PFS

PFS (Playstation File System) is the file system used by (at least) downloadable content and games on the PS4. It is loosely based on the UFS (Unix File System) used in FreeBSD. PFS typically uses a 64kB block size, although the block size is configurable and specified in the file system header.

Structure

There are four main sections in a Playstation File System:

• Header (superblock)
• Inode blocks
• Directory blocks
• Data blocks

Header/Superblock

Offset	Value	Size	Notes
0x00	version	0x8	Should be 1
0x08	magic	0x8	Should be 20130315
0x10	id	0x8
0x18	fmode	0x1
0x19	clean	0x1
0x1A	ronly	0x1	If 1, this is a readonly filesystem
0x1B	rsv	0x1
0x1C	mode	0x2
0x1E	unknown	0x2
0x20	blocksz	0x4	The size of each block in the filesystem.
0x24	nbackup	0x4
0x28	nblock	0x8
0x30	ndinode	0x8	Number of inodes in the inode blocks
0x38	ndblock	0x8	Number of data blocks
0x40	ndinodeblock	0x8	Number of inode blocks
0x48	superroot_ino	0x8

typedef struct {
    int64 version;
    int64 magic;
    int32 id[2];
    char fmode;
    char clean;
    char ronly;
    char rsv;
    int16 mode;
    int16 unk1;
    int32 blocksz;
    int32 nbackup;
    int64 nblock;
    int64 ndinode;
    int64 ndblock;
    int64 ndinodeblock;
    int64 superroot_ino;
} PFS_HDR;

Inodes

Inode table starts at the second block and continues for ndinodeblock blocks.

Offset	Value	Size	Notes
0x00	mode	0x2	Inode mode (bitwise OR of flags; file=0x8000, directory=0x4000)
0x02	nlink	0x2
0x04	flags	0x4
0x08	size	0x8
0x10	unknown	0x38
0x48	uid	0x4
0x4C	gid	0x4
0x50	unknown	0x10
0x60	blocks	0x4	Number of blocks occupied
0x64	db	0x30	Direct blocks
0x94	ib	0x14	Indirect blocks

typedef struct {
    uint16 mode;
    uint16 nlink;
    uint16 flags[2];
    uint64 size;
    char unk1[56];
    uint32 uid;
    uint32 gid;
    uint64 unk2[2];
    uint32 blocks;
    int32 db[12];
    int32 ib[5];
} di_d32;

Dirents

Dirents are 8-byte aligned. The entsize value will say the total length of this dirent. There is typically padding after name which can just be skipped.

Offset	Value	Size	Notes
0x00	ino	0x4	Inode index
0x04	type	0x4	Type of entry. 2=file, 3=directory
0x08	namelen	0x4	Length of filename (add 1 for 0-terminator)
0x10	name	namelen + 1	Filename and 0-terminator
0x11 + namelen	padding	variable	Padding so this structure is exactly entsize bytes.

typedef struct {
    int32 ino;
    int32 type;
    int32 namelen;
    int32 entsize;
    char name[namelen+1];
} dirent;

Tools

• GameArchives/ArchiveExplorer C# library/tool that supports opening and extracting from PFS images