2 // RMAC - Reboot's Macro Assembler for all Atari computers
3 // OBJECT.C - Writing Object Files
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
20 uint32_t symsize = 0; // Size of BSD/ELF symbol table
21 uint32_t strindx = 0x00000004; // BSD/ELF string table index
22 uint8_t * strtable; // Pointer to the symbol string table
23 uint8_t * objImage; // Global object image pointer
24 int elfHdrNum[9] = { 0, 0, 0, 0, 0, 0, 0, 0, 0 };
27 static uint16_t tdb_tab[] = {
29 AL_TEXT, // TEXT segment based
30 AL_DATA, 0, // DATA segment based
31 AL_BSS // BSS segment based
34 uint32_t PRGFLAGS; /* PRGFLAGS as defined in Atari Compendium Chapter 2
35 Definition Bit(s) Meaning
36 --------------- ------- --------------------------------------------------------
37 PF_FASTLOAD 0 If set, clear only the BSS area on program load,
38 otherwise clear the entire heap.
39 PF_TTRAMLOAD 1 If set, the program may be loaded into alternative RAM,
40 otherwise it must be loaded into standard RAM.
41 PF_TTRAMMEM 2 If set, the program's Malloc() requests may be satisfied
42 from alternative RAM, otherwise they must be satisfied
45 See left. 4 & 5 If these bits are set to 0 (PF_PRIVATE), the processes'
46 entire memory space will be considered private
47 (when memory protection is enabled).If these bits are
48 set to 1 (PF_GLOBAL), the processes' entire memory space
49 will be readable and writable by any process (i.e.
50 global). If these bits are set to 2 (PF_SUPERVISOR), the
51 processes' entire memory space will only be readable and
52 writable by itself and any other process in supervisor
53 mode.If these bits are set to 3 (PF_READABLE), the
54 processes' entire memory space will be readable by any
55 application but only writable by itself.
56 - 6-15 Currently unused
61 // Add entry to symbol table (in ALCYON mode)
62 // If 'globflag' is 1, make the symbol global
63 // If in .PRG mode, adjust symbol values for fake link
65 uint8_t * AddSymEntry(register uint8_t * buf, SYM * sym, int globflag)
67 // Copy symbol name to buffer (first 8 chars or less)
68 register uint8_t * s = sym->sname;
71 for(i=0; i<8 && *s; i++)
78 // Construct and deposit flag word
80 // o all symbols are AL_DEFINED
81 // o install T/D/B/A base
82 // o install 'equated'
83 // o commons (COMMON) are AL_EXTERN, but not BSS
84 // o exports (DEFINED) are AL_GLOBAL
85 // o imports (~DEFINED) are AL_EXTERN
87 register uint16_t w1 = sym->sattr;
88 register uint16_t w = AL_DEFINED | tdb_tab[w1 & TDB];
90 if (w1 & EQUATED) // Equated
95 w |= AL_EXTERN | AL_GLOBAL; // Common symbol
96 w &= ~AL_BSS; // They're not BSS in Alcyon object files
98 else if (w1 & DEFINED)
100 if (globflag) // Export the symbol
104 w |= AL_EXTERN; // Imported symbol
108 register uint32_t z = sym->svalue;
110 if (prg_flag) // Relocate value in .PRG segment
115 z += sect[TEXT].sloc;
118 z += sect[DATA].sloc;
121 SETBE32(buf, 0, z); // Deposit symbol value
129 // Add an entry to the BSD symbol table
131 uint8_t * AddBSDSymEntry(uint8_t * buf, SYM * sym, int globflag)
133 chptr = buf; // Point to buffer for depositing longs
134 D_long(strindx); // Deposit the symbol string index
136 uint16_t w1 = sym->sattr; // Obtain symbol attributes
