Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Linux on an 8-bit micro? (2012)

dmitry.gr

Post reply on HN
Print view View original

31–40 of 59 posts

Re: Linux on an 8-bit micro? (2012)

#31

Post by userbinator »

david-given wrote: post #15

See also ELKS, which can run an (extremely stripped down and extensively rewritten) Linux kernel on a 16-bit 8086: http://elks.sourceforge.net/ Also Fuzix, which can run a Unix-like on a variety of tiny, ancient processors like the Z80 and 6809; I've ported it to the MSP430, a modern micontroller, and I also have a half-finished port to the Raspberry Pi that I must get round to fixing one day (hilariously, the Pi has…

Considering that the first Unix was on a PDP-7 with roughly the same computing power, and many embedded systems are of similar capacity yet also run Unix-likes, it's not all that surprising. (Depending on what you call "Unix-like" --- I'd say any OS with a unified hierarchical filesystem and devices-as-files to varying extents qualify.)

Re: Linux on an 8-bit micro? (2012)

#32

Post by aortega »

david-given wrote: post #15

See also ELKS, which can run an (extremely stripped down and extensively rewritten) Linux kernel on a 16-bit 8086: http://elks.sourceforge.net/ Also Fuzix, which can run a Unix-like on a variety of tiny, ancient processors like the Z80 and 6809; I've ported it to the MSP430, a modern micontroller, and I also have a half-finished port to the Raspberry Pi that I must get round to fixing one day (hilariously, the Pi has…

My final project for college grad was a unix-like 8-bit OS called picix, it worked in PIC18 and supported tcp/ip via uIP

https://sourceforge.net/projects/picix/

Hey at least it doesn't take 2 hours to boot :)

Re: Linux on an 8-bit micro? (2012)

#33

Post by poizan42 »

poizan42 wrote: post #24
derefr wrote: post #16

Earlier quoted context omitted.

I think the argument is that one would expect "Linux running on architecture Foo" to imply support in Linux for Foo, rather than support in Foo for Linux that allows Linux to run unmodified. I certainly expected, when I clicked, to read about someone's effort to rewrite a minimal subset of the Linux kernel to use exclusively 8-bit registers and no MMU.

Linux can already run on MMU-less systems (CONFIG_NOMMU). GCC already supports AVRs, though you may have to tweak the backend a bit so ints are 32-bit wide etc. These are not the big issues in porting the Linux kernel to an AVR. The major problem is that AVR is Harvard architecture and there's probably tons of assumptions in the kernel that code and data resides in the same memory space.

- also ATmega1284P and ATmega644A mentioned in the article doesn't support external code memory nor changing the code memory after boot. However they do support a boot loader that can load code initially. So you would have to implement some sort of paging by resetting the cpu to give control to the bootloader to load the new code. Sound like fun. Also the kernel itself is far too large to fit in code memory, so it would constantly have to page parts in and out through this mechanism.

Re: Linux on an 8-bit micro? (2012)

#34

Post by hawski »

Cool project.

Personally I like the idea behind RetroBSD [1] - port of 2.11BSD Unix intended for microcontrollers.

I was thinking if a system like this powered by solar panel would be a good idea for poor countries. The idea is to have computing of the past in sustainable form available for poor. The main problem is probably to have a cheap and low energy display. Maybe epaper made in bulk would be enough? But probably such a computer can only be cheap if made in bulk. Maybe it could be cheaper than RaspberryPi? The question that remains is what about networking? Maybe they could function in similar fashion to BBS, but using shortwave radio?

[1] http://retrobsd.org/

Re: Linux on an 8-bit micro? (2012)

#35

Post by Jaruzel »

JonnieCache wrote: post #19
Jaruzel wrote: post #18

Earlier quoted context omitted.

Why are people TL;DRing a lot of posts recently? Surely on HN, the joy is in discovering the linked content themselves surely? If you don't have time to read HN, and need TL:DRs then you should question why you are here in the first place. -- Vote down if you like, I joined HN to get away from inane commentary and TL:DR nonsense that's so prevalent on other sites.

as much as tl;dr is increasingly irritating when used in this way, baiting downvotes is also not cool.

I'm not baiting down-votes. Far from it. Just voicing that TL;DR is annoying. There's a reason you can't have both text AND a url in a HN submission - it's to encourage people to actually visit the link.

Next, we'll have people just copy-pasting the entire article body as a comment ... :(

Re: Linux on an 8-bit micro? (2012)

#36

Post by VLM »

teddyh wrote: post #25
tomtomtom777 wrote: post #20

Earlier quoted context omitted.

I wouldn't exactly call it click-bait. The crux of both the article and the accomplishment is writing an 32-bits ARM emulator that works on an 8-bit machine. Definitely not child's play, and a valid route to run Linux on 8-bit.

