RISC-V, what do you think about ?

[legacy]

riscv dot org, they seem to be almost ready 

[HAL-42b]

I'll print one as soon as I get my FIB Milling machine

In all seriousness though, I think it has a great potential. India is already interested and may have taped out one in one of their universities. As soon as we see it taped out commercially in China we might see a serious contender to ARM.

[marshallh]

Don't know much about it but if it's like the previous "efforts" it will be a design by committee disaster and cost buttloads to produce, ensuring its demise.

Hoping I'm wrong.

[BloodyCactus]

i think this will sink like a stone and nobody will care. much like the whole open sparc thing.

maybe china will knock something out on risc-v and move on from their mips loongson stuff.

[Rasz]

brilliant .. if you are in academia

[ataradov]

I believe this core was taped out in real products. I think that was some European company doing ICs for DVRs and set-top boxes.

I can't say I'm impressed with the instruction set, but it is actually a real working core, not like one of a few thousands MIPS clones made by students and beginner FPGA designers.

[legacy]

like my soft core, which is really useless from the industry point of view(1), but very awesome for hobbyist who want to develop in assembly as they did in 1980' with m68k, but over a modern risc-like, provided with a useful TAP (debug interface (2))

(1) I wanted to reduce the complexity, so I removed the pipelining stuff, I progressively introduced the cache (coherent) and multi processing (even if up to two CPUs), also the code density is really obscene ( ) , this is not good for BRAM, but it's decent enough if you can use an external DRAM of 32 Mbyte at least

(2) I like my TAP, as THE main reason to use this toy in my free time, obviously I do not want to sell to google, or to the first chinese company, even if …
… even if ... if I was a genius at marketing, I might say that I have invented

the reality Engine, Einstein on chip

so, if someone wants to pay me thousand and thousand UKP, I might sell my super marvelous && Supercalifragilisticexpialidocious core, which is a crap from the computer science point of view (because it's not superscalar, and it comes with no pipeline under the hood) but it can easily includes a tensor do-processing unit, which can actually accelerate things within tensor components, in a quadri-dimensional coordinate system, ... whose columns are the forces per unit area, acting on the e1, e2, and e3, plus a column for e-time, which is a superset compliant with the introduction of Einstein's theory of general relativity, around 1915.

I am kidding, but I have really designed (as proof of concept, which sounds more like intellectual challenge, "we do because we can do") a TPU, and odiously nobody will ever use it even if it might be implemented

[legacy]

brilliant .. if you are in academia

in short it's what I guess

[legacy]

committee disaster

currently it's available as
1) simulator (it comes free, open source, it just takes effort to configure and compile a few things)
2) arm+fpga board (the hardware side is expensive, the software side is free but takes more effort to configure and compile things)

in choice2, the arm core initializes things, load the bitstream, bootstrap the soft core, then it provides a sort of I/O virtualization

I guess that all of this means: good only for academia, for people who want to experiment

[ataradov]

I guess that all of this means: good only for academia, for people who want to experiment

It is not. The core has been taped out in real products. They are specialty ICs, not general purpose mass-market controllers. But this thing is much more than a toy.

They also have very good documentation and toolchains.

I can't instantly find info, but I have been tracking progress of this project for quite some time. There are plenty of things I don't like about it, but it is the best shot at free and open processor we have right now.

It is like KiCad, not the best thing out there, but it is the best as far a free and open goes.

[legacy]

taped out in real products

which ones ?


edit:
and no, there is no chance to compare Kicad with Eagle/CAD (or Altium)
not for me, at least (I am used to use both to the last two, for job purposes)

[legacy]

Called boom, it's an Out-of-order RISC-V variant
RISC-V has a number of features that make an OOO machine more manageable to implement.

[legacy]

I wonder if it will teach the Tomasulo Algorithm, let's check it 

[ataradov]

and no, there is no chance to compare Kicad with Eagle/CAD (or Altium)

And yet some people do use KiCad successfully for reasonably big projects. It is not a commonplace, of course. So is RISC-V is not a common core and I would not use it in my projects in a foreseeable future, may be never. But the only way to create a competitor to ARM and others is to create anything at all and persistently work on improving it and making people aware of it existence.

[AlxDroidDev]

Supposing the industry implements this (which I don't think will happen), it's just a matter of time until each company add their own specializations and extensions to the standard, and making these extentions proprietary, just so they can advertise their product's differential. Intel will have RISC-V+, then AMD will have a RISC-V², followed by NVidia marketing a RISC-Vmax, and then in a couple of years what was meant to be an industry standard just became a sea of incompatible instruction sets, requiring tons of ifdefs in the code. So long standards!

Marketing people hate standards. Imagine this ad from NVidia: "We're just like AMD, but with a lot more hype and a nice case sticker at a higher price tag".

Besides, they don't seem to have the big players in the industry jumping on the RISC-V bandwagon. It all seems pretty limited to academia, like other forum members have stated and I agree. At the very least, they should have Samsung supporting the initiative. Intel would be nice too!

OTOH, there have been nice things that came out of Berkley, so who knows.

[ataradov]

So long standards!

And that's why you need a governing organization and certification program. They are not stupid, and I hope they have claimed proper trademarks.

Everyone had implemented the same USB specification without making changes.  The core is no different.

But you are right, there is no point for big companies to jump on it. But smaller companies may very well implement this into their products. Imagine ESP8266, but with RISC-V instead of Xtensa. Both are non-standard cores, so why not go with open if it is developed to a reasonable level.

