mspdebug/elf32.c

353 lines
7.2 KiB
C

/* MSPDebug - debugging tool for the eZ430
* Copyright (C) 2009, 2010 Daniel Beer
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#ifdef __APPLE__
#include <libelf.h>
#else
#include <elf.h>
#endif
#include "elf32.h"
#include "output.h"
#ifndef EM_MSP430
#define EM_MSP430 0x69
#endif
static const uint8_t elf32_id[] = {
ELFMAG0, ELFMAG1, ELFMAG2, ELFMAG3, ELFCLASS32
};
#define MAX_PHDRS 32
#define MAX_SHDRS 128
struct elf32_info {
Elf32_Ehdr file_ehdr;
Elf32_Phdr file_phdrs[MAX_PHDRS];
Elf32_Shdr file_shdrs[MAX_SHDRS];
char *string_tab;
int string_len;
};
static int read_ehdr(struct elf32_info *info, FILE *in)
{
/* Read and check the ELF header */
rewind(in);
if (fread(&info->file_ehdr, sizeof(info->file_ehdr), 1, in) < 0) {
pr_error("elf32: couldn't read ELF header");
return -1;
}
if (memcmp(info->file_ehdr.e_ident, elf32_id, sizeof(elf32_id))) {
printc_err("elf32: not an ELF32 file\n");
return -1;
}
return 0;
}
static int read_phdr(struct elf32_info *info, FILE *in)
{
int i;
if (info->file_ehdr.e_phnum > MAX_PHDRS) {
printc_err("elf32: too many program headers: %d\n",
info->file_ehdr.e_phnum);
return -1;
}
for (i = 0; i < info->file_ehdr.e_phnum; i++) {
if (fseek(in, i * info->file_ehdr.e_phentsize +
info->file_ehdr.e_phoff,
SEEK_SET) < 0) {
printc_err("elf32: can't seek to phdr %d\n", i);
return -1;
}
if (fread(&info->file_phdrs[i],
sizeof(info->file_phdrs[0]), 1, in) < 0) {
printc_err("elf32: can't read phdr %d: %s\n",
i, strerror(errno));
return -1;
}
}
return 0;
}
static int read_shdr(struct elf32_info *info, FILE *in)
{
int i;
if (info->file_ehdr.e_shnum > MAX_SHDRS) {
printc_err("elf32: too many section headers: %d\n",
info->file_ehdr.e_shnum);
return -1;
}
for (i = 0; i < info->file_ehdr.e_shnum; i++) {
if (fseek(in, i * info->file_ehdr.e_shentsize +
info->file_ehdr.e_shoff,
SEEK_SET) < 0) {
printc_err("elf32: can't seek to shdr %d\n", i);
return -1;
}
if (fread(&info->file_shdrs[i],
sizeof(info->file_shdrs[0]), 1, in) < 0) {
printc_err("elf32: can't read shdr %d: %s\n",
i, strerror(errno));
return -1;
}
}
return 0;
}
static uint32_t file_to_phys(struct elf32_info *info, uint32_t v)
{
int i;
for (i = 0; i < info->file_ehdr.e_phnum; i++) {
Elf32_Phdr *p = &info->file_phdrs[i];
if (v >= p->p_offset && v - p->p_offset < p->p_filesz)
return v - p->p_offset + p->p_paddr;
}
return v;
}
static int feed_section(struct elf32_info *info,
FILE *in, uint32_t offset, uint32_t size,
binfile_imgcb_t cb, void *user_data)
{
uint8_t buf[1024];
uint32_t addr = file_to_phys(info, offset);
if (fseek(in, offset, SEEK_SET) < 0) {
pr_error("elf32: can't seek to section");
return -1;
}
while (size) {
int ask = size > sizeof(buf) ? sizeof(buf) : size;
int len = fread(buf, 1, ask, in);
if (len < 0) {
pr_error("elf32: can't read section");
return -1;
}
if (cb(user_data, addr, buf, len) < 0)
return -1;
size -= len;
offset += len;
addr += len;
}
return 0;
}
static int read_all(struct elf32_info *info, FILE *in)
{
memset(info, 0, sizeof(info));
if (read_ehdr(info, in) < 0)
return -1;
