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Initial import from lwtools 3.0.1 version, with new hand built build system and file reorganization
author lost@l-w.ca
date Wed, 19 Jan 2011 22:27:17 -0700
parents
children 7317fbe024af
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-1:000000000000 0:2c24602be78f
1 /*
2 output.c
3 Copyright © 2009, 2010 William Astle
4
5 This file is part of LWASM.
6
7 LWASM is free software: you can redistribute it and/or modify it under the
8 terms of the GNU General Public License as published by the Free Software
9 Foundation, either version 3 of the License, or (at your option) any later
10 version.
11
12 This program is distributed in the hope that it will be useful, but WITHOUT
13 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
15 more details.
16
17 You should have received a copy of the GNU General Public License along with
18 this program. If not, see <http://www.gnu.org/licenses/>.
19
20
21 Contains the code for actually outputting the assembled code
22 */
23 #include <errno.h>
24 #include <stdio.h>
25 #include <string.h>
26 #include <unistd.h>
27
28 #include <lw_alloc.h>
29 #include <lw_expr.h>
30
31 #include "lwasm.h"
32
33 void write_code_raw(asmstate_t *as, FILE *of);
34 void write_code_decb(asmstate_t *as, FILE *of);
35 void write_code_rawrel(asmstate_t *as, FILE *of);
36 void write_code_obj(asmstate_t *as, FILE *of);
37 void write_code_os9(asmstate_t *as, FILE *of);
38
39 // this prevents warnings about not using the return value of fwrite()
40 #define writebytes(s, l, c, f) do { int r; r = fwrite((s), (l), (c), (f)); } while (0)
41
42 void do_output(asmstate_t *as)
43 {
44 FILE *of;
45
46 if (as -> errorcount > 0)
47 {
48 fprintf(stderr, "Not doing output due to assembly errors.\n");
49 return;
50 }
51
52 of = fopen(as -> output_file, "wb");
53 if (!of)
54 {
55 fprintf(stderr, "Cannot open '%s' for output", as -> output_file);
56 perror("");
57 return;
58 }
59
60 switch (as -> output_format)
61 {
62 case OUTPUT_RAW:
63 write_code_raw(as, of);
64 break;
65
66 case OUTPUT_DECB:
67 write_code_decb(as, of);
68 break;
69
70 case OUTPUT_RAWREL:
71 write_code_rawrel(as, of);
72 break;
73
74 case OUTPUT_OBJ:
75 write_code_obj(as, of);
76 break;
77
78 case OUTPUT_OS9:
79 write_code_os9(as, of);
80 break;
81
82 default:
83 fprintf(stderr, "BUG: unrecognized output format when generating output file\n");
84 fclose(of);
85 unlink(as -> output_file);
86 return;
87 }
88
89 fclose(of);
90 }
91
92 /*
93 rawrel output treats an ORG directive as an offset from the start of the
94 file. Undefined results will occur if an ORG directive moves the output
95 pointer backward. This particular implementation uses "fseek" to handle
96 ORG requests and to skip over RMBs.
97
98 This simple brain damanged method simply does an fseek before outputting
99 each instruction.
100 */
101 void write_code_rawrel(asmstate_t *as, FILE *of)
102 {
103 line_t *cl;
104
105 for (cl = as -> line_head; cl; cl = cl -> next)
106 {
107 if (cl -> outputl <= 0)
108 continue;
109
110 fseek(of, lw_expr_intval(cl -> addr), SEEK_SET);
111 writebytes(cl -> output, cl -> outputl, 1, of);
112 }
113 }
114
115 /*
116 raw merely writes all the bytes directly to the file as is. ORG is just a
117 reference for the assembler to handle absolute references. Multiple ORG
118 statements will produce mostly useless results
119 */
120 void write_code_raw(asmstate_t *as, FILE *of)
121 {
122 line_t *cl;
123
124 for (cl = as -> line_head; cl; cl = cl -> next)
125 {
126 if (cl -> len > 0 && cl -> outputl == 0)
127 {
128 int i;
129 for (i = 0; i < cl -> len; i++)
130 writebytes("\0", 1, 1, of);
131 continue;
132 }
133 else if (cl -> outputl > 0)
134 writebytes(cl -> output, cl -> outputl, 1, of);
135 }
136 }
137
138
139 /*
140 OS9 target also just writes all the bytes in order. No need for anything
141 else.
