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6502/vasm/output_aout.c

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/* output_aout.c a.out output driver for vasm */
/* (c) in 2008-2016 by Frank Wille */
#include "vasm.h"
#include "output_aout.h"
#if defined(OUTAOUT) && defined(MID)
static char *copyright="vasm a.out output module 0.7c (c) 2008-2016 Frank Wille";
static section *sections[3];
static utaddr secsize[3];
static utaddr secoffs[3];
static int sectype[] = { N_TEXT, N_DATA, N_BSS };
static int secweak[] = { N_WEAKT, N_WEAKD, N_WEAKB };
static struct SymTabList aoutsymlist;
static struct StrTabList aoutstrlist;
static struct list treloclist;
static struct list dreloclist;
static int mid = -1;
static int isPIC = 1;
#define SECT_ALIGN 4 /* .text and .data are aligned to 32 bits */
static int get_sec_type(section *s)
/* scan section attributes for type, 0=text, 1=data, 2=bss,
-1: ORG-section at an absolute address */
{
char *a = s->attr;
if (s->flags & ABSOLUTE)
return -1;
while (*a) {
switch (*a++) {
case 'c':
return _TEXT;
case 'd':
return _DATA;
case 'u':
return _BSS;
}
}
output_error(3,s->attr); /* section attributes not supported */
return 0;
}
static int aout_getinfo(symbol *sym)
{
int type;
switch (TYPE(sym)) {
case TYPE_UNKNOWN:
case TYPE_FILE:
case TYPE_SECTION: /* this will be ignored later */
type = AUX_UNKNOWN;
break;
case TYPE_OBJECT:
type = AUX_OBJECT;
break;
case TYPE_FUNCTION:
type = AUX_FUNC;
break;
default:
ierror(0);
break;
}
return type;
}
static int aout_getbind(symbol *sym)
{
if (sym->flags & WEAK)
return BIND_WEAK;
else if (sym->type!=IMPORT && !(sym->flags & EXPORT))
return BIND_LOCAL;
else if ((sym->type!=IMPORT && (sym->flags & EXPORT)) ||
(sym->type==IMPORT && (sym->flags & COMMON)))
return BIND_GLOBAL;
else
ierror(0);
return -1;
}
static uint32_t aoutstd_getrinfo(rlist **rl,int xtern,char *sname,int be)
/* Convert vasm relocation type into standard a.out relocations, */
/* as used by M68k and x86 targets. */
/* For xtern=-1, return true when this relocation requires a base symbol. */
{
nreloc *nr;
if (nr = (nreloc *)(*rl)->reloc) {
rlist *rl2 = (*rl)->next;
uint32_t r=0,s=4;
nreloc *nr2;
int b=0;
switch ((*rl)->type) {
case REL_ABS: b=-1; break;
case REL_PC: b=RSTDB_pcrel; break;
case REL_SD: b=RSTDB_baserel; break;
default: goto unsupp_reloc;
}
if (xtern == -1) /* just query symbol-based relocation */
return b==RSTDB_baserel || b==RSTDB_jmptable;
nr2 = rl2!=NULL ? (nreloc *)rl2->reloc : NULL;
if (nr->bitoffset==0 && (nr2==NULL || nr2->byteoffset!=nr->byteoffset)
&& (nr->mask & MAKEMASK(nr->size)) == MAKEMASK(nr->size)) {
switch (nr->size) {
case 8: s=0; break;
case 16: s=1; break;
case 32: s=2; break;
}
}
#ifdef VASM_CPU_JAGRISC
else if (nr->size==16 && nr2!=NULL && nr2->size==16 &&
nr2->byteoffset==nr->byteoffset &&
((nr->mask==0xffff && nr2->mask==0xffff0000) ||
(nr->mask==0xffff0000 && nr2->mask==0xffff)) &&
((nr->bitoffset==0 && nr2->bitoffset==16) ||
(nr->bitoffset==16 && nr2->bitoffset==0))) {
/* Jaguar RISC MOVEI instruction with swapped words, indicated by
a set RSTDB_copy bit. */
b = RSTDB_copy;
s = 2;
*rl = (*rl)->next; /* skip additional entry */
