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15c4dc5a | 1 | //----------------------------------------------------------------------------- |
2 | // Routines to support ISO 14443. This includes both the reader software and | |
3 | // the `fake tag' modes. At the moment only the Type B modulation is | |
4 | // supported. | |
5 | // Jonathan Westhues, split Nov 2006 | |
6 | //----------------------------------------------------------------------------- | |
e30c654b | 7 | #include "proxmark3.h" |
15c4dc5a | 8 | #include "apps.h" |
f7e3ed82 | 9 | #include "util.h" |
15c4dc5a | 10 | |
f7e3ed82 | 11 | #include "iso14443crc.h" |
15c4dc5a | 12 | |
f7e3ed82 | 13 | //static void GetSamplesFor14443(int weTx, int n); |
15c4dc5a | 14 | |
15 | #define DEMOD_TRACE_SIZE 4096 | |
16 | #define READER_TAG_BUFFER_SIZE 2048 | |
17 | #define TAG_READER_BUFFER_SIZE 2048 | |
18 | #define DMA_BUFFER_SIZE 1024 | |
19 | ||
20 | //============================================================================= | |
21 | // An ISO 14443 Type B tag. We listen for commands from the reader, using | |
22 | // a UART kind of thing that's implemented in software. When we get a | |
23 | // frame (i.e., a group of bytes between SOF and EOF), we check the CRC. | |
24 | // If it's good, then we can do something appropriate with it, and send | |
25 | // a response. | |
26 | //============================================================================= | |
27 | ||
28 | //----------------------------------------------------------------------------- | |
29 | // Code up a string of octets at layer 2 (including CRC, we don't generate | |
30 | // that here) so that they can be transmitted to the reader. Doesn't transmit | |
31 | // them yet, just leaves them ready to send in ToSend[]. | |
32 | //----------------------------------------------------------------------------- | |
f7e3ed82 | 33 | static void CodeIso14443bAsTag(const uint8_t *cmd, int len) |
15c4dc5a | 34 | { |
35 | int i; | |
36 | ||
37 | ToSendReset(); | |
38 | ||
39 | // Transmit a burst of ones, as the initial thing that lets the | |
40 | // reader get phase sync. This (TR1) must be > 80/fs, per spec, | |
41 | // but tag that I've tried (a Paypass) exceeds that by a fair bit, | |
42 | // so I will too. | |
43 | for(i = 0; i < 20; i++) { | |
44 | ToSendStuffBit(1); | |
45 | ToSendStuffBit(1); | |
46 | ToSendStuffBit(1); | |
47 | ToSendStuffBit(1); | |
48 | } | |
49 | ||
50 | // Send SOF. | |
51 | for(i = 0; i < 10; i++) { | |
52 | ToSendStuffBit(0); | |
53 | ToSendStuffBit(0); | |
54 | ToSendStuffBit(0); | |
55 | ToSendStuffBit(0); | |
56 | } | |
57 | for(i = 0; i < 2; i++) { | |
58 | ToSendStuffBit(1); | |
59 | ToSendStuffBit(1); | |
60 | ToSendStuffBit(1); | |
61 | ToSendStuffBit(1); | |
62 | } | |
63 | ||
64 | for(i = 0; i < len; i++) { | |
65 | int j; | |
f7e3ed82 | 66 | uint8_t b = cmd[i]; |
15c4dc5a | 67 | |
68 | // Start bit | |
69 | ToSendStuffBit(0); | |
70 | ToSendStuffBit(0); | |
71 | ToSendStuffBit(0); | |
72 | ToSendStuffBit(0); | |
73 | ||
74 | // Data bits | |
75 | for(j = 0; j < 8; j++) { | |
76 | if(b & 1) { | |
77 | ToSendStuffBit(1); | |
78 | ToSendStuffBit(1); | |
79 | ToSendStuffBit(1); | |
80 | ToSendStuffBit(1); | |
81 | } else { | |
82 | ToSendStuffBit(0); | |
83 | ToSendStuffBit(0); | |
84 | ToSendStuffBit(0); | |
85 | ToSendStuffBit(0); | |
86 | } | |
87 | b >>= 1; | |
88 | } | |
89 | ||
90 | // Stop bit | |
91 | ToSendStuffBit(1); | |
92 | ToSendStuffBit(1); | |
93 | ToSendStuffBit(1); | |
94 | ToSendStuffBit(1); | |
95 | } | |
96 | ||
97 | // Send SOF. | |
98 | for(i = 0; i < 10; i++) { | |
99 | ToSendStuffBit(0); | |
100 | ToSendStuffBit(0); | |
101 | ToSendStuffBit(0); | |
102 | ToSendStuffBit(0); | |
103 | } | |
104 | for(i = 0; i < 10; i++) { | |
105 | ToSendStuffBit(1); | |
106 | ToSendStuffBit(1); | |
107 | ToSendStuffBit(1); | |
108 | ToSendStuffBit(1); | |
109 | } | |
110 | ||
111 | // Convert from last byte pos to length | |
112 | ToSendMax++; | |
113 | ||
114 | // Add a few more for slop | |
115 | ToSendMax += 2; | |
116 | } | |
117 | ||
118 | //----------------------------------------------------------------------------- | |
119 | // The software UART that receives commands from the reader, and its state | |
120 | // variables. | |
121 | //----------------------------------------------------------------------------- | |
122 | static struct { | |
123 | enum { | |
124 | STATE_UNSYNCD, | |
125 | STATE_GOT_FALLING_EDGE_OF_SOF, | |
126 | STATE_AWAITING_START_BIT, | |
127 | STATE_RECEIVING_DATA, | |
128 | STATE_ERROR_WAIT | |
129 | } state; | |
f7e3ed82 | 130 | uint16_t shiftReg; |
15c4dc5a | 131 | int bitCnt; |
132 | int byteCnt; | |
133 | int byteCntMax; | |