142 */
143 void write_code_os9(asmstate_t *as, FILE *of)
144 {
145 line_t *cl;
146
147 for (cl = as -> line_head; cl; cl = cl -> next)
148 {
149 if (cl -> inmod == 0)
150 continue;
151 if (cl -> len > 0 && cl -> outputl == 0)
152 {
153 int i;
154 for (i = 0; i < cl -> len; i++)
155 writebytes("\0", 1, 1, of);
156 continue;
157 }
158 else if (cl -> outputl > 0)
159 writebytes(cl -> output, cl -> outputl, 1, of);
160 }
161 }
162
163 void write_code_decb(asmstate_t *as, FILE *of)
164 {
165 long preambloc;
166 line_t *cl;
167 int blocklen = -1;
168 int nextcalc = -1;
169 unsigned char outbuf[5];
170 int caddr;
171
172 for (cl = as -> line_head; cl; cl = cl -> next)
173 {
174 if (cl -> outputl < 0)
175 continue;
176 caddr = lw_expr_intval(cl -> addr);
177 if (caddr != nextcalc && cl -> outputl > 0)
178 {
179 // need preamble here
180 if (blocklen > 0)
181 {
182 // update previous preamble if needed
183 fseek(of, preambloc, SEEK_SET);
184 outbuf[0] = (blocklen >> 8) & 0xFF;
185 outbuf[1] = blocklen & 0xFF;
186 writebytes(outbuf, 2, 1, of);
187 fseek(of, 0, SEEK_END);
188 }
189 blocklen = 0;
190 nextcalc = caddr;
191 outbuf[0] = 0x00;
192 outbuf[1] = 0x00;
193 outbuf[2] = 0x00;
194 outbuf[3] = (nextcalc >> 8) & 0xFF;
195 outbuf[4] = nextcalc & 0xFF;
196 preambloc = ftell(of) + 1;
197 writebytes(outbuf, 5, 1, of);
198 }
199 nextcalc += cl -> outputl;
200 writebytes(cl -> output, cl -> outputl, 1, of);
201 blocklen += cl -> outputl;
202 }
203 if (blocklen > 0)
204 {
205 fseek(of, preambloc, SEEK_SET);
206 outbuf[0] = (blocklen >> 8) & 0xFF;
207 outbuf[1] = blocklen & 0xFF;
208 writebytes(outbuf, 2, 1, of);
209 fseek(of, 0, SEEK_END);
210 }
211
212 // now write postamble
213 outbuf[0] = 0xFF;
214 outbuf[1] = 0x00;
215 outbuf[2] = 0x00;
216 outbuf[3] = (as -> execaddr >> 8) & 0xFF;
217 outbuf[4] = (as -> execaddr) & 0xFF;
218 writebytes(outbuf, 5, 1, of);
219 }
220
221 void write_code_obj_sbadd(sectiontab_t *s, unsigned char b)
222 {
223 if (s -> oblen >= s -> obsize)
224 {
225 s -> obytes = lw_realloc(s -> obytes, s -> obsize + 128);
226 s -> obsize += 128;
227 }
228 s -> obytes[s -> oblen] = b;
229 s -> oblen += 1;
230 }
231
232
233 int write_code_obj_expraux(lw_expr_t e, void *of)
234 {
235 int tt;
236 int v;
237 unsigned char buf[16];
238
239 tt = lw_expr_type(e);
240
241 switch (tt)
242 {
243 case lw_expr_type_oper:
244 buf[0] = 0x04;
245 switch (lw_expr_whichop(e))
246 {
247 case lw_expr_oper_plus:
248 buf[1] = 0x01;
249 break;
250
251 case lw_expr_oper_minus:
252 buf[1] = 0x02;
253 break;
254
255 case lw_expr_oper_times:
256 buf[1] = 0x03;
257 break;
258
259 case lw_expr_oper_divide:
260 buf[1] = 0x04;
261 break;
262
263 case lw_expr_oper_mod:
264 buf[1] = 0x05;
265 break;
266
267 case lw_expr_oper_intdiv:
268 buf[1] = 0x06;
269 break;
270
271 case lw_expr_oper_bwand:
272 buf[1] = 0x07;
273 break;
274
275 case lw_expr_oper_bwor:
276 buf[1] = 0x08;
277 break;
278
279 case lw_expr_oper_bwxor:
280 buf[1] = 0x09;
281 break;
282
283 case lw_expr_oper_and:
284 buf[1] = 0x0A;
285 break;
286
287 case lw_expr_oper_or:
288 buf[1] = 0x0B;
289 break;
290
291 case lw_expr_oper_neg:
292 buf[1] = 0x0C;
293 break;
294
295 case lw_expr_oper_com:
296 buf[1] = 0x0D;
297 break;
298
299 default:
300 buf[1] = 0xff;
301 }
302 writebytes(buf, 2, 1, of);
303 return 0;
304
305 case lw_expr_type_int:
306 v = lw_expr_intval(e);
307 buf[0] = 0x01;
308 buf[1] = (v >> 8) & 0xff;
309 buf[2] = v & 0xff;
310 writebytes(buf, 3, 1, of);
311 return 0;
312
313 case lw_expr_type_special:
314 v = lw_expr_specint(e);
315 switch (v)
316 {
317 case lwasm_expr_secbase:
318 {
319 // replaced with a synthetic symbol
320 sectiontab_t *se;
