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Ask HN: Are there any open source RISC-V processors that I can buy and use?

• deleted 2y ago
  [deleted]
• duskwuff 2y ago
  RP2350 (Raspberry Pi Pico 2) has two Hazard3 cores, which is open-source at: https://github.com/Wren6991/Hazard3 https://github.com/Wren6991/Hazard3
  • mrlonglong 2y ago
    Just be aware there's no floating point and there's only machine mode, so you can't run a modern operating system on it. It is purely a microcontroller.
    • brucehoult 2y ago
      Which is exactly what many people want. OP said "small processor"
      • 6SixTy 2y ago
        But then is followed up using the StarFive JH7110 as an example, which is a Linux capable chip with a GPU rather than a microcontroller with neither of those. Given that OP responded to the person giving microcontroller pointers positively, some form of miscommunication is likely here.
        • applestone 2y ago
          Apologies for the miscommunication, I'm looking for Linux capable chips
• 6SixTy 2y ago
  There aren't a whole lot of RISC-V processors that abide by the strictest definition of "fully open source" that are that interesting. There's GPU silicon, encode/decode, sometimes a DSP, maybe even random elements like a memory interface that aren't open source. Strip those out and it's just kind of a text mode only computer or micro controller.
• camel-cdr 2y ago
  XuanTie open sourced their C910 [1] and C906 core [2], excluding the xtheadvector support. You can get SBCs with them for quite cheap: C910: Lichee Pi 4A, C906: MangoPi Mq pro How much of the implementation used in actual silicon overlap with their open source cores isn't clear. I was able to figure out where some non-standard CSR bits are located [3]. Personal, I wouldn't recommend buying them, especially not because they are open source. While source code has been published, the source code looks partially generated and at least for a software dev like me, very hard to read. I would recommend waiting for the RuyiBook [4], which will contain the second generation of the OpenXiangShan core [5], which is developed fully in the open on GitHub. From the information available, it seems likely that it will become available this year and that it would then be the highest performing RISC-V processor generally available. See my old comment for benchmarks I ran in the RTL simulation: https://news.ycombinator.com/item?id=41331786#41331968 https://news.ycombinator.com/item?id=41331786#41331968 The only unfortunate thing it that it will likely lack support for the vector extension. I hope they follow my suggestion of shipping the processor source code with the default Linux install. [1] https://github.com/T-head-Semi/openc910 https://github.com/T-head-Semi/openc910 [2] https://github.com/XUANTIE-RV/openc906 https://github.com/XUANTIE-RV/openc906 [3] https://github.com/camel-cdr/rvv-d1?tab=readme-ov-file#enabling-rvv-on-allwinner-d1c906-linux https://github.com/camel-cdr/rvv-d1?tab=readme-ov-file#enabl... [4] https://milkv.io/ruyibook https://milkv.io/ruyibook [5] https://github.com/OpenXiangShan/XiangShan https://github.com/OpenXiangShan/XiangShan See also, slides on the XiangShanV2 microarchitecture: https://raw.githubusercontent.com/OpenXiangShan/XiangShan-doc/main/tutorial/20231028-MICRO23-3-Microarchitecture.pdf https://raw.githubusercontent.com/OpenXiangShan/XiangShan-do...
  • applestone 2y ago
    Hey, thank you for such a good response
  • brucehoult 2y ago
    Hopefully the RuyiBook will be great but it's hardly a "small RISC-V processor". The ~$5 Milk-V Duos are great. Two C906's, one with MMU and vectors etc for running Linux and one without those for "microcontroller" / "real time" tasks.
• ElectRabbit 2y ago
  WCH is quiet famous for their Risc-V microcontrollers.
• jononor 2y ago
  What kind of performance level? RISC-V spans from 15 cent microcontrollers with 32 kB of RAM to multi-core systolic arrays with gigabytes of RAM...
  • applestone 2y ago
    Something you can run Linux on and use for normal things, web browser, text editor, watching youtube, etc