134 | int posCnt; | |
f7e3ed82 | 135 | uint8_t *output; |
15c4dc5a | 136 | } Uart; |
137 | ||
138 | /* Receive & handle a bit coming from the reader. | |
139 | * | |
140 | * LED handling: | |
141 | * LED A -> ON once we have received the SOF and are expecting the rest. | |
142 | * LED A -> OFF once we have received EOF or are in error state or unsynced | |
143 | * | |
144 | * Returns: true if we received a EOF | |
145 | * false if we are still waiting for some more | |
146 | */ | |
f7e3ed82 | 147 | static int Handle14443UartBit(int bit) |
15c4dc5a | 148 | { |
149 | switch(Uart.state) { | |
150 | case STATE_UNSYNCD: | |
151 | LED_A_OFF(); | |
152 | if(!bit) { | |
153 | // we went low, so this could be the beginning | |
154 | // of an SOF | |
155 | Uart.state = STATE_GOT_FALLING_EDGE_OF_SOF; | |
156 | Uart.posCnt = 0; | |
157 | Uart.bitCnt = 0; | |
158 | } | |
159 | break; | |
160 | ||
161 | case STATE_GOT_FALLING_EDGE_OF_SOF: | |
162 | Uart.posCnt++; | |
163 | if(Uart.posCnt == 2) { | |
164 | if(bit) { | |
165 | if(Uart.bitCnt >= 10) { | |
166 | // we've seen enough consecutive | |
167 | // zeros that it's a valid SOF | |
168 | Uart.posCnt = 0; | |
169 | Uart.byteCnt = 0; | |
170 | Uart.state = STATE_AWAITING_START_BIT; | |
171 | LED_A_ON(); // Indicate we got a valid SOF | |
172 | } else { | |
173 | // didn't stay down long enough | |
174 | // before going high, error | |
175 | Uart.state = STATE_ERROR_WAIT; | |
176 | } | |
177 | } else { | |
178 | // do nothing, keep waiting | |
179 | } | |
180 | Uart.bitCnt++; | |
181 | } | |
182 | if(Uart.posCnt >= 4) Uart.posCnt = 0; | |
183 | if(Uart.bitCnt > 14) { | |
184 | // Give up if we see too many zeros without | |
185 | // a one, too. | |
186 | Uart.state = STATE_ERROR_WAIT; | |
187 | } | |
188 | break; | |
189 | ||
190 | case STATE_AWAITING_START_BIT: | |
191 | Uart.posCnt++; | |
192 | if(bit) { | |
193 | if(Uart.posCnt > 25) { | |
194 | // stayed high for too long between | |
195 | // characters, error | |
196 | Uart.state = STATE_ERROR_WAIT; | |
197 | } | |
198 | } else { | |
199 | // falling edge, this starts the data byte | |
200 | Uart.posCnt = 0; | |
201 | Uart.bitCnt = 0; | |
202 | Uart.shiftReg = 0; | |
203 | Uart.state = STATE_RECEIVING_DATA; | |
204 | LED_A_ON(); // Indicate we're receiving | |
205 | } | |
206 | break; | |
207 | ||
208 | case STATE_RECEIVING_DATA: | |
209 | Uart.posCnt++; | |
210 | if(Uart.posCnt == 2) { | |
211 | // time to sample a bit | |
212 | Uart.shiftReg >>= 1; | |
213 | if(bit) { | |
214 | Uart.shiftReg |= 0x200; | |
215 | } | |
216 | Uart.bitCnt++; | |
217 | } | |
218 | if(Uart.posCnt >= 4) { | |
219 | Uart.posCnt = 0; | |
220 | } | |
221 | if(Uart.bitCnt == 10) { | |
222 | if((Uart.shiftReg & 0x200) && !(Uart.shiftReg & 0x001)) | |
223 | { | |
224 | // this is a data byte, with correct | |
225 | // start and stop bits | |
226 | Uart.output[Uart.byteCnt] = (Uart.shiftReg >> 1) & 0xff; | |
227 | Uart.byteCnt++; | |
228 | ||
229 | if(Uart.byteCnt >= Uart.byteCntMax) { | |
230 | // Buffer overflowed, give up | |
231 | Uart.posCnt = 0; | |
232 | Uart.state = STATE_ERROR_WAIT; | |
233 | } else { | |
234 | // so get the next byte now | |
235 | Uart.posCnt = 0; | |
236 | Uart.state = STATE_AWAITING_START_BIT; | |
237 | } | |
238 | } else if(Uart.shiftReg == 0x000) { | |
239 | // this is an EOF byte | |
240 | LED_A_OFF(); // Finished receiving | |
241 | return TRUE; | |
242 | } else { | |
243 | // this is an error | |
244 | Uart.posCnt = 0; | |
245 | Uart.state = STATE_ERROR_WAIT; | |
246 | } | |
247 | } | |
248 | break; | |
249 | ||
250 | case STATE_ERROR_WAIT: | |
251 | // We're all screwed up, so wait a little while | |
252 | // for whatever went wrong to finish, and then | |
253 | // start over. | |
254 | Uart.posCnt++; | |
255 | if(Uart.posCnt > 10) { | |
256 | Uart.state = STATE_UNSYNCD; | |
257 | } | |
258 | break; | |
259 | ||
260 | default: | |
261 | Uart.state = STATE_UNSYNCD; | |
262 | break; | |
263 | } | |
264 | ||
265 | if (Uart.state == STATE_ERROR_WAIT) LED_A_OFF(); // Error | |
266 | ||
267 | return FALSE; | |
268 | } | |
269 | ||
270 | //----------------------------------------------------------------------------- | |
271 | // Receive a command (from the reader to us, where we are the simulated tag), | |
272 | // and store it in the given buffer, up to the given maximum length. Keeps | |
273 | // spinning, waiting for a well-framed command, until either we get one | |
274 | // (returns TRUE) or someone presses the pushbutton on the board (FALSE). | |
275 | // | |
276 | // Assume that we're called with the SSC (to the FPGA) and ADC path set | |
277 | // correctly. | |
278 | //----------------------------------------------------------------------------- | |
