You did see that bit you quoted?

> (Of course the 386 is technically still segmented, but let's ignore that)

Yes, the 80386 was still technically segmented, but the overwhelming majority of operating systems (95%+) effectively abandoned segmentation for memory protection and organization, except for very broad categories such as kernel vs. user space.

Instead, they configured the 80386 registers to provide a large linear address space for user processes (and usually for the kernel as well).

> The idea that someone would create a couple descriptors with base=0:limit=4G and set all the segment register to them, in order to assure that int=void * is sorta a known possible misuse of the core architecture

The thing that you mischaracterize as a "misuse" of the architecture wasn't just some corner case that was remotely "possible", it was what 95% of the industry did.

The 8086 wasn't so much a design as a stopgap hail-mary pass following the fiasco of the iAPX 432. And the VAX existed long before the 8086.

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StillBored a day ago | parent [-]

I think my point revolves more around what the HW designers were enabling. If they thought that the flat model was the right one, they would have just kept doing what the 286 did, and fixed the segment sizes at 4G.

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mpweiher a day ago | parent [-]

Yes. The point is that the hardware designers were wrong in thinking that the segmented model was the right one.

The hardware designers kept enabling complex segmented models using complex segment machinery. Operating system designers fixed the segments as soon as the hardware made that possible in order to enable a flat (paged) memory model and never looked back.

	▲	rep_lodsb 12 hours ago \| parent [-]
		But were the software people actually right, or did they just follow the well-trodden path of VMS / UNIX, instead of making full use of the x86 hardware? Having separate segments for every object is problematic because of pointer size and limited number of selectors, but even 3 segments for code/data/stack would have eliminated many security bugs, especially at the time when there was no page-level NX bit. For single-threaded programs, the data and stack segment could have shared the same address space but with a different limit (and the "expand-down" bit set), so that 32-bit pointers could reach both using DS, while preventing [SS:EBP+x] from accessing anything outside the stack.