Shamusworld >> Repos - rmac/blob - mark.c

   1 //
   2 // RMAC - Reboot's Macro Assembler for the Atari Jaguar Console System
   3 // MARK.C - A record of things that are defined relative to any of the sections
   4 // Copyright (C) 199x Landon Dyer, 2011-2012 Reboot and Friends
   5 // RMAC derived from MADMAC v1.07 Written by Landon Dyer, 1986
   6 // Source utilised with the kind permission of Landon Dyer
   7 //
   8
   9 #include "mark.h"
  10 #include "error.h"
  11 #include "object.h"
  12 #include "riscasm.h"
  13 #include "sect.h"
  14
  15
  16 #define MARK_ALLOC_INCR 1024            // # bytes to alloc for more mark space
  17 #define MIN_MARK_MEM    (3 * sizeof(uint16_t) + 1 * sizeof(uint32_t) + sizeof(SYM *))
  18
  19 MCHUNK * firstmch;              // First mark chunk
  20 MCHUNK * curmch;                // Current mark chunk
  21 PTR markptr;                    // Deposit point in current mark chunk
  22 uint32_t mcalloc;               // # bytes alloc'd to current mark chunk
  23 uint32_t mcused;                // # bytes used in current mark chunk
  24 uint16_t curfrom;               // Current "from" section
  25
  26 // Table to convert from TDB to fixup triad
  27 static uint8_t mark_tr[] = {
  28         0,              // (N/A)
  29         2,              // TEXT relocatable
  30         1, 0,   // DATA relocatable
  31         3               // BSS relocatable
  32 };
  33
  34 //#define DEBUG_IMAGE_MARKING
  35
  36
  37 //
  38 // Initialize marker
  39 //
  40 void InitMark(void)
  41 {
  42         firstmch = curmch = NULL;
  43         mcalloc = mcused = 0;
  44         curfrom = 0;
  45         sect[TEXT].relocs = sect[DATA].relocs = sect[BSS].relocs = 0;
  46 }
  47
  48
  49 //
  50 // Wrap up marker (called after final mark is made)
  51 //
  52 void StopMark(void)
  53 {
  54         if (curmch)
  55         {
  56                 *markptr.wp = MCHEND;           // Mark end of block
  57                 curmch->mcused = mcused;        // Update # used in mark block
  58         }
  59 }
  60
  61
  62 //
  63 // Mark a word or longword as relocatable
  64 //
  65 // Record is either 2, 3, or 4 pieces of data long. A mark is of the form:
  66 // .W    <to+flags>     section mark is relative to, and flags in upper byte
  67 // .L    <loc>          location of mark in "from" section
  68 // .W    [from]         new from section (if different from current)
  69 // .L    [symbol]       symbol involved in external reference (if any)
  70 //
  71 uint32_t MarkRelocatable(uint16_t section, uint32_t loc, uint16_t to, uint16_t flags, SYM * symbol)
  72 {
  73 #ifdef DEBUG_IMAGE_MARKING
  74 printf("MarkRelocatable: section=%i, loc=$%X, to=$%X, flags=$%x, symbol=$%X\n", section, loc, to, flags, symbol);
  75 if (symbol)
  76         printf("      symbol->stype=$%02X, sattr=$%04X, sattre=$%08X, svalue=%i, sname=%s\n", symbol->stype, symbol->sattr, symbol->sattre, symbol->svalue, symbol->sname);
  77 #endif
  78
  79         if ((mcalloc - mcused) < MIN_MARK_MEM)
  80                 AllocateMark();
  81
  82         // Set up flags
  83         flags |= to;
  84
  85         if (section != curfrom)
  86                 flags |= MCHFROM;
  87
  88         if (symbol != NULL)
  89                 flags |= MSYMBOL;
  90
  91         //
  92         // Complain about some things are not allowed in '-p' (PRG) mode:
  93         //  o Marks that aren't to LONGs
  94         //  o External references
  95         //
  96         if (prg_flag)
  97         {
  98                 if ((flags & MLONG) == 0)
  99                         error("illegal word relocatable (in .PRG mode)");
 100
 101                 if (symbol != NULL)
 102                         errors("illegal external reference (in .PRG mode) to '%s'",
 103                                 symbol->sname);
 104         }
 105
 106         // Dump crap into the mark
 107         *markptr.wp++ = flags;
 108         *markptr.lp++ = loc;
 109         mcused += sizeof(uint16_t) + sizeof(uint32_t);
 110
 111         if (flags & MCHFROM)
 112         {
 113                 curfrom = section;
 114                 *markptr.wp++ = section;
 115                 mcused += sizeof(uint16_t);
 116         }
 117
 118         if (flags & MSYMBOL)
 119         {
 120                 *markptr.sy++ = symbol;
 121                 mcused += sizeof(SYM *);
 122         }
 123
 124         // Increment # of relocs in this section
 125         sect[section].relocs++;
 126
 127         // Not sure what this is about (making sure the next mark is clear until
 128         // it's marked as the end--I think)...
