diff options
Diffstat (limited to 'outbin.c')
| -rw-r--r-- | outbin.c | 303 |
1 files changed, 303 insertions, 0 deletions
diff --git a/outbin.c b/outbin.c new file mode 100644 index 00000000..82c85106 --- /dev/null +++ b/outbin.c @@ -0,0 +1,303 @@ +/* outbin.c output routines for the Netwide Assembler to produce + * flat-form binary files + * + * The Netwide Assembler is copyright (C) 1996 Simon Tatham and + * Julian Hall. All rights reserved. The software is + * redistributable under the licence given in the file "Licence" + * distributed in the NASM archive. + */ + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include "nasm.h" +#include "nasmlib.h" +#include "outform.h" + +#ifdef OF_BIN + +static FILE *fp; +static efunc error; + +static struct Section { + struct SAA *contents; + long length; + long index; +} textsect, datasect; +static long bsslen, bssindex; + +static struct Reloc { + struct Reloc *next; + long posn; + long bytes; + long secref; + long secrel; + struct Section *target; +} *relocs, **reloctail; + +static int start_point; + +static void add_reloc (struct Section *s, long bytes, long secref, + long secrel) { + struct Reloc *r; + + r = *reloctail = nasm_malloc(sizeof(struct Reloc)); + reloctail = &r->next; + r->next = NULL; + r->posn = s->length; + r->bytes = bytes; + r->secref = secref; + r->secrel = secrel; + r->target = s; +} + +static void bin_init (FILE *afp, efunc errfunc, ldfunc ldef) { + fp = afp; + + error = errfunc; + (void) ldef; /* placate optimisers */ + + start_point = 0; /* default */ + textsect.contents = saa_init(1L); + datasect.contents = saa_init(1L); + textsect.length = datasect.length = 0; + textsect.index = seg_alloc(); + datasect.index = seg_alloc(); + bsslen = 0; + bssindex = seg_alloc(); + relocs = NULL; + reloctail = &relocs; +} + +static void bin_cleanup (void) { + struct Reloc *r; + long datapos, dataalign, bsspos; + + datapos = (start_point + textsect.length + 3) & ~3;/* align on 4 bytes */ + dataalign = datapos - (start_point + textsect.length); + + saa_rewind (textsect.contents); + saa_rewind (datasect.contents); + + bsspos = (datapos + datasect.length + 3) & ~3; + + for (r = relocs; r; r = r->next) { + unsigned char *p, *q, mydata[4]; + long l; + + saa_fread (r->target->contents, r->posn, mydata, r->bytes); + p = q = mydata; + l = *p++; + l += ((long)*p++) << 8; + if (r->bytes == 4) { + l += ((long)*p++) << 16; + l += ((long)*p++) << 24; + } + + if (r->secref == textsect.index) + l += start_point; + else if (r->secref == datasect.index) + l += datapos; + else if (r->secref == bssindex) + l += bsspos; + + if (r->secrel == textsect.index) + l -= start_point; + else if (r->secrel == datasect.index) + l -= datapos; + else if (r->secrel == bssindex) + l -= bsspos; + + if (r->bytes == 4) + WRITELONG(q, l); + else + WRITESHORT(q, l); + saa_fwrite (r->target->contents, r->posn, mydata, r->bytes); + } + saa_fpwrite (textsect.contents, fp); + if (datasect.length > 0) { + fwrite ("\0\0\0\0", dataalign, 1, fp); + saa_fpwrite (datasect.contents, fp); + } + fclose (fp); + saa_free (textsect.contents); + saa_free (datasect.contents); + while (relocs) { + r = relocs->next; + nasm_free (relocs); + relocs = r; + } +} + +static void bin_out (long segto, void *data, unsigned long type, + long segment, long wrt) { + unsigned char *p, mydata[4]; + struct Section *s; + long realbytes; + + if (wrt != NO_SEG) { + wrt = NO_SEG; /* continue to do _something_ */ + error (ERR_NONFATAL, "WRT not supported by binary output format"); + } + + /* + * handle absolute-assembly (structure definitions) + */ + if (segto == NO_SEG) { + if ((type & OUT_TYPMASK) != OUT_RESERVE) + error (ERR_NONFATAL, "attempt to assemble code in [ABSOLUTE]" + " space"); + return; + } + + if (segto == bssindex) { /* BSS */ + if ((type & OUT_TYPMASK) != OUT_RESERVE) + error(ERR_WARNING, "attempt to initialise memory in the" + " BSS section: ignored"); + s = NULL; + } else if (segto == textsect.index) { + s = &textsect; + } else if (segto == datasect.index) { + s = &datasect; + } else { + error(ERR_WARNING, "attempt to assemble code in" + " segment %d: defaulting to `.text'", segto); + s = &textsect; + } + + if ((type & OUT_TYPMASK) == OUT_ADDRESS) { + if (segment != NO_SEG && + segment != textsect.index && + segment != datasect.index && + segment != bssindex) { + if (segment % 2) + error(ERR_NONFATAL, "binary output format does not support" + " segment base references"); + else + error(ERR_NONFATAL, "binary output format does not support" + " external references"); + segment = NO_SEG; + } + if (s) { + if (segment != NO_SEG) + add_reloc (s, type & OUT_SIZMASK, segment, -1L); + p = mydata; + if ((type & OUT_SIZMASK) == 4) + WRITELONG (p, *(long *)data); + else + WRITESHORT (p, *(long *)data); + saa_wbytes (s->contents, mydata, type & OUT_SIZMASK); + s->length += type & OUT_SIZMASK; + } else + bsslen += type & OUT_SIZMASK; + } else if ((type & OUT_TYPMASK) == OUT_RAWDATA) { + type &= OUT_SIZMASK; + p = data; + if (s) { + saa_wbytes (s->contents, data, type); + s->length += type; + } else + bsslen += type; + } else if ((type & OUT_TYPMASK) == OUT_RESERVE) { + if (s) { + error(ERR_WARNING, "uninitialised space declared in" + " %s section: zeroing", + (segto == textsect.index ? "code" : "data")); + } + type &= OUT_SIZMASK; + if (s) { + saa_wbytes (s->contents, NULL, type); + s->length += type; + } else + bsslen += type; + } else if ((type & OUT_TYPMASK) == OUT_REL2ADR || + (type & OUT_TYPMASK) == OUT_REL4ADR) { + realbytes = ((type & OUT_TYPMASK) == OUT_REL4ADR ? 4 : 2); + if (segment != NO_SEG && + segment != textsect.index && + segment != datasect.index && + segment != bssindex) { + if (segment % 2) + error(ERR_NONFATAL, "binary output format does not support" + " segment base references"); + else + error(ERR_NONFATAL, "binary output format does not support" + " external references"); + segment = NO_SEG; + } + if (s) { + add_reloc (s, realbytes, segment, segto); + p = mydata; + if (realbytes == 4) + WRITELONG (p, *(long*)data - realbytes - s->length); + else + WRITESHORT (p, *(long*)data - realbytes - s->length); + saa_wbytes (s->contents, mydata, realbytes); + s->length += realbytes; + } else + bsslen += realbytes; + } +} + +static void bin_deflabel (char *name, long segment, long offset, + int is_global) { + if (is_global == 2) { + error (ERR_NONFATAL, "binary output format does not support common" + " variables"); + } +} + +static long bin_secname (char *name, int pass, int *bits) { + /* + * Default is 16 bits. + */ + if (!name) + *bits = 16; + + if (!name) + return textsect.index; + + if (!strcmp(name, ".text")) + return textsect.index; + else if (!strcmp(name, ".data")) + return datasect.index; + else if (!strcmp(name, ".bss")) + return bssindex; + else + return NO_SEG; +} + +static long bin_segbase (long segment) { + return segment; +} + +static int bin_directive (char *directive, char *value, int pass) { + int rn_error; + + if (!strcmp(directive, "org")) { + start_point = readnum (value, &rn_error); + if (rn_error) + error (ERR_NONFATAL, "argument to ORG should be numeric"); + return 1; + } else + return 0; +} + +static void bin_filename (char *inname, char *outname, efunc error) { + standard_extension (inname, outname, "", error); +} + +struct ofmt of_bin = { + "flat-form binary files (e.g. DOS .COM, .SYS)", + "bin", + bin_init, + bin_out, + bin_deflabel, + bin_secname, + bin_segbase, + bin_directive, + bin_filename, + bin_cleanup +}; + +#endif /* OF_BIN */ |