tonylukasavage / retroverse

Ambitious NES stitcher for randos

Retroverse

By Tony Lukasavage, aka BloodSweatAndCode

An ambitious attempt to create NES combo world randos with an arbitrary number of games.

Patch format

Patches can be a single python file or a directory containing a patch.py file as its entry point.

Single File Patch Format

The python file should share the same name as the patch. For example, a patch named mycoolpatch should be contained in a file called mycoolpatch.py. The file has 2 requirements

1. A function named execute(data), where the data parameter is a reference to a bytearray containing the ROM data on which you are hacking.
2. a patch dictionary containing the following properties:
   • name - The name of the patch
   • desc - A brief description of the patch
   • deps - A list of patch names upon which this patch relies. Those patches will be executed before this patch.
   • execute - A reference to the execute(data) function, #1 in the list list.

Here's a simple annotated example for Castlevania 2, used only in testing:

def execute(data):
    # This list of hex values represents 9 "Z" letters on the CV2 title screen
    bytes = [0x1A, 0x1A, 0x1A, 0x1A, 0x1A, 0x1A, 0x1A, 0x1A, 0x1A]

    # The loc variable represents the location in the ROM data to which we are going
    * to write the above bytes
    loc = 0x0101A2

    # Write the bytes to the location
    data[loc: loc + len(bytes)] = bytes


patch = {
    'name': 'Z\'s',
    'desc': 'Write a bunch of Z\'s to the title screen',
    'deps': [],
    'execute': execute
}