SELF File Format

SELF stands for Signed Executable and Linkable Format.

It is the format used by the executables on the PS3 (SCE Header Version 2), PS Vita (SCE Header Version 3).

It consists of an SELF header followed by the encapsulated ELF file. ELF segments can be compressed using gzip.

System and NPDRM SELFs are encrypted and signed and are decrypted on PSVita to memory by F00D.

ELF sections might be encrypted using AES CTR and signed using ECDSA + HMAC-SHA1.

SELF file has a specific header called SCE header where it stores all the parameters for this program.

File Format

Notes:

• Numbers are stored in little endian format because of ARM endianness (whilst PS3 used big endian because of PowerPC endianness).
• Encapsulated ELF header fields are useless (only the EI_CLASS EI_DATA and EI_VERSION fields are checked)

SELF/SCE Header

Struct

typedef struct {
  uint32_t m_magic;               /* 53434500 = SCE\0 */
  uint32_t m_version;             /* header version: 3 for PSVita */
  uint16_t sdk_type;              /* key revision */
  uint16_t m_category;            /* 1 self, 2 srvk, 3 spkg, 4 spp */
  uint32_t m_ext_header_size;     /* metadata offset */
  uint64_t m_file_offset;         /* SELF header length */
  uint64_t elf_filesize;          /* ELF file length */
  uint64_t self_filesize;         /* SELF file length */
  uint64_t unknown;               /* UNKNOWN */
  uint64_t self_offset;           /* SELF offset */
  uint64_t appinfo_offset;        /* app info offset */
  uint64_t elf_offset;            /* ELF #1 offset */
  uint64_t phdr_offset;           /* program header offset */
  uint64_t shdr_offset;           /* section header offset */
  uint64_t section_info_offset;   /* section info offset */
  uint64_t sceversion_offset;     /* version offset */
  uint64_t controlinfo_offset;    /* control info offset */
  uint64_t controlinfo_size;      /* control info size */
  uint64_t padding;               
} __attribute__((packed)) SELF_header;

Table

field	offset	type	notes
Magic	0x0	u32	Must be "SCE\0".
Version	0x4	u32	Must be 3 on PSVita.
SDK type	0x8	u16	Corresponds to the revision of the decryption key.
Header type	0xA	u16	1 self, 2 rvk, 3 pkg, 4 spp
Metadata offset	0xC	u32	Offset to the checksums. Must be at least 20 bytes before the end of the header.
Header length	0x10	u64	Length of the header (including the fake ELF header) (usually 0x100).
Encrypted size	0x18	u64	Size of the encrypted part of the SELF file.
File size	0x20	u64	Size of the SELF file.
unknown	0x28	u64	Must be 0.
SELF offset	0x30	u64	Offset to the SELF (usually 0x4).
App Info offset	0x38	u64	Offset to AppInfo, (usually 0x80). See App info struct.
ELF offset	0x40	u64	Offset to the fake ELF header (usually 0xA0).
Program header offset	0x48	u64	Offset to Program Header.
Segments header offset	0x50	u64	Offset to Segments Header.
encrypted phdr sizes/offsets table offset	0x58	u64	Offset to a table which maps phdr entries to the actual offset/size within the encrypted fself. Because fselfs can be compressed, they might not match the values listed within the elf.
sceversion header offset	0x60	u64	Offset to a header which contains some version information, including an offset to the .sceversion section of the encrypted elf.
Control Information	0x68	u64	Several information containers.
Control Information Size	0x70	u64

App Info

Struct

typedef struct {
  uint64_t authority_id;          /* authority id */
  uint32_t vendorid;              /* vendor id */
  uint32_t selftype;              /* SELF type */
  uint64_t sceversion;            /* sdk version */
  uint64_t padding;               /* UNKNOWN */
} __attribute__((packed)) APP_INFO;

Table

field	offset	type	notes	example
authority_id	0x00	u64	AuthorityId	ex: 21 00 00 10 1C CA 01 30
vendorid	0x08	u32	VendorId (strangely always 00 00 00 00)	ex: 00 00 00 00
selftype	0x0C	u32	SELF type	ex: 08 00 00 00
version	0x10	u64	version	ex: 0x0000036000000000 (3.600.011), 0x0000009450000000 (0.945.040)
padding	0x18	u64		00 00 00 00 00 00 00 00

Comments

Aligned to 0x10 bytes.

