OpenWrt – Rev 1
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/*
WRT350Nv2-Builder 2.4 (previously called buildimg)
Copyright (C) 2008-2009 Dirk Teurlings <info@upexia.nl>
Copyright (C) 2009-2011 Matthias Buecher (http://www.maddes.net/)
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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
A lot of thanks to Kaloz and juhosg from OpenWRT and Lennert Buytenhek from
marvell for helping me figure this one out. This code is based on bash
scripts wrote by Peter van Valderen so the real credit should go to him.
This program reads the provided parameter file and creates an image which can
be used to flash a Linksys WRT350N v2 from stock firmware.
The trick is to fill unused space in the bin file with random, so that the
resulting zip file passes the size check of the stock firmware.
The parameter file layout for an original Linksys firmware:
:kernel 0x001A0000 /path/to/uImage
:rootfs 0 /path/to/root.squashfs
:u-boot 0 /path/to/u-boot.bin
#version 0x2020
Additionally since v2.4 an already complete image can be used:
:image 0 /path/to/openwrt-wrt350nv2-[squashfs|jffs2-64k].img
args:
1 wrt350nv2.par parameter file describing the image layout
2 wrt350nv2.img output file for linksys style image
A u-boot image inside the bin file is not necessary.
The version is not important.
The name of the bin file is not important, but still "wrt350n.bin" is used to
keep as close as possible to the stock firmware.
Linksys assumes that no mtd will be used to its maximum, so the last 16 bytes
of the mtd are abused to define the length of the next mtd content (4 bytes for
size + 12 pad bytes).
At the end of "rootfs" additional 16 bytes are abused for some data and a
highly important eRcOmM identifier, so the last 32 bytes of "rootfs" are abused.
At the end of "u-boot" 128 bytes are abused for some data, a checksum and a
highly important sErCoMm identifier.
This program uses a special GNU scanf modifier to allocate
sufficient memory for a strings with unknown length.
See http://www.kernel.org/doc/man-pages/online/pages/man3/scanf.3.html#NOTES
To extract everything from a Linksys style firmware image see
https://forum.openwrt.org/viewtopic.php?pid=92928#p92928
Changelog:
v2.4 - added ":image" definition for parameter file, this allows
to use a complete sysupgrade image without any kernel size check
v2.3 - allow jffs by adding its magic number (0x8519)
added parameter option -i to ignore unknown magic numbers
v2.2 - fixed checksum byte calculation for other versions than 0x2019
fixed rare problem with padsize
updated info to stock firmware 2.00.20
fixed typos
v2.1 - used "wrt350n.bin" for the created image (closer to stock)
added option to create the image in two separate steps (-b / -z)
v2.0 - complete re-write
*/
// includes
#define _GNU_SOURCE // for GNU's basename()
#include <assert.h>
#include <errno.h> // errno
#include <stdarg.h>
#include <stdio.h> // fopen(), fread(), fclose(), etc.
#include <stdlib.h> // system(), etc.
#include <string.h> // basename(), strerror(), strdup(), etc.
#include <unistd.h> // optopt(), access(), etc.
#include <libgen.h>
#include <sys/wait.h> // WEXITSTATUS, etc.
