tools/firmware-utils/src/motorola-bin.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * motorola-bin.c
   4  *
   5  * Copyright (C) 2005-2006 Mike Baker,
   6  *                         Imre Kaloz <kaloz@openwrt.org>
   7  *                         D. Hugh Redelmeier
   8  *                         OpenWrt.org
   9  */
  10
  11 /*
  12  * Motorola's firmware flashing code requires an extra header.
  13  * The header is eight bytes (see struct motorola below).
  14  * This program will take a firmware file and create a new one
  15  * with this header:
  16  *      motorola-bin --wr850g WR850G_V403.stripped.trx WR850G_V403.trx
  17  *
  18  * Note: Motorola's firmware is distributed with this header.
  19  * If you need to flash Motorola firmware on a router running OpenWRT,
  20  * you will to remove this header.  Use the --strip flag:
  21  *      motorola-bin --strip WR850G_V403.trx WR850G_V403.stripped.trx
  22  */
  23
  24 /*
  25  * February 1, 2006
  26  *
  27  * Add support for for creating WA840G and WE800G images
  28  */
  29
  30 #include <stdio.h>
  31 #include <stdlib.h>
  32 #include <stddef.h>
  33 #include <unistd.h>
  34 #include <errno.h>
  35 #include <fcntl.h>
  36 #include <sys/mman.h>
  37 #include <string.h>
  38 #include <netinet/in.h>
  39 #include <inttypes.h>
  40
  41 #define BPB 8 /* bits/byte */
  42
  43 static uint32_t crc32[1<<BPB];
  44
  45 static void init_crc32()
  46 {
  47         const uint32_t poly = ntohl(0x2083b8ed);
  48         int n;
  49
  50         for (n = 0; n < 1<<BPB; n++) {
  51                 uint32_t crc = n;
  52                 int bit;
  53
  54                 for (bit = 0; bit < BPB; bit++)
  55                         crc = (crc & 1) ? (poly ^ (crc >> 1)) : (crc >> 1);
  56                 crc32[n] = crc;
  57         }
  58 }
  59
  60 static uint32_t crc32buf(unsigned char *buf, size_t len)
  61 {
  62         uint32_t crc = 0xFFFFFFFF;
  63
  64         for (; len; len--, buf++)
  65                 crc = crc32[(uint8_t)crc ^ *buf] ^ (crc >> BPB);
  66         return crc;
  67 }
  68
  69 struct motorola {
  70         uint32_t crc;   // crc32 of the remainder
  71         uint32_t flags; // unknown, 105770*
  72 };
  73
  74 static const struct model {
  75         char digit;     /* a digit signifying model (historical) */
  76         const char *name;
  77         uint32_t flags;
  78 } models[] = {
  79         { '1', "WR850G", 0x10577050LU },
  80         { '2', "WA840G", 0x10577040LU },
  81         { '3', "WE800G", 0x10577000LU },
  82         { '\0', NULL, 0 }
  83 };
  84
  85 static void usage(const char *) __attribute__ (( __noreturn__ ));
  86
  87 static void usage(const char *mess)
  88 {
  89         const struct model *m;
  90
  91         fprintf(stderr, "Error: %s\n", mess);
  92         fprintf(stderr, "Usage: motorola-bin -device|--strip infile outfile\n");
  93         fprintf(stderr, "Known devices: ");
  94
  95         for (m = models; m->digit != '\0'; m++)
  96                 fprintf(stderr, " %c - %s", m->digit, m->name);
  97
  98         fprintf(stderr, "\n");
  99         exit(1);
 100 }
 101
 102 int main(int argc, char **argv)
 103 {
 104         off_t len;      // of original firmware
 105         int fd;
 106         void *trx;      // pointer to original firmware (mmmapped)
 107         struct motorola *firmware;      // pionter to prefix + copy of original firmware
 108         uint32_t flags;
 109
 110         // verify parameters
 111
 112         if (argc != 4)
 113                 usage("wrong number of arguments");
 114
 115         // mmap trx file
 116         if ((fd = open(argv[2], O_RDONLY))  < 0
 117         || (len = lseek(fd, 0, SEEK_END)) < 0
 118         || (trx = mmap(0, len, PROT_READ, MAP_SHARED, fd, 0)) == (void *) (-1)
 119         || close(fd) < 0)
 120         {
 121                 fprintf(stderr, "Error loading file %s: %s\n", argv[2], strerror(errno));
 122                 exit(1);
 123         }
