Linux on an 8-bit micro (2012)

This is from 2012. Previous discussion: <a href="https://news.ycombinator.com/item?id=5581851" rel="nofollow">https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=5581851</a><p>While this is amazing, this does prove that it is probably impossible to run Linux in 8-bit micro without such contortion. Any Turing-complete machine with enough storage and memory can simulate ARM, and also ARM Linux. So don&#x27;t use this as an argument for using a normal Linux in such platforms :)

That&#x27;s amazing. I wouldn&#x27;t even know where to start on something like this:<p>&quot;As you can see, there is an antique 30-pin SIMM memory module on the board. These were in use for 80286-based PCs. It is interfaced to the ATmega, and I wrote the code to access it as well as refresh it within spec (SDRAM requires constant refreshing to avoid losing data).&quot;<p>Though 300kb&#x2F;s is (much) slower than a hard disk, which is hard to imagine...and the result: &quot;It takes about 2 hours to boot to bash prompt&quot;

This is probably one of the crazier projects I&#x27;ve ever seen. I&#x27;ve often contemplated what running a &quot;true os&quot; on an 8 bit CPU would entail, and TBH the idea of an emulator never struck me.<p>On top of that, a hand-wired linux computer with hand-written arm emulator? Ridiculous.

This guy is amazing, look at his projects! Really inspiring.<p>Related (you may know it already): <a href="https://github.com/EtchedPixels/FUZIX" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;EtchedPixels&#x2F;FUZIX</a><p>Implementing a VM is an interesting way to workaround some Harvard architecture&#x27;s limitations as long as speed is not a factor.

&gt; uARM is certainly no speed demon. It takes about 2 hours to boot to bash prompt<p>Because he&#x27;s emulating a 32 bit system on an 8 bit system, which certainly takes some brilliant hacking skills, but takes it completely out of the realm of something practical.

<a href="https://en.m.wikipedia.org/wiki/Contiki" rel="nofollow">https:&#x2F;&#x2F;en.m.wikipedia.org&#x2F;wiki&#x2F;Contiki</a><p>Runs on 6510(6502) with 64kb on a Commodore 64. While is is cool it would be more interesting to have it run native and not via an ARM emulation layer.

I haven&#x27;t seen software-based DRAM refresh in a long time. Well done!

Unbelievable proof of concept. It is just genius that this guy made this. But what do you think that we can get out of this? Are there any practical reasons to run Linux on Micro-controller?

For something like this with fewer layers:<p><a href="http://en.wikipedia.org/wiki/OS-9" rel="nofollow">http:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;OS-9</a>

ucLinux gets you around the MMU problem... Was Linux ever built on 16-bit? The PDP-11 (the origin of Unix) was 16..

That one was one of the best myth buster in tech (not considering the time taken to boot the system!)

Does anyone know why these 8-bit processors are so expensive? The two he listed ATmega1284p and ATmega644a cost like $9.07 (qty 1) to $4.88 (qty 2.5k), and $7.08 (qty 1) to $3.79 (qty 2.5k) on Mouser.<p>I would have thought we&#x27;re talking like a $1.30 chip.<p>Meanwhile look at what you get for $6 - <a href="http://linuxgizmos.com/quad-core-allwinner-soc-targets-low-cost-4k-ott-set-top-boxes/" rel="nofollow">http:&#x2F;&#x2F;linuxgizmos.com&#x2F;quad-core-allwinner-soc-targets-low-c...</a><p>Am I missing something? Or are his 8-bit microcontrollers actually in the exact same price range as an SOC that runs Linux natively?

&gt;&gt;To conquer this obstacle, I wrote an ARM emulator.<p>So, its still running on an ARM!