Linus Torvalds has accepted the first series of changes into the Linux 7.1 kernel, expected to be released in mid-June. These changes mark the end of support for i486 processors, with options for building the kernel with support for 486DX, 486SX, and AMD ELAN processors being removed from Kconfig and Makefile. While the code for actual support for running on i486 processors remains in the kernel, building for such systems will now require applying patches to the assembly files.
The decision to remove support for i486 processors was driven by the need to maintain complex code in the kernel that emulates hardware operations like CX8 and TSC. This code has often been a source of problems, with developers spending valuable time on analysis. Additionally, very few people use modern branches of the Linux kernel on outdated 32-bit CPUs, making the continued support for i486 processors unnecessary.
Discussions about removing support for i486 CPUs have been ongoing in the Linux community, with Linus Torvalds raising the issue back in October 2022 due to a bug in the “CX8” instruction emulation code. In 2025, after another problem was identified with emulating the same instruction, Torvalds reiterated his stance on abandoning support for the i486 CPU, citing the need to prioritize developers’ time efficiently.
It is important to note that support for i386 processors was removed from the kernel in 2012. The discontinuation of support for classic i486 processors will not impact integrated processors like Intel Quark produced before 2019, as well as SoCs like Vortex86DX, which belong to the i486 class but include additional instructions typical for the Pentium generation.