2 // RMAC - Reboot's Macro Assembler for all Atari computers
3 // SECT.C - Code Generation, Fixups and Section Management
4 // Copyright (C) 199x Landon Dyer, 2011-2019 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
23 // Function prototypes
24 void MakeSection(int, uint16_t);
25 void SwitchSection(int);
27 // Section descriptors
28 SECT sect[NSECTS]; // All sections...
29 int cursect; // Current section number
31 // These are copied from the section descriptor, the current code chunk
32 // descriptor and the current fixup chunk descriptor when a switch is made into
33 // a section. They are copied back to the descriptors when the section is left.
34 uint16_t scattr; // Section attributes
35 uint32_t sloc; // Current loc in section
37 CHUNK * scode; // Current (last) code chunk
38 uint32_t challoc; // # bytes alloc'd to code chunk
39 uint32_t ch_size; // # bytes used in code chunk
40 uint8_t * chptr; // Deposit point in code chunk buffer
41 uint8_t * chptr_opcode; // Backup of chptr, updated before entering code generators
43 // Return a size (SIZB, SIZW, SIZL) or 0, depending on what kind of fixup is
44 // associated with a location.
45 static uint8_t fusiztab[] = {
56 // Offset to REAL fixup location
57 static uint8_t fusizoffs[] = {
70 // Initialize sections; setup initial ABS, TEXT, DATA and BSS sections
72 void InitSection(void)
74 // Initialize all sections
75 for(int i=0; i<NSECTS; i++)
78 // Construct default sections, make TEXT the current section
79 MakeSection(ABS, SUSED | SABS | SBSS); // ABS
80 MakeSection(TEXT, SUSED | TEXT ); // TEXT
81 MakeSection(DATA, SUSED | DATA ); // DATA
82 MakeSection(BSS, SUSED | BSS | SBSS); // BSS
83 MakeSection(M6502, SUSED | TEXT ); // 6502 code section
84 MakeSection(M56001P, SUSED | SABS ); // DSP 56001 Program RAM
85 MakeSection(M56001X, SUSED | SABS ); // DSP 56001 X RAM
86 MakeSection(M56001Y, SUSED | SABS ); // DSP 56001 Y RAM
88 // Switch to TEXT for starters
94 // Make a new (clean) section
96 void MakeSection(int sno, uint16_t attr)
98 SECT * sp = §[sno];
102 sp->scode = sp->sfcode = NULL;
103 sp->sfix = sp->sffix = NULL;
108 // Switch to another section (copy section & chunk descriptors to global vars
111 void SwitchSection(int sno)
115 SECT * sp = §[sno];
117 m6502 = (sno == M6502); // Set 6502-mode flag
123 orgaddr = sp->orgaddr;
125 // Copy code chunk vars
126 if ((cp = scode) != NULL)
128 challoc = cp->challoc;
129 ch_size = cp->ch_size;
130 chptr = cp->chptr + ch_size;
132 // For 6502 mode, add the last org'd address
135 Because the way this is set up it treats the 6502 assembly space as a single 64K space (+ 16 bytes, for some unknown reason) and just bobbles around inside that space and uses a stack of org "pointers" to show where the data ended up.
137 This is a shitty way to handle things, and we can do better than this! :-P
139 Really, there's no reason to have the 6502 (or DSP56001 for that matter) have their own private sections for this kind of thing, as there's literally *no* chance that it would be mingled with 68K+ code. It should be able to use the TEXT, DATA & BSS sections just like the 68K.
141 Or should it? After looking at the code, maybe it's better to keep the 56001 sections segregated from the rest. But we can still make the 6502 stuff better.
