Can We Replace Intel x86 With an Open Source Chip? (zdnet.com)

An anonymous reader quotes Jason Perlow, the senior technology editor at ZDNet: Perhaps the Meltdown and Spectre bugs are the impetus for making long-overdue changes to the core DNA of the semiconductor industry and how chip architectures are designed... Linux (and other related FOSS tech that forms the overall stack) is now a mainstream operating system that forms the basis of public cloud infrastructure and the foundational software technology in mobile and Internet of Things (IoT)... We need to develop a modern equivalent of an OpenSPARC that any processor foundry can build upon without licensing of IP, in order to drive down the costs of building microprocessors at immense scale for the cloud, for mobile and the IoT. It makes the $200 smartphone as well as hyperscale datacenter lifecycle management that much more viable and cost-effective.

Just as Linux and open source transformed how we view operating systems and application software, we need the equivalent for microprocessors in order to move out of the private datacenter rife with these legacy issues and into the green field of the cloud... The fact that we have these software technologies that now enable us to easily abstract from the chip hardware enables us to correct and improve the chips through community efforts as needs arise... We need to stop thinking about microprocessor systems' architectures as these licensed things that are developed in secrecy by mega-companies like Intel or AMD or even ARM... The reality is that we now need to create something new, free from any legacy entities and baggage that has been driving the industry and dragging it down the past 40 years. Just as was done with Linux.
The bigger question is which chip should take its place. "I don't see ARM donating its IP to this effort, and I think OpenSPARC may not be it either. Perhaps IBM OpenPOWER? It would certainly be a nice gesture of Big Blue to open their specification up further without any additional licensing, and it would help to maintain and establish the company's relevancy in the cloud going forward.

"RISC-V, which is being developed by UC Berkeley, is completely Open Source."

Comments

No

[Anonymous Coward]

No

Re:No

[swamp_ig]

IC design isn't something you can do in your spare time. You need a full-scale industrial process.

Re:No

[K. S. Kyosuke]

IC design isn't something you can do in your spare time. You need a full-scale industrial process.

You mean IC manufacturing? I'm pretty sure design is largely independent. If it weren't, ARM wouldn't be able to sell synthesizable CPU cores.

Re:No

[sanf780]

ARM does sell synthesizable cores. What synthesizable means is that you can convert that code into logic gates. So you need at least a standard cell library with the fine detail of those logic gates. Memories are not included, as memories are not synthesizable code if you really want a high bit density and low power usage. In order to get data in and out of the chip, you will also need a DDR interface (this is not synthesizable) with also a DDR memory controller (this one is). Add to this one that you need to generate internal clocks, so you might also want to get a few phase locked loop blocks. Recent CPUs also include some sort of dynamic voltage scaling, frequency scaling, thermal protection, etc. You also want to have peripherals connected through SPI, I2C, maybe UART, and maybe you want an interconnect fabric so that the CPU can talk to them. I am sure I am missing a lot of these things.

So, it is not just the CPU core, you need a lot more of things in order to get some product. FPGA manufacturers give you both the hardware and the software to translate the code into something you can upload to that FPGA, and usually give you some freebies like DDR and PLLs. However, there are limitations on what you can get from an FPGA. ICs are the way to go if you want to be on the bleeding edge on either performance, price or power efficiency. And as far as I know, the tools to do ICs in advanced processes like 10nm are not either free to use or open source. They are probably also a patent field. At the end of the day, you do not want to spend over one million dollars with tools that tell you "USE AT YOUR OWN RISK".

Re:No

[Pulzar]

Clock guys are like driver guys... the stuff they write and develop is quite a bit different from everything else.

The guys who work on caches, decode, fetch, etc. are all fairly interchangeable, if you've got a good architect to direct and oversee the work.

Re:No

[TooManyNames]

Yeah, no. That's very, very wrong.

Much of a processor can be designed in RTL (the type of code you could open source), but there are critical components (as in, CPUs do not function without them -- at all) that require detailed knowledge of the underlying process. Any sort of clock distribution, selection, skewing, or balancing, for example, pretty much requires not only detailed knowledge of the types of gates available in process libraries, but also exhaustive simulations across all kinds of different timing scenarios to ensure that designs work as intended. Additionally, these types of circuits are not trivial to design, and they're often tightly integrated into the rest of a design in a way that isn't exactly modular (as in, even if there are separate clocking modules, design assumptions make removal or modifications of those clocking modules quite difficult).

Maybe you could get away with an open core on an FPGA, but if you do that, you're going to sacrifice a lot in terms of performance -- as in getting at best into the 100s of MHz range compared to GHz for an ASIC. Moreover, you're not going to squeeze multiple cores and huge caches onto a single FPGA, so you'll need some sort of stitching to get anything even remotely close to your most basic Intel off-the-shelf processor.

Basically the best you'll be able to say with a purely open source CPU is, "buy this for 10x the cost and at 1/10th the performance... but you can feel good that it's open source." At that point, all I can say is, "good luck with that."

Can We Replace Intel x86 With an Open Source Chip?

[Local ID10T]

No.

How does an open source chip solve the problem?

[JoeyRox]

Being open source doesn't magically prevent bugs from reaching the silicon stage of a chip's design, nor does it make it any easier to fix bugs baked into a completed design. There are only so many people in the world smart enough to even fully understand modern superscalar designs let alone contribute usefully to it.

Re:How does an open source chip solve the problem?

[quantaman]

There are only so many people in the world smart enough to even fully understand modern superscalar designs let alone contribute usefully to it.

I doubt that's true.

The problem wasn't the lack of people smart enough to spot the bug, it was the fact the bug was created 20 years ago back when people probably weren't thinking about bugs like that. And then in the 20 years since there probably weren't many people with a reason to start digging into that level of the design.

I'm not sure open source would have made a big difference, it gives you more eyes in some cases, but as OpenSSL demonstrated people only read the code they change, so old code that "just works" tends not to get looked at too closely.

To what end?

[Anonymous Coward]

OpenSSL being open source didnâ(TM)t find or prevent Heartbleed.

An open chip likely wouldnâ(TM)t have affected meltdown or spectre. This wasnâ(TM)t negligence by Intel (as evidenced that some of the recent vulnerabilities were shared by AMD chips on a completely different architecture.

The problem isnâ(TM)t that Intel failed to secure something obvious. Itâ(TM)s that there was a mechanism that everyone knew about, but which all experts thought couldnâ(TM)t be used to extract data. Then someone found a clever technique nobody thought of before that made everyone realize it WAS vulnerable.

Being open wouldnâ(TM)t have prevented the issue. Indeed, the issue was found by third-party researchers who didnâ(TM)t have access to the low level details of the architecture.

Open Source is not a panacea.

Uh, ZDNet? Really?

[asackett]

It's not surprising that someone who doesn't seem to know that "the cloud" *is* private data centers also knows nothing of IC fab.