pupperuki / nod

Nintendo Optical Disc traversal and generation

NOD

NOD is a library and utility (nodtool) for traversing, dumping, and authoring GameCube and Wii optical disc images.

Library

The primary motivation of NOD is to supply a uniform C++11 API for accessing data from image files directly. nod::DiscBase provides a common interface for traversing partitions and individual files. Files may be individually streamed, or the whole partition may be extracted to the user's filesystem. Raw ISO and WBFS images are supported read sources.

bool isWii; /* Set by reference next line */
std::unique_ptr<nod::DiscBase> disc = nod::OpenDiscFromImage(path, isWii);
if (!disc)
    return FAILURE;

/* Access first data-partition on Wii, or full GameCube disc */
nod::Partition* dataPart = disc->getDataPartition();
if (!dataPart)
    return FAILURE;

/* One-shot extraction to filesystem */
if (!dataPart->extractToDirectory(outDir, ctx))
    return FAILURE;

return SUCCESS;

Image authoring is always done from the user's filesystem and may be integrated into a content pipeline using the nod::DiscBuilderBase interface.

/* Sample logging lambda for progress feedback */
size_t lastIdx = -1;
auto progFunc = [&](size_t idx, const nod::SystemString& name, size_t bytes)
{
    if (idx != lastIdx)
    {
        lastIdx = idx;
        /* NOD provides I/O wrappers using wchar_t on Windows;
         * _S() conditionally makes string-literals wide */
        nod::Printf(_S("\n"));
    }
    if (bytes != -1)
        nod::Printf(_S("\r%s %" PRISize " B"), name.c_str(), bytes);
    else
        nod::Printf(_S("\r%s"), name.c_str());
    fflush(stdout);
};

/* Making a GCN image */
nod::DiscBuilderGCN b(isoOutPath, progFunc);
ret = b.buildFromDirectory(fsRootDirPath);

/* Making a Wii image */
nod::DiscBuilderWii b(isoOutPath, dualLayer, progFunc);
ret = b.buildFromDirectory(fsRootDirPath);

Wii images are fakesigned using a commonly-applied signing bug.

Additionally, any *.dol files added to the disc are patched to bypass the #001 error caused by invalid signature checks. This allows games with multiple .dols to inter-boot without extensive loader-patching.

Tool

The library usage mentioned above is provided by a command-line tool called nodtool.

An extract/repack works like so:

>$ nodtool extract <image-in> [<dir-out>]
>$ cd <dir-out>

# Then one of:
>$ nodtool makegcn fsroot [<image-out>]
>$ nodtool makewii fsroot [<image-out>]