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

   1 //
   2 // RMAC - Reboot's Macro Assembler for all Atari computers
   3 // MARK.C - A record of things that are defined relative to any of the sections
   4 // Copyright (C) 199x Landon Dyer, 2011-2017 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 (symbol != NULL)
  99                         error("illegal external reference (in .PRG mode) to '%s'",
 100                                 symbol->sname);
 101         }
 102
 103         // Dump crap into the mark
 104         *markptr.wp++ = flags;
 105         *markptr.lp++ = loc;
 106         mcused += sizeof(uint16_t) + sizeof(uint32_t);
 107
 108         if (flags & MCHFROM)
 109         {
 110                 curfrom = section;
 111                 *markptr.wp++ = section;
 112                 mcused += sizeof(uint16_t);
 113         }
 114
 115         if (flags & MSYMBOL)
 116         {
 117                 *markptr.sy++ = symbol;
 118                 mcused += sizeof(SYM *);
 119         }
 120
 121         // Increment # of relocs in this section
 122         sect[section].relocs++;
 123
 124         // Not sure what this is about (making sure the next mark is clear until
 125         // it's marked as the end--I think)...
 126         *markptr.wp = 0x0000;
 127
 128         return 0;
 129 }
 130
 131
 132 //
 133 // Allocate another chunk of mark space
 134 //
 135 uint32_t AllocateMark(void)
 136 {
 137         // Alloc mark block header (and data) and set it up.
 138         MCHUNK * p = malloc(sizeof(MCHUNK) + MARK_ALLOC_INCR);
 139         p->mcnext = NULL;
 140         p->mcalloc = MARK_ALLOC_INCR;
 141         p->mcptr.cp = (uint8_t *)p + sizeof(MCHUNK);
 142         p->mcused = 0;
 143
 144         if (firstmch == NULL)
 145                 firstmch = p;
 146
 147         if (curmch)
 148         {
 149                 // Link onto previous chunk
 150                 *markptr.wp++ = MCHEND;         // Mark end of block
 151                 curmch->mcused = mcused;
 152                 curmch->mcnext = p;
 153         }
 154
 155         // Setup global vars
 156         curmch = p;
 157         markptr = p->mcptr;
 158         mcalloc = MARK_ALLOC_INCR;
 159         mcused = 0;
 160
 161         return 0;
 162 }
 163
 164
 165 //
 166 // Make mark image for Alcyon .o file
 167 // okflag: 1, ok to deposit reloc information
 168 //
 169 uint32_t MarkImage(register uint8_t * mp, uint32_t siz, uint32_t tsize, int okflag)
 170 {
 171         uint16_t from = 0;              // Section fixups are currently FROM
 172         uint32_t loc;                   // Location (temp)
 173         uint32_t lastloc;               // Last location fixed up (RELMOD)
 174         uint8_t * wp;                   // Pointer into raw relocation information
 175         register uint8_t * dp;  // Deposit point for RELMOD information
 176
 177         if (okflag)
 178                 memset(mp, 0, siz);             // zero relocation buffer
 179
 180         for(MCHUNK * mch=firstmch; mch!=NULL; mch=mch->mcnext)
 181         {
 182                 for(PTR p=mch->mcptr;;)
 183                 {
 184                         uint16_t w = *p.wp++;// w = next mark entry
 185
 186                         if (w & MCHEND)         // (end of mark chunk)
 187                                 break;
 188
 189                         // Get mark record
 190                         SYM * symbol = NULL;
 191                         loc = *p.lp++;          // mark location
 192
 193                         if (w & MCHFROM)        // maybe change "from" section
 194                                 from = *p.wp++;
 195
 196                         if (w & MSYMBOL)        // maybe includes a symbol
 197                                 symbol = *p.sy++;
 198
 199                         // Compute mark position in relocation information; in RELMOD mode,
 200                         // get address of data to fix up.