 124
 125         init_crc32();
 126
 127         if (strcmp(argv[1], "--strip") == 0)
 128         {
 129                 const char *ugh = NULL;
 130
 131                 if (len < sizeof(struct motorola)) {
 132                         ugh = "input file too short";
 133                 } else {
 134                         const struct model *m;
 135
 136                         firmware = trx;
 137                         if (htonl(crc32buf(trx + offsetof(struct motorola, flags), len - offsetof(struct motorola, flags))) != firmware->crc)
 138                                 ugh = "Invalid CRC";
 139                         for (m = models; ; m++) {
 140                                 if (m->digit == '\0') {
 141                                         if (ugh == NULL)
 142                                                 ugh = "unrecognized flags field";
 143                                         break;
 144                                 }
 145                                 if (firmware->flags == htonl(m->flags)) {
 146                                         fprintf(stderr, "Firmware for Motorola %s\n", m->name);
 147                                         break;
 148                                 }
 149                         }
 150                 }
 151
 152                 if (ugh != NULL) {
 153                         fprintf(stderr, "%s\n", ugh);
 154                         exit(3);
 155                 } else {
 156                         // all is well, write the file without the prefix
 157                         if ((fd = open(argv[3], O_CREAT|O_WRONLY|O_TRUNC,0644)) < 0
 158                         || write(fd, trx + sizeof(struct motorola), len - sizeof(struct motorola)) !=  len - sizeof(struct motorola)
 159                         || close(fd) < 0)
 160                         {
 161                                 fprintf(stderr, "Error storing file %s: %s\n", argv[3], strerror(errno));
 162                                 exit(2);
 163                         }
 164                 }
 165
 166         } else {
 167                 // setup the firmware flags magic number
 168                 const struct model *m;
 169                 const char *df = argv[1];
 170
 171                 if (*df != '-')
 172                         usage("first argument must start with -");
 173                 if (*++df == '-')
 174                         ++df;   /* allow but don't require second - */
 175
 176                 for (m = models; ; m++) {
 177                         if (m->digit == '\0')
 178                                 usage("unrecognized device specified");
 179                         if ((df[0] == m->digit && df[1] == '\0') || strcasecmp(df, m->name) == 0) {
 180                                 flags = m->flags;
 181                                 break;
 182                         }
 183                 }
 184
 185
 186                 // create a firmware image in memory
 187                 // and copy the trx to it
 188                 firmware = malloc(sizeof(struct motorola) + len);
 189                 memcpy(&firmware[1], trx, len);
 190
 191                 // setup the motorola headers
 192                 firmware->flags = htonl(flags);
 193
 194                 // CRC of flags + firmware
 195                 firmware->crc = htonl(crc32buf((unsigned char *)&firmware->flags, sizeof(firmware->flags) + len));
 196
 197                 // write the firmware
 198                 if ((fd = open(argv[3], O_CREAT|O_WRONLY|O_TRUNC,0644)) < 0
 199                 || write(fd, firmware, sizeof(struct motorola) + len) != sizeof(struct motorola) + len
 200                 || close(fd) < 0)
 201                 {
 202                         fprintf(stderr, "Error storing file %s: %s\n", argv[3], strerror(errno));
 203                         exit(2);
 204                 }
 205
 206                 free(firmware);
 207         }
 208
 209         munmap(trx,len);
 210
 211         return 0;
 212 }