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Peter Anvin" , Will Deacon , Boqun Feng , Gary Guo , Yury Norov , Rasmus Villemoes , Boris Ostrovsky , Alexander Usyskin , Tony Nguyen , Przemek Kitszel , x86@kernel.org, Linux Kernel Mailing List , linux-um@lists.infradead.org Subject: Re: Some observations regarding the ongoing x86-32 CPU configuration cleanups Message-ID: <20261109122908.GU2668804@noisy.programming.kicks-ass.net> References: X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Mon, Nov 09, 2026 at 10:34:54AM +0000, Luís Mendes wrote: > Hi everyone, > > First of all i would like to say that i both admire and appreciate all > your hard work with this lovely OS. I do understand that maintaining > some systems can cause additional burden on maintenance, but there are > some aspects that i would like you to reconsider. > > I am writing because I believe that some aspects have not been taking > into consideration regarding the removal of the 80486 32-bit support > from the kernel, namely: > - There is this active Linux distribution:https://tinycorelinnux.net/ > and the Damn Smal Linux DSL (https://damnsmalllinux.org). > - There are also these CPUs: https://www.vortex86.com/products/Vortex86EX > - There may be only a few vintage 486 systems still working, but there > are also other new x86 CPUs systems, especially in FPGAs like the > https://github.com/MiSTer-devel/ao486_MiSTer which is a 486SX core > that operates at 90MHz and can use up to 256MB RAM memory. There are > plans to update this CPU IP core to become a full 486DX core, by > adding a FPU unit to it and would turn this into a usable Desktop > system with tineycorelinux. There is a considerable retro-computing > community that utilizes the AO486 core on the MiSTer FPGA platform. > There is even a Voodoo 3dfx accelerator card: > https://github.com/victor-fisyuk/voodoo-fpga-public. > > Overall i just want to inform you that some new x86 32-bit systems are > still being sold brand new and can be utilized with Linux. I would > like that you consider this with regard to how much 80486 support > should be removed from Linux. > > Personally i do have plans to extend the AO486 core to have the FPU > and would like to be able to run a modern Linux on it. It would have > entertainment and educational applications. With tinycoreinux it can > have a usable desktop. I don't realistically see 486 support coming back -- the thing doesn't even have TSC. Getting rid of all the horrible (and completely untested) code for no-tsc alone was worth deleting 486 support for. The other option is you actually implementing RDTSC, CPUID (and possibly CMPXCHG8B) on your FPGA. I'm sure that's actually a *LOT* simpler than doing i487 support. Just add whatever instructions are required to get the bare minimal 32bit build working.