| 1 | //----------------------------------------------------------------------------- |
| 2 | // Jonathan Westhues, split Nov 2006 |
| 3 | // |
| 4 | // This code is licensed to you under the terms of the GNU GPL, version 2 or, |
| 5 | // at your option, any later version. See the LICENSE.txt file for the text of |
| 6 | // the license. |
| 7 | //----------------------------------------------------------------------------- |
| 8 | // Routines to support ISO 14443. This includes both the reader software and |
| 9 | // the `fake tag' modes. At the moment only the Type B modulation is |
| 10 | // supported. |
| 11 | //----------------------------------------------------------------------------- |
| 12 | |
| 13 | #include "proxmark3.h" |
| 14 | #include "apps.h" |
| 15 | #include "util.h" |
| 16 | #include "string.h" |
| 17 | |
| 18 | #include "iso14443crc.h" |
| 19 | |
| 20 | //static void GetSamplesFor14443(int weTx, int n); |
| 21 | |
| 22 | #define DEMOD_TRACE_SIZE 4096 |
| 23 | #define READER_TAG_BUFFER_SIZE 2048 |
| 24 | #define TAG_READER_BUFFER_SIZE 2048 |
| 25 | #define DEMOD_DMA_BUFFER_SIZE 1024 |
| 26 | |
| 27 | //============================================================================= |
| 28 | // An ISO 14443 Type B tag. We listen for commands from the reader, using |
| 29 | // a UART kind of thing that's implemented in software. When we get a |
| 30 | // frame (i.e., a group of bytes between SOF and EOF), we check the CRC. |
| 31 | // If it's good, then we can do something appropriate with it, and send |
| 32 | // a response. |
| 33 | //============================================================================= |
| 34 | |
| 35 | //----------------------------------------------------------------------------- |
| 36 | // Code up a string of octets at layer 2 (including CRC, we don't generate |
| 37 | // that here) so that they can be transmitted to the reader. Doesn't transmit |
| 38 | // them yet, just leaves them ready to send in ToSend[]. |
| 39 | //----------------------------------------------------------------------------- |
| 40 | static void CodeIso14443bAsTag(const uint8_t *cmd, int len) |
| 41 | { |
| 42 | int i; |
| 43 | |
| 44 | ToSendReset(); |
| 45 | |
| 46 | // Transmit a burst of ones, as the initial thing that lets the |
| 47 | // reader get phase sync. This (TR1) must be > 80/fs, per spec, |
| 48 | // but tag that I've tried (a Paypass) exceeds that by a fair bit, |
| 49 | // so I will too. |
| 50 | for(i = 0; i < 20; i++) { |
| 51 | ToSendStuffBit(1); |
| 52 | ToSendStuffBit(1); |
| 53 | ToSendStuffBit(1); |
| 54 | ToSendStuffBit(1); |
| 55 | } |
| 56 | |
| 57 | // Send SOF. |
| 58 | for(i = 0; i < 10; i++) { |
| 59 | ToSendStuffBit(0); |
| 60 | ToSendStuffBit(0); |
| 61 | ToSendStuffBit(0); |
| 62 | ToSendStuffBit(0); |
| 63 | } |
| 64 | for(i = 0; i < 2; i++) { |
| 65 | ToSendStuffBit(1); |
| 66 | ToSendStuffBit(1); |
| 67 | ToSendStuffBit(1); |
| 68 | ToSendStuffBit(1); |
| 69 | } |
| 70 | |
| 71 | for(i = 0; i < len; i++) { |
| 72 | int j; |
| 73 | uint8_t b = cmd[i]; |
| 74 | |
| 75 | // Start bit |
| 76 | ToSendStuffBit(0); |
| 77 | ToSendStuffBit(0); |
| 78 | ToSendStuffBit(0); |
| 79 | ToSendStuffBit(0); |
| 80 | |
| 81 | // Data bits |
| 82 | for(j = 0; j < 8; j++) { |
| 83 | if(b & 1) { |
| 84 | ToSendStuffBit(1); |
| 85 | ToSendStuffBit(1); |
| 86 | ToSendStuffBit(1); |
| 87 | ToSendStuffBit(1); |
| 88 | } else { |
| 89 | ToSendStuffBit(0); |
| 90 | ToSendStuffBit(0); |
| 91 | ToSendStuffBit(0); |
| 92 | ToSendStuffBit(0); |
| 93 | } |
| 94 | b >>= 1; |
| 95 | } |
| 96 | |
| 97 | // Stop bit |
| 98 | ToSendStuffBit(1); |
| 99 | ToSendStuffBit(1); |
| 100 | ToSendStuffBit(1); |
| 101 | ToSendStuffBit(1); |
| 102 | } |
| 103 | |
| 104 | // Send SOF. |
| 105 | for(i = 0; i < 10; i++) { |
| 106 | ToSendStuffBit(0); |
| 107 | ToSendStuffBit(0); |
| 108 | ToSendStuffBit(0); |
| 109 | ToSendStuffBit(0); |
| 110 | } |
| 111 | for(i = 0; i < 10; i++) { |
| 112 | ToSendStuffBit(1); |
| 113 | ToSendStuffBit(1); |
| 114 | ToSendStuffBit(1); |
| 115 | ToSendStuffBit(1); |
| 116 | } |
| 117 | |
| 118 | // Convert from last byte pos to length |
| 119 | ToSendMax++; |
| 120 | |
| 121 | // Add a few more for slop |
| 122 | ToSendMax += 2; |
| 123 | } |
| 124 | |
| 125 | //----------------------------------------------------------------------------- |
| 126 | // The software UART that receives commands from the reader, and its state |
| 127 | // variables. |
| 128 | //----------------------------------------------------------------------------- |
| 129 | static struct { |
| 130 | enum { |
| 131 | STATE_UNSYNCD, |
| 132 | STATE_GOT_FALLING_EDGE_OF_SOF, |
| 133 | STATE_AWAITING_START_BIT, |
| 134 | STATE_RECEIVING_DATA, |
| 135 | STATE_ERROR_WAIT |
| 136 | } state; |
| 137 | uint16_t shiftReg; |
| 138 | int bitCnt; |
| 139 | int byteCnt; |
| 140 | int byteCntMax; |
| 141 | int posCnt; |
| 142 | uint8_t *output; |
| 143 | } Uart; |
| 144 | |
| 145 | /* Receive & handle a bit coming from the reader. |
| 146 | * |
| 147 | * LED handling: |
| 148 | * LED A -> ON once we have received the SOF and are expecting the rest. |
| 149 | * LED A -> OFF once we have received EOF or are in error state or unsynced |
| 150 | * |
| 151 | * Returns: true if we received a EOF |
| 152 | * false if we are still waiting for some more |
| 153 | */ |
| 154 | static int Handle14443UartBit(int bit) |
| 155 | { |
| 156 | switch(Uart.state) { |
| 157 | case STATE_UNSYNCD: |
