1 /* `a.out' object-file definitions, including extensions to 64-bit fields */ 2 3 #ifndef __A_OUT_64_H__ 4 #define __A_OUT_64_H__ 5 6 /* This is the layout on disk of the 32-bit or 64-bit exec header. */ 7 8 #ifndef external_exec 9 struct external_exec 10 { 11 bfd_byte e_info[4]; /* magic number and stuff */ 12 bfd_byte e_text[BYTES_IN_WORD]; /* length of text section in bytes */ 13 bfd_byte e_data[BYTES_IN_WORD]; /* length of data section in bytes */ 14 bfd_byte e_bss[BYTES_IN_WORD]; /* length of bss area in bytes */ 15 bfd_byte e_syms[BYTES_IN_WORD]; /* length of symbol table in bytes */ 16 bfd_byte e_entry[BYTES_IN_WORD]; /* start address */ 17 bfd_byte e_trsize[BYTES_IN_WORD]; /* length of text relocation info */ 18 bfd_byte e_drsize[BYTES_IN_WORD]; /* length of data relocation info */ 19 }; 20 21 #define EXEC_BYTES_SIZE (4 + BYTES_IN_WORD * 7) 22 23 /* Magic numbers for a.out files */ 24 25 #if ARCH_SIZE==64 26 #define OMAGIC 0x1001 /* Code indicating object file */ 27 #define ZMAGIC 0x1002 /* Code indicating demand-paged executable. */ 28 #define NMAGIC 0x1003 /* Code indicating pure executable. */ 29 30 /* There is no 64-bit QMAGIC as far as I know. */ 31 32 #define N_BADMAG(x) (N_MAGIC(x) != OMAGIC \ 33 && N_MAGIC(x) != NMAGIC \ 34 && N_MAGIC(x) != ZMAGIC) 35 #else 36 #define OMAGIC 0407 /* ...object file or impure executable. */ 37 #define NMAGIC 0410 /* Code indicating pure executable. */ 38 #define ZMAGIC 0413 /* Code indicating demand-paged executable. */ 39 #define BMAGIC 0415 /* Used by a b.out object. */ 40 41 /* This indicates a demand-paged executable with the header in the text. 42 It is used by 386BSD (and variants) and Linux, at least. */ 43 #ifndef QMAGIC 44 #define QMAGIC 0314 45 #endif 46 # ifndef N_BADMAG 47 # define N_BADMAG(x) (N_MAGIC(x) != OMAGIC \ 48 && N_MAGIC(x) != NMAGIC \ 49 && N_MAGIC(x) != ZMAGIC \ 50 && N_MAGIC(x) != QMAGIC) 51 # endif /* N_BADMAG */ 52 #endif 53 54 #endif 55 56 #ifdef QMAGIC 57 #define N_IS_QMAGIC(x) (N_MAGIC (x) == QMAGIC) 58 #else 59 #define N_IS_QMAGIC(x) (0) 60 #endif 61 62 /* The difference between TARGET_PAGE_SIZE and N_SEGSIZE is that TARGET_PAGE_SIZE is 63 the finest granularity at which you can page something, thus it 64 controls the padding (if any) before the text segment of a ZMAGIC 65 file. N_SEGSIZE is the resolution at which things can be marked as 66 read-only versus read/write, so it controls the padding between the 67 text segment and the data segment (in memory; on disk the padding 68 between them is TARGET_PAGE_SIZE). TARGET_PAGE_SIZE and N_SEGSIZE are the same 69 for most machines, but different for sun3. */ 70 71 /* By default, segment size is constant. But some machines override this 72 to be a function of the a.out header (e.g. machine type). */ 73 74 #ifndef N_SEGSIZE 75 #define N_SEGSIZE(x) SEGMENT_SIZE 76 #endif 77 78 /* Virtual memory address of the text section. 79 This is getting very complicated. A good reason to discard a.out format 80 for something that specifies these fields explicitly. But til then... 81 82 * OMAGIC and NMAGIC files: 83 (object files: text for "relocatable addr 0" right after the header) 84 start at 0, offset is EXEC_BYTES_SIZE, size as stated. 