// custom includes
#include "md5.h" // MD5 routines
#include "upgrade.h" // Linksys definitions from firmware 2.0.19 (unchanged up to 2.0.20)
// version info
#define VERSION "2.4"
char program_info[] = "WRT350Nv2-Builder v%s by Dirk Teurlings <info@upexia.nl> and Matthias Buecher (http://www.maddes.net/)\n";
// verbosity
#define DEBUG 1
#define DEBUG_LVL2 2
int verbosity = 0;
// mtd info
typedef struct {
char *name;
int offset;
int size;
char *filename;
long int filesize;
unsigned char magic[2];
} mtd_info;
mtd_info mtd_kernel = { "kernel", 0, 0, NULL, 0L, { 0, 0 } };
mtd_info mtd_rootfs = { "rootfs", 0, 0, NULL, 0L, { 0, 0 } };
mtd_info mtd_image = { "image", 0, 0, NULL, 0L, { 0, 0 } };
mtd_info mtd_uboot = { "u-boot", 0, 0, NULL, 0L, { 0, 0 } };
#define ROOTFS_END_OFFSET 0x00760000
#define ROOTFS_MIN_OFFSET 0x00640000 // should be filled up to here, to make sure that the zip file is big enough to pass the size check of the stock firmware
// 2.0.17: filled up to 0x00640000
// 2.0.19: filled up to 0x00670000
// 2.0.20: filled up to 0x00670000
// rootfs statics via: hexdump -v -e '1/1 "0x%02X, "' -s 0x0075FFE0 -n 16 "wrt350n.bin" ; echo -en "\n"
unsigned char product_id[] = { 0x00, 0x03 }; // seems to be a fixed value
unsigned char protocol_id[] = { 0x00, 0x00 }; // seems to be a fixed value
unsigned char fw_version[] = { 0x20, 0x20 };
unsigned char rootfs_unknown[] = { 0x90, 0xF7 }; // seems to be a fixed value
unsigned char sign[] = { 0x65, 0x52, 0x63, 0x4F, 0x6D, 0x4D, 0x00, 0x00 }; // eRcOmM
// u-boot statics via: hexdump -v -e '1/1 "0x%02X, "' -s 0x007FFF80 -n 128 "wrt350n.bin" ; echo -en "\n"
//unsigned char sn[] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }; // (12) seems to be an unused value
//unsigned char pin[] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }; // (8) seems to be an unused value
//unsigned char node[] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // (25) seems to be an unused value
// 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
//unsigned char checksum[] = { 0xE9 }; // (1) is calculated, does it belong to node?
unsigned char pid[] = { 0x73, 0x45, 0x72, 0x43, 0x6F, 0x4D, 0x6D, 0x00, 0x01, 0x00, 0x00, 0x59, 0x42, 0x50, 0x00, 0x01, // (70) seems to be a fixed value, except for fw version
0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03, 0x00, // protocol id?
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03, 0x00, 0x00, // protocol id?
0x12, 0x34, // firmware version, same as in rootfs
0x00, 0x00, 0x00, 0x04,
0x73, 0x45, 0x72, 0x43, 0x6F, 0x4D, 0x6D }; // sErCoMm
// img statics via: hexdump -v -e '1/1 "0x%02X, "' -s 0 -n 512 "WRT350N-EU-ETSI-2.00.19.img" ; echo -en "\n" (unchanged up to 2.0.20)
unsigned char img_hdr[] = { 0x00, 0x01, 0x00, 0x00, 0x59, 0x42, 0x50, 0x00, 0x01, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03,
0x00, 0x00,
0x12, 0x34, // firmware version, same as in rootfs
0x00, 0x00, 0x00, 0x04, 0x61, 0x44, 0x6D, 0x42, 0x6C, 0x4B, 0x3D, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x12, 0x34, 0x56, 0x78, 0x9A, 0xBC, 0xDE, 0xF0, 0x12, 0x34, 0x56, 0x78, 0x9A, 0xBC, 0xDE, 0xF0, // md5 checksum
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
unsigned char img_eof[] = { 0xFF };
void lprintf(int outputlevel, char *fmt, ...) {
va_list argp;
if (outputlevel <= verbosity) {
va_start(argp, fmt);
vprintf(fmt, argp);
va_end(argp);
}
}
int parse_par_file(FILE *f_par) {
int exitcode = 0;
char *buffer;
size_t buffer_size;
char *line;
int lineno;
int count;
char string1[256];
char string2[256];
int value;
mtd_info *mtd;
FILE *f_in;
int f_exitcode = 0;
// read all lines
buffer_size = 1000;
buffer = NULL;
lineno = 0;
while (!feof(f_par)) {
// read next line into memory
do {
// allocate memory for input line
if (!buffer) {
buffer = malloc(buffer_size);
}
if (!buffer) {
exitcode = 1;
printf("parse_par_file: can not allocate %i bytes\n", (int) buffer_size);
break;
}
line = fgets(buffer, buffer_size, f_par);
if (!line) {
exitcode = ferror(f_par);
if (exitcode) {
printf("parse_par_file: %s\n", strerror(exitcode));
}
break;
}
// if buffer was not completely filled, then assume that line is complete
count = strlen(buffer) + 1;
if (count-- < buffer_size) {
break;
}
// otherwise....