SELF type

value	name	files
0x7	KERNEL	kernel module (.skprx)
0x8	APP	NPDRM SELF and SDK fSELF (eboot.bin, .suprx)
0x9	BOOT	kernel_boot_loader.self
0xB	SECURE	SM SELF (os0:sm/*.self and slb2:kprx_auth_sm.self)
0xD	USER	system userland SELF (.self, eboot.bin, .suprx)

ELF Header

Struct

 typedef struct {
   uint8_t e_ident[16];              /* ELF identification */
   uint16_t e_type;                  /* object file type */
   uint16_t e_machine;               /* machine type */
   uint32_t e_version;               /* object file version */
   uint32_t e_entry;                 /* entry point address */
   uint32_t e_phoff;                 /* program header offset */
   uint32_t e_shoff;                 /* section header offset */
   uint32_t e_flags;                 /* processor-specific flags */
   uint16_t e_ehsize;                /* ELF header size */
   uint16_t e_phentsize;             /* size of program header entry */
   uint16_t e_phnum;                 /* number of program header entries */
   uint16_t e_shentsize;             /* size of section header entry */
   uint16_t e_shnum;                 /* number of section header entries */
   uint16_t e_shstrndx;              /* section name string table index */
 } __attribute__((packed)) ELF;

Table

Name of the variable	Offset	Size	Notes
e_ident[0..3]	elf_offset+(0,1,2,3)	4	Magic
e_ident[4]	elf_offset+4	1	Class Type must be [ELFCLASS32 = 0x01]
e_ident[5]	elf_offset+5	1	Data Type must be [ELFDATA2LSB (i.e. le) = 0x01]
e_ident[6]	elf_offset+6	1	File version (must be 0x1)
e_ident[7..15]	elf_offset+(6->15)	1	unused
e_type	elf_offset+0x10	2	SCE-specific e_type
e_machine	elf_offset+0x12	2	Machine type must be [EM_ARM = 0x0028]
e_version	elf_offset+0x14	4	elf version (must be 0x00000001)
e_entry	elf_offset+0x18	4	Address to jump to in order to start program
e_phoff	elf_offset+0x1c	4	boundary checked, but unused (already given by SELF header)
e_shoff	elf_offset+0x20	4	unused
e_flags	elf_offset+0x24	4	unused
e_ehsize	elf_offset+0x28	2	Must be sizeof(Elf32_Ehdr) = 0x0034
e_phentsize	elf_offset+0x2a	2	Must be sizeof(Elf32_Phdr) = 0x0020
e_phnum	elf_offset+0x2c	2	Count of Program Header in this elf
e_shentsize	elf_offset+0x2e	2	unused
e_shnum	elf_offset+0x30	2	unused
e_shstrndx	elf_offset+0x32	2	unused

SCE-specific e_type

/* SCE-specific definitions for e_type: */
#define ET_SCE_ELF		0x2		/* SCE Executable file */
#define ET_SCE_EXEC		0xFE00		/* SCE Executable file */
#define ET_SCE_RELEXEC		0xFE04		/* SCE Relocatable Executable file */
#define ET_SCE_STUBLIB		0xFE0C		/* SCE SDK Stubs */
#define ET_SCE_DYNAMIC		0xFE18		/* Unused */
#define ET_SCE_PSPRELEXEC	0xFFA0		/* Unused (PSP ELF only) */
#define ET_SCE_PPURELEXEC	0xFFA4		/* Unused (SPU ELF only) */
#define ET_SCE_UNK		0xFFA5		/* Unknown */

See Specifications here: ELF Header ELF-64 Object File Format

ELF Program Headers

Struct

 typedef struct {
   uint32_t p_type;                  /* type of segment */
   uint32_t p_flags;                 /* segment attributes */
   uint64_t p_offset;                /* offset in file */
   uint64_t p_vaddr;                 /* virtual address in memory */
   uint64_t p_paddr;                 /* reserved */
   uint64_t p_filesz;                /* size of segment in file */
   uint64_t p_memsz;                 /* size of segment in memory */
   uint64_t p_align;                 /* alignment of segment */
 } __attribute__((packed)) ELF_PHDR;

Comments

See Spec here: ELF Program Headers

ELF Section Headers

Struct

 typedef struct {
   uint32_t sh_name;                 /* section name */
   uint32_t sh_type;                 /* section type */
   uint64_t sh_flags;                /* section attributes */
   uint64_t sh_addr;                 /* virtual address in memory */
   uint64_t sh_offset;               /* offset in file */
   uint64_t sh_size;                 /* size of section */
   uint32_t sh_link;                 /* link to other section */
   uint32_t sh_info;                 /* miscellaneous information */
   uint64_t sh_addralign;            /* address alignment boundary */
   uint64_t sh_entsize;              /* size of entries, if section has table */
 } __attribute__((packed)) ELF_SHDR;

Section Information

Struct

typedef struct {
   uint64_t offset;
   uint64_t size;
   uint32_t compression;
   uint32_t unk1;
   uint32_t encryption;
   uint32_t unk2;
} __attribute__((packed)) SECTION_INFO;

Table

field	offset	type	notes
Offset	0x00	u64	Offset of data
Size	0x08	u64	Size of data
Compression	0x10	u32	1 = uncompressed, 2 = compressed
unknown 1	0x14	u32
Encryption	0x18	u32	1 = encrypted, 2 = unencrypted
unknown 2	0x1C	u32

Comments

There is one of these entries (Section Information) for each phdr entry (Program Header) in the ELF file so that the console knows where to decrypt the data from (because it might also be compressed).