 129         *markptr.wp = 0x0000;
 130
 131         return 0;
 132 }
 133
 134
 135 //
 136 // Allocate another chunk of mark space
 137 //
 138 uint32_t AllocateMark(void)
 139 {
 140         // Alloc mark block header (and data) and set it up.
 141         MCHUNK * p = malloc(sizeof(MCHUNK) + MARK_ALLOC_INCR);
 142         p->mcnext = NULL;
 143         p->mcalloc = MARK_ALLOC_INCR;
 144         p->mcptr.cp = (uint8_t *)p + sizeof(MCHUNK);
 145         p->mcused = 0;
 146
 147         if (firstmch == NULL)
 148                 firstmch = p;
 149
 150         if (curmch)
 151         {
 152                 // Link onto previous chunk
 153                 *markptr.wp++ = MCHEND;         // Mark end of block
 154                 curmch->mcused = mcused;
 155                 curmch->mcnext = p;
 156         }
 157
 158         // Setup global vars
 159         curmch = p;
 160         markptr = p->mcptr;
 161         mcalloc = MARK_ALLOC_INCR;
 162         mcused = 0;
 163
 164         return 0;
 165 }
 166
 167
 168 //
 169 // Make mark image for Alcyon .o file
 170 // okflag: 1, ok to deposit reloc information
 171 //
 172 uint32_t MarkImage(register uint8_t * mp, uint32_t siz, uint32_t tsize, int okflag)
 173 {
 174         uint16_t from = 0;              // Section fixups are currently FROM
 175         uint32_t loc;                   // Location (temp)
 176         uint32_t lastloc;               // Last location fixed up (RELMOD)
 177         uint8_t * wp;                   // Pointer into raw relocation information
 178         register uint8_t * dp;  // Deposit point for RELMOD information
 179
 180         if (okflag)
 181                 memset(mp, 0, siz);             // zero relocation buffer
 182
 183         for(MCHUNK * mch=firstmch; mch!=NULL; mch=mch->mcnext)
 184         {
 185                 for(PTR p=mch->mcptr;;)
 186                 {
 187                         uint16_t w = *p.wp++;// w = next mark entry
 188
 189                         if (w & MCHEND)         // (end of mark chunk)
 190                                 break;
 191
 192                         // Get mark record
 193                         SYM * symbol = NULL;
 194                         loc = *p.lp++;          // mark location
 195
 196                         if (w & MCHFROM)        // maybe change "from" section
 197                                 from = *p.wp++;
 198
 199                         if (w & MSYMBOL)        // maybe includes a symbol
 200                                 symbol = *p.sy++;
 201
 202                         // Compute mark position in relocation information; in RELMOD mode,
 203                         // get address of data to fix up.