 201                         if (from == DATA)
 202                                 loc += tsize;
 203
 204                         wp = (uint8_t *)(mp + loc);
 205
 206                         if (okflag && (w & MLONG)) // indicate first word of long
 207                         {
 208                                 wp[1] = 5;
 209                                 wp += 2;
 210                         }
 211
 212                         if (symbol)
 213                         {
 214                                 // Deposit external reference
 215                                 if (okflag)
 216                                 {
 217                                         if (w & MPCREL)
 218                                                 w = 6;          // PC-relative fixup
 219                                         else
 220                                                 w = 4;          // Absolute fixup
 221
 222                                         w |= symbol->senv << 3;
 223                                         *wp++ = w >> 8;
 224                                         *wp = w;
 225                                 }
 226                         }
 227                         else
 228                         {
 229                                 // Deposit section-relative mark; in RELMOD mode, fix it up in
 230                                 // the chunk, kind of like a sleazoid linker.
 231                                 //
 232                                 // In RELMOD mode, marks to words (MWORDs) "cannot happen,"
 233                                 // checks are made when mark() is called, so we don't have to
 234                                 // check again here.
 235                                 w &= TDB;
 236
 237                                 if (okflag)
 238                                         wp[1] = mark_tr[w];
 239                                 else if (prg_flag && (w & (DATA | BSS)))
 240                                 {
 241                                         uint32_t diff = GETBE32(wp, 0);
 242 #ifdef DO_DEBUG
 243                                         DEBUG printf("diff=%lx ==> ", diff);
 244 #endif
 245                                         diff += sect[TEXT].sloc;
 246
 247                                         if (w == BSS)
 248                                                 diff += sect[DATA].sloc;
 249
 250                                         SETBE32(wp, 0, diff)
 251 #ifdef DO_DEBUG
 252                                         DEBUG printf("%lx\n", diff);
 253 #endif
 254                                 }
 255                         }
 256                 }
 257         }
 258
 259         // Generate ".PRG" relocation information in place in the relocation words
 260         // (the "RELMOD" operation).
 261         if (okflag && prg_flag)
 262         {
 263                 int firstp = 1;
 264                 wp = dp = mp;
 265
 266                 for(loc=0; loc<siz;)
 267                 {
 268                         if ((wp[1] & 7) == 5)
 269                         {
 270                                 if (firstp)
 271                                 {
 272                                         SETBE32(dp, 0, loc);
 273                                         dp += 4;
 274                                         firstp = 0;
 275                                 }
 276                                 else
 277                                 {
 278                                         uint32_t diff;
 279
 280                                         for(diff=loc-lastloc; diff>254; diff-=254)
 281                                                 *dp++ = 1;
 282
 283                                         *dp++ = (uint8_t)diff;
 284                                 }
 285
 286                                 lastloc = loc;
 287                                 loc += 4;
 288                                 wp += 4;
 289                         }
 290                         else
 291                         {
 292                                 loc += 2;
 293                                 wp += 2;
 294                         }
 295                 }
 296
 297                 // Terminate relocation list with 0L (if there was no relocation) or
 298                 // 0.B (if relocation information was written).
 299                 if (!firstp)
 300                         *dp++ = 0;
 301                 else
 302                         for(firstp=0; firstp<4; firstp++)
 303                                 *dp++ = 0;
 304
 305                 // Return size of relocation information
 306                 loc = dp - mp;
 307                 return loc;
 308         }
 309
 310         return siz;
 311 }
 312
 313
 314 //
 315 // Make mark image for BSD .o file
 316 //
 317 // Assumptions about mark records (for BSD): if there is a symbol, the mark is
 318 // for an undefined symbol, otherwise it's just a normal TDB relocation.
 319 // N.B.: tsize is only used if reqseg is DATA
 320 //
 321 uint32_t MarkBSDImage(uint8_t * mp, uint32_t siz, uint32_t tsize, int reqseg)
 322 {
 323         uint16_t from = 0;                      // Section fixups are currently FROM
 324         uint32_t rsize = 0;                     // Relocation table size (written to mp)
 325         int validsegment = 0;           // We are not yet in a valid segment...
