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// SPDX-License-Identifier: GPL-2.0+ OR BSD-2-Clause
/*
* Copyright 2013 Freescale Semiconductor, Inc.
*
* 64-bit and little-endian target only until we need to support a different
* arch that needs this.
*/
#include <elf.h>
#include <errno.h>
#include <inttypes.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "compiler.h"
#ifndef R_AARCH64_RELATIVE
#define R_AARCH64_RELATIVE 1027
#endif
static int ei_class;
static uint64_t rela_start, rela_end, text_base;
static const bool debug_en;
static void debug(const char *fmt, ...)
{
va_list args;
if (debug_en) {
va_start(args, fmt);
vprintf(fmt, args);
va_end(args);
}
}
static bool supported_rela(Elf64_Rela *rela)
{
uint64_t mask = 0xffffffffULL; /* would be different on 32-bit */
uint32_t type = rela->r_info & mask;
switch (type) {
#ifdef R_AARCH64_RELATIVE
case R_AARCH64_RELATIVE:
return true;
#endif
default:
fprintf(stderr, "warning: unsupported relocation type %"
PRIu32 " at %" PRIx64 "\n",
type, rela->r_offset);
return false;
}
}
static int decode_elf64(FILE *felf, char **argv)
{
size_t size;
Elf64_Ehdr header;
uint64_t section_header_base, section_header_size, sh_offset, sh_size;
Elf64_Shdr *sh_table; /* Elf symbol table */
int ret, i, machine;
char *sh_str;
debug("64bit version\n");
/* Make sure we are at start */
rewind(felf);
size = fread(&header, 1, sizeof(header), felf);
if (size != sizeof(header)) {
fclose(felf);
return 25;
}
machine = header.e_machine;
debug("Machine\t%d\n", machine);
if (machine != EM_AARCH64) {
fprintf(stderr, "%s: Not supported machine type\n", argv[0]);
return 30;
}
text_base = header.e_entry;
section_header_base = header.e_shoff;
section_header_size = header.e_shentsize * header.e_shnum;
sh_table = malloc(section_header_size);
if (!sh_table) {
fprintf(stderr, "%s: Cannot allocate space for section header\n",
argv[0]);
fclose(felf);
return 26;
}
ret = fseek(felf, section_header_base, SEEK_SET);
if (ret) {
fprintf(stderr, "%s: Can't set pointer to section header: %x/%lx\n",
argv[0], ret, section_header_base);
free(sh_table);
fclose(felf);
return 26;
}
size = fread(sh_table, 1, section_header_size, felf);
if (size != section_header_size) {
fprintf(stderr, "%s: Can't read section header: %lx/%lx\n",
argv[0], size, section_header_size);
free(sh_table);
fclose(felf);
return 27;
}
sh_size = sh_table[header.e_shstrndx].sh_size;
debug("e_shstrndx\t0x%08x\n", header.e_shstrndx);
debug("sh_size\t\t0x%08lx\n", sh_size);
sh_str = malloc(sh_size);
if (!sh_str) {
fprintf(stderr, "malloc failed\n");
free(sh_table);
fclose(felf);
return 28;
}
/*
* Specifies the byte offset from the beginning of the file
* to the first byte in the section.