144 chptr = cp->chptr + orgaddr;
147 challoc = ch_size = 0;
152 // Save current section
154 void SaveSection(void)
156 SECT * sp = §[cursect];
158 sp->scattr = scattr; // Bailout section vars
160 sp->orgaddr = orgaddr;
162 if (scode != NULL) // Bailout code chunk (if any)
163 scode->ch_size = ch_size;
168 // Test to see if a location has a fixup set on it. This is used by the
169 // listing generator to print 'xx's instead of '00's for forward references
171 int fixtest(int sno, uint32_t loc)
173 // Force update to sect[] variables
176 // Ugly linear search for a mark on our location. The speed doesn't
177 // matter, since this is only done when generating a listing, which is
179 for(FIXUP * fp=sect[sno].sffix; fp!=NULL; fp=fp->next)
181 uint32_t w = fp->attr;
182 uint32_t xloc = fp->loc + (int)fusizoffs[w & FUMASK];
185 return (int)fusiztab[w & FUMASK];
193 // Check that there are at least 'amt' bytes left in the current chunk. If
194 // there are not, allocate another chunk of at least CH_CODE_SIZE bytes or
195 // 'amt', whichever is larger.
197 // If 'amt' is zero, ensure there are at least CH_THRESHOLD bytes, likewise.
199 void chcheck(uint32_t amt)
201 DEBUG { printf("chcheck(%u)\n", amt); }
203 // If in BSS section, no allocation required
210 DEBUG { printf(" challoc=%i, ch_size=%i, diff=%i\n", challoc, ch_size, challoc - ch_size); }
212 if ((int)(challoc - ch_size) >= (int)amt)
215 if (amt < CH_CODE_SIZE)
218 DEBUG { printf(" amt (adjusted)=%u\n", amt); }
219 SECT * p = §[cursect];
220 CHUNK * cp = malloc(sizeof(CHUNK) + amt);
225 // First chunk in section
232 // Add second and on to previous chunk
235 scode->ch_size = ch_size; // Save old chunk's globals
238 // Setup chunk and global vars
240 So, whenever there's an ORG in a 56K section, it sets sloc TO THE ADDRESS IN THE ORG. Also, the loc/sloc are incremented by 1s, which means to alias correctly to the byte-oriented memory model we have here, we have to fix that kind of crap.
242 cp->chloc = sloc; // <-- HERE'S THE PROBLEM FOR 56K :-/
244 challoc = cp->challoc = amt;
245 ch_size = cp->ch_size = 0;
246 chptr = cp->chptr = ((uint8_t *)cp) + sizeof(CHUNK);
247 scode = p->scode = cp;
251 OK, so this is a bit shite, but at least it gets things working the way they should. The right way to do this is not rely on sloc & friends for the right fixup address but to have an accurate model of the thing. That will probably come with v2.0.1 :-P
253 So the problem is, d_org sets sloc to the address of the ORG statement, and that gives an incorrect base for the fixup. And so when a second (or later) chunk is allocated, it gets set wrong. Further complicating things is that the orgaddress *does not* get used in a typical way with the DSP56001 code, and, as such, causes incorrect addresses to be generated. All that has to be dealt with in order to get this right and do away with this kludge.
255 if (((cursect == M56001P) || (cursect == M56001X) || (cursect == M56001Y)) && !first)
256 cp->chloc = cp->chprev->chloc + cp->chprev->ch_size;
263 // Arrange for a fixup on a location
265 int AddFixup(uint32_t attr, uint32_t loc, TOKEN * fexpr)
267 uint16_t exprlen = 0;
269 uint32_t _orgaddr = 0;
271 // First, check to see if the expression is a bare label, otherwise, force
272 // the FU_EXPR flag into the attributes and count the tokens.
273 if ((fexpr[0] == SYMBOL) && (fexpr[2] == ENDEXPR))
275 symbol = symbolPtr[fexpr[1]];
277 // Save the org address for JR RISC instruction
278 if ((attr & FUMASKRISC) == FU_JR)
284 exprlen = ExpressionLength(fexpr);
287 // Second, check to see if it's a DSP56001 fixup, and force the FU_56001
288 // flag into the attributes if so; also save the current org address.