 326
 327 #ifdef DEBUG_IMAGE_MARKING
 328 printf("MarkBSDImage():\n");
 329 #endif
 330         // Initialize relocation table point (for D_foo macros)
 331         chptr = mp;
 332
 333         // Run through all the relocation mark chunks
 334         for(MCHUNK * mch=firstmch; mch!=NULL; mch=mch->mcnext)
 335         {
 336                 for(PTR p=mch->mcptr;;)
 337                 {
 338                         SYM * symbol = NULL;
 339                         uint16_t w = *p.wp++;   // Next mark entry
 340
 341                         // If we hit the end of a chunk, go get the next one
 342                         if (w & MCHEND)
 343                                 break;
 344
 345                         // Get the rest of the mark record
 346                         uint32_t loc = *p.lp++; // Mark location
 347
 348                         // Maybe change "from" section
 349                         if (w & MCHFROM)
 350                         {
 351                                 from = *p.wp++;
 352
 353                                 if (((reqseg == TEXT) && (from == TEXT))
 354                                         || ((reqseg == DATA) && (from == DATA)))
 355                                         validsegment = 1;
 356                                 else
 357                                         validsegment = 0;
 358                         }
 359
 360                         // Maybe includes a symbol
 361                         if (w & MSYMBOL)
 362                                 symbol = *p.sy++;
 363
 364                         if (!validsegment)
 365                                 continue;
 366
 367 #ifdef DEBUG_IMAGE_MARKING
 368 printf(" validsegment: raddr = $%08X\n", loc);
 369 #endif
 370                         uint32_t rflag = 0x00000040;    // Absolute relocation
 371
 372                         if (w & MPCREL)
 373                                 rflag = 0x000000A0;                     // PC-relative relocation
 374
 375                         // This flag tells the linker to WORD swap the LONG when doing the
 376                         // relocation.
 377                         if (w & MMOVEI)
 378                                 rflag |= 0x00000001;
 379
 380                         if (symbol != NULL)
 381                         {
 382                                 // Deposit external reference
 383                                 rflag |= 0x00000010;                    // Set external reloc flag bit
 384                                 rflag |= (symbol->senv << 8);   // Put symbol index in flags
 385
 386 #ifdef DEBUG_IMAGE_MARKING
 387 printf("  validsegment(2): rflag = $%08X\n", rflag);
 388 #endif
 389                         }
 390                         else
 391                         {
 392 #ifdef DEBUG_IMAGE_MARKING
 393 printf("  w = $%04X\n", w);
 394 #endif
 395                                 w &= TDB;                               // Set reloc flags to segment
 396
 397                                 switch (w)
 398                                 {
 399                                 case TEXT: rflag |= 0x00000400; break;
 400                                 case DATA: rflag |= 0x00000600; break;
 401                                 case BSS:  rflag |= 0x00000800; break;
 402                                 }
 403
 404 #ifdef DEBUG_IMAGE_MARKING
 405 printf("  validsegment(3): rflag = $%08X\n", rflag);
 406 #endif
 407                                 // Fix relocation by adding in start of TEXT segment, since it's
 408                                 // currently relative to the start of the DATA (or BSS) segment
 409                                 if (w & (DATA | BSS))
 410                                 {
 411                                         uint8_t * dp = objImage + BSDHDRSIZE + loc;
 412
 413                                         // Bump the start of the section if it's DATA (& not TEXT)
 414                                         if (from == DATA)
 415                                                 dp += tsize;
 416
 417                                         uint32_t diff = GETBE32(dp, 0);
 418                                         DEBUG printf("diff=%uX ==> ", diff);
 419 #ifdef DEBUG_IMAGE_MARKING
 420 printf("  validsegment(4): diff = $%08X --> ", diff);
 421 #endif
 422                                         if (rflag & 0x01)
 423                                                 diff = WORDSWAP32(diff);
 424
 425                                         diff += sect[TEXT].sloc;
 426
 427                                         if (w == BSS)
 428                                                 diff += sect[DATA].sloc;
 429
 430                                         if (rflag & 0x01)
 431                                                 diff = WORDSWAP32(diff);
 432
 433                                         SETBE32(dp, 0, diff);
 434                                         DEBUG printf("%uX\n", diff);
 435 #ifdef DEBUG_IMAGE_MARKING
 436 printf("$%08X\n", diff);
 437 #endif
 438                                 }
 439                         }
 440
 441                         D_long(loc);            // Write relocation address
 442                         D_long(rflag);          // Write relocation flags
 443                         rsize += 0x08;          // Increment relocation size
 444                 }
 445         }
 446
 447         // Return relocation table's size
 448 #ifdef DEBUG_IMAGE_MARKING
 449 printf("  rsize = $%X\n", rsize);
 450 #endif
 451         return rsize;
 452 }
 453
 454
 455 //
 456 // Make relocation record for ELF .o file.
