1 /* 2 * Copyright (c) 2006-2018, RT-Thread Development Team 3 * 4 * SPDX-License-Identifier: Apache-2.0 5 * 6 * Change Logs: 7 * Date Author Notes 8 * 2018/08/29 Bernard first version 9 */ 10 11 #ifndef DL_ELF_H__ 12 #define DL_ELF_H__ 13 14 typedef rt_uint8_t Elf_Byte; 15 16 typedef rt_uint32_t Elf32_Addr; /* Unsigned program address */ 17 typedef rt_uint32_t Elf32_Off; /* Unsigned file offset */ 18 typedef rt_int32_t Elf32_Sword; /* Signed large integer */ 19 typedef rt_uint32_t Elf32_Word; /* Unsigned large integer */ 20 typedef rt_uint16_t Elf32_Half; /* Unsigned medium integer */ 21 22 /* e_ident[] magic number */ 23 #define ELFMAG0 0x7f /* e_ident[EI_MAG0] */ 24 #define ELFMAG1 'E' /* e_ident[EI_MAG1] */ 25 #define ELFMAG2 'L' /* e_ident[EI_MAG2] */ 26 #define ELFMAG3 'F' /* e_ident[EI_MAG3] */ 27 #define RTMMAG "\177RTM" /* magic */ 28 #define ELFMAG "\177ELF" /* magic */ 29 #define SELFMAG 4 /* size of magic */ 30 31 #define EI_CLASS 4 /* file class */ 32 #define EI_NIDENT 16 /* Size of e_ident[] */ 33 34 /* e_ident[] file class */ 35 #define ELFCLASSNONE 0 /* invalid */ 36 #define ELFCLASS32 1 /* 32-bit objs */ 37 #define ELFCLASS64 2 /* 64-bit objs */ 38 #define ELFCLASSNUM 3 /* number of classes */ 39 40 /* e_ident[] data encoding */ 41 #define ELFDATANONE 0 /* invalid */ 42 #define ELFDATA2LSB 1 /* Little-Endian */ 43 #define ELFDATA2MSB 2 /* Big-Endian */ 44 #define ELFDATANUM 3 /* number of data encode defines */ 45 46 /* e_ident */ 47 #define IS_ELF(ehdr) ((ehdr).e_ident[EI_MAG0] == ELFMAG0 && \ 48 (ehdr).e_ident[EI_MAG1] == ELFMAG1 && \ 49 (ehdr).e_ident[EI_MAG2] == ELFMAG2 && \ 50 (ehdr).e_ident[EI_MAG3] == ELFMAG3) 51 52 #define ET_NONE 0 /* No file type */ 53 #define ET_REL 1 /* Relocatable file */ 54 #define ET_EXEC 2 /* Executable file */ 55 #define ET_DYN 3 /* Shared object file */ 56 #define ET_CORE 4 /* Core file */ 57 58 /* ELF Header */ 59 typedef struct elfhdr 60 { 61 unsigned char e_ident[EI_NIDENT]; /* ELF Identification */ 62 Elf32_Half e_type; /* object file type */ 63 Elf32_Half e_machine; /* machine */ 64 Elf32_Word e_version; /* object file version */ 65 Elf32_Addr e_entry; /* virtual entry point */ 66 Elf32_Off e_phoff; /* program header table offset */ 67 Elf32_Off e_shoff; /* section header table offset */ 68 Elf32_Word e_flags; /* processor-specific flags */ 69 Elf32_Half e_ehsize; /* ELF header size */ 70 Elf32_Half e_phentsize; /* program header entry size */ 71 Elf32_Half e_phnum; /* number of program header entries */ 72 Elf32_Half e_shentsize; /* section header entry size */ 73 Elf32_Half e_shnum; /* number of section header entries */ 74 Elf32_Half e_shstrndx; /* section header table's "section 75 header string table" entry offset */ 76 } Elf32_Ehdr; 77 78 /* Section Header */ 79 typedef struct 80 { 81 Elf32_Word sh_name; /* name - index into section header 82 string table section */ 83 Elf32_Word sh_type; /* type */ 84 Elf32_Word sh_flags; /* flags */ 85 Elf32_Addr sh_addr; /* address */ 86 Elf32_Off sh_offset; /* file offset */ 87 Elf32_Word sh_size; /* section size */ 88 Elf32_Word sh_link; /* section header table index link */ 89 Elf32_Word sh_info; /* extra information */ 90 Elf32_Word sh_addralign; /* address alignment */ 91 Elf32_Word sh_entsize; /* section entry size */ 92 } Elf32_Shdr; 93 94 /* Section names */ 95 #define ELF_BSS ".bss" /* uninitialized data */ 96 #define ELF_DATA ".data" /* initialized data */ 97 #define ELF_DEBUG ".debug" /* debug */ 98 #define ELF_DYNAMIC ".dynamic" /* dynamic linking information */ 99 #define ELF_DYNSTR ".dynstr" /* dynamic string table */ 100 #define ELF_DYNSYM ".dynsym" /* dynamic symbol table */ 101 #define ELF_FINI ".fini" /* termination code */ 102 #define ELF_GOT ".got" /* global offset table */ 103 #define ELF_HASH ".hash" /* symbol hash table */ 104 #define ELF_INIT ".init" /* initialization code */ 105 #define ELF_REL_DATA ".rel.data" /* relocation data */ 106 #define ELF_REL_FINI ".rel.fini" /* relocation termination code */ 107 #define ELF_REL_INIT ".rel.init" /* relocation initialization code */ 108 #define ELF_REL_DYN ".rel.dyn" /* relocaltion dynamic link info */ 109 #define ELF_REL_RODATA ".rel.rodata" /* relocation read-only data */ 110 #define ELF_REL_TEXT ".rel.text" /* relocation code */ 111 #define ELF_RODATA ".rodata" /* read-only data */ 112 #define ELF_SHSTRTAB ".shstrtab" /* section header string table */ 113 #define ELF_STRTAB ".strtab" /* string table */ 114 #define ELF_SYMTAB ".symtab" /* symbol table */ 115 #define ELF_TEXT ".text" /* code */ 116 #define ELF_RTMSYMTAB "RTMSymTab" 117 118 /* Symbol Table Entry */ 119 typedef struct elf32_sym 120 { 121 Elf32_Word st_name; /* name - index into string table */ 122 Elf32_Addr st_value; /* symbol value */ 123 Elf32_Word st_size; /* symbol size */ 124 unsigned char st_info; /* type and binding */ 125 unsigned char st_other; /* 0 - no defined meaning */ 126 Elf32_Half st_shndx; /* section header index */ 127 } Elf32_Sym; 128 129 #define STB_LOCAL 0 /* BIND */ 130 #define STB_GLOBAL 1 131 #define STB_WEAK 2 132 #define STB_NUM 3 133 134 #define STB_LOPROC 13 /* processor specific range */ 135 #define STB_HIPROC 15 136 137 #define STT_NOTYPE 0 /* symbol type is unspecified */ 138 #define STT_OBJECT 1 /* data object */ 139 #define STT_FUNC 2 /* code object */ 140 #define STT_SECTION 3 /* symbol identifies an ELF section */ 141 #define STT_FILE 4 /* symbol's name is file name */ 142 #define STT_COMMON 5 /* common data object */ 143 #define STT_TLS 6 /* thread-local data object */ 144 #define STT_NUM 7 /* # defined types in generic range */ 145 #define STT_LOOS 10 /* OS specific range */ 146 #define STT_HIOS 12 147 #define STT_LOPROC 13 /* processor specific range */ 148 #define STT_HIPROC 15 149 150 #define STN_UNDEF 0 /* undefined */ 151 152 #define ELF_ST_BIND(info) ((info) >> 4) 153 #define ELF_ST_TYPE(info) ((info) & 0xf) 154 #define ELF_ST_INFO(bind, type) (((bind)<<4)+((type)&0xf)) 155 156 /* Relocation entry with implicit addend */ 157 typedef struct 158 { 159 Elf32_Addr r_offset; /* offset of relocation */ 160 Elf32_Word r_info; /* symbol table index and type */ 161 } Elf32_Rel; 162 163 /* Relocation entry with explicit addend */ 164 typedef struct 165 { 166 Elf32_Addr r_offset; /* offset of relocation */ 167 Elf32_Word r_info; /* symbol table index and type */ 168 Elf32_Sword r_addend; 169 } Elf32_Rela; 170 171 /* Extract relocation info - r_info */ 172 #define ELF32_R_SYM(i) ((i) >> 8) 173 #define ELF32_R_TYPE(i) ((unsigned char) (i)) 174 #define ELF32_R_INFO(s,t) (((s) << 8) + (unsigned char)(t)) 175 176 /* 177 * Relocation type for arm 178 */ 179 #define R_ARM_NONE 0 180 #define R_ARM_PC24 1 181 #define R_ARM_ABS32 2 182 #define R_ARM_REL32 3 183 #define R_ARM_THM_CALL 10 184 #define R_ARM_GLOB_DAT 21 185 #define R_ARM_JUMP_SLOT 22 186 #define R_ARM_RELATIVE 23 187 #define R_ARM_GOT_BREL 26 188 #define R_ARM_PLT32 27 189 #define R_ARM_CALL 28 190 #define R_ARM_JUMP24 29 191 #define