f7e3ed82 | 279 | static int GetIso14443CommandFromReader(uint8_t *received, int *len, int maxLen) |
15c4dc5a | 280 | { |
f7e3ed82 | 281 | uint8_t mask; |
15c4dc5a | 282 | int i, bit; |
283 | ||
284 | // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen | |
285 | // only, since we are receiving, not transmitting). | |
286 | // Signal field is off with the appropriate LED | |
287 | LED_D_OFF(); | |
288 | FpgaWriteConfWord( | |
289 | FPGA_MAJOR_MODE_HF_SIMULATOR | FPGA_HF_SIMULATOR_NO_MODULATION); | |
290 | ||
291 | ||
292 | // Now run a `software UART' on the stream of incoming samples. | |
293 | Uart.output = received; | |
294 | Uart.byteCntMax = maxLen; | |
295 | Uart.state = STATE_UNSYNCD; | |
296 | ||
297 | for(;;) { | |
298 | WDT_HIT(); | |
299 | ||
300 | if(BUTTON_PRESS()) return FALSE; | |
301 | ||
302 | if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { | |
303 | AT91C_BASE_SSC->SSC_THR = 0x00; | |
304 | } | |
305 | if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { | |
f7e3ed82 | 306 | uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR; |
15c4dc5a | 307 | |
308 | mask = 0x80; | |
309 | for(i = 0; i < 8; i++, mask >>= 1) { | |
310 | bit = (b & mask); | |
311 | if(Handle14443UartBit(bit)) { | |
312 | *len = Uart.byteCnt; | |
313 | return TRUE; | |
314 | } | |
315 | } | |
316 | } | |
317 | } | |
318 | } | |
319 | ||
320 | //----------------------------------------------------------------------------- | |
321 | // Main loop of simulated tag: receive commands from reader, decide what | |
322 | // response to send, and send it. | |
323 | //----------------------------------------------------------------------------- | |
324 | void SimulateIso14443Tag(void) | |
325 | { | |
f7e3ed82 | 326 | static const uint8_t cmd1[] = { 0x05, 0x00, 0x08, 0x39, 0x73 }; |
327 | static const uint8_t response1[] = { | |
15c4dc5a | 328 | 0x50, 0x82, 0x0d, 0xe1, 0x74, 0x20, 0x38, 0x19, 0x22, |
329 | 0x00, 0x21, 0x85, 0x5e, 0xd7 | |
330 | }; | |
331 | ||
f7e3ed82 | 332 | uint8_t *resp; |
15c4dc5a | 333 | int respLen; |
334 | ||
f7e3ed82 | 335 | uint8_t *resp1 = (((uint8_t *)BigBuf) + 800); |
15c4dc5a | 336 | int resp1Len; |
337 | ||
f7e3ed82 | 338 | uint8_t *receivedCmd = (uint8_t *)BigBuf; |
15c4dc5a | 339 | int len; |
340 | ||
341 | int i; | |
342 | ||
343 | int cmdsRecvd = 0; | |
344 | ||
345 | memset(receivedCmd, 0x44, 400); | |
346 | ||
347 | CodeIso14443bAsTag(response1, sizeof(response1)); | |
348 | memcpy(resp1, ToSend, ToSendMax); resp1Len = ToSendMax; | |
349 | ||
350 | // We need to listen to the high-frequency, peak-detected path. | |
351 | SetAdcMuxFor(GPIO_MUXSEL_HIPKD); | |
352 | FpgaSetupSsc(); | |
353 | ||
354 | cmdsRecvd = 0; | |
355 | ||
356 | for(;;) { | |
f7e3ed82 | 357 | uint8_t b1, b2; |
15c4dc5a | 358 | |
359 | if(!GetIso14443CommandFromReader(receivedCmd, &len, 100)) { | |
360 | Dbprintf("button pressed, received %d commands", cmdsRecvd); | |
361 | break; | |
362 | } | |
363 | ||
364 | // Good, look at the command now. | |
365 | ||
366 | if(len == sizeof(cmd1) && memcmp(receivedCmd, cmd1, len)==0) { | |
367 | resp = resp1; respLen = resp1Len; | |
368 | } else { | |
369 | Dbprintf("new cmd from reader: len=%d, cmdsRecvd=%d", len, cmdsRecvd); | |
370 | // And print whether the CRC fails, just for good measure | |
371 | ComputeCrc14443(CRC_14443_B, receivedCmd, len-2, &b1, &b2); | |
372 | if(b1 != receivedCmd[len-2] || b2 != receivedCmd[len-1]) { | |
373 | // Not so good, try again. | |
374 | DbpString("+++CRC fail"); | |
375 | } else { | |
376 | DbpString("CRC passes"); | |
377 | } | |
378 | break; | |
379 | } | |
380 | ||
381 | memset(receivedCmd, 0x44, 32); | |
382 | ||
383 | cmdsRecvd++; | |
384 | ||
385 | if(cmdsRecvd > 0x30) { | |
386 | DbpString("many commands later..."); | |
387 | break; | |
388 | } | |
389 | ||
390 | if(respLen <= 0) continue; | |
391 | ||
392 | // Modulate BPSK | |
393 | // Signal field is off with the appropriate LED | |
394 | LED_D_OFF(); | |
395 | FpgaWriteConfWord( | |
396 | FPGA_MAJOR_MODE_HF_SIMULATOR | FPGA_HF_SIMULATOR_MODULATE_BPSK); | |
397 | AT91C_BASE_SSC->SSC_THR = 0xff; | |
398 | FpgaSetupSsc(); | |
399 | ||
400 | // Transmit the response. | |
401 | i = 0; | |
402 | for(;;) { | |
403 | if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { | |
f7e3ed82 | 404 | uint8_t b = resp[i]; |
15c4dc5a | 405 | |
406 | AT91C_BASE_SSC->SSC_THR = b; | |
407 | ||
408 | i++; | |
409 | if(i > respLen) { | |
410 | break; | |
411 | } | |
412 | } | |
413 | if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { | |
f7e3ed82 | 414 | volatile uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR; |
15c4dc5a | 415 | (void)b; |
416 | } | |
417 | } | |
418 | } | |
419 | } | |
