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Envisioning a Simplified Intel Architecture

intel.com

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Re: Envisioning a Simplified Intel Architecture

#11

Post by manuelabeledo »

jhallenworld wrote: post #6

This makes no sense to me. Backward compatibility is a huge competitive advantage for Intel, and IMHO, it's royally messed up that vm86 mode doesn't work in 64-bit mode. One DOS application I use was hurt by this: "old DOS OrCAD". It works well in Windows-XP on a 32-bit machine, but does not work at all in 64-bit Windows. (It's actually a 32-bit DPMI program and has drivers to use Windows GDI so you don't have to mes…

Legacy systems and architectures can’t be around forever.

How many people in the PC market still use 16-bit applications?

Re: Envisioning a Simplified Intel Architecture

#12

Post by mananaysiempre »

AdamH12113 wrote: post #10

> Since its introduction over 20 years ago, the Intel® 64 architecture became the dominant operating mode. *cough*[1] [1] https://en.wikipedia.org/wiki/X86-64#History

I guess we should be thankful they aren’t still calling it EM64T :) I’ve also heard that the term AMD64 also originated from marketing—the internal name during development was x86-64 (which everybody but Microsoft ended up calling it anyway).

Re: Envisioning a Simplified Intel Architecture

#13

Post by jcranmer »

muricula wrote: post #7
loeg wrote: post #2

For those truly too lazy to click through to the article, x86-S stands for "simplified," with the idea being to boot directly into 64-bit mode instead of booting into 16-bit and bootstrapping to 64-bit mode. 16-bit mode would be removed entirely. It's not clear to me if 32-bit mode would be axed as well, or if it would be retained (maybe partially).

Looks like you will still be able to run 32 bit user mode applications under a 64 bit kernel. I'm not sure, but I think 32 bit guest kernels get the ax as well. " 3.3 Removal of 16-Bit and 32-Bit Protected Mode 16-bit and 32-bit protected mode are not supported anymore and cannot be entered. The CPU always operates in long mode. The 32-bit submode of Intel64 (compatibility mode) still exists. ... "

> I'm not sure, but I think 32 bit guest kernels get the ax as well.

This is somewhat beyond my knowledge of system programming, but my read is that it's just possible to support 32-bit guest kernels in the VM with some more emulation of the de-supported instructions. I don't know how many of those instructions already cause VM exits.

Re: Envisioning a Simplified Intel Architecture

#14

Post by kinghajj »

mananaysiempre wrote: post #12
AdamH12113 wrote: post #10

> Since its introduction over 20 years ago, the Intel® 64 architecture became the dominant operating mode. *cough*[1] [1] https://en.wikipedia.org/wiki/X86-64#History

I guess we should be thankful they aren’t still calling it EM64T :) I’ve also heard that the term AMD64 also originated from marketing—the internal name during development was x86-64 (which everybody but Microsoft ended up calling it anyway).

`amd64` is still what Debian and Kubernetes use.

Re: Envisioning a Simplified Intel Architecture

#15

Post by loeg »

aforty wrote: post #4
loeg wrote: post #2

For those truly too lazy to click through to the article, x86-S stands for "simplified," with the idea being to boot directly into 64-bit mode instead of booting into 16-bit and bootstrapping to 64-bit mode. 16-bit mode would be removed entirely. It's not clear to me if 32-bit mode would be axed as well, or if it would be retained (maybe partially).

It seemed pretty obvious to me from one of the graphics that they would remove 32-bit mode as well.

> It seemed pretty obvious to me from one of the graphics that they would remove 32-bit mode as well.

I don't believe it's that simple (or obvious, since you seem to be mistaken).

Re: Envisioning a Simplified Intel Architecture

#16

Post by jhallenworld »

manuelabeledo wrote: post #11
jhallenworld wrote: post #6

This makes no sense to me. Backward compatibility is a huge competitive advantage for Intel, and IMHO, it's royally messed up that vm86 mode doesn't work in 64-bit mode. One DOS application I use was hurt by this: "old DOS OrCAD". It works well in Windows-XP on a 32-bit machine, but does not work at all in 64-bit Windows. (It's actually a 32-bit DPMI program and has drivers to use Windows GDI so you don't have to mes…

Legacy systems and architectures can’t be around forever. How many people in the PC market still use 16-bit applications?

>Legacy systems and architectures can’t be around forever.

Why not? The bits don't decay.. Yes, this leads to an architectural mess, but I'm talking about a competitive business advantage.

Re: Envisioning a Simplified Intel Architecture

#18

Post by manuelabeledo »

jhallenworld wrote: post #16
manuelabeledo wrote: post #11

Earlier quoted context omitted.

Legacy systems and architectures can’t be around forever. How many people in the PC market still use 16-bit applications?

>Legacy systems and architectures can’t be around forever. Why not? The bits don't decay.. Yes, this leads to an architectural mess, but I'm talking about a competitive business advantage.

> Why not?

> Yes, this leads to an architectural mess

Right there.

There's no notable advantage in supporting a very small minority of the applications out there, at the cost of keeping units useless for the 99%.

Re: Envisioning a Simplified Intel Architecture

#19

Post by TazeTSchnitzel »

jhallenworld wrote: post #6

This makes no sense to me. Backward compatibility is a huge competitive advantage for Intel, and IMHO, it's royally messed up that vm86 mode doesn't work in 64-bit mode. One DOS application I use was hurt by this: "old DOS OrCAD". It works well in Windows-XP on a 32-bit machine, but does not work at all in 64-bit Windows. (It's actually a 32-bit DPMI program and has drivers to use Windows GDI so you don't have to mes…

16-bit x86 code is ancient enough that a software emulation solution can be fast, efficient, and perfectly compatible, so there's no need to keep support for it in hardware at this point.

Microsoft could have used emulation to keep old 16-bit x86 apps working with Windows for AMD64 (in fact they had done this before for non-x86 architectures) but I guess they weren't interested. WINE and DOSBox did it though.

Re: Envisioning a Simplified Intel Architecture

#20

Post by MrBuddyCasino »

manuelabeledo wrote: post #11
jhallenworld wrote: post #6

This makes no sense to me. Backward compatibility is a huge competitive advantage for Intel, and IMHO, it's royally messed up that vm86 mode doesn't work in 64-bit mode. One DOS application I use was hurt by this: "old DOS OrCAD". It works well in Windows-XP on a 32-bit machine, but does not work at all in 64-bit Windows. (It's actually a 32-bit DPMI program and has drivers to use Windows GDI so you don't have to mes…

Legacy systems and architectures can’t be around forever. How many people in the PC market still use 16-bit applications?

Question is, what is the cost of keeping the old cruft around?
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