[legacy]

And yet some people do use KiCad successfully for reasonably big projects

tell me which projects

[legacy]

Supposing the industry implements this (which I don't thing will happen), it's just a matter of time until each company add their own specializations and extensions to the standard, and making these extentions proprietary, just so they can advertise their product's differential. Intel will have RISC-V+, then AMD will have a RISC-V², followed by NVidia marketing a RISC-Vmax, and then in a couple of years what was meant to be an industry standard just became a sea of incompatible instruction sets, requiring tons of ifdefs in the code. So long standards!

Marketing people hate standards. Imagine this ad from NVidia: "We're just like AMD, but a lot more hype and a nice case sticker at a higher price tag".

Besides, they don't seem to have the big players in the industry jumping on the RISC-V bandwagon. It all seems pretty limited to academia, like other forum members have stated and I agree. At the very least, they should have Samsung supporting the initiative. Intel would be nice too!

OTOH, there have been nice things that came out of Berkley, so who knows.

exactly what I think, including species { RISC-V+, RISC-V², RISC-Vmax }, which is written in a brilliant funny way 

[ataradov]

tell me which projects

They are not public. If you don't want to believe me, then don't.

I personally prefer DipTrace and hate Altium. People have different tastes and used to different things. All those tools are perfectly usable, some provide more service, some less, not a big deal.

And I'm hearing really good things about recent code contribution to KiCad from CERN, but have not tried it myself.

[aventuri]

turning back to the main topic, i.e. if RISC-V, an interesting open source CPU, could get some steam into the "real taped-out" world... let me note that those "crazy folks" at Allwinner (who you all know for the A10/A20 family of tablet chips) did put in their new lineup H3 (flagged as a 4 core ARM32 cpu), also a "fifth" CPU, called AR100: http://linux-sunxi.org/AR100

looks like this CPU should be an ASIC version of the OpenRisc project: http://github.com/openrisc/

the funny thing is that people on linux-sunxi ML are investigating how to repurpose it, supposedly born to "control" the PMIC during deep-sleep mode of main CPUs, for real time task as it seems it can drive the whole IO space. next  to that, security concerns are investigated too, as malicious code too could try to exploit it..

let's see, but these open cores are someway compelling at some degree for manufacturers, as they do not bring the usual long NDAs and licensing paper filling tasks..

[AlxDroidDev]

So long standards!

And that's why you need a governing organization and certification program.

I think differently, but there are pros and cons of having a governing body in a standard. A company's R&D might be limited if there are too many standards to follow. OTOH, if several companies are developing on the same standard, there will be more competition on the marketplace, eventually leading to price drops.

Everyone had implemented the same USB specification without making changes.  The core is no different.

Bluetooth is a standard too, but that didn't stop Apple from making bluetooth devices that were completely incompatible with everything else and still call it Bluetooth.

Imagine ESP8266, but with RISC-V instead of Xtensa. Both are non-standard cores, so why not go with open if it is developed to a reasonable level.

  Agreed, but if one is to follow RISC-V without implementing proprietary extensions, it will be just another product in the market, w/o any advantage or differential. It will just like buying 74xx chips: you choose by the price, not by the manufacturer or marketing, since there are several people manufacturing the exact same product. It isn't so interesting to be in a market where the only deciding purchase factor is the price, unless:
- you have lower production costs than the competition, so you have a better price
- you are in an area hard to reach by the other manufacturers (due to geographic location, taxes, politics, and so on)
- you have a supply contract with a big customer
- the overall demand is still high to keep all the manufacturers "happy"

How many identical chips aren't produced by Fairchild, TI, ST, KEC, ICF, NJR, NXP, and all the other semi-conductor companies? They don't even bother marketing chips like LM317, LM324, 555, 40xx, 74xx and so on, and that's why many companies in this business either disappeared, stopped producing ICs or where bought. You don't buy "TI's LM324". You buy whichever LM324 is cheapest and in the package you need. This doesn't keep companies in the business.

[MrSlack]

the funny thing is that people on linux-sunxi ML are investigating how to repurpose it, supposedly born to "control" the PMIC during deep-sleep mode of main CPUs, for real time task as it seems it can drive the whole IO space. next  to that, security concerns are investigated too, as malicious code too could try to exploit it..

That's not a new idea. Intel ME has an ARC processor derived from a Nintendo SuperFX on the PCH that runs the ThreadX RTOS. That's chock full of shitty holes under S3 sleep as well as it can talk to all sorts of things. That covers most recent Intel CPUs and chipsets. Service processors are a horrible idea if they can talk directly to the host machine.

Open cores miss strong standardisation. We'll be in Z80 clone territory again in no time. I'd rather a license dictatorship like ARM.

TBH though the only strong, standard open ISA that has been successful is the JVM and perhaps 1% of end users actually give a crap past the high level managed compiler/interpeted layer anyway. Doesn't matter what is underneath it all. The machine is a means to an end and that end us usually piles of cash.

[ataradov]

So there is real taped out OR1000.

OR has been taped out many times. As it has been pointed out, its microcontroller profile is used as a system controller in many proprietary designs.

[ataradov]

+ Agreed, but if one is to follow RISC-V without implementing proprietary extensions, it will be just another product in the market, w/o any advantage or differential.

I don't see RISC-V used in standalone general purpose MCUs.

But in things like ESP8266, you are not differentiating on the core. Wi-Fi component is the selling point here. There are many application-specific parts that a different enough on their own, the MCU core is secondary.

And from there, it can eventually spread into general purpose market. But very eventually, like 10-15 years from now.

[AlxDroidDev]

The machine is a means to an end and that end us usually piles of cash.

I believe I've been using the wrong machines then! The ones I have never ended me piles of cash, unless I exchange my salary for zimbabwe dollars!