289 if (attr & FUMASKDSP)
292 // Save the exact spot in this chunk where the fixup should go
293 _orgaddr = chptr - scode->chptr + scode->chloc;
296 // Allocate space for the fixup + any expression
297 FIXUP * fixup = malloc(sizeof(FIXUP) + (sizeof(TOKEN) * exprlen));
299 // Store the relevant fixup information in the FIXUP
303 fixup->fileno = cfileno;
304 fixup->lineno = curlineno;
306 fixup->symbol = symbol;
307 fixup->orgaddr = _orgaddr;
309 // Copy the passed in expression to the FIXUP, if any
312 fixup->expr = (TOKEN *)((uint8_t *)fixup + sizeof(FIXUP));
313 memcpy(fixup->expr, fexpr, sizeof(TOKEN) * exprlen);
316 // Finally, put the FIXUP in the current section's linked list
317 if (sect[cursect].sffix == NULL)
319 sect[cursect].sffix = fixup;
320 sect[cursect].sfix = fixup;
324 sect[cursect].sfix->next = fixup;
325 sect[cursect].sfix = fixup;
328 DEBUG { printf("AddFixup: sno=%u, l#=%u, attr=$%X, loc=$%X, expr=%p, sym=%p, org=$%X\n", cursect, fixup->lineno, fixup->attr, fixup->loc, (void *)fixup->expr, (void *)fixup->symbol, fixup->orgaddr);
330 printf(" name: %s, value: $%lX\n", symbol->sname, symbol->svalue);
338 // Resolve fixups in the passed in section
340 int ResolveFixups(int sno)
342 SECT * sc = §[sno];
344 // "Cache" first chunk
345 CHUNK * cch = sc->sfcode;
347 // Can't fixup a section with nothing in it
351 // Wire the 6502 segment's size to its allocated size (64K)
353 cch->ch_size = cch->challoc;
355 // Get first fixup for the passed in section
356 FIXUP * fixup = sect[sno].sffix;
358 while (fixup != NULL)
360 // We do it this way because we have continues everywhere... :-P
364 uint32_t dw = fup->attr; // Fixup long (type + modes + flags)
365 uint32_t loc = fup->loc; // Location to fixup
366 cfileno = fup->fileno;
367 curlineno = fup->lineno;
368 DEBUG { printf("ResolveFixups: sect#=%u, l#=%u, attr=$%X, loc=$%X, expr=%p, sym=%p, org=$%X\n", sno, fup->lineno, fup->attr, fup->loc, (void *)fup->expr, (void *)fup->symbol, fup->orgaddr); }
370 // This is based on global vars cfileno, curfname :-P
371 // This approach is kinda meh as well. I think we can do better
373 SetFilenameForErrorReporting();
375 if ((sno == M56001P) || (sno == M56001X) || (sno == M56001Y) || (sno == M56001L))
378 // Search for chunk containing location to fix up; compute a
379 // pointer to the location (in the chunk). Often we will find the
380 // Fixup is in the "cached" chunk, so the linear-search is seldom
382 if (loc < cch->chloc || loc >= (cch->chloc + cch->ch_size))
384 for(cch=sc->sfcode; cch!=NULL; cch=cch->chnext)
386 if (loc >= cch->chloc && loc < (cch->chloc + cch->ch_size))
392 // Fixup (loc) is out of range--this should never happen!
393 // Once we call this function, it winds down immediately; it
399 // Location to fix (in current chunk)
400 // We use the address of the chunk that loc is actually in, then
401 // subtract the chunk's starting location from loc to get the offset
402 // into the current chunk.
