--- /dev/null
+#include <stdlib.h>
+#include <stdio.h>
+
+
+#define IMG_SIZE 0x3e0000
+
+#define KERNEL_START 0x020000
+#define KERNEL_SIZE 0x0b0000
+
+#define ROOTFS_START 0x0d0000
+#define ROOTFS_SIZE 0x30ffb2
+
+char* app_name;
+
+
+
+
+void print_usage(void)
+{
+ fprintf(stderr, "usage: dgfirmware [<opts>] <img>\n");
+ fprintf(stderr, " <img> firmware image filename\n");
+ fprintf(stderr, " <opts> -h print this message\n");
+ fprintf(stderr, " -f fix the checksum\n");
+ fprintf(stderr, " -x <file> extract the rootfs file to <file>\n");
+ fprintf(stderr, " -xk <file> extract the kernel to <file>\n");
+ fprintf(stderr, " -m <file> merge in rootfs fil\e from <file>\n");
+ fprintf(stderr, " -k <file> merge in kernel from <file>\n");
+ fprintf(stderr, " -w <file> write back the modified firmware\n");
+}
+
+
+unsigned char* read_img(const char *fname)
+{
+ FILE *fp;
+ int size;
+ unsigned char *img;
+
+ fp = fopen(fname, "rb");
+ if (fp == NULL) {
+ perror(app_name);
+ exit(-1);
+ }
+
+ fseek(fp, 0, SEEK_END);
+ size = ftell(fp);
+
+ if (size != IMG_SIZE) {
+ fprintf(stderr, "%s: image file has wrong size\n", app_name);
+ fclose(fp);
+ exit(-1);
+ }
+
+ rewind(fp);
+
+ img = malloc(IMG_SIZE);
+ if (img == NULL) {
+ perror(app_name);
+ fclose(fp);
+ exit(-1);
+ }
+
+ if (fread(img, 1, IMG_SIZE, fp) != IMG_SIZE) {
+ fprintf(stderr, "%s: can't read image file\n", app_name);
+ fclose(fp);
+ exit(-1);
+ }
+
+ fclose(fp);
+ return img;
+}
+
+
+void write_img(unsigned char* img, const char *fname)
+{
+ FILE *fp;
+
+ fp = fopen(fname, "wb");
+ if (fp == NULL) {
+ perror(app_name);
+ exit(-1);
+ }
+
+ if (fwrite(img, 1, IMG_SIZE, fp) != IMG_SIZE) {
+ fprintf(stderr, "%s: can't write image file\n", app_name);
+ fclose(fp);
+ exit(-1);
+ }
+}
+
+
+void write_rootfs(unsigned char* img, const char *fname)
+{
+ FILE *fp;
+
+ fp = fopen(fname, "wb");
+ if (fp == NULL) {
+ perror(app_name);
+ exit(-1);
+ }
+
+ if (fwrite(img+ROOTFS_START, 1, ROOTFS_SIZE, fp) != ROOTFS_SIZE) {
+ fprintf(stderr, "%s: can't write image file\n", app_name);
+ fclose(fp);
+ exit(-1);
+ }
+}
+
+
+void write_kernel(unsigned char* img, const char *fname)
+{
+ FILE *fp;
+
+ fp = fopen(fname, "wb");
+ if (fp == NULL) {
+ perror(app_name);
+ exit(-1);
+ }
+
+ if (fwrite(img+KERNEL_START, 1, KERNEL_SIZE, fp) != KERNEL_SIZE) {
+ fprintf(stderr, "%s: can't write kernel file\n", app_name);
+ fclose(fp);
+ exit(-1);
+ }
+}
+
+
+unsigned char* read_rootfs(unsigned char* img, const char *fname)
+{
+ FILE *fp;
+ int size;
+ int i;
+
+ for (i=ROOTFS_START; i<ROOTFS_START+ROOTFS_SIZE; i++)
+ img[i] = 0xff;
+
+ fp = fopen(fname, "rb");
+ if (fp == NULL) {
+ perror(app_name);
+ exit(-1);
+ }
+
+ fseek(fp, 0, SEEK_END);
+ size = ftell(fp);
+
+ if (size > ROOTFS_SIZE) {
+ fprintf(stderr, "%s: rootfs image file is too big\n", app_name);
+ fclose(fp);
+ exit(-1);
+ }
+
+ rewind(fp);
+
+ if (fread(img+ROOTFS_START, 1, size, fp) != size) {
+ fprintf(stderr, "%s: can't read rootfs image file\n", app_name);
+ fclose(fp);
+ exit(-1);
+ }
+
+ fclose(fp);
+ return img;
+}
+
+
+unsigned char* read_kernel(unsigned char* img, const char *fname)
+{
+ FILE *fp;
+ int size;
+ int i;
+
+ for (i=KERNEL_START; i<KERNEL_START+KERNEL_SIZE; i++)
+ img[i] = 0xff;
+
+ fp = fopen(fname, "rb");
+ if (fp == NULL) {
+ perror(app_name);
+ exit(-1);
+ }
+
+ fseek(fp, 0, SEEK_END);
+ size = ftell(fp);
+
+ if (size > KERNEL_SIZE) {
+ fprintf(stderr, "%s: kernel binary file is too big\n", app_name);
+ fclose(fp);
+ exit(-1);
+ }
+
+ rewind(fp);
+
+ if (fread(img+KERNEL_START, 1, size, fp) != size) {
+ fprintf(stderr, "%s: can't read kernel file\n", app_name);
