Linux Kernel Moves to Strip Out Aging 32-bit Arm Platform Support

Thirteen patches arrived at kernel mailing lists recently, proposing deletion of 32-bit Arm platform code designated as deprecated in the upcoming Linux 7.3 release cycle. Though not yet merged, the submission represents a major step forward for Arnd Bergmann, who has pursued retirement of this legacy code for an extended period.

Bergmann's plan calls for executing these removals in Linux 7.4, expected to arrive between December 2026 and January 2027, with CPU support elimination following in the subsequent release. The timeline differs from earlier proposals that suggested removal in 2025 or 2026 following the corresponding LTS kernel release. In opening his July discussion, Bergmann acknowledged allowing the previous effort to stall for nearly two years.

The full cleanup initiative encompasses roughly 300 patches overall. This initial batch targets only the arch/arm/mach-* code and associated Kconfig dependencies.

What's going away

The targeted platforms represent a collection of 1990s and 2000s-era hardware that once held relevance but has since become obsolete.

Platforms losing support include SA1100 boards, the Acorn RiscPC, Footbridge, legacy PXA board files, and the Orion, Dove, and MV78xx0 boards. The series also removes OMAP24xx, i.MX31, and no-MMU i.MX chips, LPC18xx and Axxia, along with the STM32F4, F7 and H7 microcontrollers, Versatile MPS2, and AT91 SAMV7.

Removal of this code does not mean affected devices will cease functioning entirely. However, devices on this list will be unable to run mainline kernels from version 7.4 or 7.5 onward, as the boot code enabling their operation faces deletion.

Notably, the same 7.3 cycle brings Linux support for newer Arm-based processors including Apple's M3 Pro, Max, and Ultra, Samsung's Exynos 1580, and Qualcomm's Shikra. This pattern illustrates the kernel's continuous evolution, balancing the addition of new hardware support against the removal of legacy code serving diminishing user bases.

Linus has been here before

Linus Torvalds has consistently championed the removal of outdated code. In 2022, he questioned whether the time had come to drop i486 series CPU support from Linux, noting that i386 support had already been removed in 2012. By 2025, Torvalds stated that "there was no real reason for anybody to waste their time developing for the platform."

Given this history, acceptance of these removals appears likely unless unforeseen technical problems emerge. Nevertheless, legacy hardware retains its defenders. Organizations and individuals continue operating these machines, and Bergmann has kept the door open for anyone wishing to contest removal before the code disappears.