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645 lines
17 KiB
C
645 lines
17 KiB
C
/* outas86.c output routines for the Netwide Assembler to produce
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* Linux as86 (bin86-0.3) object files
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*
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* The Netwide Assembler is copyright (C) 1996 Simon Tatham and
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* Julian Hall. All rights reserved. The software is
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* redistributable under the licence given in the file "Licence"
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* distributed in the NASM archive.
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <ctype.h>
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#include <inttypes.h>
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#include "nasm.h"
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#include "nasmlib.h"
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#include "outform.h"
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#ifdef OF_AS86
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struct Piece {
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struct Piece *next;
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int type; /* 0 = absolute, 1 = seg, 2 = sym */
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int32_t offset; /* relative offset */
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int number; /* symbol/segment number (4=bss) */
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int32_t bytes; /* size of reloc or of absolute data */
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int relative; /* TRUE or FALSE */
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};
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struct Symbol {
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int32_t strpos; /* string table position of name */
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int flags; /* symbol flags */
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int segment; /* 4=bss at this point */
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int32_t value; /* address, or COMMON variable size */
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};
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/*
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* Section IDs - used in Piece.number and Symbol.segment.
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*/
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#define SECT_TEXT 0 /* text section */
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#define SECT_DATA 3 /* data section */
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#define SECT_BSS 4 /* bss section */
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/*
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* Flags used in Symbol.flags.
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*/
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#define SYM_ENTRY (1<<8)
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#define SYM_EXPORT (1<<7)
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#define SYM_IMPORT (1<<6)
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#define SYM_ABSOLUTE (1<<4)
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struct Section {
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struct SAA *data;
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uint32_t datalen, size, len;
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int32_t index;
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struct Piece *head, *last, **tail;
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};
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static char as86_module[FILENAME_MAX];
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static struct Section stext, sdata;
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static uint32_t bsslen;
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static int32_t bssindex;
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static struct SAA *syms;
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static uint32_t nsyms;
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static struct RAA *bsym;
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static struct SAA *strs;
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static uint32_t strslen;
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static int as86_reloc_size;
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static FILE *as86fp;
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static efunc error;
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static void as86_write(void);
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static void as86_write_section(struct Section *, int);
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static int as86_add_string(char *name);
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static void as86_sect_write(struct Section *, const uint8_t *,
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uint32_t);
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static void as86_init(FILE * fp, efunc errfunc, ldfunc ldef, evalfunc eval)
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{
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as86fp = fp;
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error = errfunc;
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(void)ldef; /* placate optimisers */
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(void)eval;
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stext.data = saa_init(1L);
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stext.datalen = 0L;
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stext.head = stext.last = NULL;
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stext.tail = &stext.head;
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sdata.data = saa_init(1L);
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sdata.datalen = 0L;
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sdata.head = sdata.last = NULL;
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sdata.tail = &sdata.head;
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bsslen =
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stext.len = stext.datalen = stext.size =
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sdata.len = sdata.datalen = sdata.size = 0;
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stext.index = seg_alloc();
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sdata.index = seg_alloc();
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bssindex = seg_alloc();
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syms = saa_init((int32_t)sizeof(struct Symbol));
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nsyms = 0;
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bsym = raa_init();
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strs = saa_init(1L);
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strslen = 0;
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as86_add_string(as86_module);
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}
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static void as86_cleanup(int debuginfo)
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{
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struct Piece *p;
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(void)debuginfo;
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as86_write();
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fclose(as86fp);
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saa_free(stext.data);
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while (stext.head) {
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p = stext.head;
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stext.head = stext.head->next;
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nasm_free(p);
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}
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saa_free(sdata.data);
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while (sdata.head) {
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p = sdata.head;
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sdata.head = sdata.head->next;
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nasm_free(p);
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}
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saa_free(syms);
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raa_free(bsym);
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saa_free(strs);
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}
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static int32_t as86_section_names(char *name, int pass, int *bits)
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{
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(void)pass;
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/*
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* Default is 16 bits.
