VitaShell/elf.h

/*
 * Copyright (c) 2015 Sergi Granell (xerpi)
 */

/* NOTE: This file has been modified to satisfy the SONY PSVita
   (PlayStation Vita) operation system's design.
 */

/* This file defines standard ELF types, structures, and macros.
   Copyright (C) 1995-2003,2004,2005,2006 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#ifndef _ELF_H
#define  _ELF_H 1

/* Standard ELF types.  */

#include <stdint.h>

/* Type for a 16-bit quantity.  */
typedef uint16_t Elf32_Half;
typedef uint16_t Elf64_Half;

/* Types for signed and unsigned 32-bit quantities.  */
typedef uint32_t Elf32_Word;
typedef  int32_t  Elf32_Sword;
typedef uint32_t Elf64_Word;
typedef  int32_t  Elf64_Sword;

/* Types for signed and unsigned 64-bit quantities.  */
typedef uint64_t Elf32_Xword;
typedef  int64_t  Elf32_Sxword;
typedef uint64_t Elf64_Xword;
typedef  int64_t  Elf64_Sxword;

/* Type of addresses.  */
typedef uint32_t Elf32_Addr;
typedef uint64_t Elf64_Addr;

/* Type of file offsets.  */
typedef uint32_t Elf32_Off;
typedef uint64_t Elf64_Off;

/* Type for section indices, which are 16-bit quantities.  */
typedef uint16_t Elf32_Section;
typedef uint16_t Elf64_Section;

/* Type for version symbol information.  */
typedef Elf32_Half Elf32_Versym;
typedef Elf64_Half Elf64_Versym;


/* The ELF file header.  This appears at the start of every ELF file.  */

#define EI_NIDENT (16)

typedef struct {
  unsigned char   e_ident[EI_NIDENT];   /* Magic number and other info */
  Elf32_Half    e_type;         /* Object file type */
  Elf32_Half    e_machine;        /* Architecture */
  Elf32_Word    e_version;        /* Object file version */
  Elf32_Addr    e_entry;        /* Entry point virtual address */
  Elf32_Off     e_phoff;        /* Program header table file offset */
  Elf32_Off     e_shoff;        /* Section header table file offset */
  Elf32_Word    e_flags;        /* Processor-specific flags */
  Elf32_Half    e_ehsize;         /* ELF header size in bytes */
  Elf32_Half    e_phentsize;      /* Program header table entry size */
  Elf32_Half    e_phnum;        /* Program header table entry count */
  Elf32_Half    e_shentsize;      /* Section header table entry size */
  Elf32_Half    e_shnum;        /* Section header table entry count */
  Elf32_Half    e_shstrndx;       /* Section header string table index */
} Elf32_Ehdr;

/* Fields in the e_ident array.  The EI_* macros are indices into the
   array.  The macros under each EI_* macro are the values the byte
   may have.  */

#define EI_MAG0   0   /* File identification byte 0 index */
#define ELFMAG0   0x7f  /* Magic number byte 0 */

#define EI_MAG1   1   /* File identification byte 1 index */
#define ELFMAG1   'E'   /* Magic number byte 1 */

#define EI_MAG2   2   /* File identification byte 2 index */
#define ELFMAG2   'L'   /* Magic number byte 2 */

#define EI_MAG3   3   /* File identification byte 3 index */
#define ELFMAG3   'F'   /* Magic number byte 3 */

/* Conglomeration of the identification bytes, for easy testing as a word.  */
#define  ELFMAG   "\177ELF"
#define  SELFMAG  4

/** EI_CLASS values */
#define EI_CLASS    4   /* File class byte index */
#define ELFCLASSNONE  0   /* Invalid class */
#define ELFCLASS32    1   /* 32-bit objects */
#define ELFCLASS64    2   /* 64-bit objects */
#define ELFCLASSNUM   3

/** EI_DATA values */
#define EI_DATA     5   /* Data encoding byte index */
#define ELFDATANONE   0   /* Invalid data encoding */
#define ELFDATA2LSB   1   /* 2's complement, little endian */
#define ELFDATA2MSB   2   /* 2's complement, big endian */
#define ELFDATANUM    3
#define EI_VERSION  6   /* File version byte index */
              /* Value must be EV_CURRENT */
#define  EI_OSABI  7   /* Operating system/ABI identification */
#define  EI_ABIVERSION  8   /* ABI version */
#define EI_PAD    9   /* Byte index of padding bytes */

