Linux : 32 bit only what is the trick 3884

But clearly that isn't true.

The real trick does not depend on whether a cpu is 8 bits, 16 bits, 32 or 64 or 1024 bits. It's memory management and supervisory states, not the number of bits on the data bus. Precessors like the 8086, Z80, and even the 68000 don't have the various capabilities required to make simple ports possible.

Not that a port can't be done if the motherboard is designed to provide the facilities needed that the cpu itself doesn't have, but in fact few such motherboards have ever been produced. The typical IBM PC with an 8088, 8086, or 80286 won't do it, but there have been boards produce using any of those and other similar microprocessors that could have Linux ported to them.

The 80386 was the first Intel chip that had the facilities in the chip itself. The 68010 was the first 68000 series chip that could easily do it, though it still required external memory management hardware.

SBC boards are still being made with chips of that quality, but if a manufacturer wants to make a board cabable of being used by a Unix OS, they don't use an 80286 and add the required hardware, they just use an 80386 or whatever and save themselves a lot of trouble.

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