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*/
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if (!name)
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*bits = 16;
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if (!name)
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return stext.index;
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if (!strcmp(name, ".text"))
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return stext.index;
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else if (!strcmp(name, ".data"))
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return sdata.index;
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else if (!strcmp(name, ".bss"))
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return bssindex;
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else
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return NO_SEG;
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}
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static int as86_add_string(char *name)
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{
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int pos = strslen;
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int length = strlen(name);
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saa_wbytes(strs, name, (int32_t)(length + 1));
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strslen += 1 + length;
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return pos;
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}
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static void as86_deflabel(char *name, int32_t segment, int32_t offset,
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int is_global, char *special)
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{
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struct Symbol *sym;
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if (special)
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error(ERR_NONFATAL, "as86 format does not support any"
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" special symbol types");
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if (name[0] == '.' && name[1] == '.' && name[2] != '@') {
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error(ERR_NONFATAL, "unrecognised special symbol `%s'", name);
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return;
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}
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sym = saa_wstruct(syms);
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sym->strpos = as86_add_string(name);
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sym->flags = 0;
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if (segment == NO_SEG)
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sym->flags |= SYM_ABSOLUTE, sym->segment = 0;
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else if (segment == stext.index)
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sym->segment = SECT_TEXT;
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else if (segment == sdata.index)
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sym->segment = SECT_DATA;
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else if (segment == bssindex)
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sym->segment = SECT_BSS;
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else {
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sym->flags |= SYM_IMPORT;
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sym->segment = 15;
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}
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if (is_global == 2)
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sym->segment = 3; /* already have IMPORT */
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if (is_global && !(sym->flags & SYM_IMPORT))
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sym->flags |= SYM_EXPORT;
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sym->value = offset;
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/*
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* define the references from external-symbol segment numbers
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* to these symbol records.
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*/
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if (segment != NO_SEG && segment != stext.index &&
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segment != sdata.index && segment != bssindex)
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bsym = raa_write(bsym, segment, nsyms);
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nsyms++;
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}
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static void as86_add_piece(struct Section *sect, int type, int32_t offset,
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int32_t segment, int32_t bytes, int relative)
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{
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struct Piece *p;
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sect->len += bytes;
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if (type == 0 && sect->last && sect->last->type == 0) {
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sect->last->bytes += bytes;
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return;
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}
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p = sect->last = *sect->tail = nasm_malloc(sizeof(struct Piece));
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sect->tail = &p->next;
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p->next = NULL;
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p->type = type;
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p->offset = offset;
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p->bytes = bytes;
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p->relative = relative;
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if (type == 1 && segment == stext.index)
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p->number = SECT_TEXT;
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else if (type == 1 && segment == sdata.index)
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p->number = SECT_DATA;
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else if (type == 1 && segment == bssindex)
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p->number = SECT_BSS;
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else if (type == 1)
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p->number = raa_read(bsym, segment), p->type = 2;
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}
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static void as86_out(int32_t segto, const void *data, uint32_t type,
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int32_t segment, int32_t wrt)
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{
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struct Section *s;
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int32_t realbytes = type & OUT_SIZMASK;
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int32_t offset;
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uint8_t mydata[4], *p;
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if (wrt != NO_SEG) {
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wrt = NO_SEG; /* continue to do _something_ */
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error(ERR_NONFATAL, "WRT not supported by as86 output format");
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}
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type &= OUT_TYPMASK;
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/*
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* handle absolute-assembly (structure definitions)
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*/
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if (segto == NO_SEG) {
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if (type != OUT_RESERVE)
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error(ERR_NONFATAL, "attempt to assemble code in [ABSOLUTE]"
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" space");
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return;