/* Legal values for e_type (object file type).  */

#define ET_NONE          0       /* No file type */
#define ET_REL          1       /* Relocatable file */
#define ET_EXEC         2       /* Executable file */
#define ET_DYN          3       /* Shared object file */
#define ET_CORE          4       /* Core file */
#define  ET_NUM          5       /* Number of defined types */
#define ET_LOOS         0xFE00    /* OS-specific range start */
#define ET_HIOS         0xFEFF    /* OS-specific range end */
#define ET_SCE_EXEC       0xFE00    /* SCE Executable file */
#define ET_SCE_RELEXEC      0xFE04    /* SCE Relocatable 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 */
#define ET_LOPROC         0xFF00    /* Processor-specific range start */
#define ET_HIPROC         0xFFFF
/* Processor-specific range end */

/* Legal values for e_machine (architecture).  */

#define EM_NONE     0     /* No machine */
#define  EM_ARM      40    /* Advanced RISC Marchines ARM */
#define EM_NUM      95

/* Legal values for e_version (version).  */

#define EV_NONE    0    /* Invalid ELF version */
#define EV_CURRENT  1    /* Current version */
#define EV_NUM    2

/* Section header.  */

typedef struct {
  Elf32_Word    sh_name;    /* Section name (string tbl index) */
  Elf32_Word    sh_type;    /* Section type */
  Elf32_Word    sh_flags;     /* Section flags */
  Elf32_Addr  sh_addr;    /* Section virtual addr at execution */
  Elf32_Off     sh_offset;    /* Section file offset */
  Elf32_Word    sh_size;    /* Section size in bytes */
  Elf32_Word    sh_link;    /* Link to another section */
  Elf32_Word    sh_info;    /* Additional section information */
  Elf32_Word    sh_addralign;   /* Section alignment */
  Elf32_Word    sh_entsize;   /* Entry size if section holds table */
} Elf32_Shdr;

/* Special section indices.  */

#define SHN_UNDEF    0        /* Undefined section */
#define SHN_LORESERVE   0xff00     /* Start of reserved indices */
#define SHN_LOPROC     0xff00     /* Start of processor-specific */
#define SHN_BEFORE     0xff00     /* Order section before all others
                       (Solaris).  */
#define SHN_AFTER    0xff01     /* Order section after all others
                       (Solaris).  */
#define SHN_HIPROC     0xff1f     /* End of processor-specific */
#define SHN_LOOS     0xff20     /* Start of OS-specific */
#define SHN_HIOS     0xff3f      /* End of OS-specific */
#define SHN_ABS      0xfff1     /* Associated symbol is absolute */
#define SHN_COMMON     0xfff2     /* Associated symbol is common */
#define SHN_XINDEX     0xffff     /* Index is in extra table.  */
#define SHN_HIRESERVE  0xffff     /* End of reserved indices */

/* Legal values for sh_type (section type).  */

#define SHT_NULL    0         /* Section header table entry unused */
#define SHT_PROGBITS  1         /* Program data */
#define SHT_SYMTAB    2         /* Symbol table */
#define SHT_STRTAB    3         /* String table */
#define SHT_HASH    5         /* Symbol hash table */
#define SHT_DYNAMIC   6         /* Dynamic linking information */
#define SHT_NOTE    7         /* Notes */
#define SHT_NOBITS    8         /* Program space with no data (bss) */
#define SHT_SCE_RELA  0x60000000    /* SCE Relocations */
#define SHT_SCE_NID   0x61000001    /* Unused (PSP ELF only) */
#define SHT_SCE_PSPRELA 0x700000A0    /* Unused (PSP ELF only) */
#define SHT_SCE_ARMRELA 0x700000A4    /* Unused (SPU ELF only) */

/* Legal values for sh_flags (section flags).  */

#define SHF_WRITE     (1 << 0)    /* Writable */
#define SHF_ALLOC     (1 << 1)    /* Occupies memory during execution */
#define SHF_EXECINSTR   (1 << 2)    /* Executable */

/*  SCE relocation entry */

// assuming LSB of bitfield is listed first
union {
  Elf32_Word r_short         : 4;
  struct {
    Elf32_Word r_short     : 4;
    Elf32_Word r_symseg    : 4;
    Elf32_Word r_code    : 8;
    Elf32_Word r_datseg    : 4;
    Elf32_Word r_offset_lo   : 12;
    Elf32_Word r_offset_hi   : 20;
    Elf32_Word r_addend    : 12;
  } r_short_entry;
  struct {
    Elf32_Word r_short     : 4;
    Elf32_Word r_symseg    : 4;
    Elf32_Word r_code    : 8;
    Elf32_Word r_datseg    : 4;
    Elf32_Word r_code2     : 8;
    Elf32_Word r_dist2     : 4;
    Elf32_Word r_addend;
    Elf32_Word r_offset;
  } r_long_entry;
} SCE_Rel;

