/**************************************************************************
 *
 * Copyright (c) 2013 Alcatel-Lucent
 *
 * Alcatel Lucent licenses this file to You under the Apache License,
 * Version 2.0 (the "License"); you may not use this file except in
 * compliance with the License.  A copy of the License is contained the
 * file LICENSE at the top level of this repository.
 * You may also obtain a copy of the License at:
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 **************************************************************************
 *
 * elf.h:
 *
 * Used to support ELF file format in TFS.
 * The data in this header file is built primarily from information in
 * the book "Understanding ELF Object Files and Debugging Tools"
 * All page references in comments refer to that book.
 *
 * Original author:     Ed Sutter (ed.sutter@alcatel-lucent.com)
 *
 */

#ifndef _ELF_H_
#define _ELF_H_

typedef unsigned short  Elf32_Half;
typedef unsigned long   Elf32_Word;
typedef unsigned long   Elf32_Addr;
typedef unsigned long   Elf32_Off;

/* Size of ELF identification field. */
#define EI_NIDENT   16

/* e_type values... */
#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


struct elf_fhdr {       /* pg 12 */
    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;
};

#define ELFFHDR struct elf_fhdr

/* sh_flags values... */
#define SHF_WRITE       0x1
#define SHF_ALLOC       0x2
#define SHF_EXECINSTR   0x4
#define SHF_MASKPROC    0xf0000000

/* sh_type values... */
#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_LOPROC      0x70000000
#define SHT_HIPROC      0x7fffffff
#define SHT_LOUSER      0x80000000
#define SHT_HIUSER      0x8fffffff

struct elf_shdr {       /* pg 19 */
    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;
};

#define ELFSHDR struct elf_shdr

#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_LOPROC   0x70000000
#define PT_HIPROC   0x7fffffff

struct elf_phdr {       /* pg 42 */
    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;
};

#define ELFPHDR struct elf_phdr

#define STB_LOCAL   0
#define STB_GLOBAL  1
#define STB_WEAK    2
#define STB_LOPROC  13
#define STB_HIPROC  15

#define STT_NOTYPE  0
#define STT_OBJECT  1
#define STT_FUNC    2
#define STT_SECTION 3
#define STT_FILE    4
#define STT_LOPROC  13
#define STT_HIPROC  15

#define SHN_UNDEF   0

struct elf_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;
};

#endif