nyxstone-rs

Official bindings for the Nyxstone assembler/disassembler engine.

Building

The project can be build via cargo build, as long as LLVM 15 supporting static linking is installed in the $PATH or the environment variable $NYXSTONE_LLVM_PREFIX points to the installation location of such a LLVM 15 library. For further information conduct the Nyxstone README.md. The bindings further expect that the Nyxstone library is installed in the nyxstone sub-directory. This can be accomplished by using the Makefile target nyxstone.

Installation

Add nyxstone as a dependency in your Cargo.toml:

[dependencies]
nyxstone = "0.0.1"

Building nyxstone requires a C/C++ compiler to be installed on your system. Furthermore, Nyxstone requires LLVM 15 to be installed. Refer to the Building section for more information about setting the install location of LLVM.

Sample

In the following is a short sample of what using Nyxstone can look like:

extern crate anyhow;
extern crate nyxstone;

use std::collections::HashMap;

use anyhow::Result;
use nyxstone::{IntegerBase, Nyxstone, NyxstoneConfig};

fn main() -> Result<()> {
    // Creating a nyxstone instance can fail, for example if the triple is invalid.
    let nyxstone = Nyxstone::new("x86_64", NyxstoneConfig::default())?;

    // Assemble a single instruction
    let instructions = nyxstone.assemble_to_instructions("xor rax, rax", 0x100)?;

    println!("Assembled: ");
    for instr in instructions {
        println!("0x{:04x}: {:15} - {:02x?}", instr.address, instr.assembly, instr.bytes);
    }

    // Assemble with a label definition
    let instructions = nyxstone.assemble_to_instructions_with(
        "mov rax, rbx; cmp rax, rdx; jne .label",
        0x100,
        &HashMap::from([(".label", 0x1200)]),
    )?;

    println!("Assembled: ");
    for instr in instructions {
        println!("0x{:04x}: {:15} - {:02x?}", instr.address, instr.assembly, instr.bytes);
    }

    let disassembly = nyxstone.disassemble(
        &[0x31, 0xd8],
        /* address= */ 0x0,
        /* #instructions= (0 = all)*/ 0,
    )?;

    assert_eq!(disassembly, "xor eax, ebx\n".to_owned());

    let config = NyxstoneConfig {
        immediate_style: IntegerBase::HexPrefix,
        ..Default::default()
    };
    let nyxstone = Nyxstone::new("x86_64", config)?;

    assert_eq!(
        nyxstone.disassemble(&[0x83, 0xc0, 0x01], 0, 0)?,
        "add eax, 0x1\n".to_owned()
    );

    Ok(())
}

Technical overview

The nyxstone-rs bindings are generated via the cxx crate. Since nyxstone is specifically a c++ library, we currently do not plan to support C bindings via bindgen.

Acknowledgements

The build script of the rust bindings borrow heavily from the llvm-sys build script.