85 * The text address, offset, and size of ZMAGIC files depend 86 on the entry point of the file: 87 * entry point below TEXT_START_ADDR: 88 (hack for SunOS shared libraries) 89 start at 0, offset is 0, size as stated. 90 * If N_HEADER_IN_TEXT(x) is true (which defaults to being the 91 case when the entry point is EXEC_BYTES_SIZE or further into a page): 92 no padding is needed; text can start after exec header. Sun 93 considers the text segment of such files to include the exec header; 94 for BFD's purposes, we don't, which makes more work for us. 95 start at TEXT_START_ADDR + EXEC_BYTES_SIZE, offset is EXEC_BYTES_SIZE, 96 size as stated minus EXEC_BYTES_SIZE. 97 * If N_HEADER_IN_TEXT(x) is false (which defaults to being the case when 98 the entry point is less than EXEC_BYTES_SIZE into a page (e.g. page 99 aligned)): (padding is needed so that text can start at a page boundary) 100 start at TEXT_START_ADDR, offset TARGET_PAGE_SIZE, size as stated. 101 102 Specific configurations may want to hardwire N_HEADER_IN_TEXT, 103 for efficiency or to allow people to play games with the entry point. 104 In that case, you would #define N_HEADER_IN_TEXT(x) as 1 for sunos, 105 and as 0 for most other hosts (Sony News, Vax Ultrix, etc). 106 (Do this in the appropriate bfd target file.) 107 (The default is a heuristic that will break if people try changing 108 the entry point, perhaps with the ld -e flag.) 109 110 * QMAGIC is always like a ZMAGIC for which N_HEADER_IN_TEXT is true, 111 and for which the starting address is TARGET_PAGE_SIZE (or should this be 112 SEGMENT_SIZE?) (TEXT_START_ADDR only applies to ZMAGIC, not to QMAGIC). 113 */ 114 115 /* This macro is only relevant for ZMAGIC files; QMAGIC always has the header 116 in the text. */ 117 #ifndef N_HEADER_IN_TEXT 118 #define N_HEADER_IN_TEXT(x) (((x).a_entry & (TARGET_PAGE_SIZE-1)) >= EXEC_BYTES_SIZE) 119 #endif 120 121 /* Sun shared libraries, not linux. This macro is only relevant for ZMAGIC 122 files. */ 123 #ifndef N_SHARED_LIB 124 #define N_SHARED_LIB(x) ((x).a_entry < TEXT_START_ADDR) 125 #endif 126 127 /* Returning 0 not TEXT_START_ADDR for OMAGIC and NMAGIC is based on 128 the assumption that we are dealing with a .o file, not an 129 executable. This is necessary for OMAGIC (but means we don't work 130 right on the output from ld -N); more questionable for NMAGIC. */ 131 132 #ifndef N_TXTADDR 133 #define N_TXTADDR(x) \ 134 (/* The address of a QMAGIC file is always one page in, */ \ 135 /* with the header in the text. */ \ 136 N_IS_QMAGIC (x) ? TARGET_PAGE_SIZE + EXEC_BYTES_SIZE : \ 137 N_MAGIC(x) != ZMAGIC ? 0 : /* object file or NMAGIC */\ 138 N_SHARED_LIB(x) ? 0 : \ 139 N_HEADER_IN_TEXT(x) ? \ 140 TEXT_START_ADDR + EXEC_BYTES_SIZE : /* no padding */\ 141 TEXT_START_ADDR /* a page of padding */\ 142 ) 143 #endif 144 145 /* If N_HEADER_IN_TEXT is not true for ZMAGIC, there is some padding 146 to make the text segment start at a certain boundary. For most 147 systems, this boundary is TARGET_PAGE_SIZE. But for Linux, in the 148 time-honored tradition of crazy ZMAGIC hacks, it is 1024 which is 149 not what TARGET_PAGE_SIZE needs to be for QMAGIC. */ 150 151 #ifndef ZMAGIC_DISK_BLOCK_SIZE 152 #define ZMAGIC_DISK_BLOCK_SIZE TARGET_PAGE_SIZE 153 #endif 154 155 #define N_DISK_BLOCK_SIZE(x) \ 156 (N_MAGIC(x) == ZMAGIC ? ZMAGIC_DISK_BLOCK_SIZE : TARGET_PAGE_SIZE) 157 158 /* Offset in an a.out of the start of the text section. */ 159 #ifndef N_TXTOFF 160 #define N_TXTOFF(x) \ 161 (/* For {O,N,Q}MAGIC, no padding. */ \ 162 N_MAGIC(x) != ZMAGIC ? EXEC_BYTES_SIZE : \ 163 N_SHARED_LIB(x) ? 