// reset file position to line start
value = fseek(f_par, -count, SEEK_CUR);
if (value == -1) {
exitcode = errno;
printf("parse_par_file: %s\n", strerror(exitcode));
break;
}
// double buffer size
free(buffer);
buffer = NULL;
buffer_size *= 2;
lprintf(DEBUG_LVL2, " extending buffer to %i bytes\n", buffer_size);
} while (1);
if ((!line) || (exitcode)) {
break;
}
lineno++; // increase line number
lprintf(DEBUG_LVL2, " line %i (%i) %s", lineno, count, line);
value = 0;
mtd = NULL;
// split line if starting with a colon
switch (line[0]) {
case ':':
count = sscanf(line, ":%255s %i %255s", string1, &value, string2);
if (count != 3) {
printf("line %i does not meet defined format (:<mtdname> <mtdsize> <file>)\n", lineno);
} else {
// populate mtd_info if supported mtd names
if (!strcmp(string1, mtd_kernel.name)) {
mtd = &mtd_kernel;
} else if (!strcmp(string1, mtd_rootfs.name)) {
mtd = &mtd_rootfs;
} else if (!strcmp(string1, mtd_uboot.name)) {
mtd = &mtd_uboot;
} else if (!strcmp(string1, mtd_image.name)) {
mtd = &mtd_image;
}
if (!mtd) {
printf("unknown mtd %s in line %i\n", string1, lineno);
} else if (mtd->filename) {
f_exitcode = 1;
printf("mtd %s in line %i multiple definitions\n", string1, lineno);
} else {
mtd->size = value;
mtd->filename = strdup(string2);
// Get file size
f_in = fopen(mtd->filename, "rb");
if (!f_in) {
f_exitcode = errno;
printf("input file %s: %s\n", mtd->filename, strerror(f_exitcode));
} else {
value = fread(&mtd->magic, 1, 2, f_in);
if (value < 2) {
if (ferror(f_in)) {
f_exitcode = ferror(f_in);
printf("input file %s: %s\n", mtd->filename, strerror(f_exitcode));
} else {
f_exitcode = 1;
printf("input file %s: smaller than two bytes, no magic code\n", mtd->filename);
}
}
value = fseek(f_in, 0, SEEK_END);
if (value == -1) {
f_exitcode = errno;
printf("input file %s: %s\n", mtd->filename, strerror(f_exitcode));
} else {
mtd->filesize = ftell(f_in);
if (mtd->filesize == -1) {
f_exitcode = errno;
printf("input file %s: %s\n", mtd->filename, strerror(f_exitcode));
}
}
fclose(f_in);
}
lprintf(DEBUG, "mtd %s in line %i: size=0x%08X, filesize=0x%08lX, magic=0x%02X%02X, file=%s\n", mtd->name, lineno, mtd->size, mtd->filesize, mtd->magic[0], mtd->magic[1], mtd->filename);
}
}
break;
case '#': // integer values
count = sscanf(line, "#%255s %i", string1, &value);
if (count != 2) {
printf("line %i does not meet defined format (#<variable name> <integer>\n", lineno);
} else {
if (!strcmp(string1, "version")) {
// changing version
fw_version[0] = 0x000000FF & ( value >> 8 );
fw_version[1] = 0x000000FF & value;
} else {
printf("unknown integer variable %s in line %i\n", string1, lineno);
}
lprintf(DEBUG, "integer variable %s in line %i: 0x%08X\n", string1, lineno, value);
}
break;
case '$': // strings
count = sscanf(line, "$%255s %255s", string1, string2);
if (count != 2) {
printf("line %i does not meet defined format (:<mtdname> <mtdsize> <file>)\n", lineno);
} else {
/*
if (!strcmp(string1, "something")) {
something = strdup(string2);
} else {
*/
printf("unknown string variable %s in line %i\n", string1, lineno);
// }
lprintf(DEBUG, "string variable %s in line %i: %s\n", string1, lineno, string2);
}
break;
default:
break;
}
}
free(buffer);
if (!exitcode) {
exitcode = f_exitcode;
}
return exitcode;
}
int create_bin_file(char *bin_filename) {
int exitcode = 0;
unsigned char *buffer;