/* Symbol table entry.  */

typedef struct {
  Elf32_Word    st_name;    /* Symbol name (string tbl index) */
  Elf32_Addr    st_value;     /* Symbol value */
  Elf32_Word    st_size;    /* Symbol size */
  unsigned char   st_info;    /* Symbol type and binding */
  unsigned char   st_other;     /* Symbol visibility */
  Elf32_Section   st_shndx;     /* Section index */
} Elf32_Sym;

/* The syminfo section if available contains additional information about
   every dynamic symbol.  */

typedef struct {
  Elf32_Half si_boundto;      /* Direct bindings, symbol bound to */
  Elf32_Half si_flags;      /* Per symbol flags */
} Elf32_Syminfo;

/* Possible values for si_boundto.  */
#define SYMINFO_BT_SELF     0xffff  /* Symbol bound to self */
#define SYMINFO_BT_PARENT     0xfffe  /* Symbol bound to parent */
#define SYMINFO_BT_LOWRESERVE   0xff00  /* Beginning of reserved entries */

/* Possible bitmasks for si_flags.  */
#define SYMINFO_FLG_DIRECT    0x0001  /* Direct bound symbol */
#define SYMINFO_FLG_PASSTHRU  0x0002  /* Pass-thru symbol for translator */
#define SYMINFO_FLG_COPY    0x0004  /* Symbol is a copy-reloc */
#define SYMINFO_FLG_LAZYLOAD  0x0008  /* Symbol bound to object to be lazy
             loaded */
/* Syminfo version values.  */
#define SYMINFO_NONE      0
#define SYMINFO_CURRENT     1
#define SYMINFO_NUM       2


/* How to extract and insert information held in the st_info field.  */

#define ELF32_ST_BIND(val)        (((unsigned char) (val)) >> 4)
#define ELF32_ST_TYPE(val)        ((val) & 0xf)
#define ELF32_ST_INFO(bind, type)     (((bind) << 4) + ((type) & 0xf))

/* Both Elf32_Sym and Elf64_Sym use the same one-byte st_info field.  */
#define ELF64_ST_BIND(val)        ELF32_ST_BIND (val)
#define ELF64_ST_TYPE(val)        ELF32_ST_TYPE (val)
#define ELF64_ST_INFO(bind, type)     ELF32_ST_INFO ((bind), (type))

/* Legal values for ST_BIND subfield of st_info (symbol binding).  */

#define STB_LOCAL     0         /* Local symbol */
#define STB_GLOBAL    1         /* Global symbol */
#define STB_WEAK    2         /* Weak symbol */
#define  STB_NUM     3         /* Number of defined types.  */
#define STB_LOOS    10        /* Start of OS-specific */
#define STB_HIOS    12        /* End of OS-specific */
#define STB_LOPROC    13        /* Start of processor-specific */
#define STB_HIPROC    15        /* End of processor-specific */

/* Legal values for ST_TYPE subfield of st_info (symbol type).  */

#define STT_NOTYPE    0         /* Symbol type is unspecified */
#define STT_OBJECT    1         /* Symbol is a data object */
#define STT_FUNC    2         /* Symbol is a code object */
#define STT_SECTION   3         /* Symbol associated with a section */
#define STT_FILE    4         /* Symbol's name is file name */
#define STT_COMMON    5         /* Symbol is a common data object */
#define STT_TLS     6         /* Symbol is thread-local data object*/
#define  STT_NUM     7         /* Number of defined types.  */
#define STT_LOOS    10        /* Start of OS-specific */
#define STT_HIOS    12        /* End of OS-specific */
#define STT_LOPROC    13        /* Start of processor-specific */
#define STT_HIPROC    15        /* End of processor-specific */


/* Symbol table indices are found in the hash buckets and chain table
   of a symbol hash table section.  This special index value indicates
   the end of a chain, meaning no further symbols are found in that bucket.  */

#define STN_UNDEF     0         /* End of a chain.  */


/* How to extract and insert information held in the st_other field.  */

#define ELF32_ST_VISIBILITY(o)  ((o) & 0x03)

/* For ELF64 the definitions are the same.  */
#define ELF64_ST_VISIBILITY(o)  ELF32_ST_VISIBILITY (o)

/* Symbol visibility specification encoded in the st_other field.  */
#define STV_DEFAULT  0    /* Default symbol visibility rules */
#define STV_INTERNAL  1    /* Processor specific hidden class */
#define STV_HIDDEN  2    /* Sym unavailable in other modules */
#define STV_PROTECTED  3    /* Not preemptible, not exported */