}
#endif
if (b!=0 && s<4) {
if (b > 0)
setbits(be,&r,sizeof(r)<<3,(unsigned)b,1,1);
setbits(be,&r,sizeof(r)<<3,RSTDB_length,RSTDS_length,s);
setbits(be,&r,sizeof(r)<<3,RSTDB_extern,RSTDS_extern,xtern?1:0);
return readbits(be,&r,sizeof(r)<<3,RELB_reloc,RELS_reloc);
}
}
unsupp_reloc:
unsupp_reloc_error(*rl);
return ~0;
}
static void aout_initwrite(section *firstsec)
{
section *sec;
if (mid == -1)
mid = MID;
initlist(&aoutstrlist.l);
aoutstrlist.hashtab = mycalloc(STRHTABSIZE*sizeof(struct StrTabNode *));
aoutstrlist.nextoffset = 4; /* first string is always at offset 4 */
initlist(&aoutsymlist.l);
aoutsymlist.hashtab = mycalloc(SYMHTABSIZE*sizeof(struct SymbolNode *));
aoutsymlist.nextindex = 0;
initlist(&treloclist);
initlist(&dreloclist);
/* find exactly one .text, .data and .bss section for a.out */
sections[_TEXT] = sections[_DATA] = sections[_BSS] = NULL;
secsize[_TEXT] = secsize[_DATA] = secsize[_BSS] = 0;
for (sec=firstsec; sec; sec=sec->next) {
int i;
/* section size is assumed to be in in (sec->pc - sec->org), otherwise
we would have to calculate it from the atoms and store it there */
if (get_sec_size(sec) > 0 || (sec->flags & HAS_SYMBOLS)) {
i = get_sec_type(sec);
if (i < 0)
continue; /* ignore ORG sections for later */
if (!sections[i]) {
sections[i] = sec;
secsize[i] = get_sec_size(sec);
sec->idx = i; /* section index 0:text, 1:data, 2:bss */
}
else
output_error(7,sec->name);
}
}
/* now scan for absolute ORG-sections and add their aligned size to .text */
for (sec=firstsec; sec; sec=sec->next) {
if (sec->flags & ABSOLUTE)
secsize[_TEXT] += balign(secsize[_TEXT],sec->align) + get_sec_size(sec);
}
secoffs[_TEXT] = 0;
secoffs[_DATA] = secsize[_TEXT] + balign(secsize[_TEXT],SECT_ALIGN);
secoffs[_BSS] = secoffs[_DATA] + secsize[_DATA] +
balign(secsize[_DATA],SECT_ALIGN);
}
static uint32_t aout_addstr(char *s)
/* add a new symbol name to the string table and return its offset */
{
struct StrTabNode **chain;
struct StrTabNode *sn;
if (s == NULL)
return 0;
if (*s == '\0')
return 0;
/* search string in hash table */
chain = &aoutstrlist.hashtab[hashcode(s)%STRHTABSIZE];
while (sn = *chain) {
if (!strcmp(s,sn->str))
return (sn->offset); /* it's already in, return offset */
chain = &sn->hashchain;
}
/* new string table entry */
*chain = sn = mymalloc(sizeof(struct StrTabNode));
sn->hashchain = NULL;
sn->str = s;
sn->offset = aoutstrlist.nextoffset;
addtail(&aoutstrlist.l,&sn->n);
aoutstrlist.nextoffset += strlen(s) + 1;
return sn->offset;
}
static struct SymbolNode *aout_addsym(char *name,uint8_t type,int8_t other,
int16_t desc,uint32_t value,int be)
/* append a new symbol to the symbol list */
{
struct SymbolNode *sym = mycalloc(sizeof(struct SymbolNode));
sym->name = name!=NULL ? name : emptystr;
sym->index = aoutsymlist.nextindex++;
setval(be,&sym->s.n_strx,4,aout_addstr(name));
sym->s.n_type = type;
sym->s.n_other = other;
setval(be,&sym->s.n_desc,2,desc);
setval(be,&sym->s.n_value,4,value);
addtail(&aoutsymlist.l,&sym->n);
return sym;
}
static uint32_t aout_addsymhash(char *name,taddr value,int bind,
int info,int type,int desc,int be)
