ISFS_Setup.c

int ISFS_Setup(ISFS *this,int init)
{
	if (init == 0)
		return 0;

	super = ISFS_LoadSuperblock(this);
	if (!super)
		return -0x8046F;

	int rc = ISFS_ProcessSuperblock(this,super,0,3,0);
	if (rc != 0)
		return rc;

	uint32_t nandClusters = this->nandSizeBytes >> 0xe;
	uint32_t superblockSize = (1 << this->metadataSizeLog2 - this->superblockCountLog2);
	uint32_t fstEntryCount = (superblockSize - (nandClusters * sizeof(u16)) - 0xc) / sizeof(FST_Entry);
	for (uint32_t i = 1; i < fstEntryCount; i++)
		if (super->fst[i].mode & 3)
			super->fst[i].size &= 0x7fffffff;


	for (uint32_t i = 0; i < nandClusters; i++)
		if (super->fat[i] == 0xffff)
			super->fat[i] = 0xfffe;

	for (int i = 0; i < 0x10; i++)
		this->structunk2[i].valid = 0;

	this->field_0x48d68 = 0xfffd;
	this->field_0x48d6a = 0xfffd;

	return ISFS_ProcessSuperblockUsage(this, super);
}

int ISFS_ProcessSuperblockUsage(ISFS *this,ISFS_Superblock *super)
{
	this->clusterSize = 0x4000;
	isfs->numClustersEmpty = 0;
	isfs->numClustersUsed = 0;
	isfs->numClustersBad = 0;
	isfs->numClustersReserved = 0;
	this->numFSTEmpty = 0;
	this->numFSTUsed = 0;

	uint32_t dataClustersStart = this->fsOffset >> 0xe;
	uint32_t dataClustersEnd = dataClustersStart + (this->dataAreaSize >> 0xe);
	for (uint32_t i = dataClustersStart; i < dataClustersEnd; i++)
	{
		if (super->fat[i] >= 0xfffe)
			this->numClustersEmpty++;
		else if (super->fat[i] < 0xfffc)
			this->numClustersUsed++;
		else if (super->fat[i] == 0xfffd)
			this->numClustersBad++;
		else if (super->fat[i] == 0xfffc)
			this->numClustersReserved++;
	}

	uint32_t nandClusters = this->nandSizeBytes >> 0xe;
	uint32_t superblockSize = (1 << this->metadataSizeLog2 - this->superblockCountLog2);
	uint32_t fstEntryCount = (superblockSize - (nandClusters * sizeof(u16)) - 0xc) / sizeof(FST_Entry);

	for (uint32_t i = 0; i < fstEntryCount; i++)
	{
		if ((super->fst[i].mode & 3) == 0)
			this->numFSTEmpty++;
		else
			this->numFSTUsed++;
	}

	return 0;
}