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Applies to: GT5, GT6 · Extension: .VOL · Endian: Big

The PS3 Volume is made with patching/updates in mind. It has also fast lookup times as it uses b-trees where names and extensions are split. The TOC is tightly bit-packed and ordered for binary searching, while also reusing the index pages for quick searching that the GT4 volume introduced.

PDIPFS Path Scrambling

PDIPFS scrambled path names are generated using an unique number, an index.

Algorithm for generating a path from a number

oldStyle is used for GT5P volumes.

private const string Charset = "K59W4S6H7DOVJPERUQMT8BAIC2YLG30Z1FNX";

public static string GetPathFromSeed(uint seed, bool oldStyle = false)
    string t = string.Empty;
    if (seed < 0x400)
        t += 'K';
        uint s = XorShift(0x499, 10, seed);
        t += GetSubPathName(s, 2, oldStyle);
    else if (seed - 0x400 < 0x8000)
        t += '5';
        uint s = XorShift(0x8891, 15, seed - 0x400);
        t += GetSubPathName(s, 3, oldStyle);
    else if (seed - 0x8400 < 0x100000)
        t += '9';
        uint s = XorShift(0x111889, 20, seed - 0x8400);
        t += GetSubPathName(s, 4, oldStyle);
    else if (seed - 0x108400 < 0x2000000)
        t += 'W';
        uint s = XorShift(0x2242211, 25, seed - 0x108400);
        t += GetSubPathName(s, 5, oldStyle);
    else if (seed + 0xfdf7c00 >= 0)
        t += '4';
        uint s = XorShift(0x8889111, 32, seed + 0xFDEFC00);
        t += GetSubPathName(s, 6, oldStyle);

    return t;

private static uint XorShift(uint x, int rounds, uint startingValue)
    for (int i = 0; i < rounds; i++)
        startingValue <<= 1;
        bool hasUpperBit = (1 << (int)rounds & startingValue) != 0;
        if (hasUpperBit)
            startingValue ^= x;

    return startingValue;

private static string GetSubPathName(uint seed, int subpathLength, bool oldStyle)
    string pathName = string.Empty;

    // Max 16 chars
    char[] chars = new char[subpathLength];

    if (subpathLength != 0)
        for (int i = 0; i < subpathLength; i++)
            char c = Charset[(int)(seed % 36)];
            seed /= 36;
            chars[i] = c;

        if (oldStyle) // GT5P Demo
            // 1 letter per folder
            for (int pos = subpathLength - 1; pos >= 0; pos--)
                pathName += '/';
                pathName += chars[pos];
            // 2 letters per folder
            int pos = subpathLength - 1;
            if (subpathLength % 2 == 0)
                pathName += '/';
                pathName += chars[pos];

            while (true)
                pathName += chars[pos];
                if (pos == 0)
                pathName += '/';
                pathName += chars[pos - 1];
                pos -= 2;

    return pathName;

The header is encrypted. It is decrypted using an index, and the volume keyset (seed/key) which is normally located in the executable boot parameters. Encryption Routine

The index is always 1, which translates to K/4D, if reading from PDIPFS and not a volume. Otherwise it is at the very beginning of GT.VOL.

Size: 0x20

Field Offset Type Description
5B 74 51 62 0x00 UInt Magic, (Enforced, can not be different)
TOC Node Index 0x04 Int Node Index of the Table of Contents (for PDIPFS)
Compressed TOC Size 0x08 Int Compressed size of the TOC or TOC file (if PDIPFS)
Uncompressed TOC Size 0x0c Int Uncompressed size of the TOC or TOC file (if PDIPFS)
Serial Number 0x10 ULong Unique serial number of the volume based on time
Total Volume Size 0x18 ULong Complete size of the volume
TitleID/Description 0x20 char[0x80] Description, not used

Table of Contents

Once the header has been decrypted, the TOC Node index is then used to decrypt the TOC contents. The TOC is also compressed (inflate).

The TOC is read from the first sector of the volume (0x800) or a path derived from the index from the header (if PDIPFS). The TOC is encrypted using the TOC's node index.

Field Offset Type Description
5B 74 51 6E 0x00 UInt Magic, (Enforced, can not be different)
Name BTree Pointer 0x04 BTree<StringNode>* BTree for all the file names
Extensions BTree Pointer 0x08 BTree<StringNode>* BTree for all the file extensions
Node BTree Pointer 0x0C BTree<FileInfoNode>* BTree for all the files in the volume
Directory BTree Count 0x10 Int Number of btrees for each folder
Directory BTree Pointers 0x14 BTree<FileNode>** Pointers to each BTree for each folder in the volume


BTrees occur immediately after the TOC's header.

BTree Header

Size: 0x06

The header fits within a page.

Field Offset Type Description
Index Page Count 0x00 byte Number of pages used to index pages containing entries
Name BTree Pointer 0x01 Int24 Offset to the index block. If there is no index block, this will just point to the start of the entries for this page, which should be 0x06
Page Count 0x04 short* Number of pages containing nodes
First Page data 0x06 ... Contents of the first page

BTree Page

Pages fits within 0x1000. A new one starts once the entries go past that.

This is bit-packed.

Field Bit Offset Description
Has Nodes 0 (1 bit) Whether this page contains nodes
Page Node Count 1-10 (11 bits) Number of nodes in this page
Node Data Offsets Each 11 bits Offset to node data, relative to start of this page
Node Data ... Node Data (until last one for this page that fits the page)
Offset to next page 12 bits Relative to the start of the page

String Node

Node that represents a string.

Field Bit Offset Description
String Value VarIntString String Value, prefixed by a 7bit variable int

For reading var ints:

public ulong ReadVarInt()
    ulong value = ReadByte();
    ulong mask = 0x80;

    while ((value & mask) != 0)
        value = ((value - mask) << 8) | (ReadByte());
        mask <<= 7;

    return value;

File Node

Node that represents a file, which points to an extension, name and file info node.

Field Bit Offset Description
Flags byte Node flags (1 = Directory, 2 = File)
Name Index VarInt File Name node index this entry points to
Extension Index VarInt Extension node index this entry points to
File Info VarInt File info node index this entry points to

File Info Node

Represents a file data node.

Field Bit Offset Description
Flags byte Node flags (0 = Uncompressed, 1 = Compressed, 2 = Custom Salsa Crypt (GT5P))
Node Index VarInt Node index for this file
Compressed Size or Size VarInt Compressed size (if compressed) or just size - compression algorithm is inflate.
Uncompressed Size VarInt If compressed only
Sector Index VarInt Sector offset to the start of data (multiply by 0x800 for actual offset)


Sector Index doesn't really matter if PDIPFS. The path location is simply derived from the node index scrambled.

Otherwise, the sector index in the volume is relative to (0x800 + TOC's Compressed Size) aligned to the nearest 0x800.

The file is encrypted using the node index aswell.