 204                         if (from == DATA)
 205                                 loc += tsize;
 206
 207                         wp = (uint8_t *)(mp + loc);
 208
 209                         if (okflag && (w & MLONG)) // indicate first word of long
 210                         {
 211                                 wp[1] = 5;
 212                                 wp += 2;
 213                         }
 214
 215                         if (symbol)
 216                         {
 217                                 // Deposit external reference
 218                                 if (okflag)
 219                                 {
 220                                         if (w & MPCREL)
 221                                                 w = 6;          // PC-relative fixup
 222                                         else
 223                                                 w = 4;          // Absolute fixup
 224
 225                                         w |= symbol->senv << 3;
 226                                         *wp++ = w >> 8;
 227                                         *wp = w;
 228                                 }
 229                         }
 230                         else
 231                         {
 232                                 // Deposit section-relative mark; in RELMOD mode, fix it up in
 233                                 // the chunk, kind of like a sleazoid linker.
 234                                 //
 235                                 // In RELMOD mode, marks to words (MWORDs) "cannot happen,"
 236                                 // checks are made when mark() is called, so we don't have to
 237                                 // check again here.
 238                                 w &= TDB;
 239
 240                                 if (okflag)
 241                                         wp[1] = mark_tr[w];
 242                                 else if (prg_flag && (w & (DATA | BSS)))
 243                                 {
 244                                         uint32_t diff = GETBE32(wp, 0);
 245 #ifdef DO_DEBUG
 246                                         DEBUG printf("diff=%lx ==> ", diff);
 247 #endif
 248                                         diff += sect[TEXT].sloc;
 249
 250                                         if (w == BSS)
 251                                                 diff += sect[DATA].sloc;
 252
 253                                         SETBE32(wp, 0, diff)
 254 #ifdef DO_DEBUG
 255                                         DEBUG printf("%lx\n", diff);
 256 #endif
 257                                 }
 258                         }
 259                 }
 260         }
 261
 262         // Generate ".PRG" relocation information in place in the relocation words
 263         // (the "RELMOD" operation).
 264         if (okflag && prg_flag)
 265         {
 266                 int firstp = 1;
 267                 wp = dp = mp;
 268
 269                 for(loc=0; loc<siz;)
 270                 {
 271                         if ((wp[1] & 7) == 5)
 272                         {
 273                                 if (firstp)
 274                                 {
 275                                         SETBE32(dp, 0, loc);
 276                                         dp += 4;
 277                                         firstp = 0;
 278                                 }
 279                                 else
 280                                 {
 281                                         uint32_t diff;
 282
 283                                         for(diff=loc-lastloc; diff>254; diff-=254)
 284                                                 *dp++ = 1;
 285
 286                                         *dp++ = (uint8_t)diff;
 287                                 }
 288
 289                                 lastloc = loc;
 290                                 loc += 4;
 291                                 wp += 4;
 292                         }
 293                         else
 294                         {
 295                                 loc += 2;
 296                                 wp += 2;
 297                         }
 298                 }
 299
 300                 // Terminate relocation list with 0L (if there was no relocation) or
 301                 // 0.B (if relocation information was written).
 302                 if (!firstp)
 303                         *dp++ = 0;
 304                 else
 305                         for(firstp=0; firstp<4; firstp++)
 306                                 *dp++ = 0;
 307
 308                 // Return size of relocation information
 309                 loc = dp - mp;
 310                 return loc;
 311         }
 312
 313         return siz;
 314 }
 315
 316
 317 //
 318 // Make mark image for BSD .o file
 319 //
 320 // Assumptions about mark records (for BSD): if there is a symbol, the mark is
 321 // for an undefined symbol, otherwise it's just a normal TDB relocation.
 322 // N.B.: tsize is only used if reqseg is DATA
 323 //
 324 uint32_t MarkBSDImage(uint8_t * mp, uint32_t siz, uint32_t tsize, int reqseg)
 325 {
 326         uint16_t from = 0;                      // Section fixups are currently FROM
 327         uint32_t rsize = 0;                     // Relocation table size (written to mp)
 328         int validsegment = 0;           // We are not yet in a valid segment...