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}
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if (segto == stext.index)
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s = &stext;
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else if (segto == sdata.index)
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s = &sdata;
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else if (segto == bssindex)
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s = NULL;
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else {
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error(ERR_WARNING, "attempt to assemble code in"
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" segment %d: defaulting to `.text'", segto);
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s = &stext;
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}
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if (!s && type != OUT_RESERVE) {
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error(ERR_WARNING, "attempt to initialize memory in the"
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" BSS section: ignored");
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if (type == OUT_REL2ADR)
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realbytes = 2;
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else if (type == OUT_REL4ADR)
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realbytes = 4;
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bsslen += realbytes;
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return;
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}
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if (type == OUT_RESERVE) {
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if (s) {
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error(ERR_WARNING, "uninitialized space declared in"
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" %s section: zeroing",
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(segto == stext.index ? "code" : "data"));
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as86_sect_write(s, NULL, realbytes);
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as86_add_piece(s, 0, 0L, 0L, realbytes, 0);
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} else
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bsslen += realbytes;
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} else if (type == OUT_RAWDATA) {
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if (segment != NO_SEG)
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error(ERR_PANIC, "OUT_RAWDATA with other than NO_SEG");
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as86_sect_write(s, data, realbytes);
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as86_add_piece(s, 0, 0L, 0L, realbytes, 0);
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} else if (type == OUT_ADDRESS) {
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if (segment != NO_SEG) {
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if (segment % 2) {
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error(ERR_NONFATAL, "as86 format does not support"
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" segment base references");
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} else {
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offset = *(int32_t *)data;
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as86_add_piece(s, 1, offset, segment, realbytes, 0);
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}
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} else {
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p = mydata;
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WRITELONG(p, *(int32_t *)data);
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as86_sect_write(s, data, realbytes);
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as86_add_piece(s, 0, 0L, 0L, realbytes, 0);
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}
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} else if (type == OUT_REL2ADR) {
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if (segment == segto)
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error(ERR_PANIC, "intra-segment OUT_REL2ADR");
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if (segment != NO_SEG) {
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if (segment % 2) {
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error(ERR_NONFATAL, "as86 format does not support"
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" segment base references");
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} else {
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offset = *(int32_t *)data;
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as86_add_piece(s, 1, offset - realbytes + 2, segment, 2L,
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1);
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}
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}
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} else if (type == OUT_REL4ADR) {
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if (segment == segto)
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error(ERR_PANIC, "intra-segment OUT_REL4ADR");
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if (segment != NO_SEG) {
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if (segment % 2) {
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error(ERR_NONFATAL, "as86 format does not support"
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" segment base references");
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} else {
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offset = *(int32_t *)data;
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as86_add_piece(s, 1, offset - realbytes + 4, segment, 4L,
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1);
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}
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}
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}
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}
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static void as86_write(void)
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{
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uint32_t i;
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int32_t symlen, seglen, segsize;
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/*
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* First, go through the symbol records working out how big
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* each will be. Also fix up BSS references at this time, and
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* set the flags words up completely.
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*/
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symlen = 0;
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saa_rewind(syms);
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for (i = 0; i < nsyms; i++) {
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struct Symbol *sym = saa_rstruct(syms);
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if (sym->segment == SECT_BSS)
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sym->segment = SECT_DATA, sym->value += sdata.len;
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sym->flags |= sym->segment;
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if (sym->value == 0)
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sym->flags |= 0 << 14, symlen += 4;
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else if (sym->value >= 0 && sym->value <= 255)
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sym->flags |= 1 << 14, symlen += 5;
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else if (sym->value >= 0 && sym->value <= 65535L)
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sym->flags |= 2 << 14, symlen += 6;
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else
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sym->flags |= 3 << 14, symlen += 8;
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}
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/*
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* Now do the same for the segments, and get the segment size
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* descriptor word at the same time.