| 158 | LED_A_OFF(); |
| 159 | if(!bit) { |
| 160 | // we went low, so this could be the beginning |
| 161 | // of an SOF |
| 162 | Uart.state = STATE_GOT_FALLING_EDGE_OF_SOF; |
| 163 | Uart.posCnt = 0; |
| 164 | Uart.bitCnt = 0; |
| 165 | } |
| 166 | break; |
| 167 | |
| 168 | case STATE_GOT_FALLING_EDGE_OF_SOF: |
| 169 | Uart.posCnt++; |
| 170 | if(Uart.posCnt == 2) { |
| 171 | if(bit) { |
| 172 | if(Uart.bitCnt >= 10) { |
| 173 | // we've seen enough consecutive |
| 174 | // zeros that it's a valid SOF |
| 175 | Uart.posCnt = 0; |
| 176 | Uart.byteCnt = 0; |
| 177 | Uart.state = STATE_AWAITING_START_BIT; |
| 178 | LED_A_ON(); // Indicate we got a valid SOF |
| 179 | } else { |
| 180 | // didn't stay down long enough |
| 181 | // before going high, error |
| 182 | Uart.state = STATE_ERROR_WAIT; |
| 183 | } |
| 184 | } else { |
| 185 | // do nothing, keep waiting |
| 186 | } |
| 187 | Uart.bitCnt++; |
| 188 | } |
| 189 | if(Uart.posCnt >= 4) Uart.posCnt = 0; |
| 190 | if(Uart.bitCnt > 14) { |
| 191 | // Give up if we see too many zeros without |
| 192 | // a one, too. |
| 193 | Uart.state = STATE_ERROR_WAIT; |
| 194 | } |
| 195 | break; |
| 196 | |
| 197 | case STATE_AWAITING_START_BIT: |
| 198 | Uart.posCnt++; |
| 199 | if(bit) { |
| 200 | if(Uart.posCnt > 25) { |
| 201 | // stayed high for too long between |
| 202 | // characters, error |
| 203 | Uart.state = STATE_ERROR_WAIT; |
| 204 | } |
| 205 | } else { |
| 206 | // falling edge, this starts the data byte |
| 207 | Uart.posCnt = 0; |
| 208 | Uart.bitCnt = 0; |
| 209 | Uart.shiftReg = 0; |
| 210 | Uart.state = STATE_RECEIVING_DATA; |
| 211 | LED_A_ON(); // Indicate we're receiving |
| 212 | } |
| 213 | break; |
| 214 | |
| 215 | case STATE_RECEIVING_DATA: |
| 216 | Uart.posCnt++; |
| 217 | if(Uart.posCnt == 2) { |
| 218 | // time to sample a bit |
| 219 | Uart.shiftReg >>= 1; |
| 220 | if(bit) { |
| 221 | Uart.shiftReg |= 0x200; |
| 222 | } |
| 223 | Uart.bitCnt++; |
| 224 | } |
| 225 | if(Uart.posCnt >= 4) { |
| 226 | Uart.posCnt = 0; |
| 227 | } |
| 228 | if(Uart.bitCnt == 10) { |
| 229 | if((Uart.shiftReg & 0x200) && !(Uart.shiftReg & 0x001)) |
| 230 | { |
| 231 | // this is a data byte, with correct |
| 232 | // start and stop bits |
| 233 | Uart.output[Uart.byteCnt] = (Uart.shiftReg >> 1) & 0xff; |
| 234 | Uart.byteCnt++; |
| 235 | |
| 236 | if(Uart.byteCnt >= Uart.byteCntMax) { |
| 237 | // Buffer overflowed, give up |
| 238 | Uart.posCnt = 0; |
| 239 | Uart.state = STATE_ERROR_WAIT; |
| 240 | } else { |
| 241 | // so get the next byte now |
| 242 | Uart.posCnt = 0; |
| 243 | Uart.state = STATE_AWAITING_START_BIT; |
| 244 | } |
| 245 | } else if(Uart.shiftReg == 0x000) { |
| 246 | // this is an EOF byte |
| 247 | LED_A_OFF(); // Finished receiving |
| 248 | return TRUE; |
| 249 | } else { |
| 250 | // this is an error |
| 251 | Uart.posCnt = 0; |
| 252 | Uart.state = STATE_ERROR_WAIT; |
| 253 | } |
| 254 | } |
| 255 | break; |
| 256 | |
| 257 | case STATE_ERROR_WAIT: |
| 258 | // We're all screwed up, so wait a little while |
| 259 | // for whatever went wrong to finish, and then |
| 260 | // start over. |
| 261 | Uart.posCnt++; |
| 262 | if(Uart.posCnt > 10) { |
| 263 | Uart.state = STATE_UNSYNCD; |
| 264 | } |
| 265 | break; |
| 266 | |
| 267 | default: |
| 268 | Uart.state = STATE_UNSYNCD; |
| 269 | break; |
| 270 | } |
| 271 | |
| 272 | // This row make the error blew circular buffer in hf 14b snoop |
| 273 | //if (Uart.state == STATE_ERROR_WAIT) LED_A_OFF(); // Error |
| 274 | |
| 275 | return FALSE; |
| 276 | } |
| 277 | |
| 278 | //----------------------------------------------------------------------------- |
| 279 | // Receive a command (from the reader to us, where we are the simulated tag), |
| 280 | // and store it in the given buffer, up to the given maximum length. Keeps |
| 281 | // spinning, waiting for a well-framed command, until either we get one |
| 282 | // (returns TRUE) or someone presses the pushbutton on the board (FALSE). |
| 283 | // |
| 284 | // Assume that we're called with the SSC (to the FPGA) and ADC path set |
| 285 | // correctly. |
| 286 | //----------------------------------------------------------------------------- |
| 287 | static int GetIso14443CommandFromReader(uint8_t *received, int *len, int maxLen) |
| 288 | { |
| 289 | uint8_t mask; |
| 290 | int i, bit; |
| 291 | |
| 292 | // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen |
| 293 | // only, since we are receiving, not transmitting). |
| 294 | // Signal field is off with the appropriate LED |
| 295 | LED_D_OFF(); |
| 296 | FpgaWriteConfWord( |
| 297 | FPGA_MAJOR_MODE_HF_SIMULATOR | FPGA_HF_SIMULATOR_NO_MODULATION); |
| 298 | |
| 299 | |
| 300 | // Now run a `software UART' on the stream of incoming samples. |
| 301 | Uart.output = received; |
| 302 | Uart.byteCntMax = maxLen; |
| 303 | Uart.state = STATE_UNSYNCD; |
| 304 | |
| 305 | for(;;) { |
| 306 | WDT_HIT(); |
| 307 | |
| 308 | if(BUTTON_PRESS()) return FALSE; |
| 309 | |
| 310 | if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { |
| 311 | AT91C_BASE_SSC->SSC_THR = 0x00; |
| 312 | } |
| 313 | if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { |
| 314 | uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR; |
| 315 | |
| 316 | mask = 0x80; |
| 317 | for(i = 0; i < 8; i++, mask >>= 1) { |
| 318 | bit = (b & mask); |
| 319 | if(Handle14443UartBit(bit)) { |
| 320 | *len = Uart.byteCnt; |
| 321 | return TRUE; |
| 322 | } |
