1 /* outas86.c output routines for the Netwide Assembler to produce
2 * Linux as86 (bin86-0.3) object files
4 * The Netwide Assembler is copyright (C) 1996 Simon Tatham and
5 * Julian Hall. All rights reserved. The software is
6 * redistributable under the license given in the file "LICENSE"
7 * distributed in the NASM archive.
26 int type; /* 0 = absolute, 1 = seg, 2 = sym */
27 int32_t offset; /* relative offset */
28 int number; /* symbol/segment number (4=bss) */
29 int32_t bytes; /* size of reloc or of absolute data */
30 bool relative; /* relative address? */
34 int32_t strpos; /* string table position of name */
35 int flags; /* symbol flags */
36 int segment; /* 4=bss at this point */
37 int32_t value; /* address, or COMMON variable size */
41 * Section IDs - used in Piece.number and Symbol.segment.
43 #define SECT_TEXT 0 /* text section */
44 #define SECT_DATA 3 /* data section */
45 #define SECT_BSS 4 /* bss section */
48 * Flags used in Symbol.flags.
50 #define SYM_ENTRY (1<<8)
51 #define SYM_EXPORT (1<<7)
52 #define SYM_IMPORT (1<<6)
53 #define SYM_ABSOLUTE (1<<4)
57 uint32_t datalen, size, len;
59 struct Piece *head, *last, **tail;
62 static char as86_module[FILENAME_MAX];
64 static struct Section stext, sdata;
65 static uint32_t bsslen;
66 static int32_t bssindex;
68 static struct SAA *syms;
69 static uint32_t nsyms;
71 static struct RAA *bsym;
73 static struct SAA *strs;
74 static uint32_t strslen;
76 static int as86_reloc_size;
81 static void as86_write(void);
82 static void as86_write_section(struct Section *, int);
83 static int as86_add_string(char *name);
84 static void as86_sect_write(struct Section *, const uint8_t *,
87 static void as86_init(FILE * fp, efunc errfunc, ldfunc ldef, evalfunc eval)
91 (void)ldef; /* placate optimisers */
93 stext.data = saa_init(1L);
95 stext.head = stext.last = NULL;
96 stext.tail = &stext.head;
97 sdata.data = saa_init(1L);
99 sdata.head = sdata.last = NULL;
100 sdata.tail = &sdata.head;
102 stext.len = stext.datalen = stext.size =
103 sdata.len = sdata.datalen = sdata.size = 0;
104 stext.index = seg_alloc();
105 sdata.index = seg_alloc();
106 bssindex = seg_alloc();
107 syms = saa_init((int32_t)sizeof(struct Symbol));
113 as86_add_string(as86_module);
116 static void as86_cleanup(int debuginfo)
124 saa_free(stext.data);
127 stext.head = stext.head->next;
130 saa_free(sdata.data);
133 sdata.head = sdata.head->next;
141 static int32_t as86_section_names(char *name, int pass, int *bits)
147 * Default is 16 bits.
155 if (!strcmp(name, ".text"))
157 else if (!strcmp(name, ".data"))
159 else if (!strcmp(name, ".bss"))
165 static int as86_add_string(char *name)
168 int length = strlen(name);
170 saa_wbytes(strs, name, (int32_t)(length + 1));
171 strslen += 1 + length;
176 static void as86_deflabel(char *name, int32_t segment, int64_t offset,
177 int is_global, char *special)
182 error(ERR_NONFATAL, "as86 format does not support any"
183 " special symbol types");
185 if (name[0] == '.' && name[1] == '.' && name[2] != '@') {
186 error(ERR_NONFATAL, "unrecognised special symbol `%s'", name);
190 sym = saa_wstruct(syms);
192 sym->strpos = as86_add_string(name);
194 if (segment == NO_SEG)
195 sym->flags |= SYM_ABSOLUTE, sym->segment = 0;
196 else if (segment == stext.index)
197 sym->segment = SECT_TEXT;
198 else if (segment == sdata.index)
199 sym->segment = SECT_DATA;
200 else if (segment == bssindex)
201 sym->segment = SECT_BSS;
203 sym->flags |= SYM_IMPORT;
208 sym->segment = 3; /* already have IMPORT */
210 if (is_global && !(sym->flags & SYM_IMPORT))
211 sym->flags |= SYM_EXPORT;
216 * define the references from external-symbol segment numbers
217 * to these symbol records.