R_ARM_THM_JUMP24 30 192 #define R_ARM_V4BX 40 193 194 /* 195 * Relocation type for x86 196 */ 197 #define R_386_NONE 0 198 #define R_386_32 1 199 #define R_386_PC32 2 200 #define R_386_GOT32 3 201 #define R_386_PLT32 4 202 #define R_386_COPY 5 203 #define R_386_GLOB_DAT 6 204 #define R_386_JMP_SLOT 7 205 #define R_386_RELATIVE 8 206 #define R_386_GOTOFF 9 207 #define R_386_GOTPC 10 208 209 /* Program Header */ 210 typedef struct 211 { 212 Elf32_Word p_type; /* segment type */ 213 Elf32_Off p_offset; /* segment offset */ 214 Elf32_Addr p_vaddr; /* virtual address of segment */ 215 Elf32_Addr p_paddr; /* physical address - ignored? */ 216 Elf32_Word p_filesz; /* number of bytes in file for seg. */ 217 Elf32_Word p_memsz; /* number of bytes in mem. for seg. */ 218 Elf32_Word p_flags; /* flags */ 219 Elf32_Word p_align; /* memory alignment */ 220 } Elf32_Phdr; 221 222 /* p_type */ 223 #define PT_NULL 0 224 #define PT_LOAD 1 225 #define PT_DYNAMIC 2 226 #define PT_INTERP 3 227 #define PT_NOTE 4 228 #define PT_SHLIB 5 229 #define PT_PHDR 6 230 #define PT_TLS 7 231 #define PT_NUM 8 232 #define PT_LOOS 0x60000000 233 #define PT_HIOS 0x6fffffff 234 #define PT_LOPROC 0x70000000 235 #define PT_HIPROC 0x7fffffff 236 237 /* p_flags */ 238 #define PF_X 1 239 #define PF_W 2 240 #define PF_R 4 241 242 /* sh_type */ 243 #define SHT_NULL 0 /* inactive */ 244 #define SHT_PROGBITS 1 /* program defined information */ 245 #define SHT_SYMTAB 2 /* symbol table section */ 246 #define SHT_STRTAB 3 /* string table section */ 247 #define SHT_RELA 4 /* relocation section with addends*/ 248 #define SHT_HASH 5 /* symbol hash table section */ 249 #define SHT_DYNAMIC 6 /* dynamic section */ 250 #define SHT_NOTE 7 /* note section */ 251 #define SHT_NOBITS 8 /* no space section */ 252 #define SHT_REL 9 /* relocation section without addends */ 253 #define SHT_SHLIB 10 /* reserved - purpose unknown */ 254 #define SHT_DYNSYM 11 /* dynamic symbol table section */ 255 #define SHT_NUM 12 /* number of section types */ 256 #define SHT_LOPROC 0x70000000 /* reserved range for processor */ 257 #define SHT_HIPROC 0x7fffffff /* specific section header types */ 258 #define SHT_LOUSER 0x80000000 /* reserved range for application */ 259 #define SHT_HIUSER 0xffffffff /* specific indexes */ 260 261 /* Section Attribute Flags - sh_flags */ 262 #define SHF_WRITE 0x1 /* Writable */ 263 #define SHF_ALLOC 0x2 /* occupies memory */ 264 #define SHF_EXECINSTR 0x4 /* executable */ 265 #define SHF_MASKPROC 0xf0000000 /* reserved bits for processor */ 266 /* specific section attributes */ 267 268 #define IS_PROG(s) (s.sh_type == SHT_PROGBITS) 269 #define IS_NOPROG(s) (s.sh_type == SHT_NOBITS) 270 #define IS_REL(s) (s.sh_type == SHT_REL) 271 #define IS_RELA(s) (s.sh_type == SHT_RELA) 272 #define IS_ALLOC(s) (s.sh_flags == SHF_ALLOC) 273 #define IS_AX(s) ((s.sh_flags & SHF_ALLOC) && (s.sh_flags & SHF_EXECINSTR)) 274 #define IS_AW(s) ((s.sh_flags & SHF_ALLOC) && (s.sh_flags & SHF_WRITE)) 275 276 #define elf_module ((Elf32_Ehdr *)module_ptr) 277 #define shdr ((Elf32_Shdr *)((rt_uint8_t *)module_ptr + elf_module->e_shoff)) 278 #define phdr ((Elf32_Phdr *)((rt_uint8_t *)module_ptr + elf_module->e_phoff)) 279 280 rt_err_t dlmodule_load_shared_object(struct rt_dlmodule* module, void *module_ptr); 281 rt_err_t dlmodule_load_relocated_object(struct rt_dlmodule* module, void *module_ptr); 282 283 int dlmodule_relocate(struct rt_dlmodule *module, Elf32_Rel *rel, Elf32_Addr sym_val); 284 285 #endif 286