403 uint8_t * locp = cch->chptr + (loc - cch->chloc);
405 uint16_t eattr = 0; // Expression attrib
406 SYM * esym = NULL; // External symbol involved in expr
407 uint64_t eval; // Expression value
408 uint16_t flags; // Mark flags
410 // Compute expression/symbol value and attributes
412 // Complex expression
415 // evexpr presumably issues the errors/warnings here
416 if (evexpr(fup->expr, &eval, &eattr, &esym) != OK)
422 SYM * sy = fup->symbol;
430 // If the symbol is not defined, but global, set esym to sy
431 if ((eattr & (GLOBAL | DEFINED)) == GLOBAL)
434 DEBUG { printf(" name: %s, value: $%" PRIX64 "\n", sy->sname, sy->svalue); }
437 uint16_t tdb = eattr & TDB;
439 // If the expression/symbol is undefined and no external symbol is
440 // involved, then that's an error.
441 if (!(eattr & DEFINED) && (esym == NULL))
449 // If a PC-relative fixup is undefined, its value is *not* subtracted
450 // from the location (that will happen in the linker when the external
451 // reference is resolved).
453 // MWC expects PC-relative things to have the LOC subtracted from the
454 // value, if the value is external (that is, undefined at this point).
456 // PC-relative fixups must be DEFINED and either in the same section
457 // (whereupon the subtraction takes place) or ABS (with no subtract).
458 if ((dw & FU_PCREL) || (dw & FU_PCRELX))
466 // In this instruction the PC is located a DWORD away
472 // Allow cross-section PCREL fixups in Alcyon mode
478 // Shouldn't there be a break here, since otherwise, it will point to the DATA section?
481 eval += sect[TEXT].sloc;
484 eval += sect[TEXT].sloc + sect[DATA].sloc;
487 error("invalid section");
493 // In this instruction the PC is located a DWORD away
499 error("PC-relative expr across sections");
504 if (sbra_flag && (dw & FU_LBRA) && (eval + 0x80 < 0x100))
505 warn("unoptimized short branch");
507 else if (obj_format == MWC)
511 // In this instruction the PC is located a DWORD away
516 // Be sure to clear any TDB flags, since we handled it just now
521 // Handle fixup classes
524 // FU_BBRA fixes up a one-byte branch offset.
526 if (!(eattr & DEFINED))
528 error("external short branch");
534 if (eval + 0x80 >= 0x100)
539 if (CHECK_OPTS(OPT_NULL_BRA))
548 error("illegal bra.s with zero offset");
553 *++locp = (uint8_t)eval;
556 // Fixup one-byte value at locp + 1.
561 // Fixup one-byte forward references
563 if (!(eattr & DEFINED))
565 error("external byte reference");
571 error("non-absolute byte reference");
575 if ((dw & FU_PCREL) && ((eval + 0x80) >= 0x100))
580 if ((eval + 0x100) >= 0x200)
583 else if (eval >= 0x100)
586 *locp = (uint8_t)eval;
589 // Fixup high/low byte off word for 6502
591 if (!(eattr & DEFINED))
593 error("external byte reference");
597 *locp = (uint8_t)(eval >> 8);
601 if (!(eattr & DEFINED))
603 error("external byte reference");
607 *locp = (uint8_t)eval;
610 // Fixup WORD forward references; the word could be unaligned in the
611 // section buffer, so we have to be careful. (? careful about what?)