420 | ||
421 | //============================================================================= | |
422 | // An ISO 14443 Type B reader. We take layer two commands, code them | |
423 | // appropriately, and then send them to the tag. We then listen for the | |
424 | // tag's response, which we leave in the buffer to be demodulated on the | |
425 | // PC side. | |
426 | //============================================================================= | |
427 | ||
428 | static struct { | |
429 | enum { | |
430 | DEMOD_UNSYNCD, | |
431 | DEMOD_PHASE_REF_TRAINING, | |
432 | DEMOD_AWAITING_FALLING_EDGE_OF_SOF, | |
433 | DEMOD_GOT_FALLING_EDGE_OF_SOF, | |
434 | DEMOD_AWAITING_START_BIT, | |
435 | DEMOD_RECEIVING_DATA, | |
436 | DEMOD_ERROR_WAIT | |
437 | } state; | |
438 | int bitCount; | |
439 | int posCount; | |
440 | int thisBit; | |
441 | int metric; | |
442 | int metricN; | |
f7e3ed82 | 443 | uint16_t shiftReg; |
444 | uint8_t *output; | |
15c4dc5a | 445 | int len; |
446 | int sumI; | |
447 | int sumQ; | |
448 | } Demod; | |
449 | ||
450 | /* | |
451 | * Handles reception of a bit from the tag | |
452 | * | |
453 | * LED handling: | |
454 | * LED C -> ON once we have received the SOF and are expecting the rest. | |
455 | * LED C -> OFF once we have received EOF or are unsynced | |
456 | * | |
457 | * Returns: true if we received a EOF | |
458 | * false if we are still waiting for some more | |
459 | * | |
460 | */ | |
f7e3ed82 | 461 | static int Handle14443SamplesDemod(int ci, int cq) |
15c4dc5a | 462 | { |
463 | int v; | |
464 | ||
465 | // The soft decision on the bit uses an estimate of just the | |
466 | // quadrant of the reference angle, not the exact angle. | |
467 | #define MAKE_SOFT_DECISION() { \ | |
468 | if(Demod.sumI > 0) { \ | |
469 | v = ci; \ | |
470 | } else { \ | |
471 | v = -ci; \ | |
472 | } \ | |
473 | if(Demod.sumQ > 0) { \ | |
474 | v += cq; \ | |
475 | } else { \ | |
476 | v -= cq; \ | |
477 | } \ | |
478 | } | |
479 | ||
480 | switch(Demod.state) { | |
481 | case DEMOD_UNSYNCD: | |
482 | v = ci; | |
483 | if(v < 0) v = -v; | |
484 | if(cq > 0) { | |
485 | v += cq; | |
486 | } else { | |
487 | v -= cq; | |
488 | } | |
489 | if(v > 40) { | |
490 | Demod.posCount = 0; | |
491 | Demod.state = DEMOD_PHASE_REF_TRAINING; | |
492 | Demod.sumI = 0; | |
493 | Demod.sumQ = 0; | |
494 | } | |
495 | break; | |
496 | ||
497 | case DEMOD_PHASE_REF_TRAINING: | |
498 | if(Demod.posCount < 8) { | |
499 | Demod.sumI += ci; | |
500 | Demod.sumQ += cq; | |
501 | } else if(Demod.posCount > 100) { | |
502 | // error, waited too long | |
503 | Demod.state = DEMOD_UNSYNCD; | |
504 | } else { | |
505 | MAKE_SOFT_DECISION(); | |
506 | if(v < 0) { | |
507 | Demod.state = DEMOD_AWAITING_FALLING_EDGE_OF_SOF; | |
508 | Demod.posCount = 0; | |
509 | } | |
510 | } | |
511 | Demod.posCount++; | |
512 | break; | |
513 | ||
514 | case DEMOD_AWAITING_FALLING_EDGE_OF_SOF: | |
515 | MAKE_SOFT_DECISION(); | |
516 | if(v < 0) { | |
517 | Demod.state = DEMOD_GOT_FALLING_EDGE_OF_SOF; | |
518 | Demod.posCount = 0; | |
519 | } else { | |
520 | if(Demod.posCount > 100) { | |
521 | Demod.state = DEMOD_UNSYNCD; | |
522 | } | |
523 | } | |
524 | Demod.posCount++; | |
525 | break; | |
526 | ||
527 | case DEMOD_GOT_FALLING_EDGE_OF_SOF: | |
528 | MAKE_SOFT_DECISION(); | |
529 | if(v > 0) { | |
530 | if(Demod.posCount < 12) { | |
531 | Demod.state = DEMOD_UNSYNCD; | |
532 | } else { | |
533 | LED_C_ON(); // Got SOF | |
534 | Demod.state = DEMOD_AWAITING_START_BIT; | |
535 | Demod.posCount = 0; | |
536 | Demod.len = 0; | |
537 | Demod.metricN = 0; | |
538 | Demod.metric = 0; | |
539 | } | |
540 | } else { | |
541 | if(Demod.posCount > 100) { | |
542 | Demod.state = DEMOD_UNSYNCD; | |
543 | } | |
544 | } | |
545 | Demod.posCount++; | |
546 | break; | |
547 | ||
548 | case DEMOD_AWAITING_START_BIT: | |
549 | MAKE_SOFT_DECISION(); | |
550 | if(v > 0) { | |
551 | if(Demod.posCount > 10) { | |
552 | Demod.state = DEMOD_UNSYNCD; | |
553 | } | |
554 | } else { | |
555 | Demod.bitCount = 0; | |
556 | Demod.posCount = 1; | |
557 | Demod.thisBit = v; | |
558 | Demod.shiftReg = 0; | |
559 | Demod.state = DEMOD_RECEIVING_DATA; | |
560 | } | |
561 | break; | |
562 | ||
563 | case DEMOD_RECEIVING_DATA: | |
564 | MAKE_SOFT_DECISION(); | |
565 | if(Demod.posCount == 0) { | |
566 | Demod.thisBit = v; | |
567 | Demod.posCount = 1; | |
568 | } else { | |
569 | Demod.thisBit += v; | |
570 | ||
571 | if(Demod.thisBit > 0) { | |
572 | Demod.metric += Demod.thisBit; | |
573 | } else { | |
574 | Demod.metric -= Demod.thisBit; | |
575 | } | |
576 | (Demod.metricN)++; | |
577 | ||
578 | Demod.shiftReg >>= 1; | |
579 | if(Demod.thisBit > 0) { | |
580 | Demod.shiftReg |= 0x200; | |
