I ran Windows 95 on a 386 SX 16MHz for a few months. Not amazing speed-wise, but it worked.
Amazing little processor for its time.
386-DX/SX support nuked from Linux Kernel
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Re: 386-DX/SX support nuked from Linux Kernel
#32To think that support for something so edge-case has been supported this long is remarkable. Even very basic embedded x86 processors are 80486 caliber. Those more feeble than that have no hope of running the current kernel in any meaningful fashion.
In 2000, someone gave me a 386 desktop that they were about to throw out, and I ran OpenBSD on it until 2005 or so. (I was a student, so getting new hardware was more of a big deal then.) To get it working I had to recompile the kernel (which I did on a "more capable" Celeron 366) without support for newfangled hardware such as USB and PCI in order to have enough memory to boot and log in in a tolerable amount of tim…
I loved my Celeron. I had a 300 which over clocked amazingly well to 450Mhz.
In fact, those were the last days of my "dinking" with hardware. The Pentium and beyond offered such diminishing rewards that it wasn't worth it.
Re: 386-DX/SX support nuked from Linux Kernel
#33Earlier quoted context omitted.
A rad hardened machine won't be running 3.7, or 3.6.x for that matter. They will be running something a bit older with (guess I don't know for sure) security patches being back ported as needed.
I'd think that most of them would be using a RTOS like VxWorks or QNX.
Linux is used in a lot of places these days, where VxWorks or QNX might've been. I've been responsible for putting Linux to work in SIL-4 critical systems all over Europe, for example, saving millions in licensing costs while at the same time, getting Linux certified for safety-critical apps. It really is taking over.
Re: 386-DX/SX support nuked from Linux Kernel
#34I ran Windows 95 on a 386 SX 16MHz for a few months. Not amazing speed-wise, but it worked. Amazing little processor for its time.
Yea, it is unfortunate MS ended up screwing the move to protected mode so badly that it took 10 years after its release in 1985 before 32-bit programming became popular. While Intel waiting until 1988 to release the SX didn't help, look up the MS OS/2 2.0 fiasco (begin with "MS OS/2 2.0 SDK" and "Microsoft Munchkins") for some pretty horrible history.
Re: 386-DX/SX support nuked from Linux Kernel
#35There are always LTS older builds.
Re: 386-DX/SX support nuked from Linux Kernel
#36Earlier quoted context omitted.
I'm into retrocomputing so these kinds of retirements always sting a bit. In realistic long term operations, deprecations don't hurt. I.e. your air traffic control system running on PA-RISC and HP-UX doesn't care that HP-UX only run on Itanium now. You keep running the old software and set up some kind of support schedule to keep the system patched during it's service life through the vendor or otherwise.
It's comforting to know others are interested in "retrocomputing". For some reason I like slow old computers too. (Not being sarcastic here at all)
It's preserving our history. We can learn a lot from what we already did.
Besides, when the machines take over, they may want to spare those who respected them ;-)
I hope they feed me and keep my cage clean.
Re: 386-DX/SX support nuked from Linux Kernel
#37To think that support for something so edge-case has been supported this long is remarkable. Even very basic embedded x86 processors are 80486 caliber. Those more feeble than that have no hope of running the current kernel in any meaningful fashion.
Support is a bit exaggerated, the 386 option hasn't compiled since the 3.2 release due to unconditional use of 486-only instructions (https://bugzilla.kernel.org/show_bug.cgi?id=44931). Who knows if it actually worked before that.
Re: 386-DX/SX support nuked from Linux Kernel
#38To think that support for something so edge-case has been supported this long is remarkable. Even very basic embedded x86 processors are 80486 caliber. Those more feeble than that have no hope of running the current kernel in any meaningful fashion.
Tangential trivia: MRI Ruby still has compiler directives and, supposedly, support for the Atari ST. Always weird bumping into them when going around the codebase. No idea if it actually works or why it's even a thing.
GNU CLISP, an small portable Common Lisp implementation supports Acorn RISC OS, NeXT, Amiga and OS/2.
Re: 386-DX/SX support nuked from Linux Kernel
#39Earlier quoted context omitted.
Tangential trivia: MRI Ruby still has compiler directives and, supposedly, support for the Atari ST. Always weird bumping into them when going around the codebase. No idea if it actually works or why it's even a thing.
GNU CLISP, an small portable Common Lisp implementation supports Acorn RISC OS, NeXT, Amiga and OS/2. http://clisp.cvs.sourceforge.net/viewvc/clisp/clisp/
RISC OS is still going (they just released a Raspberry Pi build) and OS/2 morphed into the commercial eComStation that is actively maintained. NeXT is dead though and Amiga fractured.
Re: 386-DX/SX support nuked from Linux Kernel
#40I never really got why back support should be an issue - its all x86 instructions, if only a subset of what is used today right? I'm curious to know exactly what makes supporting old cpus so hard.
It's not just instructions - it's CPU bug workarounds, too. For example, some 386s did not honor the write-protect bit in the page table when in supervisor mode. Now, since Linux normally does copies from kernel to userspace by writing straight to userspace and letting the WP bit detect writes to read-only memory, it's a problem if the WP bit doesn't work (it'd let you overwrite write-protected userspace memory). So…
That seems... odd. Why wouldn't you just swap implementations at startup, if it's a non-negligible performance hit?