SCE Version Info

Struct

typedef struct {
  uint32_t unknown1; // 0x1
  uint32_t unknown2;
  uint32_t unknown3; // 0x10 ?size?
  uint32_t unknown4;
} __attribute__((packed)) SCEVERSION_INFO;

Control Information

Struct

typedef struct {
  uint32_t type; // 4==PSVita ELF digest info; 5==PSVita NPDRM info; 6==PSVita boot param info; 7==PSVita shared secret info
  uint32_t size;
  uint64_t next; // 1 if another Control Info structure follows else 0
  
  union {
    // type 4, 0x50 bytes
    struct { // 0x40 bytes of data
      uint8_t constant[0x14]; // same for every PSVita/PS3 SELF, hardcoded in make_fself.exe: 627CB1808AB938E32C8C091708726A579E2586E4
      uint8_t elf_digest[0x20]; // on PSVita: SHA-256 of source ELF file, on PS3: SHA-1
      uint8_t padding[8];
      uint32_t min_required_fw; // ex: 0x363 for 3.63
    } PSVita_elf_digest_info;
    
    // type 5, 0x110 bytes
    struct { // 0x80 bytes of data
      uint32_t magic;               // 7F 44 52 4D (".DRM")
      uint32_t finalized_flag;      // ex: 80 00 00 01
      uint32_t drm_type;            // license_type ex: 2 local, 0xD free with license
      uint32_t padding;
      uint8_t content_id[0x30];
      uint8_t digest[0x10];         // ?sha-1 hash of debug self/sprx created using make_fself_npdrm?
      uint8_t padding_78[0x78];
      uint8_t hash_signature[0x38]; // unknown hash/signature
    } PSVita_npdrm_info;
    
    // type 6, 0x110 bytes
    struct { // 0x100 bytes of data
      uint32_t is_used; // 0=false, 1=true
      uint8_t boot_param[0x9C]; // ex: starting with 02 00 00 00
    } PSVita_boot_param_info;
    
    // type 7, 0x50 bytes
    struct { // 0x40 bytes of data
      uint8_t shared_secret_0[0x10]; // ex: 0x7E7FD126A7B9614940607EE1BF9DDF5E or full of zeroes
      uint8_t shared_secret_1[0x10]; // ex: full of zeroes
      uint8_t shared_secret_2[0x10]; // ex: full of zeroes
      uint8_t shared_secret_3[0x10]; // ex: full of zeroes
    } PSVita_shared_secret_info;
  };
} __attribute__((packed)) PSVita_CONTROL_INFO;

Relocations

Offset	Size	Description
0x0	0x4	Relocation Type
0x4	0x4	Long entry: Addend
0x4	0x4	Short entry: 0-19 = Bits 10-29 of offset, 20-31 = addend
0x8	0x4	Long entry: Offset

Relocations can be of two types: 8 byte "short" entries or 12 byte "long" entries. The relocation code is the same as ARM ELF format.

Segment start = Buffer address of segment indexed at "Patch segment"

Symbol start = Buffer address of segment indexed at "Symbol segment"

Address to patch = segment start + offset

P = address to patch

S = "Symbol segment" == 15 ? 0 : symbol start

A = addend

Relocation Type

Start	End	Description
0	3	Short entry if set
4	7	Symbol segment
8	15	Relocation code
16	19	Patch segment
20	27	Long entry: Optional relocation code 2
28	31	Long entry: Optional distance 2
20	31	Short entry: Lower 12 bits of offset

Supported Relocation Codes (1.69)

Code	Description
0	R_ARM_NONE
2	R_ARM_ABS32
3	R_ARM_REL32
10	R_ARM_THM_CALL
28	R_ARM_CALL
29	R_ARM_JUMP24
38	R_ARM_TARGET1 (same as R_ARM_ABS32)
40	R_ARM_V4BX (same as R_ARM_NONE)
41	R_ARM_TARGET2 (same as R_ARM_REL32)
42	R_ARM_PREL31
43	R_ARM_MOVW_ABS_NC
44	R_ARM_MOVT_ABS
47	R_ARM_THM_MOVW_ABS_NC
48	R_ARM_THM_MOVT_ABS