613 if ((dw & FUMASKRISC) == FU_JR)
615 int reg = (signed)((eval - ((fup->orgaddr ? fup->orgaddr : loc) + 2)) / 2);
617 if ((reg < -16) || (reg > 15))
619 error("relative jump out of range");
623 *locp |= ((uint8_t)reg >> 3) & 0x03;
625 *locp |= ((uint8_t)reg & 0x07) << 5;
628 else if ((dw & FUMASKRISC) == FU_NUM15)
630 if (((int)eval < -16) || ((int)eval > 15))
632 error("constant out of range (-16 - +15)");
636 *locp |= ((uint8_t)eval >> 3) & 0x03;
638 *locp |= ((uint8_t)eval & 0x07) << 5;
641 else if ((dw & FUMASKRISC) == FU_NUM31)
645 error("constant out of range (0-31)");
649 *locp |= ((uint8_t)eval >> 3) & 0x03;
651 *locp |= ((uint8_t)eval & 0x07) << 5;
654 else if ((dw & FUMASKRISC) == FU_NUM32)
656 if ((eval < 1) || (eval > 32))
658 error("constant out of range (1-32)");
665 eval = (eval == 32) ? 0 : eval;
666 *locp |= ((uint8_t)eval >> 3) & 0x03;
668 *locp |= ((uint8_t)eval & 0x07) << 5;
671 else if ((dw & FUMASKRISC) == FU_REGONE)
675 error("register one value out of range");
679 *locp |= ((uint8_t)eval >> 3) & 0x03;
681 *locp |= ((uint8_t)eval & 0x07) << 5;
684 else if ((dw & FUMASKRISC) == FU_REGTWO)
688 error("register two value out of range");
693 *locp |= (uint8_t)eval & 0x1F;
697 if (!(eattr & DEFINED))
704 MarkRelocatable(sno, loc, 0, flags, esym);
709 MarkRelocatable(sno, loc, tdb, MWORD, NULL);
713 if (eval + 0x10000 >= 0x20000)
718 // Range-check BRA and DBRA
721 if (eval + 0x8000 >= 0x10000)
724 else if (eval >= 0x10000)
729 // 6502 words are little endian, so handle that here
731 SETLE16(locp, 0, eval)
733 SETBE16(locp, 0, eval)
737 // Fixup LONG forward references; the long could be unaligned in the
738 // section buffer, so be careful (again).
742 if ((dw & FUMASKRISC) == FU_MOVEI)
744 // Long constant in MOVEI # is word-swapped, so fix it here
745 eval = WORDSWAP32(eval);
749 // If the symbol is undefined, make sure to pass the symbol in
750 // to the MarkRelocatable() function.
751 if (!(eattr & DEFINED))
752 MarkRelocatable(sno, loc, 0, flags, esym);
754 MarkRelocatable(sno, loc, tdb, flags, NULL);
756 SETBE32(locp, 0, eval);
759 // Fixup QUAD forward references (mainly used by the OP assembler)
763 uint64_t quad = GETBE64(locp, 0);
764 uint64_t addr = eval;
766 //Hmm, not sure how this can be set, since it's only set if it's a DSP56001 fixup or a FU_JR... :-/
768 // addr = fup->orgaddr;
770 eval = (quad & 0xFFFFFC0000FFFFFFLL) | ((addr & 0x3FFFF8) << 21);
772 else if (dw & FU_OBJDATA)
774 // If it's in a TEXT or DATA section, be sure to mark for a
777 MarkRelocatable(sno, loc, tdb, MQUAD, NULL);
779 uint64_t quad = GETBE64(locp, 0);
780 uint64_t addr = eval;
782 //Hmm, not sure how this can be set, since it's only set if it's a DSP56001 fixup or a FU_JR... :-/
784 // addr = fup->orgaddr;
786 eval = (quad & 0x000007FFFFFFFFFFLL) | ((addr & 0xFFFFF8) << 40);
789 SETBE64(locp, 0, eval);
792 // Fixup a 3-bit "QUICK" reference in bits 9..1
793 // (range of 1..8) in a word. [Really bits 1..3 in a byte.]
795 if (!(eattr & DEFINED))
797 error("External quick reference");
801 if ((eval < 1) || (eval > 8))
804 *locp |= (eval & 7) << 1;
807 // Fix up 6502 funny branch
811 if (eval + 0x80 >= 0x100)
814 *locp = (uint8_t)eval;
817 // Fixup DSP56001 addresses
819 switch (dw & FUMASKDSP)
821 // DSPIMM5 actually is clamped from 0 to 23 for our purposes
822 // and does not use the full 5 bit range.
