utils/AMS/hacking/amsinfo.c

   1 /*
   2  * Copyright © 2008 Rafaël Carré <rafael.carre@gmail.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110, USA
  17  *
  18  */
  19
  20 #define _ISOC99_SOURCE /* snprintf() */
  21 #include <stdio.h>
  22 #include <sys/types.h>
  23 #include <sys/stat.h>
  24 #include <fcntl.h>
  25 #include <errno.h>
  26 #include <unistd.h>
  27 #include <stdlib.h>
  28 #include <inttypes.h>
  29 #include <string.h>
  30
  31 #if 1 /* ANSI colors */
  32
  33 #       define color(a) printf("%s",a)
  34 char OFF[]              = { 0x1b, 0x5b, 0x31, 0x3b, '0', '0', 0x6d, '\0' };
  35
  36 char GREY[]     = { 0x1b, 0x5b, 0x31, 0x3b, '3', '0', 0x6d, '\0' };
  37 char RED[]              = { 0x1b, 0x5b, 0x31, 0x3b, '3', '1', 0x6d, '\0' };
  38 char GREEN[]    = { 0x1b, 0x5b, 0x31, 0x3b, '3', '2', 0x6d, '\0' };
  39 char YELLOW[]   = { 0x1b, 0x5b, 0x31, 0x3b, '3', '3', 0x6d, '\0' };
  40 char BLUE[]     = { 0x1b, 0x5b, 0x31, 0x3b, '3', '4', 0x6d, '\0' };
  41
  42 #else
  43         /* disable colors */
  44 #       define color(a)
  45 #endif
  46
  47 #define bug(...) do { fprintf(stderr,"ERROR: "__VA_ARGS__); exit(1); } while(0)
  48 #define bugp(a) do { perror("ERROR: "a); exit(1); } while(0)
  49
  50 /* byte swapping */
  51 #define get32le(a) ((uint32_t) \
  52     ( buf[a+3] << 24 | buf[a+2] << 16 | buf[a+1] << 8 | buf[a] ))
  53 #define get16le(a) ((uint16_t)( buf[a+1] << 8 | buf[a] ))
  54
  55 /* all blocks are sized as a multiple of 0x1ff */
  56 #define PAD_TO_BOUNDARY(x) (((x) + 0x1ff) & ~0x1ff)
  57
  58 /* If you find a firmware that breaks the known format ^^ */
  59 #define assert(a) do { if(!(a)) { fprintf(stderr,"Assertion \"%s\" failed in %s() line %d!\n\nPlease send us your firmware!\n",#a,__func__,__LINE__); exit(1); } } while(0)
  60
  61 /* globals */
  62
  63 size_t sz;      /* file size */
  64 uint8_t *buf; /* file content */
  65
  66
  67 /* 1st block description */
  68 uint32_t idx,checksum,bs_multiplier,firmware_sz;
  69 uint32_t unknown_4_1; uint16_t unknown_1, unknown_2;
  70 uint32_t unknown_4_2,unknown_4_3;
  71
  72 static void *xmalloc(size_t s) /* malloc helper */
  73 {
  74         void * r = malloc(s);
  75         if(!r) bugp("malloc");
  76         return r;
  77 }
  78
  79 /* checksums the firmware (the firmware header contains the verification) */
  80 static uint32_t do_checksum(void)
  81 {
  82         uint32_t c = 0;
  83
  84         size_t i = 0x400/4;
  85         while(i<(0x400+firmware_sz)/4)
  86                 c += ((uint32_t*)buf)[i++];
  87
  88         return c;
  89 }
  90
  91 /* verify the firmware header */
  92 static void check(void)
  93 {
  94         uint32_t checksum2;
  95
  96         assert(sz >= 0x400 && sz % 0x200 == 0);
  97
  98         size_t i;
  99         checksum2 = 0;
 100         for(i=0;i<sz/4-1;i++)
 101                 checksum2 += ((uint32_t*)buf)[i];
 102
 103         uint32_t last_word = get32le(sz - 4);
 104
 105         switch(last_word)
 106         {
 107                 case 0:                         /* no whole file checksum */
 108                         break;
 109                 case 0xefbeadde:        /* no whole file checksum */
 110                         break;
 111                 default:                        /* verify whole file checksum */
 112                         assert(last_word == checksum2);
 113         }
 114
 115         idx = get32le(0);
 116         unsigned int shift = (get32le(4) == 0x0000f000) ? 4 : 0;
 117         checksum = get32le(4 + shift);
 118         bs_multiplier = get32le(8 + shift);
 119         firmware_sz = get32le(0xc + shift);
 120         assert(bs_multiplier << 9 == PAD_TO_BOUNDARY(firmware_sz)); /* 0x200 * bs_multiplier */
 121
 122         unknown_4_1 = get32le(0x10 + shift);
 123         unknown_1 = get16le(0x14 + shift);
 124         unknown_2 = get16le(0x16 + shift);
 125         unknown_4_2 = get32le(0x18 + shift);
 126         unknown_4_3 = get32le(0x1c + shift);
 127
 128         color(GREEN);
