Param.sfo

Description

SFO (System File Object) are files used in folders whose content needs to be displayed in the PSP XMB. It is also present on PS3, PS Vita and PS4.

• The values contained in a SFO can be simplified as inputs/outputs for/from the content:
  • Boot modifyers (most of the int32 datas) that are sent to the content when it is executed to activate specific features or settings (e.g. audio and video modes of a game).
  • Information texts (most of the utf8 datas) about the content and its restrictions (e.g. title and version of a game).

SFX (System File in XML format) is similar than SFO but without the data related to its structure (the SFO metadata that has no real value).

The conversion between the two formats is direct because the important values contained in both formats are the same (version, param_key, param_fmt, param_max_len and param_data).

SFO's and SFX's can be chained in a structure of subfolders where the "main" SFO activates a special subfolder, and the subfolder contains another SFO that activates another subfolder and so on.

Internal Structure

Header

At offset 0x0, length 0x14 (20 bytes) Template:Boxcode

index_table

At offset 0x14, composed by a number of entries defined with tables_entries in the header, each entry is 0x10 length (16 bytes). Values are in Little Endian.

Every entry belongs to a key name in the key_table and defines a data area in the data_table.

Data Types

fmt		Data Type	Description	Notes
In SFO	In SFX
04 00	No?	Template:Cellcolors utf8-S	utf8 Special Mode, NOT NULL terminated	Used in SFO's generated by the system and/or linked to an user (Game Saves and Trophies). See Template:Talk page.
04 02	utf8	Template:Cellcolors utf8	utf8 character string, NULL terminated (0x00)	Can be used any character from the system fonts. The NULL byte is counted as part of the used bytes in len.
04 04	int32	Template:Cellcolors int32	integer 32 bits unsigned	Allways has a length of 4 bytes in len and max_len (even in the case some bytes are not used, all them are marked as used).

key_table

Composed by a number of key entries defined with tables_entries in the header, are short utf8 strings in capitals, NULL terminated (0x00), and ordered alphabetically (from A to Z). This alphabetically order defines the order of the associated entries in the other two tables (index_table, and data_table).

The end offset of this table needs to be aligned to a multiply of 32bits (4 bytes), this is made with a padding at the end of key_table when needed (in a few SFO's the table is aligned naturally as a coincidence caused by the length of the key names used, when this happens there is no padding needed).

data_table

Composed by a number of data entries defined with tables_entries in the header, every entry in this table is defined by the associated entry in the index_table by using: fmt, len, max_len, and offset. There is no padding between entries neither at the end of this table.

Some data entries can be filled with zeroes (not used, but available for being used). This entries can be considered reserved, and are marked with len = 0 in the associated entry in the index_table.

Internal Structure Examples

Both example files (SFO and SFX) are hand made (the structure is correct but are only a minimal example). Both contains the same info but in different format: only 1 entry (TITLE_ID) and the value for this entry (BLUS12345).

• The biggest difference between SFO and SFX is that SFX does not contain:
  • SFO header
  • Key and Data offsets
  • Data used length

This structure was taken from PS3 SFO There is no TITLE_ID inside PSP SFO

SFO

Offset(h) 00 01 02 03  04 05 06 07  08 09 0A 0B  0C 0D 0E 0F
     0x00 00 50 53 46  01 01 00 00  24 00 00 00  30 00 00 00 | .PSF....$...0... |
     0x10 01 00 00 00  00 00 04 02  0A 00 00 00  0F 00 00 00 | ................ |
     0x20 00 00 00 00  54 49 54 4C  45 5F 49 44  00 00 00 00 | ....TITLE_ID.... |
     0x30 42 4C 55 53  31 32 33 34  35 00 00 00  00 00 00 00 | BLUS12345....... |

Areas	Offset	Size	Name	Example	Notes
header	0x00	0x04	magic	PSF
	0x04	0x04	version	01 01 00 00	1.01
	0x08	0x04	key_table_start	24 00 00 00	Absolute start offset of key_table = 0x24
	0x0C	0x04	data_table_start	30 00 00 00	Absolute start offset of data_table = 0x30
	0x10	0x04	tables_entries	01 00 00 00	Number of entries in index_table, key_table, and data_table = 1
index_table	0x14	0x02	key_1_offset	00 00	key_1 relative offset. (Absolute start offset of key_1) - (Absolute start offset of key_table) = 0x24-0x24 = 0
	0x16	0x02	data_1_fmt	04 02	data_1 data type = utf8
	0x18	0x04	data_1_len	0A 00 00 00	data_1 used length (BLUS12345 = 9 bytes + 1 byte NULL termination) = 10 bytes
	0x1C	0x04	data_1_max_len	0F 00 00 00	data_1 total length. TITLE_ID is always = 16 bytes
	0x20	0x04	data_1_offset	00 00 00 00	data_1 relative offset. (Absolute start offset of data_1) - (Absolute start offset of data_table) = 0x30-0x30 = 0
key_table	0x24	0x09	key_1	TITLE_ID	Relative offset defined in the index_table
padding	0x2D	0x03	padding	00 00 00	9 bytes used by the previous entries + 3 padding = 12 (aligned to 4 bytes)
data_table	0x30	0x0F	data_1	BLUS12345	Data type, used length, total length, and relative offset defined in the index_table

SFX

• Notes
  • The function of add_hidden="false" is unknown

Parameters Descriptions

BOOTABLE

This flag tells the PSP if the game is bootable or not?

CATEGORY

A category table is needed here.

UG - PSP GAME ?