It's not only old x86 i486 CPU support being removed from the Linux kernel but a number of older ARM platforms and features are on the chopping block too. A proposal has been laid out for deprecating and then removing a number of outdated ARM platforms and features from the Linux kernel in early 2027.

Back in July 2024 was a proposal by ARM Linux maintainer Arnd Bergmann to deprecate a number of old ARM boards and features. While upstream Linux kernel maintainers were largely in agreement over the deprecation and eventual removal for 2025~2026, ultimately the effort didn't materialize in the past two years.

Arnd Bergmann started a new Linux kernel mailing list thread yesterday where he acknowledged "dropping the ball" and is now restarting the discussion over these ARM platform and feature deprecations. Given the timing, he's now looking at taking action for early 2027 following this year's Linux LTS kernel release.

Among the deprecations and removals planned:

- all board files that are still not converted to DT (except for OMAP1 and S3C)

- iWMMXt FPU support

- ARMv6/ARM1136r0 (not ARMv6K/ARM1136r1/ARM1176) along with the OMAP24xx and i.MX31 SoCs using it

- Cortex-M3/M4/M7 based microcontroller support (stm32, imxrt, lpc18xx, samv7)

- LSI Axxia platform

- OABI, OABI-compat and NWFPE are confined to StrongARM based builds and scheduled for removal once StrongARM is gone.

- DEPRECATED_PARAM_STRUCT, which was originally scheduled for removal in 2006 (!)

Additionally, big endian ARMv7 CPU support is marked as "BROKEN" but not planned for removal at this time. By marking it as broken is for lowering the testing standards and could be removed if/when ARM64 drops its big endian support.

Given the current kernel release timing, these changes are likely for Linux 7.4. More details for those interested in this LKML thread.