137 uint32_t z = 0; // Initialize resulting symbol flags
141 z = 0x02000000; // Set equated flag
147 case TEXT: z = 0x04000000; break; // Set TEXT segment flag
148 case DATA: z = 0x06000000; break; // Set DATA segment flag
149 case BSS : z = 0x08000000; break; // Set BSS segment flag
154 z |= 0x01000000; // Set global flag if requested
156 D_long(z); // Deposit symbol attribute
157 z = sym->svalue; // Obtain symbol value
159 if (w1 & (DATA | BSS))
160 z += sect[TEXT].sloc; // If DATA or BSS add TEXT segment size
163 z += sect[DATA].sloc; // If BSS add DATA segment size
165 D_long(z); // Deposit symbol value
166 strcpy(strtable + strindx, sym->sname);
167 strindx += strlen(sym->sname) + 1; // Incr string index incl null terminate
168 buf += 12; // Increment buffer to next record
169 symsize += 12; // Increment symbol table size
176 // Add entry to ELF symbol table; if `globflag' is 1, make the symbol global
178 uint8_t * AddELFSymEntry(uint8_t * buf, SYM * sym, int globflag)
181 D_long(strindx); // st_name
182 D_long(sym->svalue); // st_value
183 D_long(0); // st_size
186 register WORD w1 = sym->sattr;
190 //w |= AL_EXTERN | AL_GLOBAL; // common symbol
191 //w &= ~AL_BSS; // they're not BSS in Alcyon object files
193 else if (w1 & DEFINED)
195 if (globflag) // Export the symbol
196 st_info |= 16; //STB_GLOBAL (1<<4)
198 else if (w1 & (GLOBAL | REFERENCED))
202 D_byte(0); // st_other
204 uint16_t st_shndx = 0xFFF1; // Assume absolute (equated) number
207 st_shndx = elfHdrNum[ES_TEXT];
209 st_shndx = elfHdrNum[ES_DATA];
211 st_shndx = elfHdrNum[ES_BSS];
213 st_shndx = 0; // Global, not absolute
217 strcpy(strtable + strindx, sym->sname);
218 strindx += strlen(sym->sname) + 1; // Incr string index incl null terminate
219 symsize += 0x10; // Increment symbol table size
226 // Helper function for ELF output
228 int DepositELFSectionHeader(uint8_t * ptr, uint32_t name, uint32_t type, uint32_t flags, uint32_t addr, uint32_t offset, uint32_t size, uint32_t link, uint32_t info, uint32_t addralign, uint32_t entsize)
246 // Deposit an entry in the Section Header string table
248 uint32_t DepositELFSHSTEntry(uint8_t ** pTable, const uint8_t * s)
251 printf("DepositELFSHSTEntry: s = \"%s\"\n", s);
253 uint32_t strSize = strlen(s);
255 *pTable += strSize + 1;
261 // Deposit a symbol table entry in the ELF Symbol Table
263 uint32_t DepositELFSymbol(uint8_t * ptr, uint32_t name, uint32_t addr, uint32_t size, uint8_t info, uint8_t other, uint16_t shndx)
277 // Write an object file to the passed in file descriptor
278 // N.B.: Return value is ignored...
280 int WriteObject(int fd)
282 LONG t; // Scratch long
283 LONG tds; // TEXT & DATA segment size
284 int i; // Temporary int
285 CHUNK * cp; // Chunk (for gather)
286 uint8_t * buf; // Scratch area
287 uint8_t * p; // Temporary ptr
288 LONG ssize; // Size of symbols
289 LONG trsize, drsize; // Size of relocations
290 long unused; // For supressing 'write' warnings
294 printf("TEXT segment: %d bytes\n", sect[TEXT].sloc);
295 printf("DATA segment: %d bytes\n", sect[DATA].sloc);
296 printf("BSS segment: %d bytes\n", sect[BSS].sloc);
299 // Write requested object file...
