path: root/output/elf.h

/* ----------------------------------------------------------------------- *
 *
 *   Copyright 1996-2009 The NASM Authors - All Rights Reserved
 *   See the file AUTHORS included with the NASM distribution for
 *   the specific copyright holders.
 *
 *   Redistribution and use in source and binary forms, with or without
 *   modification, are permitted provided that the following
 *   conditions are met:
 *
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above
 *     copyright notice, this list of conditions and the following
 *     disclaimer in the documentation and/or other materials provided
 *     with the distribution.
 *
 *     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
 *     CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 *     INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 *     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 *     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 *     CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 *     NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 *     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 *     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 *     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 *     OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
 *     EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * ----------------------------------------------------------------------- */

#ifndef OUTPUT_ELF_H
#define OUTPUT_ELF_H

/*
 * Since NASM support both Elf32/64 file formats
 * we need to cover all types, structures, typedefs and etc
 */

#include "compiler.h"
#include <inttypes.h>

/* Segment types */
#define PT_NULL         0
#define PT_LOAD         1
#define PT_DYNAMIC      2
#define PT_INTERP       3
#define PT_NOTE         4
#define PT_SHLIB        5
#define PT_PHDR         6
#define PT_LOOS         0x60000000
#define PT_HIOS         0x6fffffff
#define PT_LOPROC       0x70000000
#define PT_HIPROC       0x7fffffff
#define PT_GNU_EH_FRAME 0x6474e550  /* Extension, eh? */

/* ELF file types */
#define ET_NONE         0
#define ET_REL          1
#define ET_EXEC         2
#define ET_DYN          3
#define ET_CORE         4
#define ET_LOPROC       0xff00
#define ET_HIPROC       0xffff

/* ELF machine types */
#define EM_NONE         0
#define EM_M32          1
#define EM_SPARC        2
#define EM_386          3
#define EM_68K          4
#define EM_88K          5
#define EM_486          6       /* Not used in Linux at least */
#define EM_860          7
#define EM_MIPS         8       /* R3k, bigendian(?) */
#define EM_MIPS_RS4_BE  10      /* R4k BE */
#define EM_PARISC       15
#define EM_SPARC32PLUS  18
#define EM_PPC          20
#define EM_PPC64        21
#define EM_S390         22
#define EM_SH           42
#define EM_SPARCV9      43      /* v9 = SPARC64 */
#define EM_H8_300H      47
#define EM_H8S          48
#define EM_IA_64        50
#define EM_X86_64       62
#define EM_CRIS         76
#define EM_V850         87
#define EM_ALPHA        0x9026  /* Interrim Alpha that stuck around */
#define EM_CYGNUS_V850  0x9080  /* Old v850 ID used by Cygnus */
#define EM_S390_OLD     0xA390  /* Obsolete interrim value for S/390 */

/* Dynamic type values */
#define DT_NULL         0
#define DT_NEEDED       1
#define DT_PLTRELSZ     2
#define DT_PLTGOT       3
#define DT_HASH         4
#define DT_STRTAB       5
#define DT_SYMTAB       6
#define DT_RELA         7
#define DT_RELASZ       8
#define DT_RELAENT      9
#define DT_STRSZ        10
#define DT_SYMENT       11
#define DT_INIT         12
#define DT_FINI         13
#define DT_SONAME       14
#define DT_RPATH        15
#define DT_SYMBOLIC     16
#define DT_REL          17
#define DT_RELSZ        18
#define DT_RELENT       19
#define DT_PLTREL       20
#define DT_DEBUG        21
#define DT_TEXTREL      22
#define DT_JMPREL       23
#define DT_LOPROC       0x70000000
#define DT_HIPROC       0x7fffffff

