RISC-V Is Now An Official Debian Architecture

[piorunz]

Ubuntu already does RISC-V.

https://ubuntu.com/download/risc-v

Yes, as a low-cost, royalty-free replacement for ARM microcontrollers as a way for big tech companies to cut costs and increase revenue.

However, it is not coming as a CPU to workstations, home servers, laptops, tablets or phones.
It is not going to give you any open hardware or any computing free of binary blobs.

Pinetab-V tablet already exist. Hardware already exist. Software is catching up, as we see from Debian news. Sorry to disappoint you, but Risc V doesn't need to be limited only to underpowered microcontrollers.

[coder]

Can anyone say which subsets of the RISC-V ISA they require?

Does GNU libc have anything similar to the x86-64 feature levels, for optionally exploiting more advanced subsets of the RISC-V ISA?

[coder]

Yes, as a low-cost, royalty-free replacement for ARM microcontrollers as a way for big tech companies to cut costs and increase revenue.

However, it is not coming as a CPU to workstations, home servers, laptops, tablets or phones.
It is not going to give you any open hardware or any computing free of binary blobs.

I see two good reasons to believe RISC-V will at least come to phones, laptops, and servers, if not eventually also desktops and workstations.

1. China. They really didn't like the stunt Trump pulled with restricting Huawei's access to ARM IP, by using ARM's US Patents. They're not about to let that happen again, so expect them to migrate entirely away from x86 and ARM, within a decade. They appear to be splitting their efforts between "indigenous" ISAs (let's not get side-tracked in a pointless debate over just how indigenous LoongArch really is) and RISC-V. The EU also seems determined to establish an indigenous CPU IP capability, probably for similar reasons, and that appears ultimately headed towards RISC-V.
2. ARM's lawsuit against Qualcomm, for its Nuvia IP. ARM claims that Nuvia's ARM architecture license was invalidated when Qualcomm acquired them. Furthermore, ARM wants Qualcomm to agree to a new architecture license that would have Qualcomm's customers paying royalties on the new chips.

Before #2 happened, you could imagine Intel and AMD designing ARM cores, at some point in the future. Now, that seems a lot more unlikely. If/when RISC-V gains real traction in the cloud market, expect to see one or both of these behemoths join the fray.

[Paradigm Shifter]

Ubuntu already does RISC-V.

For the SiFive VisionFive 2, it comes with a big, big caveat: USB doesn't work (so sayeth the Ubuntu website).

Yeah, so SiFive thing is compared to a 7-year-old Raspberry Pi 2and costs ten times as much.
Then Raspberry Pi 5 is coming and it will probably be great.

I'll repeat what I wrote in the other thread where you said basically the same thing:

Depends on location I guess? An 8GB SiFive VisionFive2 cost me 16,000JPY back in April. An 8GB Raspberry Pi 4 cost me 14,400JPY (I just checked) back in September last year (distributor price, elsewhere were cranking the prices up between 30% and 200%) and would cost me basically the same now, while a 4GB RPi4 cost me 12,000JPY when they first hit Japan.

So your "ten times as much" is at best hyperbole, at worst anti-RISC-V propaganda.

[coder]

Then Raspberry Pi 5 is coming and it will probably be great.

Orange Pi 5 makes it almost irrelevant. The Raspberry Pi 5 might be a little cheaper, but probably less powerful and less efficient.

MediaTek is going even further, with the MediaTek Genio 1200. The key question will be pricing:

https://www.cnx-software.com/2023/05...velopment-kit/

The board in that link won't be cost-competitive with any sort of Pi, but hopefully someone will use the SoC in a low-cost SBC.

[coder]

The fact that they already have a chip at the level of a commercial competitor from the year they were founded in is amazing, especially considering that competitor was built by a company that at the time had a 16x larger valuation and almost 15 times more employees.

I don't find that very compelling. Tenstorrent is yet another an order of magnitude smaller and made an even higher-performance RISC-V core in only about a year, over and above their work on AI cores and bringing AI chips & systems to market (whereas SiFive is just in the IP business).

The reason SiFive took so long to get to this point is that they started by addressing the microcontroller market. If they'd intended to make primarily big RISC-V cores, it wouldn't have taken them nearly so long to reach this point.

[ayumu]

Can anyone say which subsets of the RISC-V ISA they require?

RV64GC. Now what we've got profiles, it has been retroactively named RVA20.

Note that, in theory, if a new enough privileged spec is implemented as to support Linux (mainstream kernel requires v1.11 or higher, I believe), SBI can trap and emulate missing instructions, thus allowing it to work on tiny CPUs that do not implement the full RV64GC spec. (e.g. RV64IMAFC or RV64IMAC would work). But of course it'd be slow.

Does GNU libc have anything similar to the x86-64 feature levels, for optionally exploiting more advanced subsets of the RISC-V ISA?

Yes. There's the ISA profiles, the first iteration of which is already ratified (including RVA22, with the stuff ratified late 2021).

In addition to this, there's an effort to standardize the platform (think IBM PC, but modern and formalized). This is the work-in-progress RISC-V Platform spec.

It depends on multiple specs, some of which have been ratified for a while, such as the SBI interface or the UEFI protocol, specifying how the boot process should work, and how to pass control to the OS.

[ayumu]

Tenstorrent is yet another an order of magnitude smaller and made an even higher-performance RISC-V core in only about a year.

Tenstorrent has seriously strong teams that include a lot of industry veterans with a history of success behind them.

Their Ascalon RISC-V CPU project is led by the same person who successfully led Apple M1.

It is no surprise they're able to recreate/improve on previous successes, this time on RISC-V.

[topolinik]

... there's no reason to expect these chips to be simply ignored and not put into phones or tablets. They do not require much processing power in the first place.

Can't agree with you, there is a BEAST OS called Android, which requires a lot more processing power at each release.

[osw89]

I don't find that very compelling. Tenstorrent is yet another an order of magnitude smaller and made an even higher-performance RISC-V core in only about a year, over and above their work on AI cores and bringing AI chips & systems to market (whereas SiFive is just in the IP business).

From what I could find they raised 220 million and their valuation is 1 billion so not exactly an order of magnitude smaller plus they have people like Jim Keller working for them. What they seem to be doing is also quite impressive but they don't have anything on the market yet. I used sifive as an example because you can buy their chips and there's more info on them. Tenstorrent's chips aren't out yet and I couldn't find much info on them besides the couple images on their site.