300 if ((obj_format == BSD) || ((obj_format == ALCYON) && (prg_flag == 0)))
302 // Force BSD format (if it was ALCYON format)
307 printf("Total : %d bytes\n", sect[TEXT].sloc + sect[DATA].sloc + sect[BSS].sloc);
310 ssize = sy_assign(NULL, NULL); // Assign index numbers to the symbols
311 tds = sect[TEXT].sloc + sect[DATA].sloc; // Get size of TEXT and DATA segment
312 buf = malloc(0x600000); // Allocate 6mb object file image memory
316 error("cannot allocate object file memory (in BSD mode)");
320 memset(buf, 0, 0x600000); // Clear allocated memory
321 objImage = buf; // Set global object image pointer
322 strtable = malloc(0x200000); // Allocate 2MB string table buffer
324 if (strtable == NULL)
326 error("cannot allocate string table memory (in BSD mode)");
330 memset(strtable, 0, 0x200000); // Clear allocated memory
332 // Build object file header
333 chptr = buf; // Base of header (for D_foo macros)
334 D_long(0x00000107); // Magic number
335 D_long(sect[TEXT].sloc); // TEXT size
336 D_long(sect[DATA].sloc); // DATA size
337 D_long(sect[BSS].sloc); // BSS size
338 D_long(0x00000000); // Symbol size
339 D_long(0x00000000); // First entry (0L)
340 D_long(0x00000000); // TEXT relocation size
341 D_long(0x00000000); // DATA relocation size
343 // Construct TEXT and DATA segments (without relocation changes)
344 p = buf + BSDHDRSIZE;
346 for(i=TEXT; i<=DATA; i++)
348 for(cp=sect[i].sfcode; cp!=NULL; cp=cp->chnext)
350 memcpy(p, cp->chptr, cp->ch_size);
355 // Do relocation tables (and make changes to segment data)
356 p = buf + BSDHDRSIZE + tds; // Move obj image ptr to reloc info
357 trsize = MarkBSDImage(p, tds, sect[TEXT].sloc, TEXT);// Do TEXT relocation table
358 chptr = buf + 0x18; // Point to relocation hdr entry
359 D_long(trsize); // Write the relocation table size
361 // Move obj image ptr to reloc info
362 p = buf + BSDHDRSIZE + tds + trsize;
363 drsize = MarkBSDImage(p, tds, sect[TEXT].sloc, DATA);// Do DATA relocation table
364 chptr = buf + 0x1C; // Point to relocation hdr entry
365 D_long(drsize); // Write the relocation table size
367 // Point to start of symbol table
368 p = buf + BSDHDRSIZE + tds + trsize + drsize;
369 sy_assign(p, AddBSDSymEntry); // Build symbol and string tables
370 chptr = buf + 0x10; // Point to sym table size hdr entry
371 D_long(symsize); // Write the symbol table size
373 // Point to string table
374 p = buf + BSDHDRSIZE + tds + trsize + drsize + symsize;
375 memcpy(p, strtable, strindx); // Copy string table to object image
376 chptr = p; // Point to string table size long
377 D_long(strindx); // Write string table size
379 // Write the BSD object file from the object image buffer
380 unused = write(fd, buf, BSDHDRSIZE + tds + trsize + drsize + symsize + strindx + 4);
384 printf("TextRel size: %d bytes\n", trsize);
385 printf("DataRel size: %d bytes\n", drsize);
390 free(strtable); // Free allocated memory
391 free(buf); // Free allocated memory
394 else if (obj_format == ALCYON)
400 printf("TOS header : 28 bytes\n");
401 printf("Total : %d bytes\n", 28 + sect[TEXT].sloc + sect[DATA].sloc + sect[BSS].sloc);
405 printf("Total : %d bytes\n", sect[TEXT].sloc + sect[DATA].sloc + sect[BSS].sloc);
409 // Compute size of symbol table; assign numbers to the symbols...
412 // As we grabbed BSD *and* Alcyon in prg_flag == 0 mode, this is *always*
415 ssize = sy_assign(NULL, NULL) * 14;
417 // Alloc memory for header + text + data, symbol and relocation
418 // information construction.
419 t = tds = sect[TEXT].sloc + sect[DATA].sloc;
424 // Is there any reason to do this this way???
