pureikyubu/Docs/RE/dvdfs.txt

typedef struct
{
    union
    {
	struct {
    		u8      isDir;                  // 1, if directory
    		u8      nameOffsetHi;
    		u16     nameOffsetLo;
	};
	uint32 nameOffsetDirFlag;
    };
    union
    {
        struct                      // root entry
        {
            u32     reservedZero;
            s32     entryNum;
        };
        struct                      // file
        {
            s32     fileOffset;
            s32     fileLength;
        };
        struct                      // directory
        {
            s32     parentOffset;   // previous
            s32     nextOffset;     // next
        };
    };
} DVDFileEntry;

struct DVDFileInfo
{
    DVDCommandBlock cb;
    u32             startAddr;      // disk address of file
    u32             length;         // file size in bytes
    DVDCallback     callback;
};


struct DVDCommandBlock
{
    DVDCommandBlock* next;
    DVDCommandBlock* prev;
    u32          command;
    s32          state;
    u32          offset;
    u32          length;
    void*        addr;
    u32          currTransferSize;
    u32          transferredSize;
    DVDDiskID*   id;
    DVDCBCallback callback;
    void*        userData;
};


OSBootInfo   * BootInfo;                // OS boot info
DVDFileEntry * FstStart;                // begin of fs entries
s32            MaxEntryNum;             // entries count
char *         FstStringStart;          // begin of file strings
s32            currentDirectory;        // current directory entry


void __DVDFSInit(void)
{
    BootInfo = (OSBootInfo *)OSPhysicalToCached(0);

    FstStart = BootInfo->FSTLocation;
    if(FstStart)
    {
        MaxEntryNum = FstStart[0].entryNum;
        FstStringStart = (char *)(&FstStart[MaxEntryNum]);
    }
}


BOOL DVDOpen(char* fileName, DVDFileInfo* fileInfo)
{
    if(fileName == NULL)
        OSHalt("DVDOpen(): null pointer is specified to file name\n");
    if(fileInfo == NULL)
        OSHalt("DVDOpen(): null pointer is specified to file info address\n");

    s32 entrynum = DVDConvertPathToEntrynum(fileName);

    if(entrynum < 0)
    {
        char currentDir[128];
        DVDGetCurrentDir(currentDir, sizeof(currentDir));

        OSReport( "Warning: DVDOpen(): file '%s' was not found under %s.\n",
                   fileName,
                   currentDir );

        return FALSE;
    }

    DVDFileEntry * entry = &FstStart[entrynum];

    if( entry->isDir )
    {
        OSReport( "DVDOpen(): directory '%s' is specified as a filename\n",
                  fileName );
        return FALSE;
    }

    // save file information
    fileInfo->startAddr = entry->fileOffset;
    fileInfo->length = entry->fileLength;

    // reset callback
    fileInfo->callback = NULL;

    fileInfo->cb.state = DVD_STATE_END;

    return TRUE;
}


/// NOT COMPLETE !!!!!!!!!!!!!!!!!!!!!

s32 DVDConvertPathToEntrynum(char * pathPtr)
{
    char * origPathPtr = pathPtr, *ptr;
   
    r31 =  ^^^^^^^^^^^ r22 = r3

    if(pathPtr == NULL)
        DBHalt("DVDConvertPathToEntrynum(): null pointer is specified\n");

    // get current dirent (set in DVDChangeDir)
    s32 dirLookAt = currentDirectory;

    // path is empty - ""
    if(pathPtr[0] == '\0') return 0;

    // alg is pretty simple, just read if's (its almost like usual language)
    while(pathPtr[0] != '\0')
    {
        // absolute path started "/"
        if(pathPtr[0] == '/')
        {
            dirLookAt = 0;
            pathPtr++;
            continue;
        }

        // walk directory
        // ../, ./, . (path "." mean root entry), .. (".." mean parent dirent)
        if(pathPtr[0] == '.')
        {
            if(pathPtr[1] == '.')
            {
                if(pathPtr[2] == '/')
                {
                    dirLookAt = FstStart[dirLookAt].parentOffset;
                    pathPtr += 3;
                    continue;        
                }
                if(pathPtr[2] == '\0')
                {
                    return FstStart[dirLookAt].parentOffset;
                }
            }
            if(pathPtr[1] == '/')
            {
                pathPtr += 2;
                continue;
            }
            if(pathPtr[1] == '\0')
            {
                return 0;
            }
        }

        // check old 8.3 name convention, if flag disabled
        if(__DVDLongFileNameFlag == FALSE)
        {

            r26 = 0
            r27 = 0
            ptr = pathPtr

            if(ptr[0] != '\0')
            {
                if(ptr[0] == '/')
                {
                }
            }


        }
        else
        {
            ptr = pathPtr;

            // find end of directory name
            while(ptr[0] != '/' && ptr[0]) ptr++;
        }



    }


}