 329
 330 #ifdef DEBUG_IMAGE_MARKING
 331 printf("MarkBSDImage():\n");
 332 #endif
 333         // Initialize relocation table point (for D_foo macros)
 334         chptr = mp;
 335
 336         // Run through all the relocation mark chunks
 337         for(MCHUNK * mch=firstmch; mch!=NULL; mch=mch->mcnext)
 338         {
 339                 for(PTR p=mch->mcptr;;)
 340                 {
 341                         SYM * symbol = NULL;
 342                         uint16_t w = *p.wp++;   // Next mark entry
 343
 344                         // If we hit the end of a chunk, go get the next one
 345                         if (w & MCHEND)
 346                                 break;
 347
 348                         // Get the rest of the mark record
 349                         uint32_t loc = *p.lp++; // Mark location
 350
 351                         // Maybe change "from" section
 352                         if (w & MCHFROM)
 353                         {
 354                                 from = *p.wp++;
 355
 356                                 if (((reqseg == TEXT) && (from == TEXT))
 357                                         || ((reqseg == DATA) && (from == DATA)))
 358                                         validsegment = 1;
 359                                 else
 360                                         validsegment = 0;
 361                         }
 362
 363                         // Maybe includes a symbol
 364                         if (w & MSYMBOL)
 365                                 symbol = *p.sy++;
 366
 367                         if (!validsegment)
 368                                 continue;
 369
 370 #ifdef DEBUG_IMAGE_MARKING
 371 printf(" validsegment: raddr = $%08X\n", raddr);
 372 #endif
 373                         uint32_t rflag = 0x00000040;    // Absolute relocation
 374
 375                         if (w & MPCREL)
 376                                 rflag = 0x000000A0;                     // PC-relative relocation
 377
 378                         // This flag tells the linker to WORD swap the LONG when doing the
 379                         // relocation.
 380                         if (w & MMOVEI)
 381                                 rflag |= 0x00000001;
 382
 383                         if (symbol != NULL)
 384                         {
 385                                 // Deposit external reference
 386                                 rflag |= 0x00000010;                    // Set external reloc flag bit
 387                                 rflag |= (symbol->senv << 8);   // Put symbol index in flags
 388
 389 #ifdef DEBUG_IMAGE_MARKING
 390 printf("  validsegment(2): rflag = $%08X\n", rflag);
 391 #endif
 392                         }
 393                         else
 394                         {
 395 #ifdef DEBUG_IMAGE_MARKING
 396 printf("  w = $%04X\n", w);
 397 #endif
 398                                 w &= TDB;                               // Set reloc flags to segment
 399
 400                                 switch (w)
 401                                 {
 402                                 case TEXT: rflag |= 0x00000400; break;
 403                                 case DATA: rflag |= 0x00000600; break;
 404                                 case BSS:  rflag |= 0x00000800; break;
 405                                 }
 406
 407 #ifdef DEBUG_IMAGE_MARKING
 408 printf("  validsegment(3): rflag = $%08X\n", rflag);
 409 #endif
 410                                 // Fix relocation by adding in start of TEXT segment, since it's
 411                                 // currently relative to the start of the DATA (or BSS) segment
 412                                 if (w & (DATA | BSS))
 413                                 {
 414                                         uint8_t * dp = objImage + BSDHDRSIZE + loc;
 415
 416                                         // Bump the start of the section if it's DATA (& not TEXT)
 417                                         if (from == DATA)
 418                                                 dp += tsize;
 419
 420                                         uint32_t diff = GETBE32(dp, 0);
 421                                         DEBUG printf("diff=%uX ==> ", diff);
 422 #ifdef DEBUG_IMAGE_MARKING
 423 printf("  validsegment(4): diff = $%08X --> ", diff);
 424 #endif
 425                                         if (rflag & 0x01)
 426                                                 diff = WORDSWAP32(diff);
 427
 428                                         diff += sect[TEXT].sloc;
 429
 430                                         if (w == BSS)
 431                                                 diff += sect[DATA].sloc;
 432
 433                                         if (rflag & 0x01)
 434                                                 diff = WORDSWAP32(diff);
 435
 436                                         SETBE32(dp, 0, diff);
 437                                         DEBUG printf("%uX\n", diff);
 438 #ifdef DEBUG_IMAGE_MARKING
 439 printf("$%08X\n", diff);
 440 #endif
 441                                 }
 442                         }
 443
 444                         D_long(loc);            // Write relocation address
 445                         D_long(rflag);          // Write relocation flags
 446                         rsize += 0x08;          // Increment relocation size
 447                 }
 448         }
 449
 450         // Return relocation table's size
 451 #ifdef DEBUG_IMAGE_MARKING
 452 printf("  rsize = $%X\n", rsize);
 453 #endif
 454         return rsize;
 455 }
 456
 457
 458 //
 459 // Make relocation record for ELF .o file.