581 | } | |
582 | ||
583 | Demod.bitCount++; | |
584 | if(Demod.bitCount == 10) { | |
f7e3ed82 | 585 | uint16_t s = Demod.shiftReg; |
15c4dc5a | 586 | if((s & 0x200) && !(s & 0x001)) { |
f7e3ed82 | 587 | uint8_t b = (s >> 1); |
15c4dc5a | 588 | Demod.output[Demod.len] = b; |
589 | Demod.len++; | |
590 | Demod.state = DEMOD_AWAITING_START_BIT; | |
591 | } else if(s == 0x000) { | |
592 | // This is EOF | |
593 | LED_C_OFF(); | |
594 | return TRUE; | |
595 | Demod.state = DEMOD_UNSYNCD; | |
596 | } else { | |
597 | Demod.state = DEMOD_UNSYNCD; | |
598 | } | |
599 | } | |
600 | Demod.posCount = 0; | |
601 | } | |
602 | break; | |
603 | ||
604 | default: | |
605 | Demod.state = DEMOD_UNSYNCD; | |
606 | break; | |
607 | } | |
608 | ||
609 | if (Demod.state == DEMOD_UNSYNCD) LED_C_OFF(); // Not synchronized... | |
610 | return FALSE; | |
611 | } | |
612 | ||
613 | /* | |
614 | * Demodulate the samples we received from the tag | |
615 | * weTx: set to 'TRUE' if we behave like a reader | |
616 | * set to 'FALSE' if we behave like a snooper | |
617 | * quiet: set to 'TRUE' to disable debug output | |
618 | */ | |
f7e3ed82 | 619 | static void GetSamplesFor14443Demod(int weTx, int n, int quiet) |
15c4dc5a | 620 | { |
621 | int max = 0; | |
f7e3ed82 | 622 | int gotFrame = FALSE; |
15c4dc5a | 623 | |
624 | //# define DMA_BUFFER_SIZE 8 | |
f7e3ed82 | 625 | int8_t *dmaBuf; |
15c4dc5a | 626 | |
627 | int lastRxCounter; | |
f7e3ed82 | 628 | int8_t *upTo; |
15c4dc5a | 629 | |
630 | int ci, cq; | |
631 | ||
632 | int samples = 0; | |
633 | ||
634 | // Clear out the state of the "UART" that receives from the tag. | |
635 | memset(BigBuf, 0x44, 400); | |
f7e3ed82 | 636 | Demod.output = (uint8_t *)BigBuf; |
15c4dc5a | 637 | Demod.len = 0; |
638 | Demod.state = DEMOD_UNSYNCD; | |
639 | ||
640 | // And the UART that receives from the reader | |
f7e3ed82 | 641 | Uart.output = (((uint8_t *)BigBuf) + 1024); |
15c4dc5a | 642 | Uart.byteCntMax = 100; |
643 | Uart.state = STATE_UNSYNCD; | |
644 | ||
645 | // Setup for the DMA. | |
f7e3ed82 | 646 | dmaBuf = (int8_t *)(BigBuf + 32); |
15c4dc5a | 647 | upTo = dmaBuf; |
648 | lastRxCounter = DMA_BUFFER_SIZE; | |
f7e3ed82 | 649 | FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); |
15c4dc5a | 650 | |
651 | // Signal field is ON with the appropriate LED: | |
652 | if (weTx) LED_D_ON(); else LED_D_OFF(); | |
653 | // And put the FPGA in the appropriate mode | |
654 | FpgaWriteConfWord( | |
655 | FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ | | |
656 | (weTx ? 0 : FPGA_HF_READER_RX_XCORR_SNOOP)); | |
657 | ||
658 | for(;;) { | |
659 | int behindBy = lastRxCounter - AT91C_BASE_PDC_SSC->PDC_RCR; | |
660 | if(behindBy > max) max = behindBy; | |
661 | ||
662 | while(((lastRxCounter-AT91C_BASE_PDC_SSC->PDC_RCR) & (DMA_BUFFER_SIZE-1)) | |
663 | > 2) | |
664 | { | |
665 | ci = upTo[0]; | |
666 | cq = upTo[1]; | |
667 | upTo += 2; | |
668 | if(upTo - dmaBuf > DMA_BUFFER_SIZE) { | |
669 | upTo -= DMA_BUFFER_SIZE; | |
f7e3ed82 | 670 | AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) upTo; |
15c4dc5a | 671 | AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE; |
672 | } | |
673 | lastRxCounter -= 2; | |
674 | if(lastRxCounter <= 0) { | |
675 | lastRxCounter += DMA_BUFFER_SIZE; | |
676 | } | |
677 | ||
678 | samples += 2; | |
679 | ||
680 | Handle14443UartBit(1); | |
681 | Handle14443UartBit(1); | |
682 | ||
683 | if(Handle14443SamplesDemod(ci, cq)) { | |
684 | gotFrame = 1; | |
685 | } | |
686 | } | |
687 | ||
688 | if(samples > 2000) { | |
689 | break; | |
690 | } | |
691 | } | |
692 | AT91C_BASE_PDC_SSC->PDC_PTCR = AT91C_PDC_RXTDIS; | |
693 | if (!quiet) Dbprintf("%x %x %x", max, gotFrame, Demod.len); | |
694 | } | |
695 | ||
696 | //----------------------------------------------------------------------------- | |
697 | // Read the tag's response. We just receive a stream of slightly-processed | |
698 | // samples from the FPGA, which we will later do some signal processing on, | |
699 | // to get the bits. | |
700 | //----------------------------------------------------------------------------- | |
f7e3ed82 | 701 | /*static void GetSamplesFor14443(int weTx, int n) |
15c4dc5a | 702 | { |
f7e3ed82 | 703 | uint8_t *dest = (uint8_t *)BigBuf; |
15c4dc5a | 704 | int c; |
705 | ||
706 | FpgaWriteConfWord( | |
707 | FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ | | |
708 | (weTx ? 0 : FPGA_HF_READER_RX_XCORR_SNOOP)); | |
709 | ||
710 | c = 0; | |
711 | for(;;) { | |
712 | if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { | |
713 | AT91C_BASE_SSC->SSC_THR = 0x43; | |
714 | } | |
715 | if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { | |
f7e3ed82 | 716 | int8_t b; |
