Quick coyotos update and question

[Jonathan S. Shapiro]

Coyotos port to rust is making slow progress - I needed to recreate a low-level host tool first, which took a while.Some of the dirty tricks  in sys/coyotos/ that were possible in C have no analogue in Rust. Basically, anything that used preprocessor sleaze to cross the asm/src boundary needed an alternative.

It has become clear that Rust support for Coldfire doesn't exist. Coldfire was mainly of interest because of the soft TLB, but I don't see that as an urgent priority. I'm dropping coldfire.

It did raise a broader question, though. Is it reasonable at this point to skip to the 64-bit architectures? I can see a case for 32-bit arm and risc-v for embedded, but I suspect 32-bit x86 is no longer terribly interesting or useful.

I don't have the bandwidth to do all of them, so I'd appreciate input.

Jonathan

[Matt Rice]

I'm of the opinion that it would be good to pick one architecture
which has qualities desirable for a microkernel and codegen
in terms of number of registers, and context switch overhead, and it
is clear that 32-bit x86 is not that. To me support for anything
beyond that ideal arch is somewhat gravy. For some things, like where
you have a legacy bootstrap environment I can kind of see the point.
But why put on that band-aid after everybody had started to tear
theirs off.

[William ML Leslie]

I don't plan on supporting any hardware I don't own, at least, until I have a working system.  I love esoteric and antique architectures as much as the next person, but right now I want to focus on the machines I use.

--

William ML Leslie

"AI is a tool" - but not, like, a pencil or even a hammer where every problem is confused with a nail - it's more like a plastic spork; occasionally less useful than nothing.

[Valerio Bellizzomi]

It would be nice to focus on the Raspberry Pi 5 (64 bits).

[Jonathan S. Shapiro]

On Sat, Feb 7, 2026 at 12:26 AM William ML Leslie <william.l...@gmail.com> wrote:

I don't plan on supporting any hardware I don't own, at least, until I have a working system.  I love esoteric and antique architectures as much as the next person, but right now I want to focus on the machines I use.

That seems very reasonably pragmatic.

At the risk of asking you to divulge dark personal secrets, would you be willing to disclose what architectures those machines might be?

Thanks

Jonathan

[Jonathan S. Shapiro]

On Sat, Feb 7, 2026 at 12:37 AM Valerio Bellizzomi <vbell...@gmail.com> wrote:

It would be nice to focus on the Raspberry Pi 5 (64 bits).

I'm interested in that one as well, but I don't (currently) have one. The later RPi 3 (EVO+) kits have a quad core 64-bit Cortex A53 and is compatible with AArch64. Since I have one sitting in front of me, I figured I'd try to get something moving on that as a way to get started.

At some point soon I want to pick up a board that has big/little or big/medium/little, but that's mainly about scheduling, so I don't think that it's "this week" urgent to take that step.

Jonathan

[William ML Leslie]

I have an assortment of AArch64 devices, and these x86-64 systems:

* A system76 lemur pro with 12th Gen Intel(R) Core(TM) i5-1235U

* An AMD 7900X3D system built for static analysis

* A Beelink EQR6 with an 8 core 6-series AMD chip

* Some older Intel x86-64 systems, like my X1 Carbon with Core2Duo

* There's an AMD FX 6300 (bulldozer) system in the cupboard if I need it

It seemed sensible to have modern and teenage CPUs from both vendors for this undertaking.

--

William ML Leslie

"AI is a tool" - but not, like, a pencil or even a hammer where every problem is confused with a nail - it's more like a plastic spork, occasionally less useful than nothing.

[William ML Leslie]

On Sat, 7 Feb 2026 at 18:58, William ML Leslie <william.l...@gmail.com> wrote:

On Sat, 7 Feb 2026 at 18:39, Jonathan S. Shapiro <jonathan....@gmail.com> wrote:

At the risk of asking you to divulge dark personal secrets, would you be willing to disclose what architectures those machines might be?

I have an assortment of AArch64 devices, and these x86-64 systems:

Oh, and also virtual machines on Google Cloud and AWS.  I fully intend to support the set of devices you get on Cloud Compute and EC2.

 

[Valerio Bellizzomi]

Yes, Raspberry 3/4/5 with some Coyotos pin read/write utility too.