 460 // Returns the size of the relocation record.
 461 //
 462 uint32_t CreateELFRelocationRecord(uint8_t * buf, uint8_t * secBuf, uint16_t section)
 463 {
 464         uint16_t from = 0;              // Section fixups are currently FROM
 465         uint32_t rsize = 0;             // Size of the relocation table
 466
 467         // Setup pointer for D_long/word/byte macros
 468         chptr = buf;
 469
 470         for(MCHUNK * mch=firstmch; mch!=NULL; mch=mch->mcnext)
 471         {
 472                 for(register PTR p=mch->mcptr;;)
 473                 {
 474                         register uint16_t w = *p.wp++;  // w = next mark entry
 475
 476                         if (w & MCHEND)         // (end of mark chunk)
 477                                 break;
 478
 479                         // Get mark record
 480                         SYM * symbol = NULL;
 481                         uint16_t symFlags = 0;
 482                         uint32_t r_offset = *p.lp++;    // Mark's location
 483
 484                         if (w & MCHFROM)                // Maybe change "from" section
 485                                 from = *p.wp++;
 486
 487                         if (w & MSYMBOL)                // Maybe includes a symbol
 488                         {
 489                                 symbol = *p.sy++;
 490
 491                                 if (symbol)
 492                                         symFlags = symbol->sattr;
 493                         }
 494
 495                         // Create relocation record for ELF object, if the mark is in the
 496                         // current section.
 497                         if (from & section)
 498                         {
 499                                 uint32_t r_sym = 0;
 500                                 uint32_t r_type = 0;
 501                                 uint32_t r_addend = 0;
 502
 503                                 // Since we're chucking all symbols here for ELF objects by
 504                                 // default (cf. sect.c), we discriminate here (normally, if
 505                                 // there is a symbol in the mark record, it means an undefined
 506                                 // symbol) :-P
 507                                 if (symbol && !(symFlags & DEFINED) && (symFlags & GLOBAL))
 508                                         r_sym = symbol->senv + extraSyms;
 509                                 else if (w & TEXT)
 510                                         r_sym = elfHdrNum[ES_TEXT];     // Mark TEXT segment
 511                                 else if (w & DATA)
 512                                         r_sym = elfHdrNum[ES_DATA];     // Mark DATA segment
 513                                 else if (w & BSS)
 514                                         r_sym = elfHdrNum[ES_BSS];      // Mark BSS segment
 515
 516                                 // Set the relocation type next
 517                                 if (w & MPCREL)
 518                                         r_type = 5;  // R_68K_PC16
 519                                 // N.B.: Since we've established that (from & section) is non-
 520                                 //       zero, this condition will *never* be satisfied... :-P
 521                                 //       It might be better to check the symbol's senv; that is,
 522                                 //       if this is a real problem that needs addressing...
 523                                 else if ((from & section) == 0)
 524                                         // In the case of a section referring to a label in another
 525                                         // section (for example text->data) use a R_68K_PC32 mark.
 526                                         r_type = 4;  // R_68K_PC32
 527                                 else
 528                                         r_type = 1;  // R_68K_32
 529
 530                                 if (symbol != NULL)
 531                                         r_addend = symbol->svalue;    // Mark offset into section
 532                                 else
 533                                         r_addend = GETBE32(secBuf + r_offset, 0);
 534
 535                                 // Deposit the relocation record
 536                                 D_long(r_offset);
 537                                 D_long((r_sym << 8) | r_type);
 538                                 D_long(r_addend);
 539                                 rsize += 0x0C;
 540                         }
 541                 }
 542         }
 543
 544         return rsize;
 545 }
 546