int i;
mtd_info *mtd;
int addsize;
int padsize;
char *rand_filename = "/dev/urandom";
FILE *f_in;
int size;
unsigned long int csum;
unsigned char checksum;
FILE *f_out;
// allocate memory for bin file
buffer = malloc(KERNEL_CODE_OFFSET + FLASH_SIZE);
if (!buffer) {
exitcode = 1;
printf("create_bin_file: can not allocate %i bytes\n", FLASH_SIZE);
} else {
// initialize with zero
memset(buffer, 0, KERNEL_CODE_OFFSET + FLASH_SIZE);
}
// add files
if (!exitcode) {
for (i = 1; i <= 4; i++) {
addsize = 0;
padsize = 0;
switch (i) {
case 1:
mtd = &mtd_image;
padsize = ROOTFS_MIN_OFFSET - mtd->filesize;
break;
case 2:
mtd = &mtd_kernel;
break;
case 3:
mtd = &mtd_rootfs;
addsize = mtd->filesize;
padsize = ROOTFS_MIN_OFFSET - mtd_kernel.size - mtd->filesize;
break;
case 4:
mtd = &mtd_uboot;
addsize = mtd->filesize;
break;
default:
mtd = NULL;
exitcode = 1;
printf("create_bin_file: unknown mtd %i\n", i);
break;
}
if (!mtd) {
break;
}
if (!mtd->filename) {
continue;
}
lprintf(DEBUG, "adding mtd %s file %s\n", mtd->name, mtd->filename);
// adding file size
if (addsize) {
buffer[KERNEL_CODE_OFFSET + mtd->offset - 16] = 0x000000FFL & ( addsize >> 24 );
buffer[KERNEL_CODE_OFFSET + mtd->offset - 15] = 0x000000FFL & ( addsize >> 16 );
buffer[KERNEL_CODE_OFFSET + mtd->offset - 14] = 0x000000FFL & ( addsize >> 8 );
buffer[KERNEL_CODE_OFFSET + mtd->offset - 13] = 0x000000FFL & addsize;
}
// adding file content
f_in = fopen(mtd->filename, "rb");
if (!f_in) {
exitcode = errno;
printf("input file %s: %s\n", mtd->filename, strerror(exitcode));
} else {
size = fread(&buffer[KERNEL_CODE_OFFSET + mtd->offset], mtd->filesize, 1, f_in);
if (size < 1) {
if (ferror(f_in)) {
exitcode = ferror(f_in);
printf("input file %s: %s\n", mtd->filename, strerror(exitcode));
} else {
exitcode = 1;
printf("input file %s: smaller than before *doh*\n", mtd->filename);
}
}
fclose(f_in);
}
// padding
if (padsize > 0) {
addsize = padsize & 0x0000FFFF; // start on next 64KB border
padsize -= addsize;
}
if (padsize > 0) {
printf("mtd %s input file %s is too small (0x%08lX), adding 0x%08X random bytes\n", mtd->name, mtd->filename, mtd->filesize, padsize);
addsize += KERNEL_CODE_OFFSET + mtd->offset + mtd->filesize; // get offset
lprintf(DEBUG, " padding offset 0x%08X length 0x%08X\n", addsize, padsize);
f_in = fopen(rand_filename, "rb");
if (!f_in) {
exitcode = errno;
printf("input file %s: %s\n", rand_filename, strerror(exitcode));
} else {
size = fread(&buffer[addsize], padsize, 1, f_in);
if (size < 1) {
if (ferror(f_in)) {
exitcode = ferror(f_in);
printf("input file %s: %s\n", rand_filename, strerror(exitcode));
} else {
exitcode = 1;
printf("input file %s: smaller than before *doh*\n", rand_filename);
}
}
}
fclose(f_in);
}
}
}
// add special contents
if (!exitcode) {
lprintf(DEBUG, "adding rootfs special data\n");
memcpy(&buffer[KERNEL_CODE_OFFSET + PRODUCT_ID_OFFSET], product_id, 2);
memcpy(&buffer[KERNEL_CODE_OFFSET + PROTOCOL_ID_OFFSET], protocol_id, 2);
memcpy(&buffer[KERNEL_CODE_OFFSET + FW_VERSION_OFFSET], fw_version, 2);
memcpy(&buffer[KERNEL_CODE_OFFSET + FW_VERSION_OFFSET + 2], rootfs_unknown, 2);
memcpy(&buffer[KERNEL_CODE_OFFSET + SIGN_OFFSET], sign, 8); // eRcOmM
lprintf(DEBUG, "adding u-boot special data\n");
// memcpy(&buffer[KERNEL_CODE_OFFSET + SN_OFF], sn, 12); // ToDo: currently zero, find out what's this for?