/* Auxilliary table entries */
#define AT_NULL         0       /* end of vector */
#define AT_IGNORE       1       /* entry should be ignored */
#define AT_EXECFD       2       /* file descriptor of program */
#define AT_PHDR         3       /* program headers for program */
#define AT_PHENT        4       /* size of program header entry */
#define AT_PHNUM        5       /* number of program headers */
#define AT_PAGESZ       6       /* system page size */
#define AT_BASE         7       /* base address of interpreter */
#define AT_FLAGS        8       /* flags */
#define AT_ENTRY        9       /* entry point of program */
#define AT_NOTELF       10      /* program is not ELF */
#define AT_UID          11      /* real uid */
#define AT_EUID         12      /* effective uid */
#define AT_GID          13      /* real gid */
#define AT_EGID         14      /* effective gid */
#define AT_PLATFORM     15      /* string identifying CPU for optimizations */
#define AT_HWCAP        16      /* arch dependent hints at CPU capabilities */
#define AT_CLKTCK       17      /* frequency at which times() increments */
/* 18..22 = ? */
#define AT_SECURE       23      /* secure mode boolean */

/* Program header permission flags */
#define PF_X            0x1
#define PF_W            0x2
#define PF_R            0x4

/* Section header types */
#define SHT_NULL        0
#define SHT_PROGBITS    1
#define SHT_SYMTAB      2
#define SHT_STRTAB      3
#define SHT_RELA        4
#define SHT_HASH        5
#define SHT_DYNAMIC     6
#define SHT_NOTE        7
#define SHT_NOBITS      8
#define SHT_REL         9
#define SHT_SHLIB       10
#define SHT_DYNSYM      11
#define SHT_NUM         12
#define SHT_LOPROC      0x70000000
#define SHT_HIPROC      0x7fffffff
#define SHT_LOUSER      0x80000000
#define SHT_HIUSER      0xffffffff

/* Section header flags */
#define SHF_WRITE            (1 << 0)   /* Writable */
#define SHF_ALLOC            (1 << 1)   /* Occupies memory during execution */
#define SHF_EXECINSTR        (1 << 2)   /* Executable */
#define SHF_MERGE            (1 << 4)   /* Might be merged */
#define SHF_STRINGS          (1 << 5)   /* Contains nul-terminated strings */
#define SHF_INFO_LINK        (1 << 6)   /* `sh_info' contains SHT index */
#define SHF_LINK_ORDER       (1 << 7)   /* Preserve order after combining */
#define SHF_OS_NONCONFORMING (1 << 8)   /* Non-standard OS specific handling required */
#define SHF_GROUP            (1 << 9)   /* Section is member of a group.  */
#define SHF_TLS              (1 << 10)  /* Section hold thread-local data.  */

/* Special section numbers */
#define SHN_UNDEF       0
#define SHN_LORESERVE   0xff00
#define SHN_LOPROC      0xff00
#define SHN_HIPROC      0xff1f
#define SHN_ABS         0xfff1
#define SHN_COMMON      0xfff2
#define SHN_HIRESERVE   0xffff

/* Section align flag */
#define SHA_ANY         1       /* No alignment constraint */

/* Lenght of magic at the start of a file */
#define EI_NIDENT       16

/* Magic number constants... */
#define EI_MAG0         0       /* e_ident[] indexes */
#define EI_MAG1         1
#define EI_MAG2         2
#define EI_MAG3         3
#define EI_CLASS        4
#define EI_DATA         5
#define EI_VERSION      6
#define EI_OSABI        7
#define EI_PAD          8

#define ELFMAG0         0x7f    /* EI_MAG */
#define ELFMAG1         'E'
#define ELFMAG2         'L'
#define ELFMAG3         'F'
#define ELFMAG          "\177ELF"
#define SELFMAG         4

#define ELFCLASSNONE    0       /* EI_CLASS */
#define ELFCLASS32      1
#define ELFCLASS64      2
#define ELFCLASSNUM     3

#define ELFDATANONE     0       /* e_ident[EI_DATA] */
#define ELFDATA2LSB     1
#define ELFDATA2MSB     2