717 | b = (int8_t)AT91C_BASE_SSC->SSC_RHR; | |
15c4dc5a | 718 | |
f7e3ed82 | 719 | dest[c++] = (uint8_t)b; |
15c4dc5a | 720 | |
721 | if(c >= n) { | |
722 | break; | |
723 | } | |
724 | } | |
725 | } | |
726 | }*/ | |
727 | ||
728 | //----------------------------------------------------------------------------- | |
729 | // Transmit the command (to the tag) that was placed in ToSend[]. | |
730 | //----------------------------------------------------------------------------- | |
731 | static void TransmitFor14443(void) | |
732 | { | |
733 | int c; | |
734 | ||
735 | FpgaSetupSsc(); | |
736 | ||
737 | while(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { | |
738 | AT91C_BASE_SSC->SSC_THR = 0xff; | |
739 | } | |
740 | ||
741 | // Signal field is ON with the appropriate Red LED | |
742 | LED_D_ON(); | |
743 | // Signal we are transmitting with the Green LED | |
744 | LED_B_ON(); | |
745 | FpgaWriteConfWord( | |
746 | FPGA_MAJOR_MODE_HF_READER_TX | FPGA_HF_READER_TX_SHALLOW_MOD); | |
747 | ||
748 | for(c = 0; c < 10;) { | |
749 | if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { | |
750 | AT91C_BASE_SSC->SSC_THR = 0xff; | |
751 | c++; | |
752 | } | |
753 | if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { | |
f7e3ed82 | 754 | volatile uint32_t r = AT91C_BASE_SSC->SSC_RHR; |
15c4dc5a | 755 | (void)r; |
756 | } | |
757 | WDT_HIT(); | |
758 | } | |
759 | ||
760 | c = 0; | |
761 | for(;;) { | |
762 | if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { | |
763 | AT91C_BASE_SSC->SSC_THR = ToSend[c]; | |
764 | c++; | |
765 | if(c >= ToSendMax) { | |
766 | break; | |
767 | } | |
768 | } | |
769 | if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { | |
f7e3ed82 | 770 | volatile uint32_t r = AT91C_BASE_SSC->SSC_RHR; |
15c4dc5a | 771 | (void)r; |
772 | } | |
773 | WDT_HIT(); | |
774 | } | |
775 | LED_B_OFF(); // Finished sending | |
776 | } | |
777 | ||
778 | //----------------------------------------------------------------------------- | |
779 | // Code a layer 2 command (string of octets, including CRC) into ToSend[], | |
780 | // so that it is ready to transmit to the tag using TransmitFor14443(). | |
781 | //----------------------------------------------------------------------------- | |
f7e3ed82 | 782 | void CodeIso14443bAsReader(const uint8_t *cmd, int len) |
15c4dc5a | 783 | { |
784 | int i, j; | |
f7e3ed82 | 785 | uint8_t b; |
15c4dc5a | 786 | |
787 | ToSendReset(); | |
788 | ||
789 | // Establish initial reference level | |
790 | for(i = 0; i < 40; i++) { | |
791 | ToSendStuffBit(1); | |
792 | } | |
793 | // Send SOF | |
794 | for(i = 0; i < 10; i++) { | |
795 | ToSendStuffBit(0); | |
796 | } | |
797 | ||
798 | for(i = 0; i < len; i++) { | |
799 | // Stop bits/EGT | |
800 | ToSendStuffBit(1); | |
801 | ToSendStuffBit(1); | |
802 | // Start bit | |
803 | ToSendStuffBit(0); | |
804 | // Data bits | |
805 | b = cmd[i]; | |
806 | for(j = 0; j < 8; j++) { | |
807 | if(b & 1) { | |
808 | ToSendStuffBit(1); | |
809 | } else { | |
810 | ToSendStuffBit(0); | |
811 | } | |
812 | b >>= 1; | |
813 | } | |
814 | } | |
815 | // Send EOF | |
816 | ToSendStuffBit(1); | |
817 | for(i = 0; i < 10; i++) { | |
818 | ToSendStuffBit(0); | |
819 | } | |
820 | for(i = 0; i < 8; i++) { | |
821 | ToSendStuffBit(1); | |
822 | } | |
823 | ||
824 | // And then a little more, to make sure that the last character makes | |
825 | // it out before we switch to rx mode. | |
826 | for(i = 0; i < 24; i++) { | |
827 | ToSendStuffBit(1); | |
828 | } | |
829 | ||
830 | // Convert from last character reference to length | |
831 | ToSendMax++; | |
832 | } | |
833 | ||
834 | //----------------------------------------------------------------------------- | |
835 | // Read an ISO 14443 tag. We send it some set of commands, and record the | |
836 | // responses. | |
837 | // The command name is misleading, it actually decodes the reponse in HEX | |
838 | // into the output buffer (read the result using hexsamples, not hisamples) | |
839 | //----------------------------------------------------------------------------- | |
f7e3ed82 | 840 | void AcquireRawAdcSamplesIso14443(uint32_t parameter) |
15c4dc5a | 841 | { |
f7e3ed82 | 842 | uint8_t cmd1[] = { 0x05, 0x00, 0x08, 0x39, 0x73 }; |
15c4dc5a | 843 | |
844 | // Make sure that we start from off, since the tags are stateful; | |
845 | // confusing things will happen if we don't reset them between reads. | |
846 | FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); | |
847 | LED_D_OFF(); | |
848 | SpinDelay(200); | |
849 | ||
850 | SetAdcMuxFor(GPIO_MUXSEL_HIPKD); | |
851 | FpgaSetupSsc(); | |
852 | ||
853 | // Now give it time to spin up. | |
854 | // Signal field is on with the appropriate LED | |
855 | LED_D_ON(); | |