425 buf = malloc(t + HDRSIZE);
428 // Build object file header just before the text+data image
429 chptr = buf - HDRSIZE; // -> base of header
430 D_word(0x601A); // 00 - magic number
431 D_long(sect[TEXT].sloc); // 02 - TEXT size
432 D_long(sect[DATA].sloc); // 06 - DATA size
433 D_long(sect[BSS].sloc); // 0A - BSS size
434 D_long(ssize); // 0E - symbol table size
435 D_long(0); // 12 - stack size (unused)
436 D_long(PRGFLAGS); // 16 - PRGFLAGS
437 D_word(0); // 1A - relocation information exists
439 // Construct text and data segments; fixup relocatable longs in .PRG
440 // mode; finally write the header + text + data
443 for(i=TEXT; i<=DATA; i++)
445 for(cp=sect[i].sfcode; cp!=NULL; cp=cp->chnext)
447 memcpy(p, cp->chptr, cp->ch_size);
452 // Do a first pass on the Alcyon image, if in PRG mode
454 MarkImage(buf, tds, sect[TEXT].sloc, 0);
456 unused = write(fd, buf - HDRSIZE, tds + HDRSIZE);
458 // Construct and write symbol table
461 sy_assign(buf, AddSymEntry);
462 unused = write(fd, buf, ssize);
465 // Construct and write relocation information; the size of it changes if
466 // we're writing a RELMODed executable.
467 tds = MarkImage(buf, tds, sect[TEXT].sloc, 1);
468 unused = write(fd, buf, tds);
470 else if (obj_format == ELF)
472 // Allocate 6MB object file image memory
473 buf = malloc(0x600000);
477 error("cannot allocate object file memory (in BSD mode)");
481 memset(buf, 0, 0x600000);
482 objImage = buf; // Set global object image pointer
483 strtable = malloc(0x200000); // Allocate 2MB string table buffer
485 if (strtable == NULL)
487 error("cannot allocate string table memory (in BSD mode)");
491 memset(strtable, 0, 0x200000);
493 // This is pretty much a first pass at this shite, so there's room for
495 uint8_t headers[4 * 10 * 10]; // (DWORD * 10) = 1 hdr, 10 entries
497 uint8_t shstrtab[128]; // The section header string table proper
498 uint32_t shstTab[9]; // Index into shstrtab for strings
499 uint8_t * shstPtr = shstrtab; // Temp pointer
500 uint32_t shstSize = 0;
501 int numEntries = 4; // There are always at *least* 4 sections
502 int shstIndex = 1; // The section where the shstrtab lives
503 int elfSize = 0; // Size of the ELF object
504 // Clear the header numbers
505 memset(elfHdrNum, 0, 9 * sizeof(int));
508 // First step is to see what sections need to be made; we also
509 // construct the section header string table here at the same time.
511 shstTab[ES_NULL] = shstSize;
512 shstSize += DepositELFSHSTEntry(&shstPtr, "");
513 shstTab[ES_SHSTRTAB] = shstSize;
514 shstSize += DepositELFSHSTEntry(&shstPtr, ".shstrtab");
515 shstTab[ES_SYMTAB] = shstSize;
516 shstSize += DepositELFSHSTEntry(&shstPtr, ".symtab");
517 shstTab[ES_STRTAB] = shstSize;
518 shstSize += DepositELFSHSTEntry(&shstPtr, ".strtab");
520 if (sect[TEXT].sloc > 0)
522 elfHdrNum[ES_TEXT] = shstIndex;
523 shstTab[ES_TEXT] = shstSize;
524 shstSize += DepositELFSHSTEntry(&shstPtr, ".text");
529 if (sect[DATA].sloc > 0)
531 elfHdrNum[ES_DATA] = shstIndex;
532 shstTab[ES_DATA] = shstSize;
533 shstSize += DepositELFSHSTEntry(&shstPtr, ".data");
538 if (sect[BSS].sloc > 0)
540 elfHdrNum[ES_BSS] = shstIndex;
541 shstTab[ES_BSS] = shstSize;
542 shstSize += DepositELFSHSTEntry(&shstPtr, ".bss");
547 if (sect[TEXT].relocs > 0)
549 elfHdrNum[ES_RELATEXT] = shstIndex;
550 shstTab[ES_RELATEXT] = shstSize;
551 shstSize += DepositELFSHSTEntry(&shstPtr, ".relaTEXT");
556 if (sect[DATA].relocs > 0)
558 elfHdrNum[ES_RELADATA] = shstIndex;
559 shstTab[ES_RELADATA] = shstSize;
560 shstSize += DepositELFSHSTEntry(&shstPtr, ".relaDATA");
565 elfHdrNum[ES_SHSTRTAB] = shstIndex + 0;
566 elfHdrNum[ES_SYMTAB] = shstIndex + 1;
567 elfHdrNum[ES_STRTAB] = shstIndex + 2;
570 printf("ELF shstrtab size: %i bytes. Entries:\n", shstSize);
571 for(int j=0; j<i; j++)
572 printf("\"%s\"\n", shstrtab + shstTab[j]);
575 // Construct ELF header
576 // If you want to make any sense out of this you'd better take a look
577 // at Executable and Linkable Format on Wikipedia.