| 323 | } |
| 324 | } |
| 325 | } |
| 326 | } |
| 327 | |
| 328 | //----------------------------------------------------------------------------- |
| 329 | // Main loop of simulated tag: receive commands from reader, decide what |
| 330 | // response to send, and send it. |
| 331 | //----------------------------------------------------------------------------- |
| 332 | void SimulateIso14443Tag(void) |
| 333 | { |
| 334 | static const uint8_t cmd1[] = { 0x05, 0x00, 0x08, 0x39, 0x73 }; |
| 335 | static const uint8_t response1[] = { |
| 336 | 0x50, 0x82, 0x0d, 0xe1, 0x74, 0x20, 0x38, 0x19, 0x22, |
| 337 | 0x00, 0x21, 0x85, 0x5e, 0xd7 |
| 338 | }; |
| 339 | |
| 340 | uint8_t *resp; |
| 341 | int respLen; |
| 342 | |
| 343 | uint8_t *resp1 = (((uint8_t *)BigBuf) + 800); |
| 344 | int resp1Len; |
| 345 | |
| 346 | uint8_t *receivedCmd = (uint8_t *)BigBuf; |
| 347 | int len; |
| 348 | |
| 349 | int i; |
| 350 | |
| 351 | int cmdsRecvd = 0; |
| 352 | |
| 353 | FpgaDownloadAndGo(FPGA_BITSTREAM_HF); |
| 354 | memset(receivedCmd, 0x44, 400); |
| 355 | |
| 356 | CodeIso14443bAsTag(response1, sizeof(response1)); |
| 357 | memcpy(resp1, ToSend, ToSendMax); resp1Len = ToSendMax; |
| 358 | |
| 359 | // We need to listen to the high-frequency, peak-detected path. |
| 360 | SetAdcMuxFor(GPIO_MUXSEL_HIPKD); |
| 361 | FpgaSetupSsc(); |
| 362 | |
| 363 | cmdsRecvd = 0; |
| 364 | |
| 365 | for(;;) { |
| 366 | uint8_t b1, b2; |
| 367 | |
| 368 | if(!GetIso14443CommandFromReader(receivedCmd, &len, 100)) { |
| 369 | Dbprintf("button pressed, received %d commands", cmdsRecvd); |
| 370 | break; |
| 371 | } |
| 372 | |
| 373 | // Good, look at the command now. |
| 374 | |
| 375 | if(len == sizeof(cmd1) && memcmp(receivedCmd, cmd1, len)==0) { |
| 376 | resp = resp1; respLen = resp1Len; |
| 377 | } else { |
| 378 | Dbprintf("new cmd from reader: len=%d, cmdsRecvd=%d", len, cmdsRecvd); |
| 379 | // And print whether the CRC fails, just for good measure |
| 380 | ComputeCrc14443(CRC_14443_B, receivedCmd, len-2, &b1, &b2); |
| 381 | if(b1 != receivedCmd[len-2] || b2 != receivedCmd[len-1]) { |
| 382 | // Not so good, try again. |
| 383 | DbpString("+++CRC fail"); |
| 384 | } else { |
| 385 | DbpString("CRC passes"); |
| 386 | } |
| 387 | break; |
| 388 | } |
| 389 | |
| 390 | memset(receivedCmd, 0x44, 32); |
| 391 | |
| 392 | cmdsRecvd++; |
| 393 | |
| 394 | if(cmdsRecvd > 0x30) { |
| 395 | DbpString("many commands later..."); |
| 396 | break; |
| 397 | } |
| 398 | |
| 399 | if(respLen <= 0) continue; |
| 400 | |
| 401 | // Modulate BPSK |
| 402 | // Signal field is off with the appropriate LED |
| 403 | LED_D_OFF(); |
| 404 | FpgaWriteConfWord( |
| 405 | FPGA_MAJOR_MODE_HF_SIMULATOR | FPGA_HF_SIMULATOR_MODULATE_BPSK); |
| 406 | AT91C_BASE_SSC->SSC_THR = 0xff; |
| 407 | FpgaSetupSsc(); |
| 408 | |
| 409 | // Transmit the response. |
| 410 | i = 0; |
| 411 | for(;;) { |
| 412 | if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { |
| 413 | uint8_t b = resp[i]; |
| 414 | |
| 415 | AT91C_BASE_SSC->SSC_THR = b; |
| 416 | |
| 417 | i++; |
| 418 | if(i > respLen) { |
| 419 | break; |
| 420 | } |
| 421 | } |
| 422 | if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { |
| 423 | volatile uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR; |
| 424 | (void)b; |
| 425 | } |
| 426 | } |
| 427 | } |
| 428 | } |
| 429 | |
| 430 | //============================================================================= |
| 431 | // An ISO 14443 Type B reader. We take layer two commands, code them |
| 432 | // appropriately, and then send them to the tag. We then listen for the |
| 433 | // tag's response, which we leave in the buffer to be demodulated on the |
| 434 | // PC side. |
| 435 | //============================================================================= |
| 436 | |
| 437 | static struct { |
| 438 | enum { |
| 439 | DEMOD_UNSYNCD, |
| 440 | DEMOD_PHASE_REF_TRAINING, |
| 441 | DEMOD_AWAITING_FALLING_EDGE_OF_SOF, |
| 442 | DEMOD_GOT_FALLING_EDGE_OF_SOF, |
| 443 | DEMOD_AWAITING_START_BIT, |
| 444 | DEMOD_RECEIVING_DATA, |
| 445 | DEMOD_ERROR_WAIT |
| 446 | } state; |
| 447 | int bitCount; |
| 448 | int posCount; |
| 449 | int thisBit; |
| 450 | int metric; |
| 451 | int metricN; |
| 452 | uint16_t shiftReg; |
| 453 | uint8_t *output; |
| 454 | int len; |
| 455 | int sumI; |
| 456 | int sumQ; |
| 457 | } Demod; |
| 458 | |
| 459 | /* |
| 460 | * Handles reception of a bit from the tag |
| 461 | * |
| 462 | * LED handling: |
| 463 | * LED C -> ON once we have received the SOF and are expecting the rest. |
| 464 | * LED C -> OFF once we have received EOF or are unsynced |
| 465 | * |
| 466 | * Returns: true if we received a EOF |
| 467 | * false if we are still waiting for some more |
| 468 | * |
| 469 | */ |
| 470 | static RAMFUNC int Handle14443SamplesDemod(int ci, int cq) |
| 471 | { |
| 472 | int v; |
| 473 | |
| 474 | // The soft decision on the bit uses an estimate of just the |
| 475 | // quadrant of the reference angle, not the exact angle. |
| 476 | #define MAKE_SOFT_DECISION() { \ |
| 477 | if(Demod.sumI > 0) { \ |
| 478 | v = ci; \ |
| 479 | } else { \ |
| 480 | v = -ci; \ |
| 481 | } \ |
| 482 | if(Demod.sumQ > 0) { \ |
| 483 | v += cq; \ |
| 484 | } else { \ |
| 485 | v -= cq; \ |
| 486 | } \ |
| 487 | } |
| 488 | |
| 489 | switch(Demod.state) { |
| 490 | case DEMOD_UNSYNCD: |
| 491 | v = ci; |
| 492 | if(v < 0) v = -v; |
| 493 | if(cq > 0) { |
| 494 | v += cq; |
| 495 | } else { |