219 if (segment != NO_SEG && segment != stext.index &&
220 segment != sdata.index && segment != bssindex)
221 bsym = raa_write(bsym, segment, nsyms);
226 static void as86_add_piece(struct Section *sect, int type, int32_t offset,
227 int32_t segment, int32_t bytes, int relative)
233 if (type == 0 && sect->last && sect->last->type == 0) {
234 sect->last->bytes += bytes;
238 p = sect->last = *sect->tail = nasm_malloc(sizeof(struct Piece));
239 sect->tail = &p->next;
245 p->relative = relative;
247 if (type == 1 && segment == stext.index)
248 p->number = SECT_TEXT;
249 else if (type == 1 && segment == sdata.index)
250 p->number = SECT_DATA;
251 else if (type == 1 && segment == bssindex)
252 p->number = SECT_BSS;
254 p->number = raa_read(bsym, segment), p->type = 2;
257 static void as86_out(int32_t segto, const void *data,
258 enum out_type type, uint64_t size,
259 int32_t segment, int32_t wrt)
263 uint8_t mydata[4], *p;
266 wrt = NO_SEG; /* continue to do _something_ */
267 error(ERR_NONFATAL, "WRT not supported by as86 output format");
271 * handle absolute-assembly (structure definitions)
273 if (segto == NO_SEG) {
274 if (type != OUT_RESERVE)
275 error(ERR_NONFATAL, "attempt to assemble code in [ABSOLUTE]"
280 if (segto == stext.index)
282 else if (segto == sdata.index)
284 else if (segto == bssindex)
287 error(ERR_WARNING, "attempt to assemble code in"
288 " segment %d: defaulting to `.text'", segto);
292 if (!s && type != OUT_RESERVE) {
293 error(ERR_WARNING, "attempt to initialize memory in the"
294 " BSS section: ignored");
295 if (type == OUT_REL2ADR)
297 else if (type == OUT_REL4ADR)
303 if (type == OUT_RESERVE) {
305 error(ERR_WARNING, "uninitialized space declared in"
306 " %s section: zeroing",
307 (segto == stext.index ? "code" : "data"));
308 as86_sect_write(s, NULL, size);
309 as86_add_piece(s, 0, 0L, 0L, size, 0);
312 } else if (type == OUT_RAWDATA) {
313 if (segment != NO_SEG)
314 error(ERR_PANIC, "OUT_RAWDATA with other than NO_SEG");
315 as86_sect_write(s, data, size);
316 as86_add_piece(s, 0, 0L, 0L, size, 0);
317 } else if (type == OUT_ADDRESS) {
318 if (segment != NO_SEG) {
320 error(ERR_NONFATAL, "as86 format does not support"
321 " segment base references");
323 offset = *(int64_t *)data;
324 as86_add_piece(s, 1, offset, segment, size, 0);
328 WRITELONG(p, *(int64_t *)data);
329 as86_sect_write(s, data, size);
330 as86_add_piece(s, 0, 0L, 0L, size, 0);
332 } else if (type == OUT_REL2ADR) {
333 if (segment == segto)
334 error(ERR_PANIC, "intra-segment OUT_REL2ADR");
335 if (segment != NO_SEG) {
337 error(ERR_NONFATAL, "as86 format does not support"
338 " segment base references");
340 offset = *(int64_t *)data;
341 as86_add_piece(s, 1, offset - size + 2, segment, 2L,
345 } else if (type == OUT_REL4ADR) {
346 if (segment == segto)
347 error(ERR_PANIC, "intra-segment OUT_REL4ADR");
348 if (segment != NO_SEG) {
350 error(ERR_NONFATAL, "as86 format does not support"
351 " segment base references");
353 offset = *(int64_t *)data;
354 as86_add_piece(s, 1, offset - size + 4, segment, 4L,
361 static void as86_write(void)
364 int32_t symlen, seglen, segsize;
367 * First, go through the symbol records working out how big
368 * each will be. Also fix up BSS references at this time, and
369 * set the flags words up completely.
373 for (i = 0; i < nsyms; i++) {
374 struct Symbol *sym = saa_rstruct(syms);
375 if (sym->segment == SECT_BSS)
376 sym->segment = SECT_DATA, sym->value += sdata.len;
377 sym->flags |= sym->segment;
379 sym->flags |= 0 << 14, symlen += 4;
380 else if (sym->value >= 0 && sym->value <= 255)
381 sym->flags |= 1 << 14, symlen += 5;
382 else if (sym->value >= 0 && sym->value <= 65535L)
383 sym->flags |= 2 << 14, symlen += 6;
385 sym->flags |= 3 << 14, symlen += 8;
389 * Now do the same for the segments, and get the segment size
390 * descriptor word at the same time.
392 seglen = segsize = 0;
393 if ((uint32_t)stext.len > 65535L)
394 segsize |= 0x03000000L, seglen += 4;
396 segsize |= 0x02000000L, seglen += 2;
397 if ((uint32_t)sdata.len > 65535L)
398 segsize |= 0xC0000000L, seglen += 4;
400 segsize |= 0x80000000L, seglen += 2;
403 * Emit the as86 header.