0 : \ 164 N_HEADER_IN_TEXT(x) ? \ 165 EXEC_BYTES_SIZE : /* no padding */\ 166 ZMAGIC_DISK_BLOCK_SIZE /* a page of padding */\ 167 ) 168 #endif 169 /* Size of the text section. It's always as stated, except that we 170 offset it to `undo' the adjustment to N_TXTADDR and N_TXTOFF 171 for ZMAGIC files that nominally include the exec header 172 as part of the first page of text. (BFD doesn't consider the 173 exec header to be part of the text segment.) */ 174 #ifndef N_TXTSIZE 175 #define N_TXTSIZE(x) \ 176 (/* For QMAGIC, we don't consider the header part of the text section. */\ 177 N_IS_QMAGIC (x) ? (x).a_text - EXEC_BYTES_SIZE : \ 178 (N_MAGIC(x) != ZMAGIC || N_SHARED_LIB(x)) ? (x).a_text : \ 179 N_HEADER_IN_TEXT(x) ? \ 180 (x).a_text - EXEC_BYTES_SIZE: /* no padding */\ 181 (x).a_text /* a page of padding */\ 182 ) 183 #endif 184 /* The address of the data segment in virtual memory. 185 It is the text segment address, plus text segment size, rounded 186 up to a N_SEGSIZE boundary for pure or pageable files. */ 187 #ifndef N_DATADDR 188 #define N_DATADDR(x) \ 189 (N_MAGIC(x)==OMAGIC? (N_TXTADDR(x)+N_TXTSIZE(x)) \ 190 : (N_SEGSIZE(x) + ((N_TXTADDR(x)+N_TXTSIZE(x)-1) & ~(N_SEGSIZE(x)-1)))) 191 #endif 192 /* The address of the BSS segment -- immediately after the data segment. */ 193 194 #define N_BSSADDR(x) (N_DATADDR(x) + (x).a_data) 195 196 /* Offsets of the various portions of the file after the text segment. */ 197 198 /* For {Q,Z}MAGIC, there is padding to make the data segment start on 199 a page boundary. Most of the time the a_text field (and thus 200 N_TXTSIZE) already contains this padding. It is possible that for 201 BSDI and/or 386BSD it sometimes doesn't contain the padding, and 202 perhaps we should be adding it here. But this seems kind of 203 questionable and probably should be BSDI/386BSD-specific if we do 204 do it. 205 206 For NMAGIC (at least for hp300 BSD, probably others), there is 207 padding in memory only, not on disk, so we must *not* ever pad here 208 for NMAGIC. */ 209 210 #ifndef N_DATOFF 211 #define N_DATOFF(x) \ 212 (N_TXTOFF(x) + N_TXTSIZE(x)) 213 #endif 214 215 #ifndef N_TRELOFF 216 #define N_TRELOFF(x) ( N_DATOFF(x) + (x).a_data ) 217 #endif 218 #ifndef N_DRELOFF 219 #define N_DRELOFF(x) ( N_TRELOFF(x) + (x).a_trsize ) 220 #endif 221 #ifndef N_SYMOFF 222 #define N_SYMOFF(x) ( N_DRELOFF(x) + (x).a_drsize ) 223 #endif 224 #ifndef N_STROFF 225 #define N_STROFF(x) ( N_SYMOFF(x) + (x).a_syms ) 226 #endif 227 228 /* Symbols */ 229 #ifndef external_nlist 230 struct external_nlist { 231 bfd_byte e_strx[BYTES_IN_WORD]; /* index into string table of name */ 232 bfd_byte e_type[1]; /* type of symbol */ 233 bfd_byte e_other[1]; /* misc info (usually empty) */ 234 bfd_byte e_desc[2]; /* description field */ 235 bfd_byte e_value[BYTES_IN_WORD]; /* value of symbol */ 236 }; 237 #define EXTERNAL_NLIST_SIZE (BYTES_IN_WORD+4+BYTES_IN_WORD) 238 #endif 239 240 struct internal_nlist { 241 unsigned long n_strx; /* index into string table of name */ 242 unsigned char n_type; /* type of symbol */ 243 unsigned char n_other; /* misc info (usually empty) */ 244 unsigned short n_desc; /* description field */ 245 bfd_vma n_value; /* value of symbol */ 246 }; 247 248 /* The n_type field is the symbol type, containing: */ 249 250 #define N_UNDF 0 /* Undefined symbol */ 251 #define N_ABS 2 /* Absolute symbol -- defined at particular addr */ 252 #define N_TEXT 4 /* Text sym -- defined at offset in text seg */ 253 #define N_DATA 6 /* Data sym -- defined at offset in data seg */ 254 #define N_BSS 8 /* BSS sym -- defined at offset in zero'd seg */ 255 #define N_COMM 0x12 /* Common symbol (visible after shared lib dynlink) */ 256 #define N_FN 0x1f /* File name of .o file */ 257 #define N_FN_SEQ 0x0C /* N_FN from Sequent compilers (sigh) */ 258 /* Note: N_EXT can only be usefully OR-ed with N_UNDF, N_ABS, N_TEXT, 259 N_DATA, or N_BSS. When the low-order bit of other types is set, 260 (e.g. N_WARNING versus N_FN), they are two different types. */ 261 #define N_EXT 1 /* External symbol (as opposed to local-to-this-file) */ 262 #define N_TYPE 0x1e 263 #define N_STAB 0xe0 /* If any of these bits are on, it's a debug symbol */ 264 265 #define N_INDR 0x0a 266 267 /* The following symbols refer to set elements. 268 All the N_SET[ATDB] symbols with the same name form one set. 269 Space is allocated for the set in the text section, and each set 270 elements value is stored into one word of the space. 271 The first word of the space is the length of the set (number of elements). 272 273 The address of the set is made into an N_SETV symbol 274 whose name is the same as the name of the set. 275 This symbol acts like a N_DATA global symbol 276 in that it can satisfy undefined external references. */ 277 278 /* These appear as input to LD, in a .o file. */ 279 #define N_SETA 0x14 /* Absolute set element symbol */ 280 #define N_SETT 0x16 /* Text set element symbol */ 281 #define N_SETD 0x18 /* Data set element symbol */ 282 #define N_SETB 0x1A /* Bss set element symbol */ 283 284 /* This is output from LD. */ 285 #define N_SETV 0x1C /* Pointer to set vector in data area. */ 286 287 /* Warning symbol. The text gives a warning message, the next symbol 288 in the table will be undefined. When the symbol is referenced, the 289 message is printed. */ 290 291 #define N_WARNING 0x1e 292 293 /* Weak symbols. These are a GNU extension to the a.out format. The 294 semantics are those of ELF weak symbols. Weak symbols are always 295 externally visible. The N_WEAK? values are squeezed into the 296 available slots. The value of a N_WEAKU symbol is 0. The values 297 of the other types are the definitions. */ 298 #define N_WEAKU 0x0d /* Weak undefined symbol. */ 299 #define N_WEAKA 0x0e /* Weak absolute symbol. */ 300 #define N_WEAKT 0x0f /* Weak text symbol. */ 301 #define N_WEAKD 0x10 /* Weak data symbol. */ 302 #define N_WEAKB 0x11 /* Weak bss symbol. */ 303 304 /* Relocations 305 306 