| 496 | v -= cq; |
| 497 | } |
| 498 | if(v > 40) { |
| 499 | Demod.posCount = 0; |
| 500 | Demod.state = DEMOD_PHASE_REF_TRAINING; |
| 501 | Demod.sumI = 0; |
| 502 | Demod.sumQ = 0; |
| 503 | } |
| 504 | break; |
| 505 | |
| 506 | case DEMOD_PHASE_REF_TRAINING: |
| 507 | if(Demod.posCount < 8) { |
| 508 | Demod.sumI += ci; |
| 509 | Demod.sumQ += cq; |
| 510 | } else if(Demod.posCount > 100) { |
| 511 | // error, waited too long |
| 512 | Demod.state = DEMOD_UNSYNCD; |
| 513 | } else { |
| 514 | MAKE_SOFT_DECISION(); |
| 515 | if(v < 0) { |
| 516 | Demod.state = DEMOD_AWAITING_FALLING_EDGE_OF_SOF; |
| 517 | Demod.posCount = 0; |
| 518 | } |
| 519 | } |
| 520 | Demod.posCount++; |
| 521 | break; |
| 522 | |
| 523 | case DEMOD_AWAITING_FALLING_EDGE_OF_SOF: |
| 524 | MAKE_SOFT_DECISION(); |
| 525 | if(v < 0) { |
| 526 | Demod.state = DEMOD_GOT_FALLING_EDGE_OF_SOF; |
| 527 | Demod.posCount = 0; |
| 528 | } else { |
| 529 | if(Demod.posCount > 100) { |
| 530 | Demod.state = DEMOD_UNSYNCD; |
| 531 | } |
| 532 | } |
| 533 | Demod.posCount++; |
| 534 | break; |
| 535 | |
| 536 | case DEMOD_GOT_FALLING_EDGE_OF_SOF: |
| 537 | MAKE_SOFT_DECISION(); |
| 538 | if(v > 0) { |
| 539 | if(Demod.posCount < 12) { |
| 540 | Demod.state = DEMOD_UNSYNCD; |
| 541 | } else { |
| 542 | LED_C_ON(); // Got SOF |
| 543 | Demod.state = DEMOD_AWAITING_START_BIT; |
| 544 | Demod.posCount = 0; |
| 545 | Demod.len = 0; |
| 546 | Demod.metricN = 0; |
| 547 | Demod.metric = 0; |
| 548 | } |
| 549 | } else { |
| 550 | if(Demod.posCount > 100) { |
| 551 | Demod.state = DEMOD_UNSYNCD; |
| 552 | } |
| 553 | } |
| 554 | Demod.posCount++; |
| 555 | break; |
| 556 | |
| 557 | case DEMOD_AWAITING_START_BIT: |
| 558 | MAKE_SOFT_DECISION(); |
| 559 | if(v > 0) { |
| 560 | if(Demod.posCount > 10) { |
| 561 | Demod.state = DEMOD_UNSYNCD; |
| 562 | } |
| 563 | } else { |
| 564 | Demod.bitCount = 0; |
| 565 | Demod.posCount = 1; |
| 566 | Demod.thisBit = v; |
| 567 | Demod.shiftReg = 0; |
| 568 | Demod.state = DEMOD_RECEIVING_DATA; |
| 569 | } |
| 570 | break; |
| 571 | |
| 572 | case DEMOD_RECEIVING_DATA: |
| 573 | MAKE_SOFT_DECISION(); |
| 574 | if(Demod.posCount == 0) { |
| 575 | Demod.thisBit = v; |
| 576 | Demod.posCount = 1; |
| 577 | } else { |
| 578 | Demod.thisBit += v; |
| 579 | |
| 580 | if(Demod.thisBit > 0) { |
| 581 | Demod.metric += Demod.thisBit; |
| 582 | } else { |
| 583 | Demod.metric -= Demod.thisBit; |
| 584 | } |
| 585 | (Demod.metricN)++; |
| 586 | |
| 587 | Demod.shiftReg >>= 1; |
| 588 | if(Demod.thisBit > 0) { |
| 589 | Demod.shiftReg |= 0x200; |
| 590 | } |
| 591 | |
| 592 | Demod.bitCount++; |
| 593 | if(Demod.bitCount == 10) { |
| 594 | uint16_t s = Demod.shiftReg; |
| 595 | if((s & 0x200) && !(s & 0x001)) { |
| 596 | uint8_t b = (s >> 1); |
| 597 | Demod.output[Demod.len] = b; |
| 598 | Demod.len++; |
| 599 | Demod.state = DEMOD_AWAITING_START_BIT; |
| 600 | } else if(s == 0x000) { |
| 601 | // This is EOF |
| 602 | LED_C_OFF(); |
| 603 | Demod.state = DEMOD_UNSYNCD; |
| 604 | return TRUE; |
| 605 | } else { |
| 606 | Demod.state = DEMOD_UNSYNCD; |
| 607 | } |
| 608 | } |
| 609 | Demod.posCount = 0; |
| 610 | } |
| 611 | break; |
| 612 | |
| 613 | default: |
| 614 | Demod.state = DEMOD_UNSYNCD; |
| 615 | break; |
| 616 | } |
| 617 | |
| 618 | if (Demod.state == DEMOD_UNSYNCD) LED_C_OFF(); // Not synchronized... |
| 619 | return FALSE; |
| 620 | } |
| 621 | |
| 622 | /* |
| 623 | * Demodulate the samples we received from the tag |
| 624 | * weTx: set to 'TRUE' if we behave like a reader |
| 625 | * set to 'FALSE' if we behave like a snooper |
| 626 | * quiet: set to 'TRUE' to disable debug output |
| 627 | */ |
| 628 | static void GetSamplesFor14443Demod(int weTx, int n, int quiet) |
| 629 | { |
| 630 | int max = 0; |
| 631 | int gotFrame = FALSE; |
| 632 | |
| 633 | //# define DMA_BUFFER_SIZE 8 |
| 634 | int8_t *dmaBuf; |
| 635 | |
| 636 | int lastRxCounter; |
| 637 | int8_t *upTo; |
| 638 | |
| 639 | int ci, cq; |
| 640 | |
| 641 | int samples = 0; |
| 642 | |
| 643 | // Clear out the state of the "UART" that receives from the tag. |
| 644 | memset(BigBuf, 0x00, 400); |
| 645 | Demod.output = (uint8_t *)BigBuf; |
| 646 | Demod.len = 0; |
| 647 | Demod.state = DEMOD_UNSYNCD; |
| 648 | |
| 649 | // And the UART that receives from the reader |
| 650 | Uart.output = (((uint8_t *)BigBuf) + 1024); |
| 651 | Uart.byteCntMax = 100; |
| 652 | Uart.state = STATE_UNSYNCD; |
| 653 | |
| 654 | // Setup for the DMA. |
| 655 | dmaBuf = (int8_t *)(BigBuf + 32); |
| 656 | upTo = dmaBuf; |
| 657 | lastRxCounter = DEMOD_DMA_BUFFER_SIZE; |
| 658 | FpgaSetupSscDma((uint8_t *)dmaBuf, DEMOD_DMA_BUFFER_SIZE); |
| 659 | |
| 660 | // Signal field is ON with the appropriate LED: |
| 661 | if (weTx) LED_D_ON(); else LED_D_OFF(); |
| 662 | // And put the FPGA in the appropriate mode |
| 663 | FpgaWriteConfWord( |
| 664 | FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ | |
| 665 | (weTx ? 0 : FPGA_HF_READER_RX_XCORR_SNOOP)); |
| 666 | |
| 667 | for(;;) { |
| 668 | int behindBy = lastRxCounter - AT91C_BASE_PDC_SSC->PDC_RCR; |
| 669 | if(behindBy > max) max = behindBy; |
| 670 | |
| 671 | while(((lastRxCounter-AT91C_BASE_PDC_SSC->PDC_RCR) & (DEMOD_DMA_BUFFER_SIZE-1)) |
| 672 | > 2) |
| 673 | { |
| 674 | ci = upTo[0]; |
| 675 | cq = upTo[1]; |
| 676 | upTo += 2; |
| 677 | if(upTo - dmaBuf > DEMOD_DMA_BUFFER_SIZE) { |
| 678 | upTo -= DEMOD_DMA_BUFFER_SIZE; |
| 679 | AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) upTo; |
