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Tool to unpack Android boot images
/**
* unpack_bootldr!_img : tool to unpack Android boot images
* https://gist.github.com/frederic/
**/
/**
* 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 3 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, see <http://www.gnu.org/licenses/>.
**/
#include <stdlib.h>
#include <stdio.h>
#include <stdint.h>
/* msm8960 bootloader.img format */
#define BOOTLDR_MAGIC "BOOTLDR!"
#define BOOTLDR_MAGIC_SIZE 8
typedef struct {
char name[64];
uint32_t size;
}img_info_s;
typedef struct {
char magic[BOOTLDR_MAGIC_SIZE];
uint32_t num_images;
uint32_t start_offset;
uint32_t bootldr_size;
img_info_s img_info[];
}bootloader_images_header;
int main(int argc, char *argv[]){
FILE *img_file, *out_file;
bootloader_images_header *header;
size_t result, img_info_size, img_size, header_size;
int i;
char *buffer, *img_name;
if(argc < 2){
int i;
printf("Unpack msm8960 image file (magic BOOTLDR!)\n");
printf("Usage: %s <img_filename>\n", argv[0]);
return -1;
}
img_file = fopen(argv[1], "r");
if(!img_file) {
printf("Error opening img file!\n");
return -1;
}
header_size = sizeof(bootloader_images_header);
header = (bootloader_images_header*) malloc(header_size);
result = fread(header, 1, header_size, img_file);
if (result != header_size) {
printf("Error: cannot read img header !\n");
return -1;
}
if(strncmp(header->magic, BOOTLDR_MAGIC, BOOTLDR_MAGIC_SIZE)) {
printf("Error: wrong magic value in header!\n");
return -1;
}
img_info_size = sizeof(img_info_s) * header->num_images;
header_size += img_info_size;
header = realloc(header, header_size);
result = fread(header->img_info, 1, img_info_size, img_file);
if (result != img_info_size) {
printf("Error: cannot read img infos !\n");
return -1;
}
fseek (img_file, header->start_offset, SEEK_SET);
for(i = 0; i < header->num_images; i++){
img_size = header->img_info[i].size;
img_name = header->img_info[i].name;
printf("#%i %s (%i bytes)\n", i, img_name, img_size);
buffer = (char*) malloc(img_size);
result = fread(buffer, 1, img_size, img_file);
if (result != img_size) {
printf("Error: cannot read enough bytes from img file !\n");
return -1;
}
out_file = fopen(img_name, "wb");
if(!out_file) {
printf("Error opening out img file (%s)!\n", img_name);
return -1;
}
result = fwrite (buffer, 1, img_size, out_file);
if(result != img_size)
printf("Warning : out img file has not been fully written!\n");
fclose(out_file);
free(buffer);
}
free(header);
fclose(img_file);
return 0;
}
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