/* add a new symbol, return its symbol table index */
{
struct SymbolNode **chain,*sym;
chain = &aoutsymlist.hashtab[hashcode(name?name:emptystr)%SYMHTABSIZE];
while (sym = *chain)
chain = &sym->hashchain;
/* new symbol table entry */
*chain = sym = aout_addsym(name,type,((bind&0xf)<<4)|(info&0xf),
desc,value,be);
return sym->index;
}
static int aout_findsym(char *name,int be)
/* find a symbol by its name, return symbol table index or -1 */
{
struct SymbolNode **chain = &aoutsymlist.hashtab[hashcode(name)%SYMHTABSIZE];
struct SymbolNode *sym;
while (sym = *chain) {
if (!strcmp(name,sym->name) && !(sym->s.n_type & N_STAB))
return ((int)sym->index);
chain = &sym->hashchain;
}
return (-1);
}
static void aout_symconvert(symbol *sym,int symbind,int syminfo,int be)
/* convert vasm symbol into a.out symbol(s) */
{
taddr val = get_sym_value(sym);
taddr size = get_sym_size(sym);
int ext = (symbind == BIND_GLOBAL) ? N_EXT : 0;
int type = 0;
if (TYPE(sym) == TYPE_SECTION) {
return; /* section symbols are ignored in a.out! */
}
else if (TYPE(sym) == TYPE_FILE) {
type = N_FN | N_EXT; /* special case: file name symbol */
size = 0;
}
else {
if (sym->flags & COMMON) {
/* common symbol */
#if 0 /* GNU binutils prefers N_UNDF with val!=0 instead of N_COMM! */
type = N_COMM | ext;
#else
type = N_UNDF | N_EXT;
#endif
val = size;
size = 0;
}
else if (sym->flags & WEAK) {
/* weak symbol */
switch (sym->type) {
case LABSYM: type=secweak[sym->sec->idx]; break;
case IMPORT: type=N_WEAKU; break;
case EXPRESSION: type=N_WEAKA; break;
default: ierror(0); break;
}
}
else if (sym->sec) {
/* address symbol */
if (!(sym->sec->flags & ABSOLUTE)) {
type = sectype[sym->sec->idx] | ext;
val += secoffs[sym->sec->idx]; /* a.out requires to add sec. offset */
}
else /* absolute ORG section: convert labels to ABS symbols */
type = N_ABS | ext;
}
else if (sym->type==EXPRESSION) {
if (sym->flags & EXPORT) {
/* absolute symbol */
type = N_ABS | ext;
}
else
return; /* ignore local expressions */
}
/* @@@ else if (indirect symbols?) {
aout_addsymhash(sym->name,0,symbind,0,N_INDR|ext,0,be);
aout_addsymhash(sym->indir_name,0,0,0,N_UNDF|N_EXT,0,be);
return;
}*/
else
ierror(0);
}
aout_addsymhash(sym->name,val,symbind,syminfo,type,0,be);
if (size) {
/* append N_SIZE symbol declaring the previous symbol's size */
aout_addsymhash(sym->name,size,symbind,syminfo,N_SIZE,0,be);
}
}
static void aout_addsymlist(symbol *sym,int bind,int type,int be)
/* add all symbols with specified bind and type to the a.out symbol list */
{
for (; sym; sym=sym->next) {
/* ignore symbols preceded by a '.' and internal symbols */
if ((sym->type!=IMPORT || (sym->flags&WEAK) || (sym->flags&COMMON))
&& *sym->name != '.' && *sym->name!=' ' && !(sym->flags&VASMINTERN)) {
int syminfo = aout_getinfo(sym);
int symbind = aout_getbind(sym);
if (symbind == bind && (!type || (syminfo == type))) {
aout_symconvert(sym,symbind,syminfo,be);
}
}
}
}
static void aout_debugsyms(int be)
/* add stabs to the a.out symbol list */
{
struct stabdef *nlist = first_nlist;
uint32_t val;
while (nlist != NULL) {
val = nlist->value;
if (nlist->base != NULL) {
/* include section base offset in symbol value */