#define EV_NONE         0       /* e_version, EI_VERSION */
#define EV_CURRENT      1
#define EV_NUM          2

#define ELFOSABI_NONE   0
#define ELFOSABI_LINUX  3

/* 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 */

/* Symbol types */
#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.  */

/* Symbol visibilities */
#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 */

/* Both Elf32_Sym and Elf64_Sym use the same one-byte st_info field  */
#define ELF32_ST_BIND(i)      ((i) >> 4)
#define ELF32_ST_MKBIND(i)    ((i) << 4)  /* just a helper */
#define ELF32_ST_TYPE(i)      ((i) & 0xf)
#define ELF32_ST_INFO(b, i)   (ELF_ST_MKBIND(b) + ELF_ST_TYPE(i))

#define ELF64_ST_BIND(i)      ELF32_ST_BIND(i)
#define ELF64_ST_MKBIND(i)    ELF32_ST_MKBIND(i)
#define ELF64_ST_TYPE(i)      ELF32_ST_TYPE(i)
#define ELF64_ST_INFO(b, i)   ELF32_ST_INFO(b, i)

/*
 * ELF standard typedefs (yet more proof that <stdint.h> was way overdue)
 */

typedef uint16_t    Elf32_Half;
typedef int16_t     Elf32_SHalf;
typedef uint32_t    Elf32_Word;
typedef int32_t     Elf32_Sword;
typedef uint64_t    Elf32_Xword;
typedef int64_t     Elf32_Sxword;

typedef uint32_t    Elf32_Off;
typedef uint32_t    Elf32_Addr;
typedef uint16_t    Elf32_Section;

typedef uint16_t    Elf64_Half;
typedef int16_t     Elf64_SHalf;
typedef uint32_t    Elf64_Word;
typedef int32_t     Elf64_Sword;
typedef uint64_t    Elf64_Xword;
typedef int64_t     Elf64_Sxword;

typedef uint64_t    Elf64_Off;
typedef uint64_t    Elf64_Addr;
typedef uint16_t    Elf64_Section;

/*
 * Dynamic header
 */

typedef struct elf32_dyn {
    Elf32_Sword d_tag;
    union {
        Elf32_Sword d_val;
        Elf32_Addr d_ptr;
    } d_un;
} Elf32_Dyn;

typedef struct elf64_dyn {
    Elf64_Sxword d_tag;
    union {
        Elf64_Xword d_val;
        Elf64_Addr d_ptr;
    } d_un;
} Elf64_Dyn;

/*
 * Relocations
 */

#define ELF32_R_SYM(x)  ((x) >> 8)
#define ELF32_R_TYPE(x) ((x) & 0xff)

typedef struct elf32_rel {
    Elf32_Addr r_offset;
    Elf32_Word r_info;
} Elf32_Rel;

typedef struct elf32_rela {
    Elf32_Addr r_offset;
    Elf32_Word r_info;
    Elf32_Sword r_addend;
} Elf32_Rela;

enum reloc32_type {
    R_386_32            =  1,   /* ordinary absolute relocation */
    R_386_PC32          =  2,   /* PC-relative relocation */
    R_386_GOT32         =  3,   /* an offset into GOT */
    R_386_PLT32         =  4,   /* a PC-relative offset into PLT */
    R_386_COPY          =  5,   /* ??? */
    R_386_GLOB_DAT      =  6,   /* ??? */
    R_386_JUMP_SLOT     =  7,   /* ??? */
    R_386_RELATIVE      =  8,   /* ??? */
    R_386_GOTOFF        =  9,   /* an offset from GOT base */
    R_386_GOTPC         = 10,   /* a PC-relative offset _to_ GOT */
    R_386_TLS_TPOFF     = 14,   /* Offset in static TLS block */
    R_386_TLS_IE        = 15,   /* Address of GOT entry for static TLS block offset */
    /* These are GNU extensions, but useful */
    R_386_16            = 20,   /* A 16-bit absolute relocation */
    R_386_PC16          = 21,   /* A 16-bit PC-relative relocation */
    R_386_8             = 22,   /* An 8-bit absolute relocation */
    R_386_PC8           = 23    /* An 8-bit PC-relative relocation */
};