// memcpy(&buffer[KERNEL_CODE_OFFSET + PIN_OFF], pin, 8); // ToDo: currently zero, find out what's this for?
// memcpy(&buffer[KERNEL_CODE_OFFSET + NODE_BASE_OFF], node, 25); // ToDo: currently zero, find out what's this for?
memcpy(&buffer[KERNEL_CODE_OFFSET + BOOT_ADDR_BASE_OFF + PID_OFFSET], pid, 70); // sErCoMm
memcpy(&buffer[KERNEL_CODE_OFFSET + BOOT_ADDR_BASE_OFF + PID_OFFSET + 57], fw_version, 2);
lprintf(DEBUG, "adding checksum byte\n");
csum = 0;
for (i = 0; i < KERNEL_CODE_OFFSET + FLASH_SIZE; i++) {
csum += buffer[i];
}
lprintf(DEBUG_LVL2, " checksum 0x%016lX (%li)\n", csum, csum);
buffer[KERNEL_CODE_OFFSET + NODE_BASE_OFF + 25] = ~csum + 1;
lprintf(DEBUG, " byte 0x%02X\n", buffer[KERNEL_CODE_OFFSET + NODE_BASE_OFF + 25]);
}
// write bin file
if (!exitcode) {
lprintf(DEBUG, "writing file %s\n", bin_filename);
f_out = fopen(bin_filename, "wb");
if (!f_out) {
exitcode = errno;
printf("output file %s: %s\n", bin_filename, strerror(exitcode));
} else {
size = fwrite(buffer, KERNEL_CODE_OFFSET + FLASH_SIZE, 1, f_out);
if (size < 1) {
if (ferror(f_out)) {
exitcode = ferror(f_out);
printf("output file %s: %s\n", bin_filename, strerror(exitcode));
} else {
exitcode = 1;
printf("output file %s: unspecified write error\n", bin_filename);
}
}
fclose(f_out);
}
}
return exitcode;
}
int create_zip_file(char *zip_filename, char *bin_filename) {
int exitcode = 0;
char *buffer;
size_t buffer_size;
int count;
buffer_size = 1000;
buffer = NULL;
do {
// allocate memory for command line
if (!buffer) {
buffer = malloc(buffer_size);
}
if (!buffer) {
exitcode = 1;
printf("create_zip_file: can not allocate %i bytes\n", (int) buffer_size);
break;
}
// if buffer was not completely filled, then line fit in completely
count = snprintf(buffer, buffer_size, "zip \"%s\" \"%s\"", zip_filename, bin_filename);
if ((count > -1) && (count < buffer_size)) {
break;
}
// otherwise try again with more space
if (count > -1) { // glibc 2.1
buffer_size = count + 1; // precisely what is needed
} else { // glibc 2.0
buffer_size *= 2; // twice the old size
}
free(buffer);
buffer = NULL;
lprintf(DEBUG_LVL2, " extending buffer to %i bytes\n", buffer_size);
} while (1);
if (!exitcode) {
// zipping binfile
lprintf(DEBUG, "%s\n", buffer);
count = system(buffer);
if ((count < 0) || (WEXITSTATUS(count))) {
exitcode = 1;
printf("create_zip_file: can not execute %s bytes\n", buffer);
}
}
return exitcode;
}
int create_img_file(FILE *f_out, char *out_filename, char *zip_filename) {
int exitcode = 0;
md5_state_t state;
md5_byte_t digest[16];
int i;
int size;
FILE *f_in;
unsigned char buffer[1];
// copy firmware version
memcpy(&img_hdr[50], fw_version, 2);
// clear md5 checksum
memset(&img_hdr[480], 0, 16);
// prepare md5 checksum calculation
md5_init(&state);
// add img header
lprintf(DEBUG_LVL2, " adding img header\n");
for (i = 0; i < 512; i++) {
size = fputc(img_hdr[i], f_out);
if (size == EOF) {
exitcode = ferror(f_out);
printf("output file %s: %s\n", out_filename, strerror(exitcode));
break;
}
md5_append(&state, (const md5_byte_t *)&img_hdr[i], 1);
}
// adding zip file
if (!exitcode) {
lprintf(DEBUG_LVL2, " adding zip file\n");
f_in = fopen(zip_filename, "rb");
if (!f_in) {
exitcode = errno;
printf("input file %s: %s\n", zip_filename, strerror(exitcode));