321 se = lw_expr_specptr(e);
322
323 writebytes("\x03\x02", 2, 1, of);
324 writebytes(se -> name, strlen(se -> name) + 1, 1, of);
325 return 0;
326 }
327 case lwasm_expr_import:
328 {
329 importlist_t *ie;
330 ie = lw_expr_specptr(e);
331 buf[0] = 0x02;
332 writebytes(buf, 1, 1, of);
333 writebytes(ie -> symbol, strlen(ie -> symbol) + 1, 1, of);
334 return 0;
335 }
336 case lwasm_expr_syment:
337 {
338 struct symtabe *se;
339 se = lw_expr_specptr(e);
340 buf[0] = 0x03;
341 writebytes(buf, 1, 1, of);
342 writebytes(se -> symbol, strlen(se -> symbol), 1, of);
343 if (se -> context != -1)
344 {
345 sprintf(buf, "\x01%d", se -> context);
346 writebytes(buf, strlen(buf), 1, of);
347 }
348 writebytes("", 1, 1, of);
349 return 0;
350 }
351 }
352
353 default:
354 // unrecognized term type - replace with integer 0
355 // fprintf(stderr, "Unrecognized term type: %s\n", lw_expr_print(e));
356 buf[0] = 0x01;
357 buf[1] = 0x00;
358 buf[2] = 0x00;
359 writebytes(buf, 3, 1, of);
360 break;
361 }
362 return 0;
363 }
364
365
366 void write_code_obj(asmstate_t *as, FILE *of)
367 {
368 line_t *l;
369 sectiontab_t *s;
370 reloctab_t *re;
371 exportlist_t *ex;
372 struct symtabe *se;
373
374 int i;
375 unsigned char buf[16];
376
377 // output the magic number and file header
378 // the 8 is NOT an error
379 writebytes("LWOBJ16", 8, 1, of);
380
381 // run through the entire system and build the byte streams for each
382 // section; at the same time, generate a list of "local" symbols to
383 // output for each section
384 // NOTE: for "local" symbols, we will append \x01 and the ascii string
385 // of the context identifier (so sym in context 1 would be "sym\x011"
386 // we can do this because the linker can handle symbols with any
387 // character other than NUL.
388 // also we will generate a list of incomplete references for each
389 // section along with the actual definition that will be output
390
391 // once all this information is generated, we will output each section
392 // to the file
393
394 // NOTE: we build everything in memory then output it because the
395 // assembler accepts multiple instances of the same section but the
396 // linker expects only one instance of each section in the object file
397 // so we need to collect all the various pieces of a section together
398 // (also, the assembler treated multiple instances of the same section
399 // as continuations of previous sections so we would need to collect
400 // them together anyway.
401
402 for (l = as -> line_head; l; l = l -> next)
403 {
404 if (l -> csect)
405 {
406 // we're in a section - need to output some bytes
407 if (l -> outputl > 0)
408 for (i = 0; i < l -> outputl; i++)
409 write_code_obj_sbadd(l -> csect, l -> output[i]);
410 else if (l -> outputl == 0 || l -> outputl == -1)
411 for (i = 0; i < l -> len; i++)
412 write_code_obj_sbadd(l -> csect, 0);
413 }
414 }
415
416 // run through the sections
417 for (s = as -> sections; s; s = s -> next)
418 {
419 // write the name
420 writebytes(s -> name, strlen(s -> name) + 1, 1, of);
421
422 // write the flags
423 if (s -> flags & section_flag_bss)
424 writebytes("\x01", 1, 1, of);
425
426 // indicate end of flags - the "" is NOT an error
427 writebytes("", 1, 1, of);
428
429 // now the local symbols
430
431 // a symbol for section base address
432 writebytes("\x02", 1, 1, of);
433 writebytes(s -> name, strlen(s -> name) + 1, 1, of);
434 // address 0; "\0" is not an error
435 writebytes("\0", 2, 1, of);
436 for (se = as -> symtab.head; se; se = se -> next)
437 {
438 lw_expr_t te;
439
440 debug_message(as, 200, "Consider symbol %s (%p) for export in section %p", se -> symbol, se -> section, s);
441
