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Comment by kragniz | Hacker News Reader

I went to a local RISC-V meetup last night, and it seems like something interesting to play with. Does anyone know when actual chips might become affordable? The only board I could find available at the moment is the HiFive Unleashed, which is $999.

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There are a handful of micros. The lowfive and a few coming from China

Here is an AI chip:

https://hackaday.com/2018/10/08/new-part-day-the-risc-v-chip...

It's an interesting proposition b/c they using RISC for the core, but the APUs are custom - so they can create some lock-in there for themselves (without lock in it'll just be a race to the bottom with razor thin margins)

And here is RISC-on-an-FPGA in a nice package. It's very Chinese hobbyist oriented https://www.cnx-software.com/2018/09/04/licheetang-anlogic-e...

Both those projects are by Zepan. That guy is a machine

But I'm not quite sure what's holding up general purpose CPUs (even just something crappy/good-enough).. The way I understand it CPUs aren't just beefy microcontrollers and they require some extra onchip hardware, but no one has done that yet for some reason.. Maybe someone knows better :)

lowRisc and SiFive, there is no lowfive

There's the HiFive from SiFive though. Which is the Arduino form-factor board with their Freedom E310 core.

It's a breakout board for the SiFive E310

https://github.com/mwelling/lofive

> CPUs aren't just beefy microcontrollers and they require some extra onchip hardware, but no one has done that yet for some reason

For example, Graphics, Bluetooth, Wi-Fi, modem, are all heavily encumbered with patents. Very complex subsystems. Even components that have expired patents or no patents, such as an MMU, are non-trivial to create and take time. I suspect it'll take time before FOSS implementations appear.

Graphics can sit on a PCI bus. Same with Wi-Fi. The MMU is probably a blocker.

> But I'm not quite sure what's holding up general purpose CPUs (even just something crappy/good-enough).. The way I understand it CPUs aren't just beefy microcontrollers and they require some extra onchip hardware, but no one has done that yet for some reason.. Maybe someone knows better :)

There's general-purpose RISC-V CPU RTL lying around, and it's not too difficult to license the necessary peripherals, but it costs money to put together a board and fabricate at volume if you want to hit a Raspberry Pi/hobbyist price point. Unfortunately, it takes time and you need a market to justify the effort. But eventually it'll happen.

If you want actual hardware you can get:

- Kendryte KD233

- HiFive1 (https://www.sifive.com/boards)

- GAPUINO GAP8 (https://greenwaves-technologies.com/product/gapduino/)

- HiFive Unleashed (https://www.sifive.com/boards/hifive-unleashed)

Those are the only ones that exist commercially as far as I know.

You can buy affordable FPGA boards that can be configured with open-source RISC-V chip designs, like the Arty A7-35T[0] for $119. There are a number of other FPGA development boards that would run RISC-V at a much lower cost than $999.

[0]: https://store.digilentinc.com/arty-a7-artix-7-fpga-developme...

A Parallella should be faster than that Arty as it has 32-bit wide DRAM, the Arty only has 16-bit.

It looks like Richard Miller, author of the article and living UNIX legend, is using a verilog implementation by Clifford Wolf [1] in this FPGA board [2].

[1] https://github.com/cliffordwolf/picorv32 [2] https://www.tindie.com/products/Folknology/blackice-ii/

The closest seem to be Lowrisc.org and the Incore Shakti chip. LowRisc seems behind on their original timeline plan. Shakti booted Linux in August. Can't tell if they just want to make chips though...LowRisc is going to make full RPI type boards.

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