RISC-V support

[mattgenious]

Posting because I cannot find mention anywhere

I have seen that mono supports the RISC-V architecture but cannot find anything relating to .NET 5 support for RISC-V.
Are there any plans to support said architecture on future releases of .NET like ARM64 has been added?

[joperezr]

cc: @marek-safar

[DavidBurela]

SiFive just announced a new powerful RISC-V development board coming out this year. Will be a number of new developers using the hardware. Might be worth looking at RISC-V support again, especially in IoT scenarios.

https://www.sifive.com/blog/the-heart-of-risc-v-development-is-unmatched
https://www.sifive.com/boards/hifive-unmatched

[logicethos]

The First Affordable RISC-V Computer Designed to Run Linux
https://beaglev.seeed.cc/

Also the Allwinner RISC-V chip to set to debut on $13 Linux hacker board soon.

[broudy3]

I assume that libunwind needs to be ported first to RISC-V, as coreclr depends on this library. Is this statement true? There is a closed port request libunwind/libunwind#99

[0xStuart]

The BL602 is gaining popularity. It's an alternative to the hugely popular ESP32 which is everywhere.
RISC-V with Wifi and Bluetooth

[archanox]

I assume that libunwind needs to be ported first to RISC-V, as coreclr depends on this library. Is this statement true? There is a closed port request libunwind/libunwind#99

It looks like the support has been merged in upstream now.

[alexrp]

Just noticed this issue and wanted to clarify something:

I have seen that mono supports the RISC-V architecture

For the record, "supports" is an overstatement here. IIRC, you can just barely run 'hello world' with the interpreter, and not much more. The JIT backend for RISC-V is like 10% done at most. There's a lot of work to be done for Mono's RISC-V support to actually be usable.

[archanox]

You're definitely right @alexrp.
I've been trying to build mono on my RISC-V hardware for a little while now with no success.
I've noticed that there is a bit of a to do list here mono:mono/docs/riscv.md

If I can get it to build, I'd be very keen to contribute to getting the mono support working, which if I understand correctly is the first step in getting .net vanilla support?

[Xinlong-Wu]

Hi all,
Thanks for the help from @dkurt,

He just build a installable riscv64 package dotnet-sdk-8.0.100-linux-riscv64.tar.gz(CoreCLR Backend by Default) at repo dkurt/dotnet_riscv.

if you may try it.
please check your libstdc++ support GLIBCXX_3.4.32, run command strings path/to/your/libstdc++.so.6 | grep GLIBCXX_3.4.32. It will except output GLIBCXX_3.4.32.

use following command to install dotnet riscv64

wget https://github.com/dkurt/dotnet_riscv/releases/download/v8.0.100/dotnet-sdk-8.0.100-linux-riscv64.tar.gz
DOTNET_FILE=dotnet-sdk-8.0.100-linux-riscv64.tar.gz
export DOTNET_ROOT=$(pwd)/.dotnet

mkdir -p "$DOTNET_ROOT" && tar zxf "$DOTNET_FILE" -C "$DOTNET_ROOT"

export PATH=$PATH:$DOTNET_ROOT:$DOTNET_ROOT/tools

you can use dotnet at riscv64 normally.

# create project
dotnet new console -n HelloWorld

modify Program.cs as

using System;

namespace HelloWorld
{
    internal class Program
    {
        private static void Main(string[] args)
        {
            bool isMono = typeof(object).Assembly.GetType("Mono.RuntimeStructs") != null;
            Console.WriteLine($"Hello World {(isMono ? "from Mono!" : "from CoreCLR!")}");
            Console.WriteLine(typeof(object).Assembly.FullName);
            Console.WriteLine(System.Reflection.Assembly.GetEntryAssembly ());
            Console.WriteLine(System.Runtime.InteropServices.RuntimeInformation.FrameworkDescription);
        }
    }
}

# build and run 
dotnet build
dotnet run

it will output

Note: Although dotnet-sdk-8.0.100-linux-riscv64.tar.gz has been packaged, it sitll has lots of potential issues, both on CoreCLR and Mono backend.