 457 // Returns the size of the relocation record.
 458 //
 459 uint32_t CreateELFRelocationRecord(uint8_t * buf, uint8_t * secBuf, uint16_t section)
 460 {
 461         uint16_t from = 0;              // Section fixups are currently FROM
 462         uint32_t rsize = 0;             // Size of the relocation table
 463
 464         // Setup pointer for D_long/word/byte macros
 465         chptr = buf;
 466
 467         for(MCHUNK * mch=firstmch; mch!=NULL; mch=mch->mcnext)
 468         {
 469                 for(register PTR p=mch->mcptr;;)
 470                 {
 471                         register uint16_t w = *p.wp++;  // w = next mark entry
 472
 473                         if (w & MCHEND)         // (end of mark chunk)
 474                                 break;
 475
 476                         // Get mark record
 477                         SYM * symbol = NULL;
 478                         uint16_t symFlags = 0;
 479                         uint32_t r_offset = *p.lp++;    // Mark's location
 480
 481                         if (w & MCHFROM)                // Maybe change "from" section
 482                                 from = *p.wp++;
 483
 484                         if (w & MSYMBOL)                // Maybe includes a symbol
 485                         {
 486                                 symbol = *p.sy++;
 487
 488                                 if (symbol)
 489                                         symFlags = symbol->sattr;
 490                         }
 491
 492                         // Create relocation record for ELF object, if the mark is in the
 493                         // current section.
 494                         if (from & section)
 495                         {
 496                                 uint32_t r_sym = 0;
 497                                 uint32_t r_type = 0;
 498                                 uint32_t r_addend = 0;
 499
 500                                 // Since we're chucking all symbols here for ELF objects by
 501                                 // default (cf. sect.c), we discriminate here (normally, if
 502                                 // there is a symbol in the mark record, it means an undefined
 503                                 // symbol) :-P
 504                                 if (symbol && !(symFlags & DEFINED) && (symFlags & GLOBAL))
 505                                         r_sym = symbol->senv + extraSyms;
 506                                 else if (w & TEXT)
 507                                         r_sym = elfHdrNum[ES_TEXT];     // Mark TEXT segment
 508                                 else if (w & DATA)
 509                                         r_sym = elfHdrNum[ES_DATA];     // Mark DATA segment
 510                                 else if (w & BSS)
 511                                         r_sym = elfHdrNum[ES_BSS];      // Mark BSS segment
 512
 513                                 // Set the relocation type next
 514                                 if (w & MPCREL)
 515                                         r_type = 5;  // R_68K_PC16
 516                                 // N.B.: Since we've established that (from & section) is non-
 517                                 //       zero, this condition will *never* be satisfied... :-P
 518                                 //       It might be better to check the symbol's senv; that is,
 519                                 //       if this is a real problem that needs addressing...
 520                                 else if ((from & section) == 0)
 521                                         // In the case of a section referring to a label in another
 522                                         // section (for example text->data) use a R_68K_PC32 mark.
 523                                         r_type = 4;  // R_68K_PC32
 524                                 else
 525                                         r_type = 1;  // R_68K_32
 526
 527                                 r_addend = GETBE32(secBuf + r_offset, 0);
 528
 529                                 // Deposit the relocation record
 530                                 D_long(r_offset);
 531                                 D_long((r_sym << 8) | r_type);
 532                                 D_long(r_addend);
 533                                 rsize += 0x0C;
 534                         }
 535                 }
 536         }
 537
 538         return rsize;
 539 }
 540