/* Relocation table entry without addend (in section of type SHT_REL).  */

typedef struct {
  Elf32_Addr    r_offset;         /* Address */
  Elf32_Word    r_info;         /* Relocation type and symbol index */
} Elf32_Rel;

/* Relocation table entry with addend (in section of type SHT_RELA).  */

typedef struct {
  Elf32_Addr    r_offset;         /* Address */
  Elf32_Word    r_info;         /* Relocation type and symbol index */
  Elf32_Sword   r_addend;         /* Addend */
} Elf32_Rela;

/* How to extract and insert information held in the r_info field.  */

#define ELF32_R_SYM(val)        ((val) >> 8)
#define ELF32_R_TYPE(val)         ((val) & 0xff)
#define ELF32_R_INFO(sym, type)     (((sym) << 8) + ((type) & 0xff))

//#define ELF32_R_ADDR_BASE(val)  (((val) >> 16) & 0xFF)
#define ELF32_R_ADDR_BASE(val)  ((val) >> 16)
#define ELF32_R_OFS_BASE(val)   (((val) >> 8) & 0xFF)

/* Program segment header.  */

typedef struct {
  Elf32_Word    p_type;         /* Segment type */
  Elf32_Off     p_offset;         /* Segment file offset */
  Elf32_Addr    p_vaddr;        /* Segment virtual address */
  Elf32_Addr    p_paddr;        /* Segment physical address */
  Elf32_Word    p_filesz;         /* Segment size in file */
  Elf32_Word    p_memsz;        /* Segment size in memory */
  Elf32_Word    p_flags;        /* Segment flags */
  Elf32_Word    p_align;        /* Segment alignment */
} Elf32_Phdr;

/* Legal values for p_type (segment type).  */

#define  PT_NULL     0         /* Program header table entry unused */
#define PT_LOAD     1         /* Loadable program segment */
#define PT_DYNAMIC    2         /* Dynamic linking information */
#define PT_SCE_RELA   0x60000000    /* SCE Relocations */
#define PT_SCE_COMMENT  0x6FFFFF00    /* Unused */
#define PT_SCE_VERSION  0x6FFFFF01    /* Unused */
#define PT_SCE_UNK    0x70000001    /* Unknown */
#define PT_SCE_PSPRELA  0x700000A0    /* Unused (PSP ELF only) */
#define PT_SCE_PPURELA  0x700000A4    /* Unused (SPU ELF only) */

/* Legal values for p_flags (segment flags).  */

#define PF_X      (1 << 0)    /* Segment is executable */
#define PF_W      (1 << 1)    /* Segment is writable */
#define PF_R      (1 << 2)    /* Segment is readable */

/* Legal values for the note segment descriptor types for object files.  */

#define NT_VERSION    1         /* Contains a version string.  */

/* ARM relocs.  */

#define R_ARM_NONE        0
#define R_ARM_PC24        1
#define R_ARM_ABS32       2
#define R_ARM_REL32       3
#define R_ARM_THM_CALL      10
#define R_ARM_CALL        28
#define R_ARM_JUMP24      29
#define R_ARM_THM_JUMP24    30
#define R_ARM_TARGET1       38    /* Same as R_ARM_ABS32 */
#define R_ARM_V4BX        40    /* Same as R_ARM_NONE */
#define R_ARM TARGET2       41    /* Same as R_ARM_REL32 */
#define R_ARM_PREL31      42
#define R_ARM_MOVW_ABS_NC     43
#define R_ARM_MOVT_ABS      44
#define R_ARM_THM_MOVW_ABS_NC   47
#define R_ARM_THM_MOVT_ABS    48

typedef struct {
  uint64_t offset;
  uint64_t length;
  uint64_t compression; // 1 = uncompressed, 2 = compressed
  uint64_t encryption; // 1 = encrypted, 2 = plain
} segment_info;

/* Functions */

#include <stdio.h>

int elf_read_ehdr(FILE *fp, Elf32_Ehdr *ehdr);

// Precondition: ehdr is valid!
int elf_load_phdr(FILE *fp, const Elf32_Ehdr *ehdr, Elf32_Phdr **phdr);
int elf_load_shdr(FILE *fp, const Elf32_Ehdr *ehdr, Elf32_Shdr **shdr);
void elf_free_phdr(Elf32_Phdr **phdr);
void elf_free_shdr(Elf32_Shdr **shdr);

char *elf_load_shstrtab(FILE *fp, const Elf32_Ehdr *ehdr, const Elf32_Shdr *shdr);

void elf_print_ehdr(const Elf32_Ehdr *ehdr);
void elf_print_phdr(const Elf32_Phdr *phdr);


#endif  /* elf.h */