| 680 | AT91C_BASE_PDC_SSC->PDC_RNCR = DEMOD_DMA_BUFFER_SIZE; |
| 681 | } |
| 682 | lastRxCounter -= 2; |
| 683 | if(lastRxCounter <= 0) { |
| 684 | lastRxCounter += DEMOD_DMA_BUFFER_SIZE; |
| 685 | } |
| 686 | |
| 687 | samples += 2; |
| 688 | |
| 689 | Handle14443UartBit(1); |
| 690 | Handle14443UartBit(1); |
| 691 | |
| 692 | if(Handle14443SamplesDemod(ci, cq)) { |
| 693 | gotFrame = 1; |
| 694 | } |
| 695 | } |
| 696 | |
| 697 | if(samples > 2000) { |
| 698 | break; |
| 699 | } |
| 700 | } |
| 701 | AT91C_BASE_PDC_SSC->PDC_PTCR = AT91C_PDC_RXTDIS; |
| 702 | if (!quiet) Dbprintf("%x %x %x", max, gotFrame, Demod.len); |
| 703 | } |
| 704 | |
| 705 | //----------------------------------------------------------------------------- |
| 706 | // Read the tag's response. We just receive a stream of slightly-processed |
| 707 | // samples from the FPGA, which we will later do some signal processing on, |
| 708 | // to get the bits. |
| 709 | //----------------------------------------------------------------------------- |
| 710 | /*static void GetSamplesFor14443(int weTx, int n) |
| 711 | { |
| 712 | uint8_t *dest = (uint8_t *)BigBuf; |
| 713 | int c; |
| 714 | |
| 715 | FpgaWriteConfWord( |
| 716 | FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ | |
| 717 | (weTx ? 0 : FPGA_HF_READER_RX_XCORR_SNOOP)); |
| 718 | |
| 719 | c = 0; |
| 720 | for(;;) { |
| 721 | if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { |
| 722 | AT91C_BASE_SSC->SSC_THR = 0x43; |
| 723 | } |
| 724 | if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { |
| 725 | int8_t b; |
| 726 | b = (int8_t)AT91C_BASE_SSC->SSC_RHR; |
| 727 | |
| 728 | dest[c++] = (uint8_t)b; |
| 729 | |
| 730 | if(c >= n) { |
| 731 | break; |
| 732 | } |
| 733 | } |
| 734 | } |
| 735 | }*/ |
| 736 | |
| 737 | //----------------------------------------------------------------------------- |
| 738 | // Transmit the command (to the tag) that was placed in ToSend[]. |
| 739 | //----------------------------------------------------------------------------- |
| 740 | static void TransmitFor14443(void) |
| 741 | { |
| 742 | int c; |
| 743 | |
| 744 | FpgaSetupSsc(); |
| 745 | |
| 746 | while(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { |
| 747 | AT91C_BASE_SSC->SSC_THR = 0xff; |
| 748 | } |
| 749 | |
| 750 | // Signal field is ON with the appropriate Red LED |
| 751 | LED_D_ON(); |
| 752 | // Signal we are transmitting with the Green LED |
| 753 | LED_B_ON(); |
| 754 | FpgaWriteConfWord( |
| 755 | FPGA_MAJOR_MODE_HF_READER_TX | FPGA_HF_READER_TX_SHALLOW_MOD); |
| 756 | |
| 757 | for(c = 0; c < 10;) { |
| 758 | if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { |
| 759 | AT91C_BASE_SSC->SSC_THR = 0xff; |
| 760 | c++; |
| 761 | } |
| 762 | if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { |
| 763 | volatile uint32_t r = AT91C_BASE_SSC->SSC_RHR; |
| 764 | (void)r; |
| 765 | } |
| 766 | WDT_HIT(); |
| 767 | } |
| 768 | |
| 769 | c = 0; |
| 770 | for(;;) { |
| 771 | if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { |
| 772 | AT91C_BASE_SSC->SSC_THR = ToSend[c]; |
| 773 | c++; |
| 774 | if(c >= ToSendMax) { |
| 775 | break; |
| 776 | } |
| 777 | } |
| 778 | if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { |
| 779 | volatile uint32_t r = AT91C_BASE_SSC->SSC_RHR; |
| 780 | (void)r; |
| 781 | } |
| 782 | WDT_HIT(); |
| 783 | } |
| 784 | LED_B_OFF(); // Finished sending |
| 785 | } |
| 786 | |
| 787 | //----------------------------------------------------------------------------- |
| 788 | // Code a layer 2 command (string of octets, including CRC) into ToSend[], |
| 789 | // so that it is ready to transmit to the tag using TransmitFor14443(). |
| 790 | //----------------------------------------------------------------------------- |
| 791 | static void CodeIso14443bAsReader(const uint8_t *cmd, int len) |
| 792 | { |
| 793 | int i, j; |
| 794 | uint8_t b; |
| 795 | |
| 796 | ToSendReset(); |
| 797 | |
| 798 | // Establish initial reference level |
| 799 | for(i = 0; i < 40; i++) { |
| 800 | ToSendStuffBit(1); |
| 801 | } |
| 802 | // Send SOF |
| 803 | for(i = 0; i < 10; i++) { |
| 804 | ToSendStuffBit(0); |
| 805 | } |
| 806 | |
| 807 | for(i = 0; i < len; i++) { |
| 808 | // Stop bits/EGT |
| 809 | ToSendStuffBit(1); |
| 810 | ToSendStuffBit(1); |
| 811 | // Start bit |
| 812 | ToSendStuffBit(0); |
| 813 | // Data bits |
| 814 | b = cmd[i]; |
| 815 | for(j = 0; j < 8; j++) { |
| 816 | if(b & 1) { |
| 817 | ToSendStuffBit(1); |
| 818 | } else { |
| 819 | ToSendStuffBit(0); |
| 820 | } |
| 821 | b >>= 1; |
| 822 | } |
| 823 | } |
| 824 | // Send EOF |
| 825 | ToSendStuffBit(1); |
| 826 | for(i = 0; i < 10; i++) { |
| 827 | ToSendStuffBit(0); |
| 828 | } |
| 829 | for(i = 0; i < 8; i++) { |
| 830 | ToSendStuffBit(1); |
| 831 | } |
| 832 | |
| 833 | // And then a little more, to make sure that the last character makes |
| 834 | // it out before we switch to rx mode. |
| 835 | for(i = 0; i < 24; i++) { |
| 836 | ToSendStuffBit(1); |
| 837 | } |
| 838 | |
| 839 | // Convert from last character reference to length |
| 840 | ToSendMax++; |
| 841 | } |
| 842 | |
| 843 | //----------------------------------------------------------------------------- |
| 844 | // Read an ISO 14443 tag. We send it some set of commands, and record the |
| 845 | // responses. |
| 846 | // The command name is misleading, it actually decodes the reponse in HEX |
