ASMAGIX

Introduction

ASMAGIX is a command line tool assembly hackers can use to quickly modify code in a GBA ROM, with as little hassle as possible. Stop repetitive tasks getting in the way of your ASMAGIX.

Features

• Automatically inserts your code into free space
• Apply hooks, overwrite existing code, etc. using simple comment directives.
• Scaffolds your ASM project
• Development mode watches for changes to your ASM files and automatically assemble and insert
• Start at emulator automatically

Installation

First install DevkitARM and ensure its binaries are in your path. If you have Node.js and NPM, you can just:

npm install -g asmagix

Config

The asmagixfile holds the configuration information for your project. Place a file in the root of your project called asmagixfile.json. An asmagixfile resembles the following:

{
  "src": "./src",
  "roms": {
    "bpre": "./roms/bpre.gba"
  },
  "default": "bpre",
  "build": "./build"
}

src - Holds the source code for your project. All .s and .asm files in this directory will be assembled when you run the build action. roms - This is a key-value structure with a name as the key and a path as the value. When running actions you can choose a ROM from this list. The assembler is also passed the (uppercase) name so you can do conditional assembly. default - The default key in the structure above. build - Any output from the tool is placed here.

Usage

Navigate into the directory containing your asmagixfile and run:

asmagix $action $action - where $action is one of the actions below and $rom is the optional key in the roms field in your asmagixfile. The default will be used if this is not present.

Action	Description
build	Assembles everything and inserts it into your target ROM.
dev	Watches source files for changes and runs build for your target ROM if it sees anything.
init	Creates a basic project for you. You are responsible for populating the ROMS directory.

Directives

At the very top of each file in your source directory, you need to place comment directives in order to tell ASMAGIX what to do with the file. Comment directives look like

@@directiveName parameters

@ ...

Directives are allowed parameters. Directives that are just integers can be replaced with ASM constants (defined with .equ or similar) and ASMAGIX will automatically replace them.

ignore

@@ignore - The ignore directive takes no parameters and simply tells ASMAGIX to skip processing this file entirely.

action

@@action NAME PARAMETERS - The action directive is a collection of directives that control the way the file is inserted.

hook

@@action hook OFFSET REGISTER MODE - The hook action takes three parameters - an offset to place the hook code at, a (low) register number to use in this code (default 0) and the mode: "arm" or "thumb" (default is "thumb"). Examples:

• @@action hook 0xDEADBEEF 0 arm - select ARM mode
• @@action hook 0xDEADBEEF 3 - select r3 to hook in
• @@action hook 0xDEADBEEF - defaults to r0 and thumb mode

insert

@@action insert - The insert action takes no parameters and simply inserts the code in free space. If you don't specify an action, ASMAGIX will default to this one.

Direction

This is still in its early stages. I may eventually make some sort of package manager feature that allows easy installing of projects like this.