There are two types of relocation flavours for a.out systems, 307 standard and extended. The standard form is used on systems where the 308 instruction has room for all the bits of an offset to the operand, whilst 309 the extended form is used when an address operand has to be split over n 310 instructions. Eg, on the 68k, each move instruction can reference 311 the target with a displacement of 16 or 32 bits. On the sparc, move 312 instructions use an offset of 14 bits, so the offset is stored in 313 the reloc field, and the data in the section is ignored. 314 */ 315 316 /* This structure describes a single relocation to be performed. 317 The text-relocation section of the file is a vector of these structures, 318 all of which apply to the text section. 319 Likewise, the data-relocation section applies to the data section. */ 320 321 struct reloc_std_external { 322 bfd_byte r_address[BYTES_IN_WORD]; /* offset of of data to relocate */ 323 bfd_byte r_index[3]; /* symbol table index of symbol */ 324 bfd_byte r_type[1]; /* relocation type */ 325 }; 326 327 #define RELOC_STD_BITS_PCREL_BIG ((unsigned int) 0x80) 328 #define RELOC_STD_BITS_PCREL_LITTLE ((unsigned int) 0x01) 329 330 #define RELOC_STD_BITS_LENGTH_BIG ((unsigned int) 0x60) 331 #define RELOC_STD_BITS_LENGTH_SH_BIG 5 332 #define RELOC_STD_BITS_LENGTH_LITTLE ((unsigned int) 0x06) 333 #define RELOC_STD_BITS_LENGTH_SH_LITTLE 1 334 335 #define RELOC_STD_BITS_EXTERN_BIG ((unsigned int) 0x10) 336 #define RELOC_STD_BITS_EXTERN_LITTLE ((unsigned int) 0x08) 337 338 #define RELOC_STD_BITS_BASEREL_BIG ((unsigned int) 0x08) 339 #define RELOC_STD_BITS_BASEREL_LITTLE ((unsigned int) 0x10) 340 341 #define RELOC_STD_BITS_JMPTABLE_BIG ((unsigned int) 0x04) 342 #define RELOC_STD_BITS_JMPTABLE_LITTLE ((unsigned int) 0x20) 343 344 #define RELOC_STD_BITS_RELATIVE_BIG ((unsigned int) 0x02) 345 #define RELOC_STD_BITS_RELATIVE_LITTLE ((unsigned int) 0x40) 346 347 #define RELOC_STD_SIZE (BYTES_IN_WORD + 3 + 1) /* Bytes per relocation entry */ 348 349 struct reloc_std_internal 350 { 351 bfd_vma r_address; /* Address (within segment) to be relocated. */ 352 /* The meaning of r_symbolnum depends on r_extern. */ 353 unsigned int r_symbolnum:24; 354 /* Nonzero means value is a pc-relative offset 355 and it should be relocated for changes in its own address 356 as well as for changes in the symbol or section specified. */ 357 unsigned int r_pcrel:1; 358 /* Length (as exponent of 2) of the field to be relocated. 359 Thus, a value of 2 indicates 1<<2 bytes. */ 360 unsigned int r_length:2; 361 /* 1 => relocate with value of symbol. 362 r_symbolnum is the index of the symbol 363 in files the symbol table. 364 0 => relocate with the address of a segment. 