| 847 | // into the output buffer (read the result using hexsamples, not hisamples) |
| 848 | // |
| 849 | // obsolete function only for test |
| 850 | //----------------------------------------------------------------------------- |
| 851 | void AcquireRawAdcSamplesIso14443(uint32_t parameter) |
| 852 | { |
| 853 | uint8_t cmd1[] = { 0x05, 0x00, 0x08, 0x39, 0x73 }; |
| 854 | |
| 855 | SendRawCommand14443B(sizeof(cmd1),1,1,cmd1); |
| 856 | } |
| 857 | |
| 858 | //----------------------------------------------------------------------------- |
| 859 | // Read a SRI512 ISO 14443 tag. |
| 860 | // |
| 861 | // SRI512 tags are just simple memory tags, here we're looking at making a dump |
| 862 | // of the contents of the memory. No anticollision algorithm is done, we assume |
| 863 | // we have a single tag in the field. |
| 864 | // |
| 865 | // I tried to be systematic and check every answer of the tag, every CRC, etc... |
| 866 | //----------------------------------------------------------------------------- |
| 867 | void ReadSTMemoryIso14443(uint32_t dwLast) |
| 868 | { |
| 869 | uint8_t i = 0x00; |
| 870 | |
| 871 | FpgaDownloadAndGo(FPGA_BITSTREAM_HF); |
| 872 | // Make sure that we start from off, since the tags are stateful; |
| 873 | // confusing things will happen if we don't reset them between reads. |
| 874 | LED_D_OFF(); |
| 875 | FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); |
| 876 | SpinDelay(200); |
| 877 | |
| 878 | SetAdcMuxFor(GPIO_MUXSEL_HIPKD); |
| 879 | FpgaSetupSsc(); |
| 880 | |
| 881 | // Now give it time to spin up. |
| 882 | // Signal field is on with the appropriate LED |
| 883 | LED_D_ON(); |
| 884 | FpgaWriteConfWord( |
| 885 | FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ); |
| 886 | SpinDelay(200); |
| 887 | |
| 888 | // First command: wake up the tag using the INITIATE command |
| 889 | uint8_t cmd1[] = { 0x06, 0x00, 0x97, 0x5b}; |
| 890 | CodeIso14443bAsReader(cmd1, sizeof(cmd1)); |
| 891 | TransmitFor14443(); |
| 892 | // LED_A_ON(); |
| 893 | GetSamplesFor14443Demod(TRUE, 2000,TRUE); |
| 894 | // LED_A_OFF(); |
| 895 | |
| 896 | if (Demod.len == 0) { |
| 897 | DbpString("No response from tag"); |
| 898 | return; |
| 899 | } else { |
| 900 | Dbprintf("Randomly generated UID from tag (+ 2 byte CRC): %x %x %x", |
| 901 | Demod.output[0], Demod.output[1],Demod.output[2]); |
| 902 | } |
| 903 | // There is a response, SELECT the uid |
| 904 | DbpString("Now SELECT tag:"); |
| 905 | cmd1[0] = 0x0E; // 0x0E is SELECT |
| 906 | cmd1[1] = Demod.output[0]; |
| 907 | ComputeCrc14443(CRC_14443_B, cmd1, 2, &cmd1[2], &cmd1[3]); |
| 908 | CodeIso14443bAsReader(cmd1, sizeof(cmd1)); |
| 909 | TransmitFor14443(); |
| 910 | // LED_A_ON(); |
| 911 | GetSamplesFor14443Demod(TRUE, 2000,TRUE); |
| 912 | // LED_A_OFF(); |
| 913 | if (Demod.len != 3) { |
| 914 | Dbprintf("Expected 3 bytes from tag, got %d", Demod.len); |
| 915 | return; |
| 916 | } |
| 917 | // Check the CRC of the answer: |
| 918 | ComputeCrc14443(CRC_14443_B, Demod.output, 1 , &cmd1[2], &cmd1[3]); |
| 919 | if(cmd1[2] != Demod.output[1] || cmd1[3] != Demod.output[2]) { |
| 920 | DbpString("CRC Error reading select response."); |
| 921 | return; |
| 922 | } |
| 923 | // Check response from the tag: should be the same UID as the command we just sent: |
| 924 | if (cmd1[1] != Demod.output[0]) { |
| 925 | Dbprintf("Bad response to SELECT from Tag, aborting: %x %x", cmd1[1], Demod.output[0]); |
| 926 | return; |
| 927 | } |
| 928 | // Tag is now selected, |
| 929 | // First get the tag's UID: |
| 930 | cmd1[0] = 0x0B; |
| 931 | ComputeCrc14443(CRC_14443_B, cmd1, 1 , &cmd1[1], &cmd1[2]); |
| 932 | CodeIso14443bAsReader(cmd1, 3); // Only first three bytes for this one |
| 933 | TransmitFor14443(); |
| 934 | // LED_A_ON(); |
| 935 | GetSamplesFor14443Demod(TRUE, 2000,TRUE); |
| 936 | // LED_A_OFF(); |
| 937 | if (Demod.len != 10) { |
| 938 | Dbprintf("Expected 10 bytes from tag, got %d", Demod.len); |
| 939 | return; |
| 940 | } |
| 941 | // The check the CRC of the answer (use cmd1 as temporary variable): |
| 942 | ComputeCrc14443(CRC_14443_B, Demod.output, 8, &cmd1[2], &cmd1[3]); |
| 943 | if(cmd1[2] != Demod.output[8] || cmd1[3] != Demod.output[9]) { |
| 944 | Dbprintf("CRC Error reading block! - Below: expected, got %x %x", |
| 945 | (cmd1[2]<<8)+cmd1[3], (Demod.output[8]<<8)+Demod.output[9]); |
| 946 | // Do not return;, let's go on... (we should retry, maybe ?) |
| 947 | } |
| 948 | Dbprintf("Tag UID (64 bits): %08x %08x", |
| 949 | (Demod.output[7]<<24) + (Demod.output[6]<<16) + (Demod.output[5]<<8) + Demod.output[4], |
| 950 | (Demod.output[3]<<24) + (Demod.output[2]<<16) + (Demod.output[1]<<8) + Demod.output[0]); |
| 951 | |
| 952 | // Now loop to read all 16 blocks, address from 0 to last block |
| 953 | Dbprintf("Tag memory dump, block 0 to %d",dwLast); |
| 954 | cmd1[0] = 0x08; |
| 955 | i = 0x00; |
| 956 | dwLast++; |
| 957 | for (;;) { |
| 958 | if (i == dwLast) { |
| 959 | DbpString("System area block (0xff):"); |
| 960 | i = 0xff; |
| 961 | } |
| 962 | cmd1[1] = i; |
| 963 | ComputeCrc14443(CRC_14443_B, cmd1, 2, &cmd1[2], &cmd1[3]); |
| 964 | CodeIso14443bAsReader(cmd1, sizeof(cmd1)); |
| 965 | TransmitFor14443(); |
| 966 | // LED_A_ON(); |
| 967 | GetSamplesFor14443Demod(TRUE, 2000,TRUE); |
| 968 | // LED_A_OFF(); |
| 969 | if (Demod.len != 6) { // Check if we got an answer from the tag |
| 970 | DbpString("Expected 6 bytes from tag, got less..."); |
| 971 | return; |
| 972 | } |