*/
sh_offset = sh_table[header.e_shstrndx].sh_offset;
debug("sh_offset\t0x%08x\n", header.e_shnum);
ret = fseek(felf, sh_offset, SEEK_SET);
if (ret) {
fprintf(stderr, "Setting up sh_offset failed\n");
free(sh_str);
free(sh_table);
fclose(felf);
return 29;
}
size = fread(sh_str, 1, sh_size, felf);
if (size != sh_size) {
fprintf(stderr, "%s: Can't read section: %lx/%lx\n",
argv[0], size, sh_size);
free(sh_str);
free(sh_table);
fclose(felf);
return 30;
}
for (i = 0; i < header.e_shnum; i++) {
/* fprintf(stderr, "%s\n", sh_str + sh_table[i].sh_name); Debug only */
if (!strcmp(".rela.dyn", (sh_str + sh_table[i].sh_name))) {
debug("Found section\t\".rela_dyn\"\n");
debug(" at addr\t0x%08x\n",
(unsigned int)sh_table[i].sh_addr);
debug(" at offset\t0x%08x\n",
(unsigned int)sh_table[i].sh_offset);
debug(" of size\t0x%08x\n",
(unsigned int)sh_table[i].sh_size);
rela_start = sh_table[i].sh_addr;
rela_end = rela_start + sh_table[i].sh_size;
break;
}
}
/* Clean up */
free(sh_str);
free(sh_table);
fclose(felf);
debug("text_base\t0x%08lx\n", text_base);
debug("rela_start\t0x%08lx\n", rela_start);
debug("rela_end\t0x%08lx\n", rela_end);
if (!rela_start)
return 1;
return 0;
}
static int decode_elf(char **argv)
{
FILE *felf;
size_t size;
unsigned char e_ident[EI_NIDENT];
felf = fopen(argv[2], "r+b");
if (!felf) {
fprintf(stderr, "%s: Cannot open %s: %s\n",
argv[0], argv[5], strerror(errno));
return 2;
}
size = fread(e_ident, 1, EI_NIDENT, felf);
if (size != EI_NIDENT) {
fclose(felf);
return 25;
}
/* Check if this is really ELF file */
if (e_ident[0] != 0x7f &&
e_ident[1] != 'E' &&
e_ident[2] != 'L' &&
e_ident[3] != 'F') {
fclose(felf);
return 1;
}
ei_class = e_ident[4];
debug("EI_CLASS(1=32bit, 2=64bit) %d\n", ei_class);
if (ei_class == 2)
return decode_elf64(felf, argv);
return 1;
}
static int rela_elf64(char **argv, FILE *f)
{
int i, num;
if ((rela_end - rela_start) % sizeof(Elf64_Rela)) {
fprintf(stderr, "%s: rela size isn't a multiple of Elf64_Rela\n", argv[0]);
return 3;
}
num = (rela_end - rela_start) / sizeof(Elf64_Rela);
for (i = 0; i < num; i++) {
Elf64_Rela rela, swrela;
uint64_t pos = rela_start + sizeof(Elf64_Rela) * i;
uint64_t addr;
if (fseek(f, pos, SEEK_SET) < 0) {
fprintf(stderr, "%s: %s: seek to %" PRIx64
" failed: %s\n",
argv[0], argv[1], pos, strerror(errno));
}
if (fread(&rela, sizeof(rela), 1, f) != 1) {
fprintf(stderr, "%s: %s: read rela failed at %"
PRIx64 "\n",
argv[0], argv[1], pos);
return 4;
}
swrela.r_offset = cpu_to_le64(rela.r_offset);
swrela.r_info = cpu_to_le64(rela.r_info);
swrela.r_addend = cpu_to_le64(rela.r_addend);
if (!supported_rela(&swrela))
continue;
debug("Rela %" PRIx64 " %" PRIu64 " %" PRIx64 "\n",
swrela.r_offset, swrela.r_info, swrela.r_addend);
if (swrela.r_offset < text_base) {
fprintf(stderr, "%s: %s: bad rela at %" PRIx64 "\n",
argv[0], argv[1], pos);
return 4;
}
addr = swrela.r_offset - text_base;
if (fseek(f, addr, SEEK_SET) < 0) {
fprintf(stderr, "%s: %s: seek to %"
PRIx64 " failed: %s\n",
argv[0], argv[1], addr, strerror(errno));
}
if (fwrite(&rela.r_addend, sizeof(rela.r_addend), 1, f) != 1) {
fprintf(stderr, "%s: %s: write failed at %" PRIx64 "\n",
argv[0], argv[1], addr);
return 4;
}
}
return 0;
}
int main(int argc, char **argv)
{
FILE *f;
int ret;
uint64_t file_size;
if (argc != 3) {
fprintf(stderr, "Statically apply ELF rela relocations\n");
fprintf(stderr, "Usage: %s <bin file> <u-boot ELF>\n",
argv[0]);
return 1;
}
ret = decode_elf(argv);
if (ret) {
fprintf(stderr, "ELF decoding failed\n");
return ret;
}
if (rela_start > rela_end || rela_start < text_base) {
fprintf(stderr, "%s: bad rela bounds\n", argv[0]);
return 3;
}
rela_start -= text_base;
rela_end -= text_base;
f = fopen(argv[1], "r+b");
if (!f) {
fprintf(stderr, "%s: Cannot open %s: %s\n",
argv[0], argv[1], strerror(errno));
return 2;
}
fseek(f, 0, SEEK_END);
file_size = ftell(f);
rewind(f);
if (rela_end > file_size) {
// Most likely compiler inserted some section that didn't get
// objcopy-ed into the final binary
rela_end = file_size;
}
if (ei_class == 2)
ret = rela_elf64(argv, f);
if (fclose(f) < 0) {
fprintf(stderr, "%s: %s: close failed: %s\n",
argv[0], argv[1], strerror(errno));
return 4;
}
return ret;
}
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