365 r_symbolnum is N_TEXT, N_DATA, N_BSS or N_ABS 366 (the N_EXT bit may be set also, but signifies nothing). */ 367 unsigned int r_extern:1; 368 /* The next three bits are for SunOS shared libraries, and seem to 369 be undocumented. */ 370 unsigned int r_baserel:1; /* Linkage table relative */ 371 unsigned int r_jmptable:1; /* pc-relative to jump table */ 372 unsigned int r_relative:1; /* "relative relocation" */ 373 /* unused */ 374 unsigned int r_pad:1; /* Padding -- set to zero */ 375 }; 376 377 378 /* EXTENDED RELOCS */ 379 380 struct reloc_ext_external { 381 bfd_byte r_address[BYTES_IN_WORD]; /* offset of of data to relocate */ 382 bfd_byte r_index[3]; /* symbol table index of symbol */ 383 bfd_byte r_type[1]; /* relocation type */ 384 bfd_byte r_addend[BYTES_IN_WORD]; /* datum addend */ 385 }; 386 387 #define RELOC_EXT_BITS_EXTERN_BIG ((unsigned int) 0x80) 388 #define RELOC_EXT_BITS_EXTERN_LITTLE ((unsigned int) 0x01) 389 390 #define RELOC_EXT_BITS_TYPE_BIG ((unsigned int) 0x1F) 391 #define RELOC_EXT_BITS_TYPE_SH_BIG 0 392 #define RELOC_EXT_BITS_TYPE_LITTLE ((unsigned int) 0xF8) 393 #define RELOC_EXT_BITS_TYPE_SH_LITTLE 3 394 395 /* Bytes per relocation entry */ 396 #define RELOC_EXT_SIZE (BYTES_IN_WORD + 3 + 1 + BYTES_IN_WORD) 397 398 enum reloc_type 399 { 400 /* simple relocations */ 401 RELOC_8, /* data[0:7] = addend + sv */ 402 RELOC_16, /* data[0:15] = addend + sv */ 403 RELOC_32, /* data[0:31] = addend + sv */ 404 /* pc-rel displacement */ 405 RELOC_DISP8, /* data[0:7] = addend - pc + sv */ 406 RELOC_DISP16, /* data[0:15] = addend - pc + sv */ 407 RELOC_DISP32, /* data[0:31] = addend - pc + sv */ 408 /* Special */ 409 RELOC_WDISP30, /* data[0:29] = (addend + sv - pc)>>2 */ 410 RELOC_WDISP22, /* data[0:21] = (addend + sv - pc)>>2 */ 411 RELOC_HI22, /* data[0:21] = (addend + sv)>>10 */ 412 RELOC_22, /* data[0:21] = (addend + sv) */ 413 RELOC_13, /* data[0:12] = (addend + sv) */ 414 RELOC_LO10, /* data[0:9] = (addend + sv) */ 415 RELOC_SFA_BASE, 416 RELOC_SFA_OFF13, 417 /* P.I.C. (base-relative) */ 418 RELOC_BASE10, /* Not sure - maybe we can do this the */ 419 RELOC_BASE13, /* right way now */ 420 RELOC_BASE22, 421 /* for some sort of pc-rel P.I.C. (?) */ 422 RELOC_PC10, 423 RELOC_PC22, 424 /* P.I.C. jump table */ 425 RELOC_JMP_TBL, 426 /* reputedly for shared libraries somehow */ 427 RELOC_SEGOFF16, 428 RELOC_GLOB_DAT, 429 RELOC_JMP_SLOT, 430 RELOC_RELATIVE, 431 432 RELOC_11, 433 RELOC_WDISP2_14, 434 RELOC_WDISP19, 435 RELOC_HHI22, /* data[0:21] = (addend + sv) >> 42 */ 436 RELOC_HLO10, /* data[0:9] = (addend + sv) >> 32 */ 437 438 /* 29K relocation types */ 439 RELOC_JUMPTARG, 440 RELOC_CONST, 441 RELOC_CONSTH, 442 443 /* All the new ones I can think of, for sparc v9 */ 444 445 RELOC_64, /* data[0:63] = addend + sv */ 446 RELOC_DISP64, /* data[0:63] = addend - pc + sv */ 447 RELOC_WDISP21, /* data[0:20] = (addend + sv - pc)>>2 */ 448 RELOC_DISP21, /* data[0:20] = addend - pc + sv */ 449 RELOC_DISP14, /* data[0:13] = addend - pc + sv */ 450 /* Q . 451 What are the other ones, 452 Since this is a clean slate, can we throw away the ones we dont 453 understand ? Should we sort the values ? What about using a 454 microcode format like the 68k ? 455 */ 456 NO_RELOC 457 }; 458 459 460 struct reloc_internal { 461 bfd_vma r_address; /* offset of of data to relocate */ 462 long r_index; /* symbol table index of symbol */ 463 enum reloc_type r_type; /* relocation type */ 464 bfd_vma r_addend; /* datum addend */ 465 }; 466 467 /* Q. 468 Should the length of the string table be 4 bytes or 8 bytes ? 469 470 Q. 471 What about archive indexes ? 472 473 */ 474 475 #endif /* __A_OUT_64_H__ */ 476