AS/REPL

AS/REPL> lea rbx, [rsp + 4]
488d5c2404
AS/REPL> 31c0
xor eax, eax

A brief example of what interacting with AS/REPL looks like.

AS/REPL is a REPL-style interface for assembling and disassembling code; input assembly mnemonics or opcodes, get back the other. Thanks to WebAssembly, AS/REPL is available as both a native CLI application as well as a website. If you want, you can try AS/REPL online right now!

Supported architectures

At this time, only the following architectures are supported:

• Intel, 32-bit
• Intel, 64-bit
• ARM, 32-bit
• ARM, 64-bit

However, since AS/REPL uses both Capstone and Keystone under the hood, adding support for more architectures should be trivial, and is planned.

Build dependencies

AS/REPL uses the following libraries:

• Keystone, for assembling instructions;
• Capstone, for disassembling instructions;
• linenoise, for the CLI's REPL interface; and
• Emscripten, for targeting WebAssembly.

With the exception of Emscripten, AS/REPL compiles all of its dependencies from source, so there is no need to install anything via your package manager. While Emscripten may be available in your package manager, it is recommended to install the Emscripten SDK.

Build instructions

AS/REPL is rather easy to build. All builds will require you to clone the repository and all of its submodules:

git clone https://github.com/jonpalmisc/asrepl.git && cd asrepl
git submodule update --init --recursive

Next, run CMake either of the following ways depending on the desired target:

# Native CLI
cmake -S . -B build

# Web application
emcmake cmake -S . -B build -DASREPL_CLI=OFF -DASREPL_WEB=ON

For the latter, you need to have already activated the Emscripten SDK in your environment so the emcmake command is available. Starting a web server in the build directory once AS/REPL is built will allow you to use AS/REPL's web interface. Easy solutions include python3 -m http.server or php -S localhost:8000.

License and credits

AS/REPL is licensed under the GNU General Public License, Version 3. For more information, see LICENSE.txt.

This project was inspired by jsasm, and is not related to asrepl, which I discovered after publishing this project.