[0xStuart]

I tried this on a $8 Milk-V 256M running ubuntu.

root@milkvduo-ubuntu:~# dotnet new console -n HelloWorld
Illegal instruction

Probably not surprising with such a low hardware spec. Maybe if we can do AOT compilation it might work.

[dkurt]

@0xStuart, might be related to fence.tso hardware bug. Please try GCC version: https://github.com/dkurt/dotnet_riscv/releases/download/v8.0.101/dotnet-sdk-8.0.101-linux-riscv64-gcc.tar.gz

[0xStuart]

@dkurt It worked, although I had to kill it as it was taking forever to complete. I had htop running in another terminal, and it was visible that all the RAM got used up. Maybe adding swap will help.

Anyway, this is fantastic. These new RISC-V SOC's are opening up new possibilities.

[clamp03]

I don't know why it's not mentioned here but for those interested there is a $ 500,- bounty on this issue. https://gitpay.me/#/task/607/risc-v-support

@dotnet/samsung team has done excellent work! They deserve that bounty and more. 🏆

@JaneX8 @archanox @am11 Thank you so much! And @Xinlong-Wu also did great work in Mono runtime. Actually, we are supported by @Samsung. So I hope @Xinlong-Wu get the bounty.

@jkotas If you don't mind, could you add our developers to dotnet org (and/or to @dotnet/samsung team)? I know, even if they are added, nothing changed for them. However, when I was added and got a badge, I was so happy and proud. They worked hard for .net runtime and I think they deserve it.

Could you please add?
+ You can remove all existing members in @dotnet/samsung except these 17 members.
@wscho77 @HJLeee @clamp03 @JongHeonChoi
@t-mustafin @gbalykov @viewizard @ashaurtaev @brucehoult @denis-paranichev @o-lek
@sirntar @yurai007 @Bajtazar @bartlomiejko @rzsc @tomeksowi

@gbalykov @bartlomiejko Could you check the members?

[gbalykov]

Could you check the members?

@clamp03 it is correct, thank you!

[bartlomiejko]

Could you check the members?

@clamp03 thanks, it is correct, some of us already joined.

[clamp03]

@gbalykov @bartlomiejko Thank you.

[BruceForstall]

@clamp03 Based on the above, I updated the @dotnet/samsung group as follows:

Removed @leemgs @idkiller @myungjoo @jyoungyun @sjsinju
Added @JongHeonChoi @denis-paranichev @o-lek

I could not add @rzsc because they are not a member of the dotnet org. I believe @jkotas has sent them an invite.

Note that @denis-paranichev @o-lek @rzsc GitHub profiles do not indicate they are affiliated with Samsung.

[Xinlong-Wu]

If you don't mind, could you add our developers to dotnet org

hi @BruceForstall, same thing, I would be greatful if you can add me to dotnet org.

[jkotas]

@Xinlong-Wu We have added the folks above so that we can include them in dotnet samsung team that we have been working with closely for a long time and the team alias is convenient for github workflows. We do not add folks to the dotnet org without a demonstrated need.

[vargaz]

@Xinlong-Wu has been contributing riscv support for mono.

[jkotas]

I appreciate @Xinlong-Wu contributions. dotnet org membership is not required for contributing. It is only needed for membership in a dotnet org team alias or to grant additional permissions.

[clamp03]

@clamp03 Based on the above, I updated the @dotnet/samsung group as follows:

Removed @leemgs @idkiller @myungjoo @jyoungyun @sjsinju Added @JongHeonChoi @denis-paranichev @o-lek

I could not add @rzsc because they are not a member of the dotnet org. I believe @jkotas has sent them an invite.

Note that @denis-paranichev @o-lek @rzsc GitHub profiles do not indicate they are affiliated with Samsung.

Thank you so much!!!!!
@rzsc Please check your email inbox. (@bartlomiejko Could you please let him know?)

[rzsc]

I have turned on two-factor authentication and accepted invitation to the @dotnet organization. Is anything more I need to do, please?

