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// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
#include "l.h"
#include "lib.h"
#include "../ld/elf.h"
/*
* We use the 64-bit data structures on both 32- and 64-bit machines
* in order to write the code just once. The 64-bit data structure is
* written in the 32-bit format on the 32-bit machines.
*/
#define NSECT 32
static int elf64;
static ElfEhdr hdr;
static ElfPhdr *phdr[NSECT];
static ElfShdr *shdr[NSECT];
static char *interp;
/*
Initialize the global variable that describes the ELF header. It will be updated as
we write section and prog headers.
*/
void
elfinit(void)
{
switch(thechar) {
// 64-bit architectures
case '6':
elf64 = 1;
hdr.phoff = ELF64HDRSIZE; /* Must be be ELF64HDRSIZE: first PHdr must follow ELF header */
hdr.shoff = ELF64HDRSIZE; /* Will move as we add PHeaders */
hdr.ehsize = ELF64HDRSIZE; /* Must be ELF64HDRSIZE */
hdr.phentsize = ELF64PHDRSIZE; /* Must be ELF64PHDRSIZE */
hdr.shentsize = ELF64SHDRSIZE; /* Must be ELF64SHDRSIZE */
break;
// 32-bit architectures
default:
hdr.phoff = ELF32HDRSIZE; /* Must be be ELF32HDRSIZE: first PHdr must follow ELF header */
hdr.shoff = ELF32HDRSIZE; /* Will move as we add PHeaders */
hdr.ehsize = ELF32HDRSIZE; /* Must be ELF32HDRSIZE */
hdr.phentsize = ELF32PHDRSIZE; /* Must be ELF32PHDRSIZE */
hdr.shentsize = ELF32SHDRSIZE; /* Must be ELF32SHDRSIZE */
}
}
void
elf64phdr(ElfPhdr *e)
{
LPUT(e->type);
LPUT(e->flags);
VPUT(e->off);
VPUT(e->vaddr);
VPUT(e->paddr);
VPUT(e->filesz);
VPUT(e->memsz);
VPUT(e->align);
}
void
elf32phdr(ElfPhdr *e)
{
LPUT(e->type);
LPUT(e->off);
LPUT(e->vaddr);
LPUT(e->paddr);
LPUT(e->filesz);
LPUT(e->memsz);
LPUT(e->flags);
LPUT(e->align);
}
void
elf64shdr(ElfShdr *e)
{
LPUT(e->name);
LPUT(e->type);
VPUT(e->flags);
VPUT(e->addr);
VPUT(e->off);
VPUT(e->size);
LPUT(e->link);
LPUT(e->info);
VPUT(e->addralign);
VPUT(e->entsize);
}
void
elf32shdr(ElfShdr *e)
{
LPUT(e->name);
LPUT(e->type);
LPUT(e->flags);
LPUT(e->addr);
LPUT(e->off);
LPUT(e->size);
LPUT(e->link);
LPUT(e->info);
LPUT(e->addralign);
LPUT(e->entsize);
}
uint32
elfwriteshdrs(void)
{
int i;
if (elf64) {
for (i = 0; i < hdr.shnum; i++)
elf64shdr(shdr[i]);
return hdr.shnum * ELF64SHDRSIZE;
}
for (i = 0; i < hdr.shnum; i++)
elf32shdr(shdr[i]);
return hdr.shnum * ELF32SHDRSIZE;
}
uint32
elfwritephdrs(void)
{
int i;
if (elf64) {
for (i = 0; i < hdr.phnum; i++)
elf64phdr(phdr[i]);
return hdr.phnum * ELF64PHDRSIZE;
}
for (i = 0; i < hdr.phnum; i++)
elf32phdr(phdr[i]);
return hdr.phnum * ELF32PHDRSIZE;
}
ElfPhdr*
newElfPhdr(void)
{
ElfPhdr *e;
e = malloc(sizeof *e);
memset(e, 0, sizeof *e);
if (hdr.phnum >= NSECT)
diag("too many phdrs");
else
phdr[hdr.phnum++] = e;
if (elf64)
hdr.shoff += ELF64PHDRSIZE;
else
hdr.shoff += ELF32PHDRSIZE;
return e;
}
ElfShdr*
newElfShstrtab(vlong name)
{
hdr.shstrndx = hdr.shnum;
return newElfShdr(name);
}
ElfShdr*
newElfShdr(vlong name)
{
ElfShdr *e;
e = malloc(sizeof *e);
memset(e, 0, sizeof *e);
e->name = name;
if (hdr.shnum >= NSECT) {
diag("too many shdrs");
} else {
shdr[hdr.shnum++] = e;
}
return e;
}
ElfEhdr*
getElfEhdr(void)
{
return &hdr;
}
uint32
elf64writehdr(void)
{
int i;
for (i = 0; i < EI_NIDENT; i++)
cput(hdr.ident[i]);
WPUT(hdr.type);
WPUT(hdr.machine);
LPUT(hdr.version);
VPUT(hdr.entry);
VPUT(hdr.phoff);
VPUT(hdr.shoff);
LPUT(hdr.flags);
WPUT(hdr.ehsize);
WPUT(hdr.phentsize);
WPUT(hdr.phnum);
WPUT(hdr.shentsize);
WPUT(hdr.shnum);
WPUT(hdr.shstrndx);
return ELF64HDRSIZE;
}
uint32
elf32writehdr(void)
{
int i;
for (i = 0; i < EI_NIDENT; i++)
cput(hdr.ident[i]);
WPUT(hdr.type);
WPUT(hdr.machine);
LPUT(hdr.version);
LPUT(hdr.entry);
LPUT(hdr.phoff);
LPUT(hdr.shoff);
LPUT(hdr.flags);
WPUT(hdr.ehsize);
WPUT(hdr.phentsize);
WPUT(hdr.phnum);
WPUT(hdr.shentsize);
WPUT(hdr.shnum);
WPUT(hdr.shstrndx);
return ELF32HDRSIZE;
}
uint32
elfwritehdr(void)
{
if(elf64)
return elf64writehdr();
return elf32writehdr();
}
/* Taken directly from the definition document for ELF64 */
uint32
elfhash(uchar *name)
{
uint32 h = 0, g;
while (*name) {
h = (h << 4) + *name++;
if (g = h & 0xf0000000)
h ^= g >> 24;
h &= 0x0fffffff;
}
return h;
}
void
elfwritedynent(Sym *s, int tag, uint64 val)
{
if(elf64) {
adduint64(s, tag);
adduint64(s, val);
} else {
adduint32(s, tag);
adduint32(s, val);
}
}
void
elfwritedynentsym(Sym *s, int tag, Sym *t)
{
if(elf64)
adduint64(s, tag);
else
adduint32(s, tag);
addaddr(s, t);
}
void
elfwritedynentsymsize(Sym *s, int tag, Sym *t)
{
if(elf64)
adduint64(s, tag);
else
adduint32(s, tag);
addsize(s, t);
}
int
elfwriteinterp(void)
{
int n;
if(interp == nil)
return 0;
n = strlen(interp)+1;
seek(cout, ELFRESERVE-n, 0);
write(cout, interp, n);
return n;
}
void
elfinterp(ElfShdr *sh, uint64 startva, char *p)
{
int n;
interp = p;
n = strlen(interp)+1;
sh->addr = startva + ELFRESERVE - n;
sh->off = ELFRESERVE - n;
sh->size = n;
}
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