What's your opinion of lowRISC? Are there any other RISC-V projects you find more interesting?

What's your opinion of lowRISC? Are there any other RISC-V projects you find more interesting?

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youtube.com/watch?v=qm67wbB5GmI
github.com/sergeykhbr/riscv_vhdl
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No love for completely open SoC's?

I've been making a big list of computers that are at least relatively botnet-free. LowRISC is on that list.

Should I learn RISC-V or ARM assembly? I know 6502 and some x86.

ARM has the same shit as x86 cpu's where there's a part of it that is completely closed and at the very least vulnerable to botnet.

Sure, but I wondering which is better, more fun, more educational, etc. to program in assembly regardless of the botnet.

It's an interesting idea and I hope it goes somewhere but right now it's just an idea.

It has a couple major issues:
- It lacks a GPU design so it has very few uses. Maybe it could be used in a router or other embedded device, but anything with a screen is out.
- Small batches of silicon aren't a thing so you aren't going to be able to make your own
- Medium batches are expensive so this is really going to have to take off if you actually want to get your hands on one.

You can play with it on an FPGA if have one. My guess is that's how most people will experience them.


ARM if you actually want to do things on real hardware. RISC-V is mostly theoretical right now.

I'm sure as soon as they come out, people will be working on RISC-V GPU's.

>Small batches of silicon aren't a thing
Why?

The whole process is labor intensive, requires lots of expensive specialized hardware, and special materials. It costs about the same to make one chip on a wafer as it does to fill the whole thing. You need the volume to make the individual chips at a reasonable prices. It costs $50,000-$100,000 to get a wafer made.

This is a little out of date, and is basically an add for the fab, but should give you a good idea of the process: youtube.com/watch?v=qm67wbB5GmI

Interesting. So nobody has figured out a counterpart to 3D printing/CNC for the CPU world yet? What I mean is something specifically designed to produce small batches cheaper (and isn't an FPGA).

github.com/sergeykhbr/riscv_vhdl is interesting. Has an alternative CPU to the Rocket core used in most other projects, which performs better in benchmarks. Also written in VHDL which is simple, and I'm not really a fan of Chisel.

learn x86-64

not isnt x86-64 just x86 with some extra instructions and changes in register names? (i just know some REALLY basic x86)

I want a risc-v rpi equivalent

I want a RISC-V chip that runs RISC-V from start to finish, rather than being an FPGA that needs an ARM chip to start it up.

Exactly.

IMO you're right about riskv being not there yet. The classic chicken egg problem. And afaik the open house projects have all stalled.

That said, if you can contribute, you can make a big difference. You'll also learn a lot that applies to arm as well.

I want a RISC-V rpi equivalent that can be easily run in parallel. If it can be turned into a fucking supercomputer with little effort, then the mass production problem will vanish pretty quickly.

Weren't the lowRISC guys involved in the development of the raspberry pi?

Like everything else, you need to sell it so I can buy it. I am sure there is market for this.

They were supposed to launch a kickstarter for it in 2017, but that's coming to a close.

FPGA's don't need a cpu to startup. You can hook an eeprom straight up to the fpga pins. The hardware of the fpga itself pulls the bitstream off the prom, validates it, and writes it into its internal configuration registers.

You can use a microcontroller or a cpu for the same task, - on Xilinx fpga's you have a couple pins you can strap to vccio or gnd to configure its startup state machine - but many if not most fpga development boards don't do this and just have a simple prom.

I would recommend risc-v over arm because I think the lack of royalties on risc-v is going to lead to its rapid adoption. BUT don't learn it for no reason. The risc-v ISA is super simple, and if you have programmed anything else in asm, you will pick it up immediately when you need it.