Virtual_machine_builder NPM

virtual_machine_builder

A small *language to build virtual machines.

Contact me for help, because I will respond. Discord: amukh1#9613

Prerequisites

This project requires NodeJS (version 8 or later) and NPM. Node and NPM are really easy to install. To make sure you have them available on your machine, try running the following command.

$ npm -v && node -v
6.4.1
v8.16.0

Getting Started

These instructions will get you a copy of the project up and running on your local machine for development and testing purposes. See deployment for notes on how to deploy the project on a live system.

Installation

BEFORE YOU INSTALL: please read the prerequisites

To install and set up the library, run:

$ npm install virtual_machine_builder

Or if you prefer using Yarn:

$ yarn add --dev virtual_machine_builder

Usage

virtual_machine_builder has one file extension: .vm to define a new intruction, write it in the file as follows:

instruction:
add, <-- name
0001, <-- opcode
3, <-- number of operands
instruc-end;

instruction:
sub,
0010,
3,
instruc-end;

End your instruction with instruc-end; You can have as many instructions as you want in one file.

To add functionality to your intructions, you must make functions for each instruction (MAKE SURE THE FUNCTION NAMES MATCH THE INSTRUCTION), and pass them each into an object. Then when you call the object into the prep() method (see later), include this object.

function add(operands, vm){
    vm.registers[operands[3]] = vm.registers[operands[1]] + vm.registers[operands[2]]
    // console.log(operands); // [opcode, 1, 2, 3]
    // vm.registers
    // vm.stack
    // vm.ram
}

// Customize the intruction however you want in the javascript file.

module.exports = add;

Example program:

instruction:
add,
0001,
3,
instruc-end;

instruction:
sub,
0010,
3,
instruc-end;

instruction:
ld_immd,
0011,
2,
instruc-end;

instruction:
output,
0100,
1,
instruc-end;

See "example" folder for the Javascript implementations.

Actually using your new VM:

In another Javascript file (outside the instructions folder), import the library

var VM = require('virtual_machine_builder');
var fs = require('fs'); // file system

Then, create a new virtual machine and run it:

var vm_schematic = fs.readFileSync('./file.vm', 'utf8');
var vm = new VM(schematic, true); // takes in the contents of the .vm file, and a boolean for "console" mode or not.
vm.prep({
    add: add,
    sub: sub,
    ld_immd: ld_immd,
    output: output
}); // prepares the virtual machine for execution and parses vm file

vm.run(`binary_code\n`); // runs the virtual machine with many lines of binary code separated by newlines
vm.runln(`0001 1 2 3`); // adds 1 and 2, and stores the result in register 3 (4th register including 0)
// vm.runln(`binary_code`); // runs the virtual machine with one line of binary code

Passing false into the second argument of the initial VM declaration will make it so the vm doesnt log all the instructions while prepping.