Slashdot Mirror
GNU/Linux Running On An 8-Bit Processor
dartttt writes, quoting Ubuntu Vibe: "Dmitry Grinberg has successfully booted Ubuntu 9.04 on an 8 bit micro machine with 6.5 KHz CPU and 16 MB RAM. Grinberg did this experiment on a ATmega1284p, 8-bit RISC microcontroller clocked at 24MHz and equipped with 16KB of SRAM and 128KB of flash storage. Since the RAM was too low, he added 30-pin 16MB SIMM to the machine and a 1 GB SD card to host Ubuntu image. ... To get the world's slowest Linux Computer running, he had to write an ARMv5 emulator which supports a 32bit processor and MMU. A similar machine can be made very easily and everything should come in about $20."
There is source code available, but it's under a non-commercial use only license. Just how slow is it? "It takes about 2 hours to boot to bash prompt ('init=/bin/bash' kernel command line). Then 4 more hours to boot up the entire Ubuntu ('exec init' and then login). Starting X takes a lot longer. The effective emulated CPU speed is about 6.5KHz, which is on par with what you'd expect emulating a 32-bit CPU & MMU on a measly 8-bit micro. Curiously enough, once booted, the system is somewhat usable. You can type a command and get a reply within a minute." If you like watching a whole lot of nothing, there's a video of the boot process below the fold.
Why?
On one level this shows just how clever Dmitry is and it shows excellent problem solving skills. However, I would be more impressed if he could do something interesting with more modern technology. The technical challenges of booting a modern OS on dinosaur hardware are amazing and if he could take his innovation ability and apply it to state of the art technology, image what he could achieve.
My old stuff works so much better then my new stuff...%#@&*&(@+++ NO CARRIER Sorry Computer crashed. Because old software was so optimized... $#@%^^++ NO CARRIER For the old equipment. The only trade off was fault tolerance.
You will not believe how much Computing power goes to making sure your computer doesn't crash every day.
Back in the old days computers crashed much more then it does now. And it isn't that they are better programmers but more to the fact that there was a trade off on how much code in the back end needed to be done to protect the system.
If something is so important that you feel the need to post it on the internet... It probably isn't that important.
That's simply not true. Those little 8-bit microcontrollers are used all over the place. You probably have several in your desktop, some in your monitor, more in your TV, a whole bunch in your car. You just never see anyone trying to run one as the primary CPU on an interactive computer these days.
That's how this is best thought of. In effect, he used an AVR chip as the microengine for a vertically-microcoded implementation of ARMv5, with some extensions. It's not as if Linux is running natively on an 8-bit architecture; that's be like saying, for example, that when OS/360 was running on a 90-bit-instruction/32-bit data VLIWish Harvard architecture machine when it's running on a System/360 Model 50.
You mean we're supposed to use a fork??
You can mod your friends, you can mod your nose, but you can't mod your friend's nose.
An awful lot of stuff doesn't need that kind of compute power.
And AVR chips actually pack a massive amount of power. 24mhz is faster than a 486 and when you are reading sensors and similar things thats tons.
Its only 6.5khz if you try emulating a ARM chip on it.