#define ELF64_R_SYM(x)  ((x) >> 32)
#define ELF64_R_TYPE(x) ((x) & 0xffffffff)

typedef struct elf64_rel {
    Elf64_Addr r_offset;
    Elf64_Xword r_info;
} Elf64_Rel;

typedef struct elf64_rela {
    Elf64_Addr r_offset;
    Elf64_Xword r_info;
    Elf64_Sxword r_addend;
} Elf64_Rela;

enum reloc64_type {
    R_X86_64_NONE       =  0,   /* No reloc */
    R_X86_64_64         =  1,   /* Direct 64 bit  */
    R_X86_64_PC32       =  2,   /* PC relative 32 bit signed */
    R_X86_64_GOT32      =  3,   /* 32 bit GOT entry */
    R_X86_64_PLT32      =  4,   /* 32 bit PLT address */
    R_X86_64_COPY       =  5,   /* Copy symbol at runtime */
    R_X86_64_GLOB_DAT   =  6,   /* Create GOT entry */
    R_X86_64_JUMP_SLOT  =  7,   /* Create PLT entry */
    R_X86_64_RELATIVE   =  8,   /* Adjust by program base */
    R_X86_64_GOTPCREL   =  9,   /* 32 bit signed PC relative offset to GOT */
    R_X86_64_32         = 10,   /* Direct 32 bit zero extended */
    R_X86_64_32S        = 11,   /* Direct 32 bit sign extended */
    R_X86_64_16         = 12,   /* Direct 16 bit zero extended */
    R_X86_64_PC16       = 13,   /* 16 bit sign extended pc relative */
    R_X86_64_8          = 14,   /* Direct 8 bit sign extended  */
    R_X86_64_PC8        = 15,   /* 8 bit sign extended pc relative */
    R_X86_64_DTPMOD64   = 16,   /* ID of module containing symbol */
    R_X86_64_DTPOFF64   = 17,   /* Offset in module's TLS block */
    R_X86_64_TPOFF64    = 18,   /* Offset in initial TLS block */
    R_X86_64_TLSGD      = 19,   /* 32 bit signed PC relative offset to two GOT entries for GD symbol */
    R_X86_64_TLSLD      = 20,   /* 32 bit signed PC relative offset to two GOT entries for LD symbol */
    R_X86_64_DTPOFF32   = 21,   /* Offset in TLS block */
    R_X86_64_GOTTPOFF   = 22,   /* 32 bit signed PC relative offset to GOT entry for IE symbol */
    R_X86_64_TPOFF32    = 23,   /* Offset in initial TLS block */
    R_X86_64_PC64       = 24,   /* word64 S + A - P */
    R_X86_64_GOTOFF64   = 25,   /* word64 S + A - GOT */
    R_X86_64_GOTPC32    = 26,   /* word32 GOT + A - P */
    R_X86_64_GOT64      = 27,   /* word64 G + A */
    R_X86_64_GOTPCREL64 = 28,   /* word64 G + GOT - P + A */
    R_X86_64_GOTPC64    = 29,   /* word64 GOT - P + A */
    R_X86_64_GOTPLT64   = 30,   /* word64 G + A */
    R_X86_64_PLTOFF64   = 31,   /* word64 L - GOT + A */
    R_X86_64_SIZE32     = 32,   /* word32 Z + A */
    R_X86_64_SIZE64     = 33,   /* word64 Z + A */
    R_X86_64_GOTPC32_TLSDESC = 34,  /* word32 */
    R_X86_64_TLSDESC_CALL    = 35,  /* none */
    R_X86_64_TLSDESC    = 36    /* word64?2 */
};