| 973 | // The check the CRC of the answer (use cmd1 as temporary variable): |
| 974 | ComputeCrc14443(CRC_14443_B, Demod.output, 4, &cmd1[2], &cmd1[3]); |
| 975 | if(cmd1[2] != Demod.output[4] || cmd1[3] != Demod.output[5]) { |
| 976 | Dbprintf("CRC Error reading block! - Below: expected, got %x %x", |
| 977 | (cmd1[2]<<8)+cmd1[3], (Demod.output[4]<<8)+Demod.output[5]); |
| 978 | // Do not return;, let's go on... (we should retry, maybe ?) |
| 979 | } |
| 980 | // Now print out the memory location: |
| 981 | Dbprintf("Address=%x, Contents=%x, CRC=%x", i, |
| 982 | (Demod.output[3]<<24) + (Demod.output[2]<<16) + (Demod.output[1]<<8) + Demod.output[0], |
| 983 | (Demod.output[4]<<8)+Demod.output[5]); |
| 984 | if (i == 0xff) { |
| 985 | break; |
| 986 | } |
| 987 | i++; |
| 988 | } |
| 989 | } |
| 990 | |
| 991 | |
| 992 | //============================================================================= |
| 993 | // Finally, the `sniffer' combines elements from both the reader and |
| 994 | // simulated tag, to show both sides of the conversation. |
| 995 | //============================================================================= |
| 996 | |
| 997 | //----------------------------------------------------------------------------- |
| 998 | // Record the sequence of commands sent by the reader to the tag, with |
| 999 | // triggering so that we start recording at the point that the tag is moved |
| 1000 | // near the reader. |
| 1001 | //----------------------------------------------------------------------------- |
| 1002 | /* |
| 1003 | * Memory usage for this function, (within BigBuf) |
| 1004 | * 0-4095 : Demodulated samples receive (4096 bytes) - DEMOD_TRACE_SIZE |
| 1005 | * 4096-6143 : Last Received command, 2048 bytes (reader->tag) - READER_TAG_BUFFER_SIZE |
| 1006 | * 6144-8191 : Last Received command, 2048 bytes(tag->reader) - TAG_READER_BUFFER_SIZE |
| 1007 | * 8192-9215 : DMA Buffer, 1024 bytes (samples) - DEMOD_DMA_BUFFER_SIZE |
| 1008 | */ |
| 1009 | void RAMFUNC SnoopIso14443(void) |
| 1010 | { |
| 1011 | // We won't start recording the frames that we acquire until we trigger; |
| 1012 | // a good trigger condition to get started is probably when we see a |
| 1013 | // response from the tag. |
| 1014 | int triggered = TRUE; |
| 1015 | |
| 1016 | FpgaDownloadAndGo(FPGA_BITSTREAM_HF); |
| 1017 | // The command (reader -> tag) that we're working on receiving. |
| 1018 | uint8_t *receivedCmd = (uint8_t *)(BigBuf) + DEMOD_TRACE_SIZE; |
| 1019 | // The response (tag -> reader) that we're working on receiving. |
| 1020 | uint8_t *receivedResponse = (uint8_t *)(BigBuf) + DEMOD_TRACE_SIZE + READER_TAG_BUFFER_SIZE; |
| 1021 | |
| 1022 | // As we receive stuff, we copy it from receivedCmd or receivedResponse |
| 1023 | // into trace, along with its length and other annotations. |
| 1024 | uint8_t *trace = (uint8_t *)BigBuf; |
| 1025 | int traceLen = 0; |
| 1026 | |
| 1027 | // The DMA buffer, used to stream samples from the FPGA. |
| 1028 | int8_t *dmaBuf = (int8_t *)(BigBuf) + DEMOD_TRACE_SIZE + READER_TAG_BUFFER_SIZE + TAG_READER_BUFFER_SIZE; |
| 1029 | int lastRxCounter; |
| 1030 | int8_t *upTo; |
| 1031 | int ci, cq; |
| 1032 | int maxBehindBy = 0; |
| 1033 | |
| 1034 | // Count of samples received so far, so that we can include timing |
| 1035 | // information in the trace buffer. |
| 1036 | int samples = 0; |
| 1037 | |
| 1038 | // Initialize the trace buffer |
| 1039 | memset(trace, 0x44, DEMOD_TRACE_SIZE); |
| 1040 | |
| 1041 | // Set up the demodulator for tag -> reader responses. |
| 1042 | Demod.output = receivedResponse; |
| 1043 | Demod.len = 0; |
| 1044 | Demod.state = DEMOD_UNSYNCD; |
| 1045 | |
| 1046 | // And the reader -> tag commands |
| 1047 | memset(&Uart, 0, sizeof(Uart)); |
| 1048 | Uart.output = receivedCmd; |
| 1049 | Uart.byteCntMax = 100; |
| 1050 | Uart.state = STATE_UNSYNCD; |
| 1051 | |
| 1052 | // Print some debug information about the buffer sizes |
| 1053 | Dbprintf("Snooping buffers initialized:"); |
| 1054 | Dbprintf(" Trace: %i bytes", DEMOD_TRACE_SIZE); |
| 1055 | Dbprintf(" Reader -> tag: %i bytes", READER_TAG_BUFFER_SIZE); |
| 1056 | Dbprintf(" tag -> Reader: %i bytes", TAG_READER_BUFFER_SIZE); |
| 1057 | Dbprintf(" DMA: %i bytes", DEMOD_DMA_BUFFER_SIZE); |
| 1058 | |
| 1059 | // And put the FPGA in the appropriate mode |
| 1060 | // Signal field is off with the appropriate LED |
| 1061 | LED_D_OFF(); |
| 1062 | FpgaWriteConfWord( |
| 1063 | FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ | |
| 1064 | FPGA_HF_READER_RX_XCORR_SNOOP); |
| 1065 | SetAdcMuxFor(GPIO_MUXSEL_HIPKD); |
| 1066 | |
| 1067 | // Setup for the DMA. |
| 1068 | FpgaSetupSsc(); |
| 1069 | upTo = dmaBuf; |
| 1070 | lastRxCounter = DEMOD_DMA_BUFFER_SIZE; |
| 1071 | FpgaSetupSscDma((uint8_t *)dmaBuf, DEMOD_DMA_BUFFER_SIZE); |
| 1072 | |
| 1073 | LED_A_ON(); |
| 1074 | |
| 1075 | // And now we loop, receiving samples. |
| 1076 | for(;;) { |
| 1077 | int behindBy = (lastRxCounter - AT91C_BASE_PDC_SSC->PDC_RCR) & |
| 1078 | (DEMOD_DMA_BUFFER_SIZE-1); |
| 1079 | if(behindBy > maxBehindBy) { |
| 1080 | maxBehindBy = behindBy; |
| 1081 | if(behindBy > (DEMOD_DMA_BUFFER_SIZE-2)) { // TODO: understand whether we can increase/decrease as we want or not? |
| 1082 | Dbprintf("blew circular buffer! behindBy=0x%x", behindBy); |
| 1083 | goto done; |
| 1084 | } |
| 1085 | } |
| 1086 | if(behindBy < 2) continue; |
| 1087 | |
| 1088 | ci = upTo[0]; |
| 1089 | cq = upTo[1]; |