856 | FpgaWriteConfWord( | |
857 | FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ); | |
858 | SpinDelay(200); | |
859 | ||
860 | CodeIso14443bAsReader(cmd1, sizeof(cmd1)); | |
861 | TransmitFor14443(); | |
862 | // LED_A_ON(); | |
863 | GetSamplesFor14443Demod(TRUE, 2000, FALSE); | |
864 | // LED_A_OFF(); | |
865 | } | |
866 | ||
867 | //----------------------------------------------------------------------------- | |
868 | // Read a SRI512 ISO 14443 tag. | |
869 | // | |
870 | // SRI512 tags are just simple memory tags, here we're looking at making a dump | |
871 | // of the contents of the memory. No anticollision algorithm is done, we assume | |
872 | // we have a single tag in the field. | |
873 | // | |
874 | // I tried to be systematic and check every answer of the tag, every CRC, etc... | |
875 | //----------------------------------------------------------------------------- | |
f7e3ed82 | 876 | void ReadSRI512Iso14443(uint32_t parameter) |
15c4dc5a | 877 | { |
878 | ReadSTMemoryIso14443(parameter,0x0F); | |
879 | } | |
f7e3ed82 | 880 | void ReadSRIX4KIso14443(uint32_t parameter) |
15c4dc5a | 881 | { |
882 | ReadSTMemoryIso14443(parameter,0x7F); | |
883 | } | |
884 | ||
f7e3ed82 | 885 | void ReadSTMemoryIso14443(uint32_t parameter,uint32_t dwLast) |
15c4dc5a | 886 | { |
f7e3ed82 | 887 | uint8_t i = 0x00; |
15c4dc5a | 888 | |
889 | // Make sure that we start from off, since the tags are stateful; | |
890 | // confusing things will happen if we don't reset them between reads. | |
891 | LED_D_OFF(); | |
892 | FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); | |
893 | SpinDelay(200); | |
894 | ||
895 | SetAdcMuxFor(GPIO_MUXSEL_HIPKD); | |
896 | FpgaSetupSsc(); | |
897 | ||
898 | // Now give it time to spin up. | |
899 | // Signal field is on with the appropriate LED | |
900 | LED_D_ON(); | |
901 | FpgaWriteConfWord( | |
902 | FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ); | |
903 | SpinDelay(200); | |
904 | ||
905 | // First command: wake up the tag using the INITIATE command | |
f7e3ed82 | 906 | uint8_t cmd1[] = { 0x06, 0x00, 0x97, 0x5b}; |
15c4dc5a | 907 | CodeIso14443bAsReader(cmd1, sizeof(cmd1)); |
908 | TransmitFor14443(); | |
909 | // LED_A_ON(); | |
910 | GetSamplesFor14443Demod(TRUE, 2000,TRUE); | |
911 | // LED_A_OFF(); | |
912 | ||
913 | if (Demod.len == 0) { | |
914 | DbpString("No response from tag"); | |
915 | return; | |
916 | } else { | |
917 | Dbprintf("Randomly generated UID from tag (+ 2 byte CRC): %x %x %x", | |
918 | Demod.output[0], Demod.output[1],Demod.output[2]); | |
919 | } | |
920 | // There is a response, SELECT the uid | |
921 | DbpString("Now SELECT tag:"); | |
922 | cmd1[0] = 0x0E; // 0x0E is SELECT | |
923 | cmd1[1] = Demod.output[0]; | |
924 | ComputeCrc14443(CRC_14443_B, cmd1, 2, &cmd1[2], &cmd1[3]); | |
925 | CodeIso14443bAsReader(cmd1, sizeof(cmd1)); | |
926 | TransmitFor14443(); | |
927 | // LED_A_ON(); | |
928 | GetSamplesFor14443Demod(TRUE, 2000,TRUE); | |
929 | // LED_A_OFF(); | |
930 | if (Demod.len != 3) { | |
931 | Dbprintf("Expected 3 bytes from tag, got %d", Demod.len); | |
932 | return; | |
933 | } | |
934 | // Check the CRC of the answer: | |
935 | ComputeCrc14443(CRC_14443_B, Demod.output, 1 , &cmd1[2], &cmd1[3]); | |
936 | if(cmd1[2] != Demod.output[1] || cmd1[3] != Demod.output[2]) { | |
937 | DbpString("CRC Error reading select response."); | |
938 | return; | |
939 | } | |
940 | // Check response from the tag: should be the same UID as the command we just sent: | |
941 | if (cmd1[1] != Demod.output[0]) { | |
942 | Dbprintf("Bad response to SELECT from Tag, aborting: %x %x", cmd1[1], Demod.output[0]); | |
943 | return; | |
944 | } | |
945 | // Tag is now selected, | |
946 | // First get the tag's UID: | |
947 | cmd1[0] = 0x0B; | |
948 | ComputeCrc14443(CRC_14443_B, cmd1, 1 , &cmd1[1], &cmd1[2]); | |
949 | CodeIso14443bAsReader(cmd1, 3); // Only first three bytes for this one | |
950 | TransmitFor14443(); | |
951 | // LED_A_ON(); | |
952 | GetSamplesFor14443Demod(TRUE, 2000,TRUE); | |
953 | // LED_A_OFF(); | |
954 | if (Demod.len != 10) { | |
955 | Dbprintf("Expected 10 bytes from tag, got %d", Demod.len); | |
956 | return; | |
957 | } | |
958 | // The check the CRC of the answer (use cmd1 as temporary variable): | |
959 | ComputeCrc14443(CRC_14443_B, Demod.output, 8, &cmd1[2], &cmd1[3]); | |
960 | if(cmd1[2] != Demod.output[8] || cmd1[3] != Demod.output[9]) { | |
961 | Dbprintf("CRC Error reading block! - Below: expected, got %x %x", | |
962 | (cmd1[2]<<8)+cmd1[3], (Demod.output[8]<<8)+Demod.output[9]); | |
963 | // Do not return;, let's go on... (we should retry, maybe ?) | |
964 | } | |
965 | Dbprintf("Tag UID (64 bits): %08x %08x", | |