579 D_long(0x7F454C46); // 00 - "<7F>ELF" Magic Number
580 D_byte(0x01); // 04 - 32 vs 64 (1 = 32, 2 = 64)
581 D_byte(0x02); // 05 - Endianness (1 = LE, 2 = BE)
582 D_byte(0x01); // 06 - Original version of ELF (set to 1)
583 D_byte(0x00); // 07 - Target OS ABI (0 = System V)
584 D_byte(0x00); // 08 - ABI Extra (unneeded)
585 D_byte(0x00); // 09 - Pad bytes
588 D_word(0x01); // 10 - ELF Type (1 = relocatable)
589 D_word(0x04); // 12 - Architecture (EM_68K = 4, Motorola M68K family)
590 D_long(0x01); // 14 - Version (1 = original ELF)
591 D_long(0x00); // 18 - Entry point virtual address (unneeded)
592 D_long(0x00); // 1C - Program header table offset (unneeded)
593 D_long(0x00); // 20 - Section header table offset (to be determined)
597 // Specifically for 68000 CPU
598 D_long(0x01000000) // 24 - Processor-specific flags - EF_M68K_M68000
602 // CPUs other than 68000 (68020...)
603 D_long(0); // 24 - Processor-specific flags (ISA dependent)
606 D_word(0x0034); // 28 - ELF header size in bytes
607 D_word(0); // 2A - Program header table entry size
608 D_word(0); // 2C - Program header table entry count
609 D_word(0x0028); // 2E - Section header entry size - 40 bytes for ELF32
610 D_word(numEntries); // 30 - Section header table entry count
611 D_word(shstIndex); // 32 - Section header string table index
615 // Deposit section header 0 (NULL)
616 headerSize += DepositELFSectionHeader(headers + headerSize, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0);
618 int textLoc = elfSize;
620 // Construct TEXT section, if any
621 if (sect[TEXT].sloc > 0)
623 headerSize += DepositELFSectionHeader(headers + headerSize, shstTab[ES_TEXT], 1, 6, 0, elfSize, sect[TEXT].sloc, 0, 0, largestAlign[0], 0);
625 for(CHUNK * cp=sect[TEXT].sfcode; cp!=NULL; cp=cp->chnext)
627 memcpy(buf + elfSize, cp->chptr, cp->ch_size);
628 elfSize += cp->ch_size;
631 // Pad for next section (LONG boundary)
632 elfSize = (elfSize + 3) & ~3;
635 int dataLoc = elfSize;
637 // Construct DATA section, if any
638 if (sect[DATA].sloc > 0)
640 headerSize += DepositELFSectionHeader(headers + headerSize, shstTab[ES_DATA], 1, 3, 0, elfSize, sect[DATA].sloc, 0, 0, largestAlign[1], 0);
642 for(CHUNK * cp=sect[DATA].sfcode; cp!=NULL; cp=cp->chnext)
644 memcpy(buf + elfSize, cp->chptr, cp->ch_size);
645 elfSize += cp->ch_size;
648 // Pad for next section (LONG boundary)
649 elfSize = (elfSize + 3) & ~3;
652 // Construct BSS section, if any
653 if (sect[BSS].sloc > 0)
655 headerSize += DepositELFSectionHeader(headers + headerSize, shstTab[ES_BSS], 8, 3, 0, elfSize, sect[BSS].sloc, 0, 0, largestAlign[2], 0);
658 int textrelLoc = headerSize;
660 // Add headers for relocated sections, if any...