Rhetorical question: If writing the emulator was the “crux”, then why doesn’t the headline mention it? Why isn’t the whole article about it? I would certainly have upvoted and whole-heartedly lauded a story entitled “An 32-bit ARM emulator for an 8-bit CPU”. Instead, they used the headline and article content to heavily imply to actually have ported Linux to an 8-bit processor. It’s not until into about half the arti…

There is some wonderousness that they completed the emulation enough to run something complicated like linux.

Its very easy to use something limited, say a HP48 in RPN mode and some arrays as "memory" and variables as registers to implement a couple opcodes of say a 68hc11. I did that around '93 or so when the 'hc11 was contemporary (its ancient history now, but it was kind of a 6809-like microcontroller with pretty good specs for the era)

On the other hand its hard to get a complete emulator working of everything, or at least close enough to everything to boot a major software project on top of it.

Sort of like implement a system/360 emulator that only does opcode ADD, well, ok cool, but when you can boot MVS/360 thats a whole nother level of wow.

Re: Linux on an 8-bit micro? (2012)

#37

Post by 3chelon »

aortega wrote: post #32
david-given wrote: post #15

See also ELKS, which can run an (extremely stripped down and extensively rewritten) Linux kernel on a 16-bit 8086: http://elks.sourceforge.net/ Also Fuzix, which can run a Unix-like on a variety of tiny, ancient processors like the Z80 and 6809; I've ported it to the MSP430, a modern micontroller, and I also have a half-finished port to the Raspberry Pi that I must get round to fixing one day (hilariously, the Pi has…

My final project for college grad was a unix-like 8-bit OS called picix, it worked in PIC18 and supported tcp/ip via uIP https://sourceforge.net/projects/picix/ Hey at least it doesn't take 2 hours to boot :)

I did something very similar, way back in '92, on a 68000 SBC. I pretty much copied the important bits of the Unix kernel, but all in assembler!

Re: Linux on an 8-bit micro? (2012)

#38

Post by pjc50 »

hawski wrote: post #34

Cool project. Personally I like the idea behind RetroBSD [1] - port of 2.11BSD Unix intended for microcontrollers. I was thinking if a system like this powered by solar panel would be a good idea for poor countries. The idea is to have computing of the past in sustainable form available for poor. The main problem is probably to have a cheap and low energy display. Maybe epaper made in bulk would be enough? But probab…

It sounds like you're about to re-invent the failures of "One Laptop Per Child".

The one thing people in poor countries do not want is special weird incompatible systems designed for the poor. They want a solution which is adequately close to the western ones, just cheaper. Look at cellphones: http://qz.com/451844/africas-smartphone-market-is-on-the-ris...

Re: Linux on an 8-bit micro? (2012)

#39

Post by pjc50 »

Jaruzel wrote: post #35
JonnieCache wrote: post #19

Earlier quoted context omitted.

as much as tl;dr is increasingly irritating when used in this way, baiting downvotes is also not cool.

I'm not baiting down-votes. Far from it. Just voicing that TL;DR is annoying. There's a reason you can't have both text AND a url in a HN submission - it's to encourage people to actually visit the link. Next, we'll have people just copy-pasting the entire article body as a comment ... :(

> it's to encourage people to actually visit the link.

You read the links? I'm just here for the commenting. If the comments imply the article is good enough I'll read it.

(This effect used to be very strong on the Guardian's commentisfree site, where the top comments often contained valuable correction/context to the tritness of the article)

> Next, we'll have people just copy-pasting the entire article body as a comment

I've seen that done a few times; it's useful if it's paywalled/adwalled/unusuable-crashy-javascript-walled.

Re: Linux on an 8-bit micro? (2012)

#40

Post by hawski »

pjc50 wrote: post #38
hawski wrote: post #34

Cool project. Personally I like the idea behind RetroBSD [1] - port of 2.11BSD Unix intended for microcontrollers. I was thinking if a system like this powered by solar panel would be a good idea for poor countries. The idea is to have computing of the past in sustainable form available for poor. The main problem is probably to have a cheap and low energy display. Maybe epaper made in bulk would be enough? But probab…

It sounds like you're about to re-invent the failures of "One Laptop Per Child". The one thing people in poor countries do not want is special weird incompatible systems designed for the poor. They want a solution which is adequately close to the western ones, just cheaper. Look at cellphones: http://qz.com/451844/africas-smartphone-market-is-on-the-ris...

I also think that smartphone will get there faster. Maybe Chromebooks if Google will play it nice, because of Android apps support and normal keyboard.

However I think OLPC is different from what I have in mind. OLPC targeted children with OS designed for children. I am thinking about something more like RaspberryPi with integrated power and display systems, but with external keyboard. Also I think about it to be extremely cheap. $100 laptop is already done by Chromebooks, but it is not cheap enough. It would have to be around $25 or less. It should expose GPIOs like RaspberryPi so it could be used in more settings. It would be black and white and mostly text only. Basically my pipe dream. Maybe I would just like to go back in time sometimes and I am just projecting?

It is just a loose idea, but outside of people's preferences economics of scale are certainly supporting smartphones.

Post reply on HN