An Interactive-Speed Linux Computer Made of Only 3 8-Pin Chips

Software engineer and longtime Slashdot reader, Dmitry Grinberg (dmitrygr), shares a recent project they've been working on: "an interactive-speed Linux on a tiny board you can easily build with only 3 8-pin chips": There was a time when one could order a kit and assemble a computer at home. It would do just about what a contemporary store-bought computer could do. That time is long gone. Modern computers are made of hundreds of huge complex chips with no public datasheets and many hundreds of watts of power supplied to them over complex power delivery topologies. It does not help that modern operating systems require gigabytes of RAM, terabytes of storage, and always-on internet connectivity to properly spy on you. But what if one tried to fit a modern computer into a kit that could be easily assembled at home? What if the kit only had three chips, each with only 8 pins? Can it be done? Yes. The system runs a custom MIPS emulator written in ARMv6 assembly and includes a custom bootloader that supports firmware updates via FAT16-formatted SD cards. Clever pin-sharing hacks allow all components (RAM, SD, serial I/O) to work despite the 6 usable I/O pins. Overclocked to up to 150MHz, the board boots into a full Linux shell in about a minute and performs at ~1.65MHz MIPS-equivalent speed.

It's not fast, writes Dmitry, but it's fully functional -- you can edit files, compile code, and even install Debian packages. A kit may be made available if a partner is found.

Oblig.

[SeaFox]

imagine a beowulf breadboard of these...

Re:

[jfdavis668]

No need to ask if it will run Linux.

Re:

[Mr. Dollar Ton]

But can a Gentoo install upgrade itself in finite time?

Re:

[93 Escort Wagon]

Just like any other Gentoo install, it can be upgraded over a weekend.

However, in this case, it's referring to a weekend on Pluto...

Re:

[Mr. Dollar Ton]

Unless you emerge the compiler suite and the desktop environment, stretching the weekend into a Venusian one...

Re:

[LordHighExecutioner]

But what about Natalie Portman ?!?

Why emulate MIPS? Why not just native ARM or MIPS?

[kriston]

I'm curious: Why emulate MIPS? Why not just run ARM on ARM or MIPS on MIPS natively?

Re:

[Anonymous Coward]

Because it has to emulate the entire machine and MIPS is a sane architecture. ARM is nearly as baroque as x86, only with fixed-size opcodes. If you read the story (I know, I know) you'd see he already had written a MIPS emulator and this was easy to re-appropriate. The actual STM32G031 chip does not have an MMU so an emulator is needed to run a modern version of Linux (recognizing that some ancient versions were ported to 8086 etc.).

Re:Why emulate MIPS? Why not just native ARM or MI

[Annymouse Cowherd]

Linux requires an MMU, and this ARM chip does not have one.

Re:

[kriston]

I read the article and noticed he had written a MIPS emulator in ARM assembly but I didn't realize that ARM still makes chips that don't have MMUs.

Re:

[viperidaenz]

Most microcontrollers don't have an MMU

Re:

[angel'o'sphere]

A) Linux does not require an MMU
B) Emulating a MIPS processor, does not magically add an MMU

Re: Why emulate MIPS? Why not just native ARM or M

[dmitrygr]

Linux kernel doesnâ(TM)t is built for nommu. Debian does require MMU. And not magically at all. I emulated it.

Re: Why emulate MIPS? Why not just native ARM or

[dmitrygr]

I published the source code. You can look at how I did it. In fact youâ(TM)ll find TWO implementations. One in c and one in assembly.

Re:

[angel'o'sphere]

Cool, did not see ARM assembly since a very long time!

Re:

[tigersha]

MIPS is not a dead architecture, at least not indirectly. RISC-V is very much a MIPS that had many flaws ironed out. They are very similar and was developed by the same people (+ new ones for RISC-V). Which brings me to... why does Dmitry have personal issues with RISC-V?

Re:Why emulate MIPS? Why not just native ARM or MI

[karmawarrior]

Well in terms of why MIPS (rather than ARM, ix86, 68000, etc), he'd already written a MIPS emulator.

But in terms of "Why emulate to begin with", the problem is that the microcontroller this is implemented on (the STM32G031) has virtually no RAM (officially only 8K although I think he says 16K is the actual amount. Either way it's puny.) So the microcontroller cannot run a Linux kernel on its bare hardware, it's simply too small. What can be done though is to write a CPU emulator that reads and writes to an external RAM module outside of the microcontroller.

A similar project (maybe the same guy? Unsure) that came out recently ran Linux on an Intel 4004 using much the same trick. The 4004 is way too crude for Linux to be ported to it directly, but it's entirely possible to write a CPU emulator in it that accesses memory outside of the 4004's usual memory range using a paging system or something similar. Unlike that though, this project seems to result in something usable, that boots (relatively) quickly and can run useful programs.

Nice project!

Re: Why emulate MIPS? Why not just native ARM or M

[dmitrygr]

Same guy :)

Re:

[serviscope_minor]

I don't have anything sensible to add technically, but damn it's impressive!

I also love the idea of using a small emulator to cream Linux onto smaller chips than would normally be expected.

Re:

[karmawarrior]

Well, now I know you're here, let me just say I found what you did (with the 4004 as well as the project under discussion) completely awesome! A fun read and concept, thank you for sharing it!

Re:

[tigersha]

Why do you have personal issues with RISC-V?

Whar wifi?

[algaeman]

You can do this on a esp32-s3 as well, for around $5.
https://github.com/ESP32DE/Boo... [github.com]

Re: Whar wifi?

[dmitrygr]

And on many other things. But none of them are 8-pin chips.

Re:

[Mr. Dollar Ton]

Great project, one of the rare recent posts that are interesting to read.

Re:

[Gideon Fubar]

Yeah thanks for this.
Great work, really inspirational.

I wish we spent more time talking about this kind of stuff around here. It's what the site is supposed to be for.

Re:

[Canberra1]

Could a pocket calculator be loaded with an OS??An Australian company is already offering HP calculator drop in board replacements. Some TI's run 68000 code faster than original Macs.

"Hundreds of chips"?

[smoot123]

I can run Linux on a Raspberry Pi. It's got one main chip and maybe a dozen smaller ones.

Even a modern laptop probably doesn't have hundreds of chips. A processor, I/O bridge, memory, and a handful of add-ons. I'd be surprised if it hit 100.

Re: "Hundreds of chips"?

[dmitrygr]

You would very likely be wrong. Youâ(TM)re not thinking of all the small glue logic, power, management chips, BMS, audio, amplifiers, all sorts of stuff really

Re: "Hundreds of chips"?

[Åke Malmgren]

I sometimes repair laptops at work. I think "hundreds" of chips is a bit high, but "dozens" is absolutely safe to say.

A minute?

[pz]

If this impoverished --- but really cool --- system can boot Linux in about a minute, why isn't my laptop, which is likely three orders of magnitude faster, booting in a few tens of milliseconds?

I've long suspected that much of the normal boot sequence in modern computers is spent in various timeouts.

Re:

[drinkypoo]

I don't know about timeouts, I suspect a lot of it is just delays.

My BIOS has an ultra fast boot mode, but I can't reasonably use it because you can't turn it off without either using a Windows tool (and I am not running Windows) or clearing CMOS, and I have a whole bunch of settings so that would be irritating on top of already being irritated because I had to do something that required I screw with the BIOS. That's never a good sign unless you're doing some performance tweaking. I have it configured to us