 129         printf("4 Index                  %d\n",idx);
 130         assert(idx == 0);
 131         color(GREEN);
 132         printf("4 Firmware Checksum      %x",checksum);
 133         checksum2=do_checksum();
 134         color(GREEN);
 135         printf(" (%x)\n",checksum2);
 136         assert(checksum == checksum2);
 137         color(GREEN);
 138         printf("4 Block Size Multiplier  %x\n",bs_multiplier);
 139         color(GREEN);
 140         printf("4 Firmware block size    %x (%d)\n",firmware_sz,firmware_sz);
 141
 142         color(GREEN);
 143         printf("4 Unknown (should be 3)  %x\n",unknown_4_1);
 144         assert(unknown_4_1 == 3);
 145
 146         /* variable */
 147         color(GREEN);
 148         printf("1 Unknown                %x\n",unknown_1);
 149
 150         color(GREEN);
 151         printf("2 Unknown (should be 0)  %x\n",unknown_2);
 152         assert(unknown_2 == 0);
 153
 154         color(GREEN);
 155         printf("4 Unknown (should be 40) %x\n",unknown_4_2);
 156         assert(unknown_4_2 == 0x40 );
 157
 158         color(GREEN);
 159         printf("4 Unknown (should be 1)  %x\n",unknown_4_3);
 160         assert(unknown_4_3 == 1);
 161
 162         /* the 2nd block is identical, except that the 1st byte has been incremented */
 163         assert(buf[0x0]==0&&buf[0x200]==1);
 164         assert(!memcmp(&buf[1],&buf[0x201],0x1FF - shift));
 165 }
 166
 167 typedef enum
 168 {
 169 #if 0
 170         FW_HEADER,
 171         FW,
 172 #endif
 173         LIB,
 174         PAD,
 175         HEADER,
 176         UNKNOWN
 177 } type;
 178
 179 static unsigned int n_libs = 0, n_pads_ff = 0, n_pads_deadbeef = 0, n_unkn = 0, n_headers = 0;
 180
 181 static void show_lib(size_t off)
 182 {
 183         /* first word: char* */
 184         uint32_t start = get32le(off+4);
 185         uint32_t stop = get32le(off+8);
 186
 187         uint32_t size = get32le(off+0xc);
 188
 189 #if 0 /* library block hacking */
 190         /* assert(stop > start); */
 191
 192         /* assert(stop - start == size); */
 193
 194         if(stop - start != size)
 195         {
 196                 color(RED);
 197                 printf("STOP - START != SIZE || 0x%.8x - 0x%.8x == 0x%.8x != 0x%.8x\n",
 198                                 stop, start, stop - start, size);
 199         }
 200
 201         color(RED);
 202         printf("0x%.8x -> 0x%.8x SIZE 0x%.6x\n", start, stop, size);
 203
 204         uint32_t first = get32le(off+0x10); /* ? */
 205         printf("? = 0x%.8x , ",first);
 206 #endif
 207
 208         uint32_t funcs = get32le(off+0x14); /* nmbr of functions */
 209         color(YELLOW);
 210         printf("\t%d funcs",funcs);
 211
 212         unsigned int i;
 213         for(i=0;i<funcs;i++)
 214         {
 215                 uint32_t fptr = get32le(off+0x18+i*4);
 216                 if(!fptr)
 217                 {
 218                         assert(funcs==1); /* if 1 function is exported, it's empty */
 219                 }
 220                 else
 221                 {
 222                         assert(fptr - start < 0x0000ffff);
 223                         /* printf("0x%.4x ",fptr); */
 224                 }
 225         }
 226
 227         color(BLUE);
 228         printf("\tBASE 0x%.8x (code + 0x%x) END 0x%.8x : SIZE 0x%.8x\n",start, 0x18 + i*4, stop, stop - start);
 229
 230         char name[12+1];
 231         memcpy(name,&buf[off+get32le(off)],12);
 232         name[12] = '\0';
 233
 234         FILE *out = fopen(name,"w");
 235         if(!out)
 236                 bug("library block");
 237
 238         if(fwrite(&buf[off],size,1,out)!=1)
 239                 bug();
 240
 241         fclose(out);
 242 }
 243
 244 static int unknown = 0;
 245 static int padding = 0;
 246 static void print_block(size_t off, type t)
 247 {
 248         /* reset counters if needed */
 249         if(t != UNKNOWN && unknown)
 250         {       /* print only the number of following blocks */
 251                 color(GREY);
