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Unicorn CPU emulator framework port for JavaScript
JavaScript C HTML Python
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Latest commit dedbfca Nov 3, 2019
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unicorn @ 5dbc640 Updated Unicorn to v1.0.1 Jan 15, 2019
.editorconfig Patching Unicorn files for Emscripten build Jun 22, 2016
.gitignore Added all Unicorn.js variants to dist folder Apr 20, 2017
.gitmodules Added draft script Jun 19, 2016
Gruntfile.js Fixed Gruntfile script Jan 15, 2019 Using emsdk 1.37.9+ to compile Unicorn.js May 15, 2017
bower.json Bump to v1.0 Apr 19, 2017 Updated Unicorn to v1.0.1 Jan 15, 2019
demo.html Fixed hook callbacks (closes #2) Mar 30, 2017
index.html Demos: Added MIPS code and minor improvements Feb 4, 2017
package-lock.json Bump bower from 1.8.4 to 1.8.8 Nov 2, 2019


Last Release

Port of the Unicorn CPU emulator framework for JavaScript. Powered by Emscripten.

Notes: Unicorn is a lightweight multi-architecture CPU emulator framework originally developed by Nguyen Anh Quynh, Dang Hoang Vu et al. and released under GPLv2 license. More information about contributors and license terms can be found in the files AUTHORS.TXT, CREDITS.TXT and COPYING inside the unicorn submodule of this repository.


To add Unicorn.js to your web application, include it with:

<script src="unicorn.min.js"></script>

or install it with the Bower command:

bower install unicornjs


var addr = 0x10000;
var code = [
  0x37, 0x00, 0xA0, 0xE3,  // mov r0, #0x37
  0x03, 0x10, 0x42, 0xE0,  // sub r1, r2, r3

// Initialize engine
var e = new uc.Unicorn(uc.ARCH_ARM, uc.MODE_ARM);

// Write registers and memory
e.reg_write_i32(uc.ARM_REG_R2, 0x456);
e.reg_write_i32(uc.ARM_REG_R3, 0x123);
e.mem_map(addr, 4*1024, uc.PROT_ALL);
e.mem_write(addr, code)

// Start emulator
var begin = addr;
var until = addr + code.length;
e.emu_start(begin, until, 0, 0);

// Read registers
var r0 = e.reg_read_i32(uc.ARM_REG_R0);  // 0x37
var r1 = e.reg_read_i32(uc.ARM_REG_R1);  // 0x333


To build the Unicorn.js library, clone the master branch of this repository on a Linux machine, and do the following:

  1. Initialize the original Unicorn submodule: git submodule update --init.

  2. Install the latest Python 2.x (64-bit) and the Emscripten SDK 1.37.9+. Follow the respective instructions and make sure all environment variables are configured correctly.

  3. Install the development dependencies with: npm install.

  4. Finally, build the source with: grunt build.

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