if (LOCREF(nlist->base)) {
if (!(nlist->base->sec->flags & ABSOLUTE))
val += secoffs[nlist->base->sec->idx];
}
else
ierror(0); /* @@@ handle external references! How? */
}
aout_addsym(nlist->name.ptr,nlist->type,nlist->other,nlist->desc,val,be);
nlist = nlist->next;
}
}
static void aout_addreloclist(struct list *rlst,uint32_t raddr,
uint32_t rindex,uint32_t rinfo,int be)
/* add new relocation_info to .text or .data reloc-list */
{
struct RelocNode *rn = mymalloc(sizeof(struct RelocNode));
setval(be,rn->r.r_address,4,raddr);
setbits(be,rn->r.r_info,32,RELB_symbolnum,RELS_symbolnum,rindex);
setbits(be,rn->r.r_info,32,RELB_reloc,RELS_reloc,rinfo);
addtail(rlst,&rn->n);
if (isPIC && !readbits(be,rn->r.r_info,32,RSTDB_pcrel,1)
&& !readbits(be,rn->r.r_info,32,RSTDB_baserel,1)) {
/* the relocation is probably absolute, so it is no PIC anymore */
isPIC = 0;
}
}
static uint32_t aout_convert_rlist(int be,atom *a,int secid,
struct list *rlst,taddr pc,
uint32_t (*getrinfo)
(rlist **,int,char *,int))
/* convert all of an atom's relocs into a.out relocations */
{
uint32_t rsize = 0;
rlist *rl;
if (a->type == DATA)
rl = a->content.db->relocs;
else if (a->type == SPACE)
rl = a->content.sb->relocs;
else
rl = NULL;
if (rl == NULL)
return 0; /* no relocs or not the right atom type */
do {
nreloc *r = (nreloc *)rl->reloc;
symbol *refsym = r->sym;
taddr val = get_sym_value(refsym);
taddr add = nreloc_real_addend(r);
#if SDAHACK
int based = getrinfo(&rl,-1,sections[secid]->name,be) != 0;
#endif
if (LOCREF(refsym)) {
/* this is a local relocation */
int rsecid = refsym->sec->idx;
aout_addreloclist(rlst,pc+r->byteoffset,sectype[rsecid],
getrinfo(&rl,0,sections[secid]->name,be),
be);
#if SDAHACK
if (!based) /* @@@ 'based' does not really happen under Unix */
#endif
val += secoffs[rsecid];
rsize += sizeof(struct relocation_info);
}
else if (EXTREF(refsym)) {
/* this is an external symbol reference */
int symidx;
if ((symidx = aout_findsym(refsym->name,be)) == -1)
symidx = aout_addsymhash(refsym->name,0,0,0,N_UNDF|N_EXT,0,be);
aout_addreloclist(rlst,pc+r->byteoffset,symidx,
getrinfo(&rl,1,sections[secid]->name,be),
be);
rsize += sizeof(struct relocation_info);
}
else
ierror(0);
/* patch addend for a.out */
if (rl->type == REL_PC)
val -= pc + r->byteoffset;
if (a->type == DATA)
setval(be,a->content.db->data+r->byteoffset,r->size>>3,val+add);
else if (a->type==SPACE && a->content.sb->space!=0) {
setval(be,a->content.sb->fill,r->size>>3,val+add);
a->content.sb->space = 0; /* we only need to patch 'fill' once */
}
}
while (rl = rl->next);
return rsize;
}
static uint32_t aout_addrelocs(int be,int secid,struct list *rlst,
uint32_t (*getrinfo)(rlist **,int,char *,int))
/* creates a.out relocations for a single section (.text or .data) */
{
uint32_t rtabsize=0;
if (sections[secid]) {
atom *a;
taddr pc=0,npc;
for (a=sections[secid]->first; a; a=a->next) {
npc = pcalign(a,pc);
rtabsize += aout_convert_rlist(be,a,secid,rlst,npc,getrinfo);
pc = npc + atom_size(a,sections[secid],npc);
}
}
return rtabsize;
}
static void aout_header(FILE *f,uint32_t mag,uint32_t flag,
uint32_t tsize,uint32_t dsize,uint32_t bsize,
