1/* 2 * GRUB -- GRand Unified Bootloader 3 * Copyright (C) 2001,2002 Free Software Foundation, Inc. 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License as published by 7 * the Free Software Foundation; either version 2 of the License, or 8 * (at your option) any later version. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to the Free Software 17 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 18 */ 19 20/* 32-bit data types */ 21 22typedef unsigned long Elf32_Addr; 23typedef unsigned short Elf32_Half; 24typedef unsigned long Elf32_Off; 25typedef signed long Elf32_Sword; 26typedef unsigned long Elf32_Word; 27/* "unsigned char" already exists */ 28 29/* ELF header */ 30typedef struct 31{ 32 33#define EI_NIDENT 16 34 35 /* first four characters are defined below */ 36#define EI_MAG0 0 37#define ELFMAG0 0x7f 38#define EI_MAG1 1 39#define ELFMAG1 'E' 40#define EI_MAG2 2 41#define ELFMAG2 'L' 42#define EI_MAG3 3 43#define ELFMAG3 'F' 44 45#define EI_CLASS 4 /* data sizes */ 46#define ELFCLASS32 1 /* i386 -- up to 32-bit data sizes present */ 47 48#define EI_DATA 5 /* data type and ordering */ 49#define ELFDATA2LSB 1 /* i386 -- LSB 2's complement */ 50 51#define EI_VERSION 6 /* version number. "e_version" must be the same */ 52#define EV_CURRENT 1 /* current version number */ 53 54#define EI_OSABI 7 /* operating system/ABI indication */ 55#define ELFOSABI_FREEBSD 9 56 57#define EI_ABIVERSION 8 /* ABI version */ 58 59#define EI_PAD 9 /* from here in is just padding */ 60 61#define EI_BRAND 8 /* start of OS branding (This is 62 obviously illegal against the ELF 63 standard.) */ 64 65 unsigned char e_ident[EI_NIDENT]; /* basic identification block */ 66 67#define ET_EXEC 2 /* we only care about executable types */ 68 Elf32_Half e_type; /* file types */ 69 70#define EM_386 3 /* i386 -- obviously use this one */ 71 Elf32_Half e_machine; /* machine types */ 72 Elf32_Word e_version; /* use same as "EI_VERSION" above */ 73 Elf32_Addr e_entry; /* entry point of the program */ 74 Elf32_Off e_phoff; /* program header table file offset */ 75 Elf32_Off e_shoff; /* section header table file offset */ 76 Elf32_Word e_flags; /* flags */ 77 Elf32_Half e_ehsize; /* elf header size in bytes */ 78 Elf32_Half e_phentsize; /* program header entry size */ 79 Elf32_Half e_phnum; /* number of entries in program header */ 80 Elf32_Half e_shentsize; /* section header entry size */ 81 Elf32_Half e_shnum; /* number of entries in section header */ 82 83#define SHN_UNDEF 0 84#define SHN_LORESERVE 0xff00 85#define SHN_LOPROC 0xff00 86#define SHN_HIPROC 0xff1f 87#define SHN_ABS 0xfff1 88#define SHN_COMMON 0xfff2 89#define SHN_HIRESERVE 0xffff 90 Elf32_Half e_shstrndx; /* section header table index */ 91} 92Elf32_Ehdr; 93 94 95#define BOOTABLE_I386_ELF(h) \ 96 ((h.e_ident[EI_MAG0] == ELFMAG0) & (h.e_ident[EI_MAG1] == ELFMAG1) \ 97 & (h.e_ident[EI_MAG2] == ELFMAG2) & (h.e_ident[EI_MAG3] == ELFMAG3) \ 98 & (h.e_ident[EI_CLASS] == ELFCLASS32) & (h.e_ident[EI_DATA] == ELFDATA2LSB) \ 99 & (h.e_ident[EI_VERSION] == EV_CURRENT) & (h.e_type == ET_EXEC) \ 100 & (h.e_machine == EM_386) & (h.e_version == EV_CURRENT)) 101 102/* section table - ? */ 103typedef struct 