libziskos for RISC-V 64-bit

Static library builds of ziskos for RISC-V 64-bit architecture with IMA extensions, suitable for Nethermind's bflat compiler. Additionally it includes a thin layer with C# bindings.

About

This project provides pre-built static libraries for the zisk zkVM runtime, compiled for RISC-V 64-bit targets. The builds are specifically configured for:

• ISA: RV64IMAD (Integer, Multiplication, Atomic, Double-precision FP)
• ABI: LP64D
• Target OS: zkvm
• Vendor: zisk

The reason for choosing this target over rv64im is pretty simple. It is much more compatible with dotnet-riscv images already used in bflat. Still, these binaries are normally guaranteed to have no C, A, D instructions.

Artifacts

Each release includes:

• lib.a - static library with ziskos functionality (precompiles) and direct system call wrappers (zisk_syscalls.S assembled for rv64ima).
• lib.dll - .NET managed library.

Usage

Use bflat's ability to link to external libraries and provide the link to this repository.

Building Locally

Prerequisites

• Docker
• Git
• Bash

Build Instructions

1. Clone this repository:

git clone https://github.com/nethermindeth/bflat-libziskos.git
cd bflat-libziskos

2. Set the zisk version tag you want to build:

export ZISK_TAG=v0.15.0

3. Run the build script:

./build.sh

4. Find the built libraries in the output/ directory:

ls -lh output/

Build Details

The build process:

1. Clones the zisk repository at the specified tag
2. Applies minimal patches:
   • Adds crate-type = ["staticlib", "rlib"] to Cargo.toml
   • Skips C++ library compilation for zkvm target in lib-c/build.rs
3. Builds Rust library using a custom RISC-V target specification (riscv64imad-zisk-zkvm-elf)
4. Assembles system call wrappers from zisk_syscalls/zisk_syscalls.S with riscv64-linux-gnu-as --march=rv64ima --mabi=lp64
5. Adds syscalls to lib.a using ar to merge the object file into the static library
6. Builds .NET library if the project exists in the zisk repository

The final lib.a contains:

• ziskos core functionality (precompiles, runtime)
• Direct system call wrappers for zkVM syscalls

Contributing

Contributions are welcome! Please feel free to submit issues or pull requests.