uint32_t syms,uint32_t entry,
uint32_t trsize,uint32_t drsize,int be)
/* write an a.out header */
{
struct aout_hdr h;
SETMIDMAG(&h,mag,mid,flag);
setval(be,h.a_text,4,tsize);
setval(be,h.a_data,4,dsize);
setval(be,h.a_bss,4,bsize);
setval(be,h.a_syms,4,syms);
setval(be,h.a_entry,4,entry);
setval(be,h.a_trsize,4,trsize);
setval(be,h.a_drsize,4,drsize);
fwdata(f,&h,sizeof(struct aout_hdr));
}
static void aout_writesection(FILE *f,section *sec,taddr sec_align)
{
if (sec) {
atom *a;
taddr pc=0,npc;
for (a=sec->first; a; a=a->next) {
npc = fwpcalign(f,a,sec,pc);
if (a->type == DATA)
fwdata(f,a->content.db->data,a->content.db->size);
else if (a->type == SPACE)
fwsblock(f,a->content.sb);
pc = npc + atom_size(a,sec,npc);
}
fwalign(f,pc,sec_align);
}
}
static void aout_writeorg(FILE *f,section *sec,taddr sec_align)
/* write all absolute ORG-sections appended to .text */
{
taddr pc = get_sec_size(sections[_TEXT]);
taddr npc;
atom *a;
for (; sec; sec=sec->next) {
if (sec->flags & ABSOLUTE) {
fwalign(f,pc,sec->align);
for (a=sec->first; a; a=a->next) {
npc = fwpcalign(f,a,sec,pc);
if (a->type == DATA)
fwdata(f,a->content.db->data,a->content.db->size);
else if (a->type == SPACE)
fwsblock(f,a->content.sb);
pc = npc + atom_size(a,sec,npc);
}
}
}
fwalign(f,pc,sec_align);
}
void aout_writerelocs(FILE *f,struct list *l)
{
struct RelocNode *rn;
while (rn = (struct RelocNode *)remhead(l))
fwdata(f,&rn->r,sizeof(struct relocation_info));
}
void aout_writesymbols(FILE *f)
{
struct SymbolNode *sym;
while (sym = (struct SymbolNode *)remhead(&aoutsymlist.l))
fwdata(f,&sym->s,sizeof(struct nlist32));
}
void aout_writestrings(FILE *f,int be)
{
if (aoutstrlist.nextoffset > 4) {
struct StrTabNode *stn;
fw32(f,aoutstrlist.nextoffset,be);
while (stn = (struct StrTabNode *)remhead(&aoutstrlist.l))
fwdata(f,stn->str,strlen(stn->str)+1);
}
}
static void write_output(FILE *f,section *sec,symbol *sym)
{
int be = BIGENDIAN;
uint32_t trsize,drsize;
aout_initwrite(sec);
aout_addsymlist(sym,BIND_GLOBAL,0,be);
aout_addsymlist(sym,BIND_WEAK,0,be);
if (!no_symbols) {
aout_addsymlist(sym,BIND_LOCAL,0,be);
aout_debugsyms(be);
}
trsize = aout_addrelocs(be,_TEXT,&treloclist,aoutstd_getrinfo);
drsize = aout_addrelocs(be,_DATA,&dreloclist,aoutstd_getrinfo);
aout_header(f,OMAGIC,isPIC?EX_PIC:0,
secsize[_TEXT] + balign(secsize[_TEXT],SECT_ALIGN),
secsize[_DATA] + balign(secsize[_DATA],SECT_ALIGN),
secsize[_BSS],
aoutsymlist.nextindex * sizeof(struct nlist32),
0,trsize,drsize,be);
aout_writesection(f,sections[_TEXT],0);
aout_writeorg(f,sec,SECT_ALIGN);
aout_writesection(f,sections[_DATA],SECT_ALIGN);
aout_writerelocs(f,&treloclist);
aout_writerelocs(f,&dreloclist);
aout_writesymbols(f);
aout_writestrings(f,be);
}
static int output_args(char *p)
{
if (!strncmp(p,"-mid=",5)) {
mid = atoi(p+5);
return 1;
}
return 0;
}
int init_output_aout(char **cp,void (**wo)(FILE *,section *,symbol *),
int (**oa)(char *))
{
*cp = copyright;
*wo = write_output;
*oa = output_args;
return 1;
}
#else
int init_output_aout(char **cp,void (**wo)(FILE *,section *,symbol *),
int (**oa)(char *))
{
return 0;
}
#endif
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