if (info->file_ehdr.e_machine != EM_MSP430)
printc_err("elf32: warning: unknown machine type: 0x%x\n",
info->file_ehdr.e_machine);
if (read_phdr(info, in) < 0)
return -1;
if (read_shdr(info, in) < 0)
return -1;
return 0;
}
int elf32_extract(FILE *in, binfile_imgcb_t cb, void *user_data)
{
struct elf32_info info;
int i;
if (read_all(&info, in) < 0)
return -1;
for (i = 0; i < info.file_ehdr.e_shnum; i++) {
Elf32_Shdr *s = &info.file_shdrs[i];
if (s->sh_type == SHT_PROGBITS && s->sh_flags & SHF_ALLOC &&
feed_section(&info, in, s->sh_offset, s->sh_size,
cb, user_data) < 0)
return -1;
}
return 0;
}
int elf32_check(FILE *in)
{
int i;
rewind(in);
for (i = 0; i < sizeof(elf32_id); i++)
if (fgetc(in) != elf32_id[i])
return 0;
return 1;
}
static Elf32_Shdr *find_shdr(struct elf32_info *info, Elf32_Word type)
{
int i;
for (i = 0; i < info->file_ehdr.e_shnum; i++) {
Elf32_Shdr *s = &info->file_shdrs[i];
if (s->sh_type == type)
return s;
}
return NULL;
}
static int syms_load_strings(struct elf32_info *info, FILE *in, Elf32_Shdr *s)
{
int len = s->sh_size;
if (!len)
return 0;
if (fseek(in, s->sh_offset, SEEK_SET) < 0) {
pr_error("elf32: can't seek to strings");
return -1;
}
info->string_len = len;
info->string_tab = malloc(len + 1);
if (!info->string_tab) {
pr_error("elf32: can't allocate string table memory");
return -1;
}
if (!fread(info->string_tab, 1, info->string_len, in)) {
if (ferror(in)) {
pr_error("elf32: error reading strings");
return -1;
}
printc_err("elf32: eof reading strings\n");
return -1;
}
info->string_tab[info->string_len] = 0;
return 0;
}
#define N_SYMS 128
static int syms_load_syms(struct elf32_info *info, FILE *in,
Elf32_Shdr *s, stab_t stab)
{
Elf32_Sym syms[N_SYMS];
int len = s->sh_size / sizeof(syms[0]);
if (fseek(in, s->sh_offset, SEEK_SET) < 0) {
pr_error("elf32: can't seek to symbols");
return -1;
}
while (len) {
int req = N_SYMS > len ? len : N_SYMS;
int count = fread(syms, sizeof(syms[0]), req, in);
int i;
if (!count) {
printc_err("elf32: eof reading symbols\n");
return -1;
}
if (count < 0) {
pr_error("elf32: error reading symbols");
return -1;
}
for (i = 0; i < count; i++) {
Elf32_Sym *y = &syms[i];
int st = ELF32_ST_TYPE(y->st_info);
const char *name = info->string_tab + y->st_name;
if (y->st_name > info->string_len) {
printc_err("elf32: symbol out of "
"bounds\n");
return -1;
}
if (name[0] &&
(st == STT_OBJECT || st == STT_FUNC ||
st == STT_SECTION || st == STT_COMMON ||
st == STT_TLS) &&
stab_set(stab, info->string_tab + y->st_name,
y->st_value) < 0)
return -1;
}
len -= count;
}
return 0;
}
int elf32_syms(FILE *in, stab_t stab)
{
struct elf32_info info;
Elf32_Shdr *s;
int ret = 0;
if (read_all(&info, in) < 0)
return -1;
s = find_shdr(&info, SHT_SYMTAB);
if (!s) {
printc_err("elf32: no symbol table\n");
return -1;
}
if (s->sh_link <= 0 || s->sh_link >= info.file_ehdr.e_shnum) {
printc_err("elf32: no string table\n");
return -1;
}
if (syms_load_strings(&info, in, &info.file_shdrs[s->sh_link]) < 0 ||
syms_load_syms(&info, in, s, stab) < 0)
ret = -1;
if (info.string_tab)
free(info.string_tab);
return ret;
}