[BruceForstall]

@rzsc I have added you to the https://github.com/orgs/dotnet/teams/samsung team.

[ivanjx]

is native aot for risc-v also covered here?

[raffaeler]

is native aot for risc-v also covered here?

AOT on risc-v would open a huge possibilities even on small microcontrollers having a decent amount of DRAM (I have some of them)

[tomeksowi]

@BruceForstall @jkotas Could you add @SzpejnaDawid to @dotnet/samsung (and @dotnet if necessary)? He joined our team in April and will be contributing to .NET RISC-V. Thank you.

[am11]

MuseBook risc-v! 🎉 (it’s RVA22 + V ext) will unpack, then try out dotnet and run runtime tests! 🤞

[archanox]

MuseBook risc-v! 🎉 (it’s RVA22 + V ext) will unpack, then try out dotnet and run runtime tests! 🤞

I've got the DC ROMA2 version. Do you have instructions on how to get dotnet running in its prerelease form?

[am11]

@archanox, I will polish up https://github.com/am11/CrossRepoCITesting/blob/master/.github/workflows/linux-riscv64-runtime-build.yml to upload artifacts, then we will get the runtime package in its releases. Later I will switch it to build source build (runtime+aspnetcore+sdk+everything-else). For now, having runtime will be enough to run .NET assemblies.

[filipnavara]

I uploaded somewhat recent .NET SDK build for Risc-V here: https://github.com/filipnavara/dotnet-riscv/releases/tag/v9.0.0-preview.7.24405.7 (should be .NET 9 Preview 7). It has the same baseline requirements as the build from @am11, which means that the official Debian images for StarFive VisionFive 2 don't work (too old glibc). I checked that it runs on Ubuntu 24.04 which has some prebuilt images for common boards/machines.

[ww898]

@filipnavara I got error on Ubuntu 24.04 riscv64 on StarFive VisionFive 2:

$ dotnet restore
/usr/local/dotnet/sdk/9.0.100-preview.7.24407.1/Sdks/Microsoft.NET.Sdk/targets/Microsoft.NET.TargetFrameworkInference.targets(187,5): warning NETSDK1215: Targeting .NET Standard prior to 2.0 is no longer recommended. See https://aka.ms/dotnet/dotnet-standard-guidance for more details.
    /usr/local/dotnet/sdk/9.0.100-preview.7.24407.1/NuGet.targets(180,5): error : Root element is missing.

Restore failed with 1 error(s) and 1 warning(s) in 22.2s

Update §1: Started working after remove ~/.dotnet and ~/.nuget directories...

Update §2: All tests in my OSS projects are 🟢 green for now!!! Thanks a lot!!!

[pvelesko]

@filipnavara

https://github.com/pvelesko/dotnet_riscv/releases/tag/v8.0.101

built dotnet with statically linked libstc++ the binary above works on the starfive visionfive 2 Debian image (old glibc)

[tkstanczak]

would really need RISC-V support for https://github.com/NethermindEth/nethermind 🙏

[archanox]

I understand that the work on this is not undertaken by Microsoft, but rather Samsung hence having no official releases. But I'm wondering what the current state is for having a dotnet 9 release, if there's a release timeline, any blockers, outstanding work? I have a pioneer that's waiting in the midst that's waiting to run some of my workloads.

[sirntar]

@archanox

I understand that the work on this is not undertaken by Microsoft, but rather Samsung hence having no official releases.

Yes, that's correct. You can truck current state of the project here: #84834

But I'm wondering what the current state is for having a dotnet 9 release, if there's a release timeline, any blockers, outstanding work? I have a pioneer that's waiting in the midst that's waiting to run some of my workloads.

At this moment tests pass rate for coreCLR is 99.8% and for coreFX about 97%, although there is still a lot of work to be done. Technically we have a working runtime, but the sdk is not yet fully built (there are some problems with msbuild - I'm working on it).
As for release of risc-v port for dotnet 9, there is currently no timeline, but I can tell you that it probably won't happen in the first quarter of 2025.