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/*
* Copyright (C) 2010 Tobias Klauser <tklauser@distanz.ch>
*
* This file is part of nios2sim-ng.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <stdio.h>
#include <stdint.h>
#include <libelf.h>
#include <gelf.h>
#include "nios2sim-ng.h"
#include "image.h"
/* not defined with libelf */
#define EM_ALTERA_NIOS2 113
/*
* http://elftoolchain.sourceforge.net/for-review/libelf-by-example-20100112.pdf
*/
static int elf_read_sections(Elf *e, struct memory *mem)
{
Elf_Scn *scn = NULL;
size_t shstrndx;
char *name;
if (elf_getshdrstrndx(e, &shstrndx) != 0) {
err("elf_getshdrstrndx() failed: %s\n", elf_errmsg(-1));
return -1;
}
while ((scn = elf_nextscn(e, scn)) != NULL) {
GElf_Shdr shdr;
GElf_Phdr phdr;
if (gelf_getshdr(scn, &shdr) == NULL) {
err("Couldn't get section header: %s\n", elf_errmsg(-1));
return -1;
}
/* Is it a .text section? */
if (shdr.sh_type == SHT_PROGBITS
&& (shdr.sh_flags & ~SHF_WRITE) == (SHF_ALLOC | SHF_EXECINSTR)) {
Elf_Data *data;
size_t n;
if ((name = elf_strptr(e, shstrndx, shdr.sh_name)) == NULL) {
err("Couldn't get section name: %s\n", elf_errmsg(-1));
return -1;
}
dbg("Section %zu: %s (size=%zu, flags=%08lx, addr=%08lx, off=%08lx)\n", elf_ndxscn(scn), name, shdr.sh_size, shdr.sh_flags, shdr.sh_addr, shdr.sh_offset);
data = NULL;
n = 0;
while (n < shdr.sh_size &&
(data = elf_getdata(scn, data)) != NULL) {
memcpy(&mem->base[(shdr.sh_addr + n) / 4], data->d_buf, data->d_size);
n += data->d_size;
}
}
}
return 0;
}
int elf_load(FILE *fp, const char *name, struct memory *mem)
{
int fd = fileno(fp);
int ret;
Elf *e;
GElf_Ehdr ehdr;
size_t n;
if (unlikely(fd < 0)) {
err("Couldn't get file descriptor for '%s'\n", name);
return -1;
}
if (elf_version(EV_CURRENT) == EV_NONE) {
err("ELF library initialization failed\n");
return -1;
}
ret = -1;
e = elf_begin(fd, ELF_C_READ, NULL);
if (unlikely(e == NULL)) {
err("Couldn't get ELF file handle for '%s': %s\n", name, elf_errmsg(-1));
goto out;
}
if (elf_kind(e) != ELF_K_ELF) {
err("'%s' is not an ELF object\n", name);
goto out;
}
if (gelf_getclass(e) != ELFCLASS32) {
err("'%s' has invalid ELF class\n", name);
goto out;
}
if (gelf_getehdr(e, &ehdr) == NULL) {
err("gelf_getehdr() failed: %s\n", elf_errmsg(-1));
goto out;
}
if (ehdr.e_type != ET_EXEC || ehdr.e_machine != EM_ALTERA_NIOS2) {
err("'%s' is not a Nios2 ELF executable (%x, %x)\n", name, ehdr.e_type, ehdr.e_machine);
goto out;
}
ret = elf_read_sections(e, mem);
out:
elf_end(e);
return ret;
}
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