SELF File Format

File Format

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

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).

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 Types|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;