PKG files

Firmware Packages

File Header

All values are in big endian format.

 typedef struct {
   u32 0x00, 0x53434500// magic
   u32 0x04, 2		// version
   u16 0x08, 0		// sdk type?
   u16 0x0a, 3		// SCE header type; pkg
   u32 0x0c, 0		// meta offset
   u64 0x10,           // size of sce_hdr + sizeof meta_hdr
   u64 0x18, 0x80      // + content_size_real
 }

Game Packages

All game packages are signed with the ECDSA signature. The public key for it can be found in download_plugin.prx or in nas_plugin.prx (this also applies to NPDRM SELFs). Usually game packages are signed with two signatures - one for the header and the other for the entry table.

File Header

All values are in big endian format.

 typedef struct {
   u32 magic;
   u32 pkg_type;
   u32 pkg_info_offset;
   u32 pkg_info_size;
   u32 header_size;
   u32 item_count;
   u64 total_size;
   u64 data_offset;
   u64 data_size;
   char contentid[0x30];
   u8 digest[0x10];
   u8 k_licensee[0x10];
 } PKG_HEADER;

field	offset	size	type	notes
Unencrypted header
magic	0x0	4	u32	Magic value of 0x7f504b47 "\x7fPKG"
pkg_type	0x4	4	u32	The package type is 1 for PS3 pkg and 2 for PSP (minis also)/Vita packages. the flag 0x80000000 is used for retail.
pkg_info_offset	0x8	4	u32	offset of the pkg_info structure
pkg_info_size	0xC	4	u32	pkg_info_size*8 = size of the pkg_info structure
header_size	0x10	4	u32	Size of the header
item_count	0x14	4	u32	Variable (0x**)
total_size	0x18	8	u64
data_offset	0x20	8	u64
data_size	0x28	8	u64
contentid	0x30	48	u8[48]	See PARAM.SFO#CONTENT_ID
digest	0x60	16	u8[16]
k_licensee	0x70	16	u8[16]

File Entry

All values are in big endian format

 typedef struct {
   u32 filename_offset;
   u32 filename_size;
   u64 data_offset;
   u64 data_size;
   u32 flags;
   u32 padding;
 } PKG_FILE_HEADER;

field	offset	type	notes
filename_offset	0x0	u32
filename_size	0x4	u32
data_offset	0x8	u64
data_size	0x10	u64
flags	0x18	u32	The file type
padding	0x1C	u32	zero

Misc/Note

From FW 4.00, install PKG from root device (but not as "bubble") for PS1 classic if not containing .EDAT files license type Free will abort or install directly as bubble according to the cfw.