[PATCH] arm64: Kconfig: Make CPU_BIG_ENDIAN depend on BROKEN

[Hanjun Guo]

Hi Will,

On 2025/9/20 2:40, Will Deacon wrote:
> Big-endian arm64 configurations are vanishingly rare, yet we still claim
> to support them in Linux despite very limited testing or visible
> interest. Supporting big-endian adds unnecessary burden to reviewers and
> contributors which, without any known active users, is hard to justify.
> For example, recent work to improve our futex routines and to implement
> nested virtualisation support is non-trivially complicated by having to
> support both big- and little-endianness.
> 
> Back in 2019 [1], it was claimed that Huawei were using arm64 big-endian
> machines in their telecommunication products but I don't know whether
> that's still the case and certainly haven't seen any patch contributions
> to help support or maintain it.
> 
> Make CPU_BIG_ENDIAN depend on BROKEN as an initial deprecation step
> towards its removal.
> 
> Cc: Catalin Marinas <catalin.marinas at arm.com>
> Cc: Marc Zyngier <maz at kernel.org>
> Cc: Ard Biesheuvel <ardb at kernel.org>
> Cc: Arnd Bergmann <arnd at arndb.de>
> Cc: Hanjun Guo <guohanjun at huawei.com>
> Cc: Jonathan Cameron <Jonathan.Cameron at huawei.com>
> Cc: Guenter Roeck <linux at roeck-us.net>
> Link: https://lore.kernel.org/linux-arm-kernel/73701e9f-bee1-7ae8-2277-7a3576171cd4@huawei.com/ [1]
> Signed-off-by: Will Deacon <will at kernel.org>
> ---
> 
> Cc'ing Guenter as a heads-up in case he needs to turn down his testing
> to avoid this causing a false regression report.
> 
> Cc'ing Hanjun and Jonathan for clarity on the telecommunication
> situation.

Sorry for the late reply, the current products are still using the ARM64 
big-endian architecture on Linux, but the future evolution will not.

It will take quite a while (for years) for the end of the product life
cycle, please keep it as BROKEN.

Thanks
Hanjun