Linux Kernel Developers Discuss Dropping A Bunch Of Old CPUs

[strtj]

Careful now. While the 68000 had only a 24-bit address bus (16 Mbyte directly addressable), later revisions of the 68000 family from the 68020 onwards had 32-bit address buses (4 Gbyte directly addressable), and are still available now:

https://www.rocelec.com/search?q=MC680

Gives availability of 68020, '030, '040, '060

So I wouldn't be so quick to kill the 68000 architecture.

I was assuming that "68000" in the article meant the literal 68000 chip, not the 68k family. Of course you can stuff an '040 full of RAM. Heck, even my Mac IIci will take 128MB.

[Old Grouch]

I was assuming that "68000" in the article meant the literal 68000 chip, not the 68k family. Of course you can stuff an '040 full of RAM. Heck, even my Mac IIci will take 128MB.

Well, if your assumption is correct, then it would seem reasonable to drop support. I used to use a IIfx (68030) with a large greyscale display running a Macintosh X Window System client (probably MacX) as an intelligent multi-terminal workstation so I could administer a cluster of Vaxes. The ability to run an up-to-date Linux kernel on it now seems almost like magic.

[DRanged]

ARM64 percentages should spike if Microsoft would openly announce Windows 10 on ARM instead of keeping it as an WindowsInsider-only product.

It should lead to OEMs at least considering the use of ARM64, which in turn results in potentially more ARM64 laptops and desktop machines for Linux to work on.

Don't forget even more Raspberry PI's. I already have 2 of them RasPi 1st gen and a RasPi 3 B+ the latter one using aarch64.

[DRanged]

I was just thinking about how may 386, 486sx, dx, etc systems I tossed in the dumpster years ago. Junk, stacked floor to ceiling Many working order. I could have rummaged through the stacks and come with CPUs from 8808s till the modern Intel CPU at the time which at the time I think was the Bloomfield.

I managed to run OS/2 Warp on a 386sx and a 486sx both with 4MB of mem. Win95/Win98SE refused to run on both of them. IIRC upgraded the 486SX to 8MB and still OS/2 would kick the crap out of windows at that time.

[baryluk]

Isn't 486 a very bad example? It's x86, so it should share a lot of code with modern x86 CPUs.

I doubt they will remove 486, it still has uses, including Vortex86 SX.

But I think maybe they should remove the 486SX support and FPU emulation.

I use 486DX and some Vortex86 with FPU, frequently for some hacking and testing.

Also, because of simplicity of hardware, compared to Pentium and later, it really makes learning things about hardware and kernel, mm, io, dma, irq, quite a bit easier, than other stuff. Also, even on more modern hardware, you still need to deal with all 486-like stuff during early boot anyway, because of hardware works.

[baryluk]

Is there confirmation about the 486? I have a computer with Linux and that processor. I know a couple of people who use Linux in a couple of 486DX machines. I also have Linux on a Pentium 1 MMX, and that's the next one on the line.... :/

There are no plans for dropping it, in fact there was strong opposite to this idea.

I wouldn't probably mind dropping 486SX support tho. Could allow removing the FPU emulation code at least. It works and is there, could stay too, but 486SX and FPU emulation would make things really slow. There are some people using first Vortex86 with no FPU, but considering pricing and availability, one can use the ones with FPU quite easily, and remaining people in embedded world, don't update frequently to new kernels anyway, so SX can be probably dropped safely.