104{ 105 Elf32_Word sh_name; /* Section name (string tbl index) */ 106 Elf32_Word sh_type; /* Section type */ 107 Elf32_Word sh_flags; /* Section flags */ 108 Elf32_Addr sh_addr; /* Section virtual addr at execution */ 109 Elf32_Off sh_offset; /* Section file offset */ 110 Elf32_Word sh_size; /* Section size in bytes */ 111 Elf32_Word sh_link; /* Link to another section */ 112 Elf32_Word sh_info; /* Additional section information */ 113 Elf32_Word sh_addralign; /* Section alignment */ 114 Elf32_Word sh_entsize; /* Entry size if section holds table */ 115} 116Elf32_Shdr; 117 118/* symbol table - page 4-25, figure 4-15 */ 119typedef struct 120{ 121 Elf32_Word st_name; 122 Elf32_Addr st_value; 123 Elf32_Word st_size; 124 unsigned char st_info; 125 unsigned char st_other; 126 Elf32_Half st_shndx; 127} 128Elf32_Sym; 129 130/* symbol type and binding attributes - page 4-26 */ 131 132#define ELF32_ST_BIND(i) ((i) >> 4) 133#define ELF32_ST_TYPE(i) ((i) & 0xf) 134#define ELF32_ST_INFO(b,t) (((b)<<4)+((t)&0xf)) 135 136/* symbol binding - page 4-26, figure 4-16 */ 137 138#define STB_LOCAL 0 139#define STB_GLOBAL 1 140#define STB_WEAK 2 141#define STB_LOPROC 13 142#define STB_HIPROC 15 143 144/* symbol types - page 4-28, figure 4-17 */ 145 146#define STT_NOTYPE 0 147#define STT_OBJECT 1 148#define STT_FUNC 2 149#define STT_SECTION 3 150#define STT_FILE 4 151#define STT_LOPROC 13 152#define STT_HIPROC 15 153 154 155/* Macros to split/combine relocation type and symbol page 4-32 */ 156 157#define ELF32_R_SYM(__i) ((__i)>>8) 158#define ELF32_R_TYPE(__i) ((unsigned char) (__i)) 159#define ELF32_R_INFO(__s, __t) (((__s)<<8) + (unsigned char) (__t)) 160 161 162/* program header - page 5-2, figure 5-1 */ 163 164typedef struct 165{ 166 Elf32_Word p_type; 167 Elf32_Off p_offset; 168 Elf32_Addr p_vaddr; 169 Elf32_Addr p_paddr; 170 Elf32_Word p_filesz; 171 Elf32_Word p_memsz; 172 Elf32_Word p_flags; 173 Elf32_Word p_align; 174} 175Elf32_Phdr; 176 177/* segment types - page 5-3, figure 5-2 */ 178 179#define PT_NULL 0 180#define PT_LOAD 1 181#define PT_DYNAMIC 2 182#define PT_INTERP 3 183#define PT_NOTE 4 184#define PT_SHLIB 5 185#define PT_PHDR 6 186 187#define PT_LOPROC 0x70000000 188#define PT_HIPROC 0x7fffffff 189 190/* segment permissions - page 5-6 */ 191 192#define PF_X 0x1 193#define PF_W 0x2 194#define PF_R 0x4 195#define PF_MASKPROC 0xf0000000 196 197 198/* dynamic structure - page 5-15, figure 5-9 */ 199 200typedef struct 201{ 202 Elf32_Sword d_tag; 203 union 204 { 205 Elf32_Word d_val; 206 Elf32_Addr d_ptr; 207 } 208 d_un; 209} 210Elf32_Dyn; 211 212/* Dynamic array tags - page 5-16, figure 5-10. */ 213 214#define DT_NULL 0 215#define DT_NEEDED 1 216#define DT_PLTRELSZ 2 217#define DT_PLTGOT 3 218#define DT_HASH 4 219#define DT_STRTAB 5 220#define DT_SYMTAB 6 221#define DT_RELA 7 222#define DT_RELASZ 8 223#define DT_RELAENT 9 224#define DT_STRSZ 10 225#define DT_SYMENT 11 226#define DT_INIT 12 227#define DT_FINI 13 228#define DT_SONAME 14 229#define DT_RPATH 15 230#define DT_SYMBOLIC 16 231#define DT_REL 17 232#define DT_RELSZ 18 233#define DT_RELENT 19 234#define DT_PLTREL 20 235#define DT_DEBUG 21 236#define DT_TEXTREL 22 237#define DT_JMPREL 23 238