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590 lines
14 KiB
C
590 lines
14 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 "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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long offset; /* relative offset */
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int number; /* symbol/segment number (4=bss) */
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long 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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long 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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long 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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unsigned long datalen, size, len;
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long 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 unsigned long bsslen;
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static long bssindex;
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static struct SAA *syms;
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static unsigned long nsyms;
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static struct RAA *bsym;
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static struct SAA *strs;
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static unsigned long 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 unsigned char *, unsigned long);
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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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stext.data = saa_init(1L); 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); 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((long)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 long as86_section_names (char *name, int pass, int *bits)
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{
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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, (long)(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, long segment, long 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, long offset,
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long segment, long 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 (long segto, const void *data, unsigned long type,
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long segment, long wrt)
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{
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struct Section *s;
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long realbytes = type & OUT_SIZMASK;
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long offset;
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unsigned char 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 initialise 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, "uninitialised 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 = * (long *) 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, * (long *) 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 = * (long *) data;
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as86_add_piece (s, 1, offset-realbytes+2, segment, 2L, 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 = * (long *) data;
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as86_add_piece (s, 1, offset-realbytes+4, segment, 4L, 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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unsigned long i;
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long 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 ((unsigned long) 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 ((unsigned long) 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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fwritelong (0x000186A3L, as86fp);
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fputc (0x2A, as86fp);
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fwritelong (27+symlen+seglen+strslen, as86fp); /* header length */
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fwritelong (stext.len+sdata.len, as86fp);
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fwriteshort (strslen, as86fp);
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fwriteshort (0, as86fp); /* class = revision = 0 */
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fwritelong (0x55555555L, as86fp); /* segment max sizes: always this */
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fwritelong (segsize, as86fp); /* segment size descriptors */
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if (segsize & 0x01000000L)
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fwritelong (stext.len, as86fp);
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else
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fwriteshort (stext.len, as86fp);
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if (segsize & 0x40000000L)
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fwritelong (sdata.len, as86fp);
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else
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fwriteshort (sdata.len, as86fp);
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fwriteshort (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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fwriteshort (sym->strpos, as86fp);
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fwriteshort (sym->flags, as86fp);
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switch (sym->flags & (3<<14)) {
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case 0<<14: break;
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case 1<<14: fputc (sym->value, as86fp); break;
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case 2<<14: fwriteshort (sym->value, as86fp); break;
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case 3<<14: fwritelong (sym->value, as86fp); 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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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: fputc (0x01, as86fp); break;
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case 2: fputc (0x02, as86fp); break;
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case 4: fputc (0x03, as86fp); break;
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default: 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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unsigned long s;
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long 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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long 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.
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*/
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if (p->number == SECT_BSS)
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p->number = SECT_DATA, p->offset += sdata.len;
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as86_set_rsize (p->bytes);
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fputc (0x80 | (p->relative ? 0x20 : 0) | p->number, as86fp);
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if (as86_reloc_size == 2)
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fwriteshort (p->offset, as86fp);
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else
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fwritelong (p->offset, as86fp);
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break;
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case 2:
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/*
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* A symbol-type relocation.
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*/
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as86_set_rsize (p->bytes);
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s = p->offset;
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if (s > 65535L)
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s = 3;
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else if (s > 255)
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s = 2;
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else if (s > 0)
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s = 1;
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else
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s = 0;
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fputc (0xC0 |
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(p->relative ? 0x20 : 0) |
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(p->number > 255 ? 0x04 : 0) | s, as86fp);
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if (p->number > 255)
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fwriteshort (p->number, as86fp);
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else
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fputc (p->number, as86fp);
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switch ((int)s) {
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case 0: break;
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case 1: fputc (p->offset, as86fp); break;
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case 2: fwriteshort (p->offset, as86fp); break;
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|
case 3: fwritelong (p->offset, as86fp); break;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
|
|
static void as86_sect_write (struct Section *sect,
|
|
const unsigned char *data, unsigned long len)
|
|
{
|
|
saa_wbytes (sect->data, data, len);
|
|
sect->datalen += len;
|
|
}
|
|
|
|
static long as86_segbase (long segment)
|
|
{
|
|
return segment;
|
|
}
|
|
|
|
static int as86_directive (char *directive, char *value, int 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)
|
|
{
|
|
return 0;
|
|
}
|
|
void as86_linenumber (char *name, long segment, long offset, int is_main,
|
|
int 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 */
|