 252                 printf("%d unknown blocks (0x%.6x bytes)\n",unknown,unknown*0x200);
 253                 unknown = 0;
 254         }
 255         else if(t != PAD && padding)
 256         {       /* same */
 257                 color(GREY);
 258                 printf("%d padding blocks (0x%.6x bytes)\n",padding,padding*0x200);
 259                 padding = 0;
 260         }
 261
 262         if(t != UNKNOWN && t != PAD) /* for other block types, always print the offset */
 263         {
 264                 color(GREEN);
 265                 printf("0x%.6x\t", (unsigned int)off);
 266                 color(OFF);
 267         }
 268
 269         switch(t)
 270         {
 271                 size_t s;
 272                 FILE *f;
 273                 char filename[8+4]; /* unknown\0 , 10K max */
 274 #if 0
 275                 case FW_HEADER:
 276                         printf("firmware header 0x%x\n",off);
 277                         break;
 278                 case FW:
 279                         printf("firmware block  0x%x\n",off);
 280                         break;
 281 #endif
 282                 case LIB:
 283                         s = get32le(off+12);
 284                         color(RED);
 285                         printf("library block   0x%.6x\t->\t0x%.6x\t\"%s\"\n",
 286                                         (unsigned int)s, (unsigned int)(off+s),
 287                     &buf[off+get32le(off)]);
 288                         show_lib(off);
 289                         n_libs++;
 290                         break;
 291                 case PAD:
 292                         if(buf[off] == 0xff)
 293                                 n_pads_ff++;
 294                         else
 295                                 n_pads_deadbeef++;
 296                         padding++;
 297                         break;
 298                 case UNKNOWN:
 299                         unknown++;
 300             n_unkn++;
 301 #if 0       /* do not dump unknown blocks */
 302                         snprintf(filename, sizeof(filename), "unknown%d", n_unkn);
 303                         f = fopen(filename, "w");
 304                         if(f)
 305                         {
 306                                 if( fwrite(buf+off, 0x200, 1, f) != 1 )
 307                                         bugp("unknown block");
 308                                 fclose(f);
 309                         }
 310                         else
 311                                 bugp("unknown block");
 312 #endif
 313                         break;
 314                 case HEADER:
 315                         color(YELLOW);
 316                         printf("header block    0x%.6x\t->\t0x%.6x\n",
 317                                         PAD_TO_BOUNDARY(get32le(off)),
 318                                         (unsigned int)PAD_TO_BOUNDARY(off+get32le(off)));
 319                 snprintf(filename, sizeof(filename), "header%d", n_headers++);
 320                 f = fopen(filename,"w");
 321                 if(!f)
 322                     bug("header");
 323
 324                 if(fwrite(&buf[off],get32le(off),1,f)!=1)
 325                     bug();
 326
 327                 fclose(f);
 328
 329                         break;
 330                 default:
 331                         abort();
 332         }
 333
 334         if(t != PAD && t != UNKNOWN)
 335                 printf("\n");
 336 }
 337
 338 static size_t verify_block(size_t off)
 339 {
 340         assert(!(off%0x200));
 341         assert(off+0x200 < sz);
 342
 343         size_t s = 0x200;
 344         type t = UNKNOWN;
 345
 346         size_t offset_str = get32le(off);
 347         if(get32le(off) == 0xefbeadde )
 348         {
 349 #if 0 /* some blocks begin with 0xdeadbeef but aren't padded with that value */
 350                 unsigned int i;
 351                 for(i=0;i<s;i+=4)
 352                         assert(get32le(off+i) == 0xefbeadde);
 353 #endif
 354                 t = PAD;
 355         }