826 error("immediate value must be between 0 and 23");
833 // This is a 12-bit address encoded into the lower 12
834 // bits of a DSP word
838 error("address out of range ($0-$FFF)");
842 locp[1] |= eval >> 8;
843 locp[2] = eval & 0xFF;
846 // This is a full DSP word containing Effective Address Extension
849 if (eval >= 0x1000000)
851 error("value out of range ($0-$FFFFFF)");
855 locp[0] = (uint8_t)((eval >> 16) & 0xFF);
856 locp[1] = (uint8_t)((eval >> 8) & 0xFF);
857 locp[2] = (uint8_t)(eval & 0xFF);
860 // This is a 16bit absolute address into a 24bit field
864 error("address out of range ($0-$FFFF)");
868 locp[1] = (uint8_t)(eval >> 8);
869 locp[2] = (uint8_t)eval;
872 // This is 12-bit immediate short data
873 // The upper nibble goes into the last byte's low nibble
874 // while the remainder 8 bits go into the 2nd byte.
878 error("immediate out of range ($0-$FFF)");
882 locp[1] = (uint8_t)eval;
883 locp[2] |= (uint8_t)(eval >> 8);
886 // This is 8-bit immediate short data
887 // which goes into the middle byte of a DSP word.
891 error("immediate out of range ($0-$FF)");
895 locp[1] = (uint8_t)eval;
898 // This is a 6 bit absoulte short address. It occupies
899 // the low 6 bits of the middle byte of a DSP word.
903 error("address must be between 0 and 63");
910 // This is a 6 bit absoulte short address. It occupies
911 // the low 6 bits of the middle byte of a DSP word.
913 if (eval < 0xFFFFFFC0)
915 error("address must be between $FFC0 and $FFFF");
919 locp[1] |= eval & 0x3F;
922 // Shamus: I'm pretty sure these don't make any sense...
924 warn("FU_DSPIMMFL8 missing implementation\n%s", "And you may ask yourself, \"Self, how did I get here?\"");
928 warn("FU_DSPIMMFL16 missing implementation\n%s", "And you may ask yourself, \"Self, how did I get here?\"");
932 warn("FU_DSPIMMFL24 missing implementation\n%s", "And you may ask yourself, \"Self, how did I get here?\"");
935 // Bad fixup type--this should *never* happen!
942 // Fixup a 4-byte float
944 warn("FU_FLOATSING missing implementation\n%s", "And you may ask yourself, \"Self, how did I get here?\"");
947 // Fixup a 8-byte float
949 warn("FU_FLOATDOUB missing implementation\n%s", "And you may ask yourself, \"Self, how did I get here?\"");
952 // Fixup a 12-byte float
954 warn("FU_FLOATEXT missing implementation\n%s", "And you may ask yourself, \"Self, how did I get here?\"");
958 // Bad fixup type--this should *never* happen!
959 // Once we call this function, it winds down immediately; it
966 error("expression out of range");
974 // Resolve all fixups
976 int ResolveAllFixups(void)
978 // Make undefined symbols GLOBL
980 ForceUndefinedSymbolsGlobal();
982 DEBUG printf("Resolving TEXT sections...\n");
984 DEBUG printf("Resolving DATA sections...\n");
986 DEBUG printf("Resolving 6502 sections...\n");
987 ResolveFixups(M6502); // Fixup 6502 section (if any)
988 DEBUG printf("Resolving DSP56001 P: sections...\n");
989 ResolveFixups(M56001P); // Fixup 56001 P: section (if any)
990 DEBUG printf("Resolving DSP56001 X: sections...\n");
991 ResolveFixups(M56001X); // Fixup 56001 X: section (if any)
992 DEBUG printf("Resolving DSP56001 Y: sections...\n");
993 ResolveFixups(M56001Y); // Fixup 56001 Y: section (if any)