Deprecation/removal of nios2 target support

[Dinh Nguyen]

Hi Simon,

On 3/24/25 05:03, Arnd Bergmann wrote:
> On Mon, Mar 24, 2025, at 10:26, Simon Schuster wrote:
>> On Thu, 18 Apr 2024, Arnd Bergmann wrote:
>>>
>>> We should probably remove nios2 from the kernel in the near future,
>>> but even if we decide not to, I think deprecating it from gcc is the
>>> right idea: If there are a few remaining users that still plan
>>> to update their kernels, gcc-14 will still be able to build new
>>> kernels for several years.
>>
>> Sorry to dig this up after nearly one year, but this thread has only now
>> come to my attention. I'm a colleague of Andreas Oetken at Siemens
>> Energy (unfortunately the original mail got lost somewhere between our
>> carveout from Siemens and daily business).
>>
>> First of: We continue to actively use the linux kernel (and the
>> associated gcc/binutils-based toolchain) on the NiosII platform, perform
>> tests regularly on hardware and inspect any failures we encounter.
>> Furthermore, we are also in the (so far internal) process of upstreaming
>> two stability fixes related to NiosII memory-management facilities in
>> the kernel. As soon as they have passed their required degree of testing
>> on our side, we plan to send them to the LKML mailing list.
> 
> Generally speaking, it probably won't hurt to just post what you
> have after you have identified a problem and fix, so it can be
> discussed while you are still testing.
> 
>> We are aware that the architecture was removed from binutils, GDB, gcc
>> and QEMU as developing new features for a deprecated architecture makes
>> no sense. However, with the relatively recent deprecation (announced by
>> Intel on 2023-06-09), we, and probably others, still see high value in
>> continued support by runtime components (especially in the linux kernel
>> and glibc) for the foreseeable future to support existing deployments;
>> at least on the level of minimal lifesupport. We also would be glad to
>> continue providing periodic testing support to this end for the NiosII
>> architecture on hardware (along with bugfixing as required).
> 
> I think that is fine: while reducing the number of architectures
> in the kernel is something that will help reduce the amount of work
> for cross-architecture patches in the long run, nios2 is particularly
> small, and keeping it around for another few years is not going to
> make a huge difference. There are a few other architectures that
> are in a similar position, with only a single person or team actually
> interested in keeping it around after the product is no longer
> actively marketed for Linux based products (arc, csky, hexagon,
> microblaze, nios2, openrisc, sparc32 and xtensa). Pretty much all
> of these have been replaced by 64-bit risc-v cores in products,
> 
> There are a few things you can do to help keep nios2 in the kernel
> for a while longer, as I'm sure we will keep getting requests to
> remove support otherwise:
> 
> - add yourself to the MAINTAINERS file (R: or M:) in order to
>    get Cc's on cross-architecture patches and test them before
>    the make it into the kernel.

Per Arnd's recommendation, can I add your name to the MAINTAINERS file?

Dinh