 356         else if( *(uint32_t*)(&buf[off]) == 0xffffffff)
 357         {
 358                 unsigned int i;
 359                 for(i=0;i<s;i++)
 360                         assert(buf[off+i] == 0xff);
 361                 t = PAD;
 362         }
 363         else if(off+offset_str+12<sz) /* XXX: we should check that the address at which
 364                                                                         * the string is located is included in this
 365                                                                         * library block's size, but we only know the
 366                                                                         * block's size after we confirmed that this is
 367                                                                         * a library block (by looking at the 11 chars
 368                                                                         * ASCII string). */
 369         {
 370                 short int ok = 1;
 371                 unsigned int i;
 372                 for(i=0;i<11;i++)
 373                         if(buf[off+offset_str+i] >> 7 || !buf[off+offset_str+i])
 374                                 ok = 0;
 375                 if(buf[off+offset_str+11])
 376                         ok = 0;
 377                 if(ok) /* library block */
 378                 {
 379                         t = LIB;
 380                         s = get32le(off+12);
 381                 }
 382                 else
 383                         t = UNKNOWN;
 384         }
 385         else
 386                 t = UNKNOWN;
 387
 388         if(t==UNKNOWN)
 389         {
 390                 if(!strncmp((char*)buf+off+8,"HEADER",6))
 391                 {
 392                         s = PAD_TO_BOUNDARY(get32le(off)); /* first 4 bytes le are the block size */
 393                         t = HEADER;
 394                 }
 395         }
 396
 397         print_block(off,t);
 398
 399         return PAD_TO_BOUNDARY(s);
 400 }
 401
 402 static void extract(void)
 403 {
 404         FILE *out = fopen("firmware","w");
 405         if(!out)
 406                 bug("firmware");
 407
 408         if(fwrite(&buf[0x400],firmware_sz,1,out)!=1)
 409                 bug("firmare writing");
 410         fclose(out);
 411
 412         off_t off = PAD_TO_BOUNDARY(0x400 + firmware_sz);
 413         unsigned int n = 0;
 414
 415         printf("\n");
 416         color(RED);
 417         printf("Extracting\n\n");
 418
 419         while((unsigned int)(off+0x200)<sz)
 420         {
 421                 /* look at the next 0x200 bytes if we can recognize a block type */
 422                 off += verify_block(off); /* then skip its real size */
 423                 n++;    /* and look at the next block ;) */
 424         }
 425
 426         /* statistics */
 427         printf("\n");
 428         color(RED);
 429         printf("TOTAL\t%d\tblocks (%d unknown)\n",n,n_unkn);
 430         color(BLUE);
 431         printf("\t%d\tlibs\n",n_libs);
 432         color(GREY);
 433         printf("\t%d\tpads ff\n",n_pads_ff);
 434         color(GREY);
 435         printf("\t%d\tpads deadbeef\n",n_pads_deadbeef);
 436         color(GREEN);
 437         printf("\t%d\theaders\n",n_headers);
 438 }
 439
 440 int main(int argc, const char **argv)
 441 {
 442         int fd;
 443         struct stat st;
 444         if(argc != 2)
 445                 bug("Usage: %s <firmware>\n",*argv);
 446
 447         if( (fd = open(argv[1],O_RDONLY)) == -1 )
 448                 bugp("opening firmware failed");
 449
 450         if(fstat(fd,&st) == -1)
 451                 bugp("firmware stat() failed");
 452         sz = st.st_size;
 453
 454         buf=xmalloc(sz);
 455         if(read(fd,buf,sz)!=(ssize_t)sz) /* load the whole file into memory */
 456                 bugp("reading firmware");
 457
 458         close(fd);
 459
 460         check();        /* verify header and checksums */
 461         extract();      /* split in blocks */
 462
 463         free(buf);
 464         return 0;
 465 }