosis.