| 1090 | upTo += 2; |
| 1091 | lastRxCounter -= 2; |
| 1092 | if(upTo - dmaBuf > DEMOD_DMA_BUFFER_SIZE) { |
| 1093 | upTo -= DEMOD_DMA_BUFFER_SIZE; |
| 1094 | lastRxCounter += DEMOD_DMA_BUFFER_SIZE; |
| 1095 | AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) upTo; |
| 1096 | AT91C_BASE_PDC_SSC->PDC_RNCR = DEMOD_DMA_BUFFER_SIZE; |
| 1097 | } |
| 1098 | |
| 1099 | samples += 2; |
| 1100 | |
| 1101 | #define HANDLE_BIT_IF_BODY \ |
| 1102 | if(triggered) { \ |
| 1103 | trace[traceLen++] = ((samples >> 0) & 0xff); \ |
| 1104 | trace[traceLen++] = ((samples >> 8) & 0xff); \ |
| 1105 | trace[traceLen++] = ((samples >> 16) & 0xff); \ |
| 1106 | trace[traceLen++] = ((samples >> 24) & 0xff); \ |
| 1107 | trace[traceLen++] = 0; \ |
| 1108 | trace[traceLen++] = 0; \ |
| 1109 | trace[traceLen++] = 0; \ |
| 1110 | trace[traceLen++] = 0; \ |
| 1111 | trace[traceLen++] = Uart.byteCnt; \ |
| 1112 | memcpy(trace+traceLen, receivedCmd, Uart.byteCnt); \ |
| 1113 | traceLen += Uart.byteCnt; \ |
| 1114 | if(traceLen > 1000) break; \ |
| 1115 | } \ |
| 1116 | /* And ready to receive another command. */ \ |
| 1117 | memset(&Uart, 0, sizeof(Uart)); \ |
| 1118 | Uart.output = receivedCmd; \ |
| 1119 | Uart.byteCntMax = 100; \ |
| 1120 | Uart.state = STATE_UNSYNCD; \ |
| 1121 | /* And also reset the demod code, which might have been */ \ |
| 1122 | /* false-triggered by the commands from the reader. */ \ |
| 1123 | memset(&Demod, 0, sizeof(Demod)); \ |
| 1124 | Demod.output = receivedResponse; \ |
| 1125 | Demod.state = DEMOD_UNSYNCD; \ |
| 1126 | |
| 1127 | if(Handle14443UartBit(ci & 1)) { |
| 1128 | HANDLE_BIT_IF_BODY |
| 1129 | } |
| 1130 | if(Handle14443UartBit(cq & 1)) { |
| 1131 | HANDLE_BIT_IF_BODY |
| 1132 | } |
| 1133 | |
| 1134 | if(Handle14443SamplesDemod(ci, cq)) { |
| 1135 | // timestamp, as a count of samples |
| 1136 | trace[traceLen++] = ((samples >> 0) & 0xff); |
| 1137 | trace[traceLen++] = ((samples >> 8) & 0xff); |
| 1138 | trace[traceLen++] = ((samples >> 16) & 0xff); |
| 1139 | trace[traceLen++] = 0x80 | ((samples >> 24) & 0xff); |
| 1140 | // correlation metric (~signal strength estimate) |
| 1141 | if(Demod.metricN != 0) { |
| 1142 | Demod.metric /= Demod.metricN; |
| 1143 | } |
| 1144 | trace[traceLen++] = ((Demod.metric >> 0) & 0xff); |
| 1145 | trace[traceLen++] = ((Demod.metric >> 8) & 0xff); |
| 1146 | trace[traceLen++] = ((Demod.metric >> 16) & 0xff); |
| 1147 | trace[traceLen++] = ((Demod.metric >> 24) & 0xff); |
| 1148 | // length |
| 1149 | trace[traceLen++] = Demod.len; |
| 1150 | memcpy(trace+traceLen, receivedResponse, Demod.len); |
| 1151 | traceLen += Demod.len; |
| 1152 | if(traceLen > DEMOD_TRACE_SIZE) { |
| 1153 | DbpString("Reached trace limit"); |
| 1154 | goto done; |
| 1155 | } |
| 1156 | |
| 1157 | triggered = TRUE; |
| 1158 | LED_A_OFF(); |
| 1159 | LED_B_ON(); |
| 1160 | |
| 1161 | // And ready to receive another response. |
| 1162 | memset(&Demod, 0, sizeof(Demod)); |
| 1163 | Demod.output = receivedResponse; |
| 1164 | Demod.state = DEMOD_UNSYNCD; |
| 1165 | } |
| 1166 | WDT_HIT(); |
| 1167 | |
| 1168 | if(BUTTON_PRESS()) { |
| 1169 | DbpString("cancelled"); |
| 1170 | goto done; |
| 1171 | } |
| 1172 | } |
| 1173 | |
| 1174 | done: |
| 1175 | LED_A_OFF(); |
| 1176 | LED_B_OFF(); |
| 1177 | LED_C_OFF(); |
| 1178 | AT91C_BASE_PDC_SSC->PDC_PTCR = AT91C_PDC_RXTDIS; |
| 1179 | DbpString("Snoop statistics:"); |
| 1180 | Dbprintf(" Max behind by: %i", maxBehindBy); |
| 1181 | Dbprintf(" Uart State: %x", Uart.state); |
| 1182 | Dbprintf(" Uart ByteCnt: %i", Uart.byteCnt); |
| 1183 | Dbprintf(" Uart ByteCntMax: %i", Uart.byteCntMax); |
| 1184 | Dbprintf(" Trace length: %i", traceLen); |
| 1185 | } |
| 1186 | |
| 1187 | /* |
| 1188 | * Send raw command to tag ISO14443B |
| 1189 | * @Input |
| 1190 | * datalen len of buffer data |
| 1191 | * recv bool when true wait for data from tag and send to client |
| 1192 | * powerfield bool leave the field on when true |
| 1193 | * data buffer with byte to send |
| 1194 | * |
| 1195 | * @Output |
| 1196 | * none |
| 1197 | * |
| 1198 | */ |
| 1199 | |
| 1200 | void SendRawCommand14443B(uint32_t datalen, uint32_t recv,uint8_t powerfield, uint8_t data[]) |
| 1201 | { |
| 1202 | FpgaDownloadAndGo(FPGA_BITSTREAM_HF); |
| 1203 | if(!powerfield) |
| 1204 | { |
| 1205 | // Make sure that we start from off, since the tags are stateful; |
| 1206 | // confusing things will happen if we don't reset them between reads. |
| 1207 | FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); |
| 1208 | LED_D_OFF(); |
| 1209 | SpinDelay(200); |
| 1210 | } |
| 1211 | |
| 1212 | if(!GETBIT(GPIO_LED_D)) |
| 1213 | { |
| 1214 | SetAdcMuxFor(GPIO_MUXSEL_HIPKD); |
| 1215 | FpgaSetupSsc(); |
| 1216 | |
| 1217 | // Now give it time to spin up. |
| 1218 | // Signal field is on with the appropriate LED |
| 1219 | LED_D_ON(); |
| 1220 | FpgaWriteConfWord( |
| 1221 | FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ); |
| 1222 | SpinDelay(200); |
| 1223 | } |
| 1224 | |
| 1225 | CodeIso14443bAsReader(data, datalen); |
| 1226 | TransmitFor14443(); |
| 1227 | if(recv) |
| 1228 | { |
| 1229 | uint16_t iLen = MIN(Demod.len,USB_CMD_DATA_SIZE); |
| 1230 | GetSamplesFor14443Demod(TRUE, 2000, TRUE); |
| 1231 | cmd_send(CMD_ACK,iLen,0,0,Demod.output,iLen); |
| 1232 | } |
| 1233 | if(!powerfield) |
| 1234 | { |
| 1235 | FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); |
| 1236 | LED_D_OFF(); |
| 1237 | } |
| 1238 | } |
| 1239 | |