} else {
while ((size = fgetc(f_in)) != EOF) {
buffer[0] = size;
size = fputc(buffer[0], f_out);
if (size == EOF) {
exitcode = ferror(f_out);
printf("output file %s: %s\n", out_filename, strerror(exitcode));
break;
}
md5_append(&state, (const md5_byte_t *)buffer, 1);
}
if (ferror(f_in)) {
exitcode = ferror(f_in);
printf("input file %s: %s\n", zip_filename, strerror(exitcode));
}
}
}
// add end byte
if (!exitcode) {
lprintf(DEBUG_LVL2, " adding img eof byte\n");
size = fputc(img_eof[0], f_out);
if (size == EOF) {
exitcode = ferror(f_out);
printf("output file %s: %s\n", out_filename, strerror(exitcode));
}
md5_append(&state, (const md5_byte_t *)img_eof, 1);
}
// append salt to md5 checksum
md5_append(&state, (const md5_byte_t *)"A^gU*<>?RFY@#DR&Z", 17);
// finish md5 checksum calculation
md5_finish(&state, digest);
// write md5 checksum into img header
if (!exitcode) {
lprintf(DEBUG_LVL2, " writing md5 checksum into img header of file\n");
size = fseek(f_out, 480, SEEK_SET);
if (size == -1) {
exitcode = errno;
printf("output file %s: %s\n", out_filename, strerror(exitcode));
} else {
size = fwrite(digest, 16, 1, f_out);
if (size < 1) {
if (ferror(f_out)) {
exitcode = ferror(f_out);
printf("output file %s: %s\n", out_filename, strerror(exitcode));
} else {
exitcode = 1;
printf("output file %s: unspecified write error\n", out_filename);
}
}
}
fclose(f_in);
}
return exitcode;
}
int main(int argc, char *argv[]) {
int exitcode = 0;
int help;
int onlybin;
int havezip;
int ignoremagic;
char option;
char *par_filename = NULL;
char *img_filename = NULL;
char *base_filename = NULL;
char *bin_filename = NULL;
char *zip_filename = NULL;
FILE *f_par = NULL;
FILE *f_img = NULL;
int i;
mtd_info *mtd;
int noupdate;
int sizecheck;
int magiccheck;
int magicerror;
// display program header
printf(program_info, VERSION);
// command line processing
// options
help = 0;
onlybin = 0;
havezip = 0;
ignoremagic = 0;
while ((option = getopt(argc, argv, "hbzif:v")) != -1) {
switch(option) {
case 'h':
help = 1;
break;
case 'b':
onlybin = 1;
break;
case 'z':
havezip = 1;
break;
case 'i':
ignoremagic = 1;
break;
case 'f':
sizecheck = sscanf(optarg, "%i", &i);
if (sizecheck != 1) {
printf("Firmware version of -f option not a valid integer\n");
exitcode = 1;
} else {
fw_version[0] = 0x000000FF & ( i >> 8 );
fw_version[1] = 0x000000FF & i;
}
break;
case 'v':
verbosity++;
break;
case ':': // option with missing operand
printf("Option -%c requires an operand\n", optopt);
exitcode = 1;
break;
case '?':
printf("Unrecognized option: -%c\n", optopt);
exitcode = 1;
break;
}
}
// files
for ( ; optind < argc; optind++) {
if (!par_filename) {
par_filename = argv[optind];
if (access(par_filename, R_OK)) {
if (havezip) {
printf("No read access to zip file %s\n", par_filename);
} else {
printf("No read access to parameter or zip file %s\n", par_filename);
}
exitcode = 1;
}
continue;
}
if ((!onlybin) && (!img_filename)) {
img_filename = argv[optind];
if (!access(img_filename, F_OK)) { // if file already exists then check write access
if (access(img_filename, W_OK)) {
printf("No write access to image file %s\n", img_filename);
exitcode = 1;
}
}
continue;
}
printf("Too many files stated\n");
exitcode = 1;
break;
}
// file name checks
