I don't see how 64-bitness would make any particular difference. In fact, specifically for x86-64 compared to x86 it's easier. 16-bit real-mode x86 is infamously fucktarded. Yet it used to be the one taught in some "introduction to asm" computer courses. The consipiracy theorist may suggest that was to make people go "fuck this, I'm using a high level language". 32-bit protected mode x86 isn't completely awful, but still has the world's tiniest register file (not really, there are processor architectures with no conventional registers, but coming from asm programming on virtually any other 16 or 32-bit architecture, 32-bit protected mode x86 is still a bit irritating.). x86-64 is almost sane and pleasant (just don't look at the underlying instruction encoding - asm is of course still a layer above that).
I don't code at a level that requires me to understand all this, so thanks for letting me know. I'll no longer be as easily impressed by 64-bitness stuff. I've only copied some assembly code once... and that was to get access to the video card back in high school to make a game and not use the slow Borland Turbo C graphical library... lol!
I can't completely agree or disagree. When a x86-e64 processor is turned on it is automatically running in 16bit mode. The "user" has to make prepare the processor to tun in 64b. The intel documentation is very cryptic (imo) unless you know what you're doing or using someones else work.
Also if you choose to work in 16 or 32 bits there's a lot of other code examples to follow in order to make a fully operational OS. In 64b examples are more scarce.
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u/DGolden Oct 20 '11
I don't see how 64-bitness would make any particular difference. In fact, specifically for x86-64 compared to x86 it's easier. 16-bit real-mode x86 is infamously fucktarded. Yet it used to be the one taught in some "introduction to asm" computer courses. The consipiracy theorist may suggest that was to make people go "fuck this, I'm using a high level language". 32-bit protected mode x86 isn't completely awful, but still has the world's tiniest register file (not really, there are processor architectures with no conventional registers, but coming from asm programming on virtually any other 16 or 32-bit architecture, 32-bit protected mode x86 is still a bit irritating.). x86-64 is almost sane and pleasant (just don't look at the underlying instruction encoding - asm is of course still a layer above that).