442 // ignore symbols not in this section
443 if (se -> section != s)
444 continue;
445
446 debug_message(as, 200, " In section");
447
448 if (se -> flags & symbol_flag_set)
449 continue;
450
451 debug_message(as, 200, " Not symbol_flag_set");
452
453 te = lw_expr_copy(se -> value);
454 debug_message(as, 200, " Value=%s", lw_expr_print(te));
455 as -> exportcheck = 1;
456 as -> csect = s;
457 lwasm_reduce_expr(as, te);
458 as -> exportcheck = 0;
459
460 debug_message(as, 200, " Value2=%s", lw_expr_print(te));
461
462 // don't output non-constant symbols
463 if (!lw_expr_istype(te, lw_expr_type_int))
464 {
465 lw_expr_destroy(te);
466 continue;
467 }
468
469 writebytes(se -> symbol, strlen(se -> symbol), 1, of);
470 if (se -> context >= 0)
471 {
472 writebytes("\x01", 1, 1, of);
473 sprintf(buf, "%d", se -> context);
474 writebytes(buf, strlen(buf), 1, of);
475 }
476 // the "" is NOT an error
477 writebytes("", 1, 1, of);
478
479 // write the address
480 buf[0] = (lw_expr_intval(te) >> 8) & 0xff;
481 buf[1] = lw_expr_intval(te) & 0xff;
482 writebytes(buf, 2, 1, of);
483 lw_expr_destroy(te);
484 }
485 // flag end of local symbol table - "" is NOT an error
486 writebytes("", 1, 1, of);
487
488 // now the exports -- FIXME
489 for (ex = as -> exportlist; ex; ex = ex -> next)
490 {
491 int eval;
492 lw_expr_t te;
493 line_t tl;
494
495 if (ex -> se == NULL)
496 continue;
497 if (ex -> se -> section != s)
498 continue;
499 te = lw_expr_copy(ex -> se -> value);
500 as -> csect = ex -> se -> section;
501 as -> exportcheck = 1;
502 tl.as = as;
503 as -> cl = &tl;
504 lwasm_reduce_expr(as, te);
505 as -> exportcheck = 0;
506 as -> cl = NULL;
507 if (!lw_expr_istype(te, lw_expr_type_int))
508 {
509 lw_expr_destroy(te);
510 continue;
511 }
512 eval = lw_expr_intval(te);
513 lw_expr_destroy(te);
514 writebytes(ex -> symbol, strlen(ex -> symbol) + 1, 1, of);
515 buf[0] = (eval >> 8) & 0xff;
516 buf[1] = eval & 0xff;
517 writebytes(buf, 2, 1, of);
518 }
519
520 // flag end of exported symbols - "" is NOT an error
521 writebytes("", 1, 1, of);
522
523 // FIXME - relocation table
524 for (re = s -> reloctab; re; re = re -> next)
525 {
526 int offset;
527 lw_expr_t te;
528 line_t tl;
529
530 tl.as = as;
531 as -> cl = &tl;
532 as -> csect = s;
533 as -> exportcheck = 1;
534
535 if (re -> expr == NULL)
536 {
537 // this is an error but we'll simply ignore it
538 // and not output this expression
539 continue;
540 }
541
542 // work through each term in the expression and output
543 // the proper equivalent to the object file
544 if (re -> size == 1)
545 {
546 // flag an 8 bit relocation (low 8 bits will be used)
547 buf[0] = 0xFF;
548 buf[1] = 0x01;
549 writebytes(buf, 2, 1, of);
550 }
551
552 te = lw_expr_copy(re -> offset);
553 lwasm_reduce_expr(as, te);
554 if (!lw_expr_istype(te, lw_expr_type_int))
555 {
556 lw_expr_destroy(te);
557 continue;
558 }
559 offset = lw_expr_intval(te);
560 lw_expr_destroy(te);
561
562 // output expression
563 lw_expr_testterms(re -> expr, write_code_obj_expraux, of);
564
565 // flag end of expressions
566 writebytes("", 1, 1, of);
567
568 // write the offset
569 buf[0] = (offset >> 8) & 0xff;
570 buf[1] = offset & 0xff;
571 writebytes(buf, 2, 1, of);
572 }
573
574 // flag end of incomplete references list
575 writebytes("", 1, 1, of);
576
577 // now blast out the code
578
579 // length
580 buf[0] = s -> oblen >> 8 & 0xff;
581 buf[1] = s -> oblen & 0xff;
582 writebytes(buf, 2, 1, of);
583
584 if (!(s -> flags & section_flag_bss))
585 {
586 writebytes(s -> obytes, s -> oblen, 1, of);
587 }
588 }
589
590 // flag no more sections
591 // the "" is NOT an error
592 writebytes("", 1, 1, of);
593 }