/*
 * Symbol
 */

typedef struct elf32_sym {
    Elf32_Word st_name;
    Elf32_Addr st_value;
    Elf32_Word st_size;
    unsigned char st_info;
    unsigned char st_other;
    Elf32_Half st_shndx;
} Elf32_Sym;

typedef struct elf64_sym {
    Elf64_Word st_name;
    unsigned char st_info;
    unsigned char st_other;
    Elf64_Half st_shndx;
    Elf64_Addr st_value;
    Elf64_Xword st_size;
} Elf64_Sym;

/*
 * Main file header
 */

typedef struct elf32_hdr {
    unsigned char e_ident[EI_NIDENT];
    Elf32_Half e_type;
    Elf32_Half e_machine;
    Elf32_Word e_version;
    Elf32_Addr e_entry;
    Elf32_Off e_phoff;
    Elf32_Off e_shoff;
    Elf32_Word e_flags;
    Elf32_Half e_ehsize;
    Elf32_Half e_phentsize;
    Elf32_Half e_phnum;
    Elf32_Half e_shentsize;
    Elf32_Half e_shnum;
    Elf32_Half e_shstrndx;
} Elf32_Ehdr;

typedef struct elf64_hdr {
    unsigned char e_ident[EI_NIDENT];
    Elf64_Half e_type;
    Elf64_Half e_machine;
    Elf64_Word e_version;
    Elf64_Addr e_entry;
    Elf64_Off e_phoff;
    Elf64_Off e_shoff;
    Elf64_Word e_flags;
    Elf64_Half e_ehsize;
    Elf64_Half e_phentsize;
    Elf64_Half e_phnum;
    Elf64_Half e_shentsize;
    Elf64_Half e_shnum;
    Elf64_Half e_shstrndx;
} Elf64_Ehdr;

/*
 * Program header
 */

typedef struct elf32_phdr {
    Elf32_Word p_type;
    Elf32_Off p_offset;
    Elf32_Addr p_vaddr;
    Elf32_Addr p_paddr;
    Elf32_Word p_filesz;
    Elf32_Word p_memsz;
    Elf32_Word p_flags;
    Elf32_Word p_align;
} Elf32_Phdr;

typedef struct elf64_phdr {
    Elf64_Word p_type;
    Elf64_Word p_flags;
    Elf64_Off p_offset;
    Elf64_Addr p_vaddr;
    Elf64_Addr p_paddr;
    Elf64_Xword p_filesz;
    Elf64_Xword p_memsz;
    Elf64_Xword p_align;
} Elf64_Phdr;

/*
 * Section header
 */

typedef struct elf32_shdr {
    Elf32_Word sh_name;
    Elf32_Word sh_type;
    Elf32_Word sh_flags;
    Elf32_Addr sh_addr;
    Elf32_Off sh_offset;
    Elf32_Word sh_size;
    Elf32_Word sh_link;
    Elf32_Word sh_info;
    Elf32_Word sh_addralign;
    Elf32_Word sh_entsize;
} Elf32_Shdr;

typedef struct elf64_shdr {
    Elf64_Word sh_name;
    Elf64_Word sh_type;
    Elf64_Xword sh_flags;
    Elf64_Addr sh_addr;
    Elf64_Off sh_offset;
    Elf64_Xword sh_size;
    Elf64_Word sh_link;
    Elf64_Word sh_info;
    Elf64_Xword sh_addralign;
    Elf64_Xword sh_entsize;
} Elf64_Shdr;

/*
 * Note header
 */
typedef struct elf32_note {
    Elf32_Word n_namesz;    /* Name size */
    Elf32_Word n_descsz;    /* Content size */
    Elf32_Word n_type;      /* Content type */
} Elf32_Nhdr;

typedef struct elf64_note {
    Elf64_Word n_namesz;    /* Name size */
    Elf64_Word n_descsz;    /* Content size */
    Elf64_Word n_type;      /* Content type */
} Elf64_Nhdr;

#endif /* OUTPUT_ELF_H */