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*/
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seglen = segsize = 0;
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if ((uint32_t)stext.len > 65535L)
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segsize |= 0x03000000L, seglen += 4;
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else
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segsize |= 0x02000000L, seglen += 2;
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if ((uint32_t)sdata.len > 65535L)
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segsize |= 0xC0000000L, seglen += 4;
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else
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segsize |= 0x80000000L, seglen += 2;
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/*
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* Emit the as86 header.
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*/
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fwriteint32_t(0x000186A3L, as86fp);
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fputc(0x2A, as86fp);
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fwriteint32_t(27 + symlen + seglen + strslen, as86fp); /* header length */
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fwriteint32_t(stext.len + sdata.len + bsslen, as86fp);
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fwriteint16_t(strslen, as86fp);
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fwriteint16_t(0, as86fp); /* class = revision = 0 */
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fwriteint32_t(0x55555555L, as86fp); /* segment max sizes: always this */
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fwriteint32_t(segsize, as86fp); /* segment size descriptors */
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if (segsize & 0x01000000L)
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fwriteint32_t(stext.len, as86fp);
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else
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fwriteint16_t(stext.len, as86fp);
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if (segsize & 0x40000000L)
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fwriteint32_t(sdata.len + bsslen, as86fp);
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else
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fwriteint16_t(sdata.len + bsslen, as86fp);
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fwriteint16_t(nsyms, as86fp);
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/*
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* Write the symbol table.
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*/
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saa_rewind(syms);
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for (i = 0; i < nsyms; i++) {
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struct Symbol *sym = saa_rstruct(syms);
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fwriteint16_t(sym->strpos, as86fp);
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fwriteint16_t(sym->flags, as86fp);
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switch (sym->flags & (3 << 14)) {
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case 0 << 14:
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break;
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case 1 << 14:
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fputc(sym->value, as86fp);
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break;
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case 2 << 14:
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fwriteint16_t(sym->value, as86fp);
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break;
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case 3 << 14:
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fwriteint32_t(sym->value, as86fp);
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break;
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}
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}
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/*
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* Write out the string table.
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*/
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saa_fpwrite(strs, as86fp);
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/*
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* Write the program text.
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*/
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as86_reloc_size = -1;
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as86_write_section(&stext, SECT_TEXT);
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as86_write_section(&sdata, SECT_DATA);
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/*
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* Append the BSS section to the .data section
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*/
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if (bsslen > 65535L) {
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fputc(0x13, as86fp);
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fwriteint32_t(bsslen, as86fp);
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} else if (bsslen > 255) {
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fputc(0x12, as86fp);
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fwriteint16_t(bsslen, as86fp);
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} else if (bsslen) {
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fputc(0x11, as86fp);
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fputc(bsslen, as86fp);
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}
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fputc(0, as86fp); /* termination */
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}
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static void as86_set_rsize(int size)
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{
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if (as86_reloc_size != size) {
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switch (as86_reloc_size = size) {
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case 1:
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fputc(0x01, as86fp);
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break;
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case 2:
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fputc(0x02, as86fp);
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break;
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case 4:
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fputc(0x03, as86fp);
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break;
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default:
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error(ERR_PANIC, "bizarre relocation size %d", size);
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}
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}
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}
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static void as86_write_section(struct Section *sect, int index)
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{
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struct Piece *p;
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uint32_t s;
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int32_t length;
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fputc(0x20 + index, as86fp); /* select the right section */
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saa_rewind(sect->data);
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for (p = sect->head; p; p = p->next)
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switch (p->type) {
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case 0:
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/*
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* Absolute data. Emit it in chunks of at most 64
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* bytes.