661 if (sect[TEXT].relocs > 0)
662 headerSize += DepositELFSectionHeader(headers + headerSize, shstTab[ES_RELATEXT], 4, 0x00, 0, 0, 0, elfHdrNum[ES_SYMTAB], elfHdrNum[ES_TEXT], 4, 0x0C);
664 int datarelLoc = headerSize;
666 if (sect[DATA].relocs > 0)
667 headerSize += DepositELFSectionHeader(headers + headerSize, shstTab[ES_RELADATA], 4, 0x40, 0, 0, 0, elfHdrNum[ES_SYMTAB], elfHdrNum[ES_DATA], 4, 0x0C);
670 headerSize += DepositELFSectionHeader(headers + headerSize, shstTab[ES_SHSTRTAB], 3, 0, 0, elfSize, shstSize, 0, 0, 1, 0);
671 memcpy(buf + elfSize, shstrtab, shstSize);
673 // Pad for next section (LONG boundary)
674 elfSize = (elfSize + 3) & ~3;
676 // Add section headers
677 int headerLoc = elfSize;
678 chptr = buf + 0x20; // Set section header offset in ELF header
680 elfSize += (4 * 10) * numEntries;
682 // Add symbol table & string table
683 int symtabLoc = elfSize;
684 strindx = 0; // Make sure we start at the beginning...
685 elfSize += DepositELFSymbol(buf + elfSize, 0, 0, 0, 0, 0, 0);
690 if (sect[TEXT].sloc > 0)
692 elfSize += DepositELFSymbol(buf + elfSize, 0, 0, 0, 3, 0, elfHdrNum[ES_TEXT]);
696 if (sect[DATA].sloc > 0)
698 elfSize += DepositELFSymbol(buf + elfSize, 0, 0, 0, 3, 0, elfHdrNum[ES_DATA]);
702 if (sect[BSS].sloc > 0)
704 elfSize += DepositELFSymbol(buf + elfSize, 0, 0, 0, 3, 0, elfHdrNum[ES_BSS]);
708 int numSymbols = sy_assign_ELF(buf + elfSize, AddELFSymEntry);
709 elfSize += numSymbols * 0x10;
712 int strtabLoc = elfSize;
713 memcpy(buf + elfSize, strtable, strindx);
715 // Pad for next section (LONG boundary)
716 elfSize = (elfSize + 3) & ~3;
718 headerSize += DepositELFSectionHeader(headers + headerSize, shstTab[ES_SYMTAB], 2, 0, 0, symtabLoc, (numSymbols + extraSyms) * 0x10, shstIndex + 2, firstglobal + extraSyms, 4, 0x10);
719 headerSize += DepositELFSectionHeader(headers + headerSize, shstTab[ES_STRTAB], 3, 0, 0, strtabLoc, strindx, 0, 0, 1, 0);
721 // Add relocation tables, if any (no need to align after these, they're
722 // already on DWORD boundaries)
723 if (sect[TEXT].relocs > 0)
725 uint32_t textrelSize = CreateELFRelocationRecord(buf + elfSize, buf + textLoc, TEXT);
726 // Deposit offset & size, now that we know them
727 chptr = headers + textrelLoc + 0x10;
730 elfSize += textrelSize;
733 if (sect[DATA].relocs > 0)
735 uint32_t datarelSize = CreateELFRelocationRecord(buf + elfSize, buf + dataLoc, DATA);
736 // Deposit offset & size, now that we know them
737 chptr = headers + datarelLoc + 0x10;
740 elfSize += datarelSize;
743 // Copy headers into the object
744 memcpy(buf + headerLoc, headers, headerSize);
746 // Finally, write out the object
747 unused = write(fd, buf, elfSize);
749 // Free allocated memory
756 else if (obj_format == XEX)
758 // Just write the object file