GPD

GPD (Gamer Profile Data) files are used by the Xbox 360 to store information inside a profile. They are based on the XDBF format. Profiles are composed of many of these files, each named under their respective executable's title id (e.g. 4D5307E6.gpd for Halo 3). The dashboard GPD (FFFE07D1.gpd) contains information and sync information about the titles.

Entry Table

An ID of 0x100000000 indicates that the entry is a Sync List, an ID of 0x200000000 means its a Sync Data entry.

The Settings, Achievement and Title namespaces each have their own Sync List and Sync Data entries.

An ID of 0x8000 usually indicates that entry is information to do with the title (image/name).

Entry Namespaces

Value	Description
1	Achievement
2	Image
3	Setting
4	Title
5	String
6	Achievement Security (created by GFWL for offline unlocked achievements?)
6	Avatar Award (360 only, this is only stored with in the PEC version of the GPD)

Entry Structures

Achievement Entries

Offset	Length	Type	Information
0x0	0x4	unsigned int	Magic (0x1C)
0x4	0x4	unsigned int	Achievement ID
0x8	0x4	unsigned int	Image ID
0xC	0x4	signed int	Gamerscore
0x10	0x4	unsigned int	Flags (see below)
0x14	0x8	signed long	Unlock Time
0x18	null terminated	unicode string	Name
0x18 + Name length	null terminated	unicode string	Locked Description
0x18 + Name length + Locked Description length	null terminated	unicode string	Unlocked Description

Setting Entries

Offset	Length	Type	Information
0	4	Int32	SettingID
4	12	Unknown	Unknown
16	Till end of entry.	Dependent on setting	Actual setting data

Image Entries

Image entries are composed of a PNG image.

Title Entries

These entries are located in the FFFE07D1.gpd. To get to them, the id for the XDBF entry is the title ID of the game, and the XDBF entry type is String. For more information about XDBF go to http://www.free60.org/XDBF

Offset	Length	Type	Information
0x0	0x4	unsigned int	Title ID
0x4	0x4	signed int	Achievement Count
0x8	0x4	signed int	Achievement Unlocked Count
0xC	0x4	signed int	Gamerscore Total
0x10	0x4	signed int	Gamerscore Unlocked
0x14	0x8	signed long	Unknown
0x1C	0x4	signed int	Unknown
0x20	0x8	signed long	Last Played Time
0x28	null terminated	unicode string	Title Name

String Entries

String entries are simply a unicode string, to the length specified by the entry.

Sync Lists

This is a list of "Sync Items".

You can find the total sync items by,

((SyncList.Length / 16) - 1)

Sync Item

Offset	Length	Type	Information
0x0	0x8	Long(Int64)	EntryID
0x8	0x8	Long(Int64)	ID(Sync?)

I don't know much about the second id, however I believe it to have something to do with the SyncData's "Next Sync ID". I wouldn't recommend playing with it on a live profile as it is the only thing left in the gpd that is unknown and ms ban people some way.

Sync Data

Offset	Length	Type	Information
0x0	0x8	unsigned long	Next Sync ID
0x8	0x8	unsigned long	Last Synced ID
0x10	0x8	signed long	Last Synced Time