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*/
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length = p->bytes;
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do {
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char buf[64];
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int32_t tmplen = (length > 64 ? 64 : length);
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fputc(0x40 | (tmplen & 0x3F), as86fp);
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saa_rnbytes(sect->data, buf, tmplen);
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fwrite(buf, 1, tmplen, as86fp);
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length -= tmplen;
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} while (length > 0);
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break;
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case 1:
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/*
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* A segment-type relocation. First fix up the BSS.
|
|
*/
|
|
if (p->number == SECT_BSS)
|
|
p->number = SECT_DATA, p->offset += sdata.len;
|
|
as86_set_rsize(p->bytes);
|
|
fputc(0x80 | (p->relative ? 0x20 : 0) | p->number, as86fp);
|
|
if (as86_reloc_size == 2)
|
|
fwriteint16_t(p->offset, as86fp);
|
|
else
|
|
fwriteint32_t(p->offset, as86fp);
|
|
break;
|
|
case 2:
|
|
/*
|
|
* A symbol-type relocation.
|
|
*/
|
|
as86_set_rsize(p->bytes);
|
|
s = p->offset;
|
|
if (s > 65535L)
|
|
s = 3;
|
|
else if (s > 255)
|
|
s = 2;
|
|
else if (s > 0)
|
|
s = 1;
|
|
else
|
|
s = 0;
|
|
fputc(0xC0 |
|
|
(p->relative ? 0x20 : 0) |
|
|
(p->number > 255 ? 0x04 : 0) | s, as86fp);
|
|
if (p->number > 255)
|
|
fwriteint16_t(p->number, as86fp);
|
|
else
|
|
fputc(p->number, as86fp);
|
|
switch ((int)s) {
|
|
case 0:
|
|
break;
|
|
case 1:
|
|
fputc(p->offset, as86fp);
|
|
break;
|
|
case 2:
|
|
fwriteint16_t(p->offset, as86fp);
|
|
break;
|
|
case 3:
|
|
fwriteint32_t(p->offset, as86fp);
|
|
break;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
|
|
static void as86_sect_write(struct Section *sect,
|
|
const uint8_t *data, uint32_t len)
|
|
{
|
|
saa_wbytes(sect->data, data, len);
|
|
sect->datalen += len;
|
|
}
|
|
|
|
static int32_t as86_segbase(int32_t segment)
|
|
{
|
|
return segment;
|
|
}
|
|
|
|
static int as86_directive(char *directive, char *value, int pass)
|
|
{
|
|
(void)directive;
|
|
(void)value;
|
|
(void)pass;
|
|
return 0;
|
|
}
|
|
|
|
static void as86_filename(char *inname, char *outname, efunc error)
|
|
{
|
|
char *p;
|
|
|
|
if ((p = strrchr(inname, '.')) != NULL) {
|
|
strncpy(as86_module, inname, p - inname);
|
|
as86_module[p - inname] = '\0';
|
|
} else
|
|
strcpy(as86_module, inname);
|
|
|
|
standard_extension(inname, outname, ".o", error);
|
|
}
|
|
|
|
static const char *as86_stdmac[] = {
|
|
"%define __SECT__ [section .text]",
|
|
"%macro __NASM_CDecl__ 1",
|
|
"%endmacro",
|
|
NULL
|
|
};
|
|
|
|
static int as86_set_info(enum geninfo type, char **val)
|
|
{
|
|
(void)type;
|
|
(void)val;
|
|
return 0;
|
|
}
|
|
void as86_linenumber(char *name, int32_t segment, int32_t offset, int is_main,
|
|
int lineno)
|
|
{
|
|
(void)name;
|
|
(void)segment;
|
|
(void)offset;
|
|
(void)is_main;
|
|
(void)lineno;
|
|
}
|
|
struct ofmt of_as86 = {
|
|
"Linux as86 (bin86 version 0.3) object files",
|
|
"as86",
|
|
NULL,
|
|
null_debug_arr,
|
|
&null_debug_form,
|
|
as86_stdmac,
|
|
as86_init,
|
|
as86_set_info,
|
|
as86_out,
|
|
as86_deflabel,
|
|
as86_section_names,
|
|
as86_segbase,
|
|
as86_directive,
|
|
as86_filename,
|
|
as86_cleanup
|
|
};
|
|
|
|
#endif /* OF_AS86 */
|