+ fclose(fp);
+ exit(-1);
+ }
+
+ fclose(fp);
+ return img;
+}
+
+
+int get_checksum(unsigned char* img)
+{
+ short unsigned s;
+
+ s = img[0x3dfffc] + (img[0x3dfffd]<<8);
+
+ return s;
+}
+
+
+void set_checksum(unsigned char*img, unsigned short sum)
+{
+ img[0x3dfffc] = sum & 0xff;
+ img[0x3dfffd] = (sum>>8) & 0xff;
+}
+
+
+int compute_checksum(unsigned char* img)
+{
+ int i;
+ short s=0;
+
+ for (i=0; i<0x3dfffc; i++)
+ s += img[i];
+
+ return s;
+}
+
+
+int main(int argc, char* argv[])
+{
+ char *img_fname = NULL;
+ char *rootfs_fname = NULL;
+ char *kernel_fname = NULL;
+ char *new_img_fname = NULL;
+
+ int do_fix_checksum = 0;
+ int do_write = 0;
+ int do_write_rootfs = 0;
+ int do_read_rootfs = 0;
+ int do_write_kernel = 0;
+ int do_read_kernel = 0;
+
+ int i;
+ unsigned char *img;
+ unsigned short img_checksum;
+ unsigned short real_checksum;
+
+ app_name = argv[0];
+
+ for (i=1; i<argc; i++) {
+ if (!strcmp(argv[i], "-h")) {
+ print_usage();
+ return 0;
+ }
+ else if (!strcmp(argv[i], "-f")) {
+ do_fix_checksum = 1;
+ }
+ else if (!strcmp(argv[i], "-x")) {
+ if (i+1 >= argc) {
+ fprintf(stderr, "%s: missing argument\n", app_name);
+ return -1;
+ }
+ do_write_rootfs = 1;
+ rootfs_fname = argv[i+1];
+ i++;
+ }
+ else if (!strcmp(argv[i], "-xk")) {
+ if (i+1 >= argc) {
+ fprintf(stderr, "%s: missing argument\n", app_name);
+ return -1;
+ }
+ do_write_kernel = 1;
+ kernel_fname = argv[i+1];
+ i++;
+ }
+ else if (!strcmp(argv[i], "-m")) {
+ if (i+1 >= argc) {
+ fprintf(stderr, "%s: missing argument\n", app_name);
+ return -1;
+ }
+ do_read_rootfs = 1;
+ rootfs_fname = argv[i+1];
+ i++;
+ }
+ else if (!strcmp(argv[i], "-k")) {
+ if (i+1 >= argc) {
+ fprintf(stderr, "%s: missing argument\n", app_name);
+ return -1;
+ }
+ do_read_kernel = 1;
+ kernel_fname = argv[i+1];
+ i++;
+ }
+ else if (!strcmp(argv[i], "-w")) {
+ if (i+1 >= argc) {
+ fprintf(stderr, "%s: missing argument\n", app_name);
+ return -1;
+ }
+ do_write = 1;
+ new_img_fname = argv[i+1];
+ i++;
+ }
+ else if (img_fname != 0) {
+ fprintf(stderr, "%s: too many arguments\n", app_name);
+ return -1;
+ }
+ else {
+ img_fname = argv[i];
+ }
+ }
+
+ if (img_fname == NULL) {
+ fprintf(stderr, "%s: missing argument\n", app_name);
+ return -1;
+ }
+
+ if ((do_read_rootfs && do_write_rootfs) ||
+ (do_read_kernel && do_write_kernel)) {
+ fprintf(stderr, "%s: conflictuous options\n", app_name);
+ return -1;
+ }
+
+ printf ("** Read firmware file\n");
+ img = read_img(img_fname);
+
+ printf ("Firmware product: %s\n", img+0x3dffbd);
+ printf ("Firmware version: 1.%02d.%02d\n", (img[0x3dffeb] & 0x7f), img[0x3dffec]);
+
+ if (do_write_rootfs) {
+ printf ("** Write rootfs file\n");
+ write_rootfs(img, rootfs_fname);
+ }
+
+ if (do_write_kernel) {
+ printf ("** Write kernel file\n");
+ write_kernel(img, kernel_fname);
+ }
+
+ if (do_read_rootfs) {
+ printf ("** Read rootfs file\n");
+ read_rootfs(img, rootfs_fname);
+ do_fix_checksum = 1;
+ }
+
+ if (do_read_kernel) {
+ printf ("** Read kernel file\n");
+ read_kernel(img, kernel_fname);
+ do_fix_checksum = 1;
+ }
+
+ img_checksum = get_checksum(img);
+ real_checksum = compute_checksum(img);
+
+ printf ("image checksum = %04x\n", img_checksum);
+ printf ("real checksum = %04x\n", real_checksum);
+
+ if (do_fix_checksum) {
+ if (img_checksum != real_checksum) {
+ printf ("** Bad Checksum, fix it\n");
+ set_checksum(img, real_checksum);
+ }
+ else {
+ printf ("** Checksum is correct, good\n");
+ }
+ }
+
+ if (do_write) {
+ printf ("** Write image file\n");
+ write_img(img, new_img_fname);
+ }
+
+ free(img);
+ return 0;
+}
+
projects / openwrt.git / blobdiff