if (!par_filename) {
if (havezip) {
printf("Zip file not stated\n");
} else {
printf("Parameter file not stated\n");
}
exitcode = 1;
} else {
base_filename = basename(par_filename);
if (!base_filename) {
if (havezip) {
printf("Zip file is a directory\n");
} else {
printf("Parameter file is a directory\n");
}
exitcode = 1;
}
}
if (!onlybin) {
if (!img_filename) {
printf("Image file not stated\n");
exitcode = 1;
} else {
base_filename = basename(img_filename);
if (!base_filename) {
printf("Image file is a directory\n");
exitcode = 1;
}
}
}
// check for mutually exclusive options
if ((onlybin) && (havezip)) {
printf("Option -b and -z are mutually exclusive\n");
exitcode = 1;
}
// react on option problems or help request, then exit
if ((exitcode) || (help)) {
if (help) {
printf("This program creates Linksys style images for the WRT350Nv2 router.\n");
}
printf(" Usage:\n\
%s [-h] [-b] [-z] [-i] [-f <version>] [-v] <parameter or zip file> [<image file>]\n\n\
Options:\n\
-h - Show this help\n\
-b - Create only bin file, no img or zip file is created\n\
-z - Have zip file, the img file will be directly created from it\n\
-i - Ignore unknown magic numbers\n\
-f <version> - Wanted firmware version to use with -z\n\
Default firmware version is 0x2020 = 2.00.20.\n\
Note: version from parameter file will supersede this\n\
-v - Increase debug verbosity level\n\n\
Example:\n\
%s wrt350nv2.par wrt350nv2.img\n\n", argv[0], argv[0]);
return exitcode;
}
// handle special case when zipfile is stated
if (havezip) {
zip_filename = par_filename;
par_filename = NULL;
}
lprintf(DEBUG_LVL2, " Verbosity: %i\n", verbosity);
lprintf(DEBUG_LVL2, " Program: %s\n", argv[0]);
if (par_filename) {
lprintf(DEBUG, "Parameter file: %s\n", par_filename);
}
if (zip_filename) {
lprintf(DEBUG, "Zip file: %s\n", zip_filename);
}
if (img_filename) {
lprintf(DEBUG, "Image file: %s\n", img_filename);
}
// open files from command line
// parameter/zip file
if (par_filename) {
f_par = fopen(par_filename, "rt");
if (!f_par) {
exitcode = errno;
printf("Input file %s: %s\n", par_filename, strerror(exitcode));
}
}
// image file
if (img_filename) {
f_img = fopen(img_filename, "wb");
if (!f_img) {
exitcode = errno;
printf("Output file %s: %s\n", img_filename, strerror(exitcode));
}
}
if (exitcode) {
return exitcode;
}
// parameter file processing
if ((!exitcode) && (f_par)) {
lprintf(DEBUG, "parsing parameter file...\n");
exitcode = parse_par_file(f_par);
lprintf(DEBUG, "...done parsing file\n");
}
if (f_par) {
fclose(f_par);
}
// check all input data
if ((!exitcode) && (par_filename)) {
lprintf(DEBUG, "checking mtd data...\n");
for (i = 1; i <= 4; i++) {
noupdate = 0;
sizecheck = 0;
magiccheck = 0;
switch (i) {
case 1:
mtd = &mtd_image;
sizecheck = ROOTFS_END_OFFSET;
magiccheck = 1;
break;
case 2:
mtd = &mtd_kernel;
sizecheck = mtd_kernel.size - 16;
magiccheck = 1;
break;
case 3:
mtd = &mtd_rootfs;
mtd->offset = mtd_kernel.size;
mtd->size = ROOTFS_END_OFFSET - mtd_kernel.size;
sizecheck = PRODUCT_ID_OFFSET - mtd_kernel.size;
magiccheck = 1;
break;
case 4:
mtd = &mtd_uboot;
mtd->offset = BOOT_ADDR_BASE_OFF;
noupdate = 1;
sizecheck = SN_OFF - BOOT_ADDR_BASE_OFF;
break;
default:
mtd = NULL;
exitcode = 1;
printf("unknown mtd check %i\n", i);
break;
}
if (!mtd) {