405 fwriteint32_t(0x000186A3L, as86fp);
407 fwriteint32_t(27 + symlen + seglen + strslen, as86fp); /* header length */
408 fwriteint32_t(stext.len + sdata.len + bsslen, as86fp);
409 fwriteint16_t(strslen, as86fp);
410 fwriteint16_t(0, as86fp); /* class = revision = 0 */
411 fwriteint32_t(0x55555555L, as86fp); /* segment max sizes: always this */
412 fwriteint32_t(segsize, as86fp); /* segment size descriptors */
413 if (segsize & 0x01000000L)
414 fwriteint32_t(stext.len, as86fp);
416 fwriteint16_t(stext.len, as86fp);
417 if (segsize & 0x40000000L)
418 fwriteint32_t(sdata.len + bsslen, as86fp);
420 fwriteint16_t(sdata.len + bsslen, as86fp);
421 fwriteint16_t(nsyms, as86fp);
424 * Write the symbol table.
427 for (i = 0; i < nsyms; i++) {
428 struct Symbol *sym = saa_rstruct(syms);
429 fwriteint16_t(sym->strpos, as86fp);
430 fwriteint16_t(sym->flags, as86fp);
431 switch (sym->flags & (3 << 14)) {
435 fputc(sym->value, as86fp);
438 fwriteint16_t(sym->value, as86fp);
441 fwriteint32_t(sym->value, as86fp);
447 * Write out the string table.
449 saa_fpwrite(strs, as86fp);
452 * Write the program text.
454 as86_reloc_size = -1;
455 as86_write_section(&stext, SECT_TEXT);
456 as86_write_section(&sdata, SECT_DATA);
458 * Append the BSS section to the .data section
460 if (bsslen > 65535L) {
462 fwriteint32_t(bsslen, as86fp);
463 } else if (bsslen > 255) {
465 fwriteint16_t(bsslen, as86fp);
468 fputc(bsslen, as86fp);
471 fputc(0, as86fp); /* termination */
474 static void as86_set_rsize(int size)
476 if (as86_reloc_size != size) {
477 switch (as86_reloc_size = size) {
488 error(ERR_PANIC, "bizarre relocation size %d", size);
493 static void as86_write_section(struct Section *sect, int index)
499 fputc(0x20 + index, as86fp); /* select the right section */
501 saa_rewind(sect->data);
503 for (p = sect->head; p; p = p->next)
507 * Absolute data. Emit it in chunks of at most 64
513 int32_t tmplen = (length > 64 ? 64 : length);
514 fputc(0x40 | (tmplen & 0x3F), as86fp);
515 saa_rnbytes(sect->data, buf, tmplen);
516 fwrite(buf, 1, tmplen, as86fp);
518 } while (length > 0);
522 * A segment-type relocation. First fix up the BSS.
524 if (p->number == SECT_BSS)
525 p->number = SECT_DATA, p->offset += sdata.len;
526 as86_set_rsize(p->bytes);
527 fputc(0x80 | (p->relative ? 0x20 : 0) | p->number, as86fp);
528 if (as86_reloc_size == 2)
529 fwriteint16_t(p->offset, as86fp);
531 fwriteint32_t(p->offset, as86fp);
535 * A symbol-type relocation.
537 as86_set_rsize(p->bytes);
548 (p->relative ? 0x20 : 0) |
549 (p->number > 255 ? 0x04 : 0) | s, as86fp);
551 fwriteint16_t(p->number, as86fp);
553 fputc(p->number, as86fp);
558 fputc(p->offset, as86fp);
561 fwriteint16_t(p->offset, as86fp);
564 fwriteint32_t(p->offset, as86fp);
571 static void as86_sect_write(struct Section *sect,
572 const uint8_t *data, uint32_t len)
574 saa_wbytes(sect->data, data, len);
575 sect->datalen += len;
578 static int32_t as86_segbase(int32_t segment)
583 static int as86_directive(char *directive, char *value, int pass)
591 static void as86_filename(char *inname, char *outname, efunc error)
595 if ((p = strrchr(inname, '.')) != NULL) {
596 strncpy(as86_module, inname, p - inname);
597 as86_module[p - inname] = '\0';
599 strcpy(as86_module, inname);
601 standard_extension(inname, outname, ".o", error);
604 static const char *as86_stdmac[] = {
605 "%define __SECT__ [section .text]",
606 "%macro __NASM_CDecl__ 1",
611 static int as86_set_info(enum geninfo type, char **val)
617 void as86_linenumber(char *name, int32_t segment, int32_t offset, int is_main,
626 struct ofmt of_as86 = {
627 "Linux as86 (bin86 version 0.3) object files",