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Is it time for open processors?

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Re: Is it time for open processors?

#111

Post by simias »

lambda wrote: post #106
simias wrote: post #72

Earlier quoted context omitted.

I'd pay good money for an open and simpler platform to run my security-critical tasks that don't require top performance. Auditing a modern high-end CPU is probably a huge task even if you have access to the HDL because of how complex they are. A simpler design (RISC, no out-of-order execution, basic branch prediction and prefetching...) ought to be fast enough with modern lithography to browse the web, send emails a…

Why give up on performance? IA-64 ( https://en.wikipedia.org/wiki/IA-64#Architecture ) already exists, with its explicitly parallel instruction set, which leaves branch prediction and speculative execution up to the software. So you can still get many of the performance benefits, but it's under control of the software, giving a lot more flexibility for being able to mitigate or eliminate these kinds of issues. I thin…

If you're not only concerned about bugs but also about people inserting backdoors into your hardware it's not enough to have access to the architecture design, you want to be able to publicly audit and review the entire manufacturing process (to make sure that the design you audited is actually the one etched on the silicon). I doubt Intel & friends would open their high-end fabs to public scrutiny so I think you'd have to use older technology available "in the open". For this reason alone I don't think a truly open processor could compete directly performance-wise with the current high-end CPUs regardless of architectural choices.

Re: Is it time for open processors?

#112

Post by tachyonbeam »

tombert wrote: post #102

I know that there are probably a billion technical hurdles for this, but in my perfect universe, CPUs would all be FPGA based; at that point, couldn't updates be almost as simple as a software update? I know that laws of physics kind of preclude this idea, but a guy can dream.

Main problem I see is that FPGAs themselves are currently not at all open hardware, and they are subject to vulnerabilities and backdoors too.

Re: Is it time for open processors?

#113

Post by nerdponx »

B-Con wrote: post #34

The problem is less about openness itself and more about quality of auditing. Open isn't a magic bullet. As I understand, these latest CPU vulnerabilities were in the spec themselves. You could've found them by reading the manual. See what good that did us. But I posit that open projects do better with audits than closed because they are more likely to have open audits as well, and an open audit is harder to ignore o…

As I understand it, according to an article that was posted here a day or two ago, Meltdown was in fact discovered by a young Google engineer poring over the x86 manual.

Re: Is it time for open processors?

#114

Post by mandelbulb »

B-Con wrote: post #34

The problem is less about openness itself and more about quality of auditing. Open isn't a magic bullet. As I understand, these latest CPU vulnerabilities were in the spec themselves. You could've found them by reading the manual. See what good that did us. But I posit that open projects do better with audits than closed because they are more likely to have open audits as well, and an open audit is harder to ignore o…

>Open isn't a magic bullet. As I understand, these latest CPU vulnerabilities were in the spec themselves. You could've found them by reading the manual. See what good that did us.

How about, discovering it? That's one of the points of openness, not somehow being inherently better in a way. At least we have a spec manual in this case.

Also, audits should be peer-reviewed, that's difficult without openness.

Re: Is it time for open processors?

#115

Post by masklinn »

_lbaq wrote: post #83
zaxomi wrote: post #71

Maybe it is time to rethink how computers are built? For example, that the kernel is running on a dedicated cpu, with dedicated cache and memory.

I think the problem have more to do with software, CPU's are just built to meet the demands. Today most software can only scale if you add a faster processor, that has to stop, before that happens, there is not much the processor manufacturer can do, their hands are tied IMO

> I think the problem have more to do with software, CPU's are just built to meet the demands.

> Today most software can only scale if you add a faster processor, that has to stop, before that happens, there is not much the processor manufacturer can do, their hands are tied IMO

These are not recent developments, chip makers could have opted not to use them and software developers would have done otherwise.

The hardware is developed to make the existing software faster, but the software is also developed to run well on the current hardware.

Re: Is it time for open processors?

#116

Post by justincormack »

lambda wrote: post #109
walterbell wrote: post #93

Earlier quoted context omitted.

Can either be purchased online by customers outside of those countries?

You used to be able to buy Lemote Yeeloong notebooks, which in addition to having Loongsong processors had completely free software BIOS, making them one of the only RMS approved pieces of hardware. But I'm not seeing those readily available any longer.

I believe you can still get them but its not as easy.

Re: Is it time for open processors?

#117

Post by mar77i »

amelius wrote: post #82
mar77i wrote: post #4

Friend of mine went to Hong Kong (from Europe) to work on exactly this: http://libresilicon.com/

What is the approach? Are they starting a new fab? Or will they simply lower costs by batching multiple projects together?

They work on their collection of processes to produce these things, as to basically have non-proprietary way to produce chips from scratch. The other thing I know is that the guy at least has been involved in other layers of production, namely generation and validation of circuitry.

The website I posted links a few pdfs for more info.

Re: Is it time for open processors?

#118

Post by fmap »

_lbaq wrote: post #83
zaxomi wrote: post #71

Maybe it is time to rethink how computers are built? For example, that the kernel is running on a dedicated cpu, with dedicated cache and memory.

I think the problem have more to do with software, CPU's are just built to meet the demands. Today most software can only scale if you add a faster processor, that has to stop, before that happens, there is not much the processor manufacturer can do, their hands are tied IMO

I think the problems have more to do with economics. Creating new modern CPUs requires a lot of capital investment, making CPU vendors more risk averse. That's why modern CPUs by and large are not built to meet the demands of future software - they're built to meet the demands of Excel 97 (exaggerating slightly for effect).

The programming interface of a modern x86 CPU is best thought of as a virtual machine with a JIT. The JIT performs some optimizations to make old code run more in parallel without the need for recompilation. This is a terrible model for compilers and programmers, since it makes optimizations hit or miss, and of course it's why we're in this whole spectre/meltdown mess at the moment. If we switched to a more reasonable programming model which actually met the needs of software (fine grained interprocessor communication without going through central memory, many more registers, actual software access to pipelines, caches, etc.) then it would make a lot of old software run slower (through emulation), but new software could finally make better use of your hardware...

Re: Is it time for open processors?

#120

Post by skummetmaelk »

tombert wrote: post #102

I know that there are probably a billion technical hurdles for this, but in my perfect universe, CPUs would all be FPGA based; at that point, couldn't updates be almost as simple as a software update? I know that laws of physics kind of preclude this idea, but a guy can dream.

Then you can increase the power consumption of all electronics by 50+% and halve the processing power. And that is optimistic.
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