break;
}
lprintf(DEBUG_LVL2, " checking mtd %s\n", mtd->name);
// general checks
// no further checks if no file data present
if (!mtd->filename) {
continue;
}
// not updated by stock firmware
if (noupdate) {
printf("mtd %s is specified, but will not be updated as of Linksys firmware 2.0.19\n", mtd->name);
}
// general magic number check
magicerror = 0;
if (magiccheck) {
switch (i) {
case 1: // image
case 2: // kernel
if (!(
((mtd->magic[0] == 0x27) && (mtd->magic[1] == 0x05)) // uImage
)) {
magicerror = 1;
}
break;
case 3: // rootfs
if (!(
((mtd->magic[0] == 0x68) && (mtd->magic[1] == 0x73)) // squashfs
|| ((mtd->magic[0] == 0x85) && (mtd->magic[1] == 0x19)) // jffs
)) {
magicerror = 1;
}
break;
default:
magicerror = 1;
break;
}
if (magicerror) {
printf("mtd %s input file %s has unknown magic number (0x%02X%02X)", mtd->name, mtd->filename, mtd->magic[0], mtd->magic[1]);
if (ignoremagic) {
printf("...ignoring");
} else {
exitcode = 1;
}
printf("\n");
}
}
// mtd specific size check
if (mtd == &mtd_image) {
if (mtd->filesize < 0x00200000) {
exitcode = 1;
printf("mtd %s input file %s too unrealistic small (0x%08lX)\n", mtd->name, mtd->filename, mtd->filesize);
}
}
if (mtd == &mtd_kernel) {
if (mtd->filesize < 0x00080000) {
exitcode = 1;
printf("mtd %s input file %s too unrealistic small (0x%08lX)\n", mtd->name, mtd->filename, mtd->filesize);
}
}
// general size check
if (sizecheck) {
if (sizecheck <= 0) {
exitcode = 1;
printf("mtd %s bad file size check (%i) due to input data\n", mtd->name, sizecheck);
} else {
if (mtd->filesize > sizecheck) {
exitcode = 1;
printf("mtd %s input file %s too big (0x%08lX)\n", mtd->name, mtd->filename, mtd->filesize);
}
}
}
}
// Check for mandatory parts
if ((!mtd_image.filename) && (!mtd_kernel.filename || !mtd_rootfs.filename)) {
exitcode = 1;
if (mtd_kernel.filename && !mtd_rootfs.filename) {
printf("Kernel without rootfs, either incorrectly specified or not at all in parameter file\n");
} else if (!mtd_kernel.filename && mtd_rootfs.filename) {
printf("Rootfs without kernel, either incorrectly specified or not at all in parameter file\n");
} else {
printf("Neither an image nor kernel with rootfs was/were correctly specified or at all in parameter file\n");
}
}
// Check for duplicate parts
if ((mtd_image.filename) && (mtd_kernel.filename || mtd_rootfs.filename)) {
exitcode = 1;
printf("Image and kernel/rootfs specified in parameter file\n");
}
lprintf(DEBUG, "...done checking mtd data\n");
}
// bin creation in memory
if ((!exitcode) && (par_filename)) {
bin_filename = "wrt350n.bin";
lprintf(DEBUG, "creating bin file %s...\n", bin_filename);
exitcode = create_bin_file(bin_filename);
lprintf(DEBUG, "...done creating bin file\n");
}
// zip file creation
if ((!exitcode) && (!onlybin) && (!zip_filename)) {
zip_filename = "wrt350n.zip";
lprintf(DEBUG, "creating zip file %s...\n", zip_filename);
exitcode = create_zip_file(zip_filename, bin_filename);
lprintf(DEBUG, "...done creating zip file\n");
}
// img file creation
if ((!exitcode) && (f_img)) {
lprintf(DEBUG, "creating img file...\n");
exitcode = create_img_file(f_img, img_filename, zip_filename);
lprintf(DEBUG, "...done creating img file\n");
}
// clean up
if (f_img) {
fclose(f_img);
}
// end program
return exitcode;
}