Hi Ethan, Arnd, Peter and Dinh, On Mon, May 18, 2026 at 11:29:48AM +0200, Arnd Bergmann wrote: > We last discussed this a year ago when Simon Schuster mentioned[1] > that Siemens Energy is still using NIOS-2 in production and would > prefer to have this still included in Linux for at least another > few years until the obligation for kernel updates ends.
First off, thank you, Arnd, for remembering us as this patch series came up and also to Dinh for his maintenance of the architecture! Regarding our status in relation to nios2, Arnd's response already gives you the gist: We are well aware that the architecture was deprecated by Intel and are therefore phasing it out in favour of more contemporary hardware. I'm also fully aware of the uncertain future of 32-bit architectures as a whole [0] and that this fate will come to nios2 sooner or later. But as of now, the mainline support is still in very good shape. On Mon, May 18, 2026 at 12:57:35PM +0200, Peter Zijlstra wrote: > Isn't that what we have LTS branches for? Unfortunately, as we are an infrastructure provider for civil energy infrastructure, the refurbishment cycle is a bit slower than for traditional consumer systems. This implies that the traditional LTS support duration (max. Dec 2028 as of writing [1]) is rather short, and we would be glad if we could keep the architecture in mainline for at least 5 years and only then "decay" to LTS. On Mon, May 18, 2026 at 11:29:48AM +0200, Arnd Bergmann wrote: > My feeling is that the maintenance burden of keeping nios2 is > relatively low. On the other hand, maintaining it out of tree > as a patch set is also something that should not be all that > hard if it does get removed. Judging from the architecture's git history, it seems that it's currently mainly touched by treewide refactors, which are extremely helpful as we therefore do not have to piece these changes together downstream. In other respects, we try to be good citizens and contribute bugfixes as well as required cleanups (such as implementing clone3 [2] and fixing its flag behaviour on 32-bit architectures) as they come up. If desired, we also would be happy to intensify our support regarding reviews or testing to share the maintnance burden if it helps to keep nios2 in mainline a bit longer. Best regards, Simon 0: https://lwn.net/Articles/1035727/ 1: https://www.kernel.org/category/releases.html 2: https://lore.kernel.org/lkml/20250821-nios2-implement-clone3-v1-0-1bb240173...@siemens-energy.com/
