cstool

Disassembles machine code.

Usage

cstool [FLAGS] [OPTIONS] --arch <arch> --mode <mode> <--file <file>|--stdin|--code <code>>

FLAGS:
    -d, --detail     Print details about instructions
    -h, --help       Prints help information
    -x, --hex        Treat input has hex; only select characters that are [a-fA-F0-9]
    -s, --stdin      read binary instructions from stdin
    -V, --version    Prints version information
    -v               Sets the level of verbosity

OPTIONS:
    -r, --addr <address>      address of code
    -a, --arch <arch>         Architecture [possible values: arm, arm64, mips, x86, ppc, sparc, sysz, xcore, m68k,
                              tms320c64x, m680x, evm]
    -c, --code <code>         instruction bytes (implies --hex)
    -n, --endian <endian>     Endianness [possible values: little, big]
    -e, --extra <extra>...    Extra Mode [possible values: mclass, v8, micro]
    -f, --file <file>         input file with binary instructions
    -m, --mode <mode>         mode [possible values: arm, mode16, mode32, mode64, thumb, mips2, mips3, mips32r6, mips32,
                              mips64, v9, qpx, m68k000, m68k010, m68k020, m68k030, m68k040, m680x6301, m680x6309,
                              m680x6800, m680x6801, m680x6805, m680x6808, m680x6809, m680x6811, m680xcpu12, m680xhcs08,
                              default]

Example

# Disassemble 32-bit X86 (non-hex characters are ignored)
cstool --arch x86 --mode mode32 --code "90 42 e812345678"
      1000:  90                                  nop
      1001:  42                                  inc     edx
      1002:  e8 12 34 56 78                      call    0x78564419

Build

Requirements:

• Rust language toolchain (such as from rustup)
• C compiler (such as clang, gcc, msvc)

Run with cargo:

cargo run -- [arguments]

Build for WASI

WebAssembly System Interface (WASI) provides APIs to run WebAssembly in various contexts, not just the web.

Requirements:

• clang-8 (available at https://apt.llvm.org/)
• WASI sysroot from https://github.com/CraneStation/wasi-libc
  • Assumed to be installed at $WASI_SYSROOT
• wasm-wasi target rust toolchain (tested with Rust 1.36.0):

  rustup target add wasm32-wasi
  

• WASI runner to run WASI executable, such as:
  • wasmtime
  • wasmer

Build cstool:

Tell cc crate to use our WASI sysroot and clang-8 compiler:

cd cstool  # go to path with cstool dir
CFLAGS_wasm32_wasi="--sysroot="$WASI_SYSROOT" \
    CC=clang-8 \
    cargo +nightly build --target=wasm32-wasi

Run cstool:

cd cstool  # go to path with cstool dir

Run with wasmer:

wasmer run ../target/wasm32-wasi/debug/cstool.wasm -- --arch x86 --mode mode32 --code "90 42 e812345678"

Run with wasmtime:

wasmtime ../target/wasm32-wasi/debug/cstool.wasm -- --arch x86 --mode mode32 --code "90 42 e812345678"

Should give output:

      1000:  90                                  nop
      1001:  42                                  inc     edx
      1002:  e8 12 34 56 78                      call    0x78564419