Booting a 486 from floppy with the most up-to-date stable Linux kernel • Hacker News Board

Re: Booting a 486 from floppy with the most up-to-date stable Linux kernel

#51

Post by compsciphd » Mon, Jul 06, 2020, 10:24 PM UTC

back in 2002, I built a floppy that had a linux kernel (2.4.18-rc4) with multiple ethernet drivers (back then tulip was taking over the 100mbps ethernet world, so pretty sure that was included, as well as the 3c509 driver), X (vesa driver), busybox (or proto/fork busybox), rdesktop to build a a thin client on a floppy. I even had a version that was able to squeeze in vncviewer by using the over 1.44MB modes of writing floppy disks.

the project's point was to showcase stripping shared libraries of unused symbols to get the per binary density of statically linking across one's entire set of binaries. (useful for saving space on embedded systems) i wouldnt claim that it was unique (I believe Debian did something similar), but was a fun project.

Re: Booting a 486 from floppy with the most up-to-date stable Linux kernel

#52

Post by robohoe » Mon, Jul 06, 2020, 10:30 PM UTC

locao wrote: post #37

Does anyone else miss having this level of motivation? And that's not an isolation effect on me, I gave up on trying fun things like this for a long long time now.

I used to do this kind of stuff in junior high, high school, and college...back when I had the time now. Now with a day job it's time to find some time to muck around and really explore things with your curiosity and imagination. I totally see where you're coming from.

Re: Booting a 486 from floppy with the most up-to-date stable Linux kernel

#53

Post by giantrobot » Mon, Jul 06, 2020, 10:33 PM UTC

quotemstr wrote: post #11

drt1245 wrote: post #9

Earlier quoted context omitted.

Recent versions of Debian require a 686. https://www.debian.org/releases/stable/i386/ch02s01.en.html#...

Would it be feasible to just build a Debian image for the i486? Few packages should depend on something newer.

Since the modern Linux kernel doesn't make any promises of 486 support there's very likely plenty of places inline assembly uses instructions unavailable on a 486.

So even if you compiled it with strict -march i486 you'd end up with unsupported instructions. Modern GCC also doesn't like emitting strict i386 or i486 code anymore so you'd be likely to end up with unsupported instructions even without any inline assembly.

Re: Booting a 486 from floppy with the most up-to-date stable Linux kernel

#54

Post by twoodfin » Mon, Jul 06, 2020, 10:38 PM UTC

znpy wrote: post #27

drt1245 wrote: post #9

Earlier quoted context omitted.

Recent versions of Debian require a 686. https://www.debian.org/releases/stable/i386/ch02s01.en.html#...

also, this video features a 486 cpu because linux dropped 386 support a while ago. https://www.zdnet.com/article/good-bye-386-linux-to-drop-sup...

Anyone know what in particular the 486SX had that the 386 didn’t to make keeping only the former alive practical? Unfortunately the kernel mailing list link in the zdnet article appears to be rotted away.

Re: Booting a 486 from floppy with the most up-to-date stable Linux kernel

#55

Post by jfkebwjsbx » Mon, Jul 06, 2020, 10:38 PM UTC

zozbot234 wrote: post #6

josteink wrote: post #2

Posts like this showcase how malleable Linux really is without getting overly complicated to follow. Really a nice quick read.

But not nearly as malleable as it could be. Hopefully, true 80386 support can be reintroduced to the kernel in a way that keeps it properly self-contained and easy to support. There are also a few kernel-tinification approaches floating around that could make the kernel smaller and easy to fit in a floppy-using scenario.

No, it will not be reintroduced. There is no use for it. That belongs in a fork.

Re: Booting a 486 from floppy with the most up-to-date stable Linux kernel

#56

Post by Symbiote » Mon, Jul 06, 2020, 10:38 PM UTC

pan69 wrote: post #48

znpy wrote: post #27

Earlier quoted context omitted.

also, this video features a 486 cpu because linux dropped 386 support a while ago. https://www.zdnet.com/article/good-bye-386-linux-to-drop-sup...

I was always under the impression that Linux 386 simply meant 32 bit support. So, no 386 support would mean no 32 bit support rather than the 386 specifically.

No, that's x86.

They dropped 386 support, but a 486 still works.

Re: Booting a 486 from floppy with the most up-to-date stable Linux kernel

#57

Post by radicaldreamer » Mon, Jul 06, 2020, 10:40 PM UTC

locao wrote: post #37

Does anyone else miss having this level of motivation? And that's not an isolation effect on me, I gave up on trying fun things like this for a long long time now.

I've just become a lot lazier

Re: Booting a 486 from floppy with the most up-to-date stable Linux kernel

#58

Post by anthk » Mon, Jul 06, 2020, 10:40 PM UTC

There was a Nethack floopy for 3.4.3 (still played a lot by tons of people) which was booted up from a tiny Linux floppy. Amazing. It may work under a 486. Search for "nehabodi".

http://nehabodi.sourceforge.net/

Re: Booting a 486 from floppy with the most up-to-date stable Linux kernel

#59

Post by treeman79 » Mon, Jul 06, 2020, 10:43 PM UTC

aksss wrote: post #45

reaperducer wrote: post #29

Earlier quoted context omitted.

I guess it depends on if noise and power are your primary considerations. For some, they'd rather not see a useful machine take up space in a landfill, leech toxins into the environment, and simultaneously drive unneeded demand for the production of yet another computer. I guess one would have to do the math and figure out what the environmental impact of a new Pi 3 B+ is. Or they could figure out if the increased el…

I fully empathize with this - I hate throwing out/recycling electronics. The power side it truly does depend on your local rates of course. If you consider a 24/7 draw of about 35 watts to power an out-of-box 486 DX2 (headless) vs like 3 watts for an RPI, you can do the math with some variance and figure out just how long the $60 will last you. But a 10-fold reduction in power consumption is pretty remarkable. When y…

Dad told me he got a new computer. I asked how long he had the old one.

Apparently it was my old team fortress computer. So like 15 years.

Re: Booting a 486 from floppy with the most up-to-date stable Linux kernel

#60

Post by BruiseLee » Mon, Jul 06, 2020, 10:45 PM UTC

twoodfin wrote: post #54

znpy wrote: post #27

Earlier quoted context omitted.

also, this video features a 486 cpu because linux dropped 386 support a while ago. https://www.zdnet.com/article/good-bye-386-linux-to-drop-sup...

Anyone know what in particular the 486SX had that the 386 didn’t to make keeping only the former alive practical? Unfortunately the kernel mailing list link in the zdnet article appears to be rotted away.

I believe 386 did not have certain "atomic" instructions like CMPXCHG or XADD. So in order to support 386, the kernel had to have special versions of all locking primitives just for 386.