966 | (Demod.output[7]<<24) + (Demod.output[6]<<16) + (Demod.output[5]<<8) + Demod.output[4], | |
967 | (Demod.output[3]<<24) + (Demod.output[2]<<16) + (Demod.output[1]<<8) + Demod.output[0]); | |
968 | ||
969 | // Now loop to read all 16 blocks, address from 0 to 15 | |
970 | DbpString("Tag memory dump, block 0 to 15"); | |
971 | cmd1[0] = 0x08; | |
972 | i = 0x00; | |
973 | dwLast++; | |
974 | for (;;) { | |
975 | if (i == dwLast) { | |
976 | DbpString("System area block (0xff):"); | |
977 | i = 0xff; | |
978 | } | |
979 | cmd1[1] = i; | |
980 | ComputeCrc14443(CRC_14443_B, cmd1, 2, &cmd1[2], &cmd1[3]); | |
981 | CodeIso14443bAsReader(cmd1, sizeof(cmd1)); | |
982 | TransmitFor14443(); | |
983 | // LED_A_ON(); | |
984 | GetSamplesFor14443Demod(TRUE, 2000,TRUE); | |
985 | // LED_A_OFF(); | |
986 | if (Demod.len != 6) { // Check if we got an answer from the tag | |
987 | DbpString("Expected 6 bytes from tag, got less..."); | |
988 | return; | |
989 | } | |
990 | // The check the CRC of the answer (use cmd1 as temporary variable): | |
991 | ComputeCrc14443(CRC_14443_B, Demod.output, 4, &cmd1[2], &cmd1[3]); | |
992 | if(cmd1[2] != Demod.output[4] || cmd1[3] != Demod.output[5]) { | |
993 | Dbprintf("CRC Error reading block! - Below: expected, got %x %x", | |
994 | (cmd1[2]<<8)+cmd1[3], (Demod.output[4]<<8)+Demod.output[5]); | |
995 | // Do not return;, let's go on... (we should retry, maybe ?) | |
996 | } | |
997 | // Now print out the memory location: | |
998 | Dbprintf("Address=%x, Contents=%x, CRC=%x", i, | |
999 | (Demod.output[3]<<24) + (Demod.output[2]<<16) + (Demod.output[1]<<8) + Demod.output[0], | |
1000 | (Demod.output[4]<<8)+Demod.output[5]); | |
1001 | if (i == 0xff) { | |
1002 | break; | |
1003 | } | |
1004 | i++; | |
1005 | } | |
1006 | } | |
1007 | ||
1008 | ||
1009 | //============================================================================= | |
1010 | // Finally, the `sniffer' combines elements from both the reader and | |
1011 | // simulated tag, to show both sides of the conversation. | |
1012 | //============================================================================= | |
1013 | ||
1014 | //----------------------------------------------------------------------------- | |
1015 | // Record the sequence of commands sent by the reader to the tag, with | |
1016 | // triggering so that we start recording at the point that the tag is moved | |
1017 | // near the reader. | |
1018 | //----------------------------------------------------------------------------- | |
1019 | /* | |
1020 | * Memory usage for this function, (within BigBuf) | |
1021 | * 0-4095 : Demodulated samples receive (4096 bytes) - DEMOD_TRACE_SIZE | |
1022 | * 4096-6143 : Last Received command, 2048 bytes (reader->tag) - READER_TAG_BUFFER_SIZE | |
1023 | * 6144-8191 : Last Received command, 2048 bytes(tag->reader) - TAG_READER_BUFFER_SIZE | |
1024 | * 8192-9215 : DMA Buffer, 1024 bytes (samples) - DMA_BUFFER_SIZE | |
1025 | */ | |
1026 | void SnoopIso14443(void) | |
1027 | { | |
1028 | // We won't start recording the frames that we acquire until we trigger; | |
1029 | // a good trigger condition to get started is probably when we see a | |
1030 | // response from the tag. | |
f7e3ed82 | 1031 | int triggered = FALSE; |
15c4dc5a | 1032 | |
1033 | // The command (reader -> tag) that we're working on receiving. | |
f7e3ed82 | 1034 | uint8_t *receivedCmd = (uint8_t *)(BigBuf) + DEMOD_TRACE_SIZE; |
15c4dc5a | 1035 | // The response (tag -> reader) that we're working on receiving. |
f7e3ed82 | 1036 | uint8_t *receivedResponse = (uint8_t *)(BigBuf) + DEMOD_TRACE_SIZE + READER_TAG_BUFFER_SIZE; |
15c4dc5a | 1037 | |
1038 | // As we receive stuff, we copy it from receivedCmd or receivedResponse | |
1039 | // into trace, along with its length and other annotations. | |
f7e3ed82 | 1040 | uint8_t *trace = (uint8_t *)BigBuf; |
15c4dc5a | 1041 | int traceLen = 0; |
1042 | ||
1043 | // The DMA buffer, used to stream samples from the FPGA. | |
f7e3ed82 | 1044 | int8_t *dmaBuf = (int8_t *)(BigBuf) + DEMOD_TRACE_SIZE + READER_TAG_BUFFER_SIZE + TAG_READER_BUFFER_SIZE; |
15c4dc5a | 1045 | int lastRxCounter; |
f7e3ed82 | 1046 | int8_t *upTo; |
15c4dc5a | 1047 | int ci, cq; |
1048 | int maxBehindBy = 0; | |
1049 | ||
1050 | // Count of samples received so far, so that we can include timing | |
1051 | // information in the trace buffer. | |
1052 | int samples = 0; | |
1053 | ||
1054 | // Initialize the trace buffer | |
1055 | memset(trace, 0x44, DEMOD_TRACE_SIZE); | |
1056 | ||
1057 | // Set up the demodulator for tag -> reader responses. | |
1058 | Demod.output = receivedResponse; | |
1059 | Demod.len = 0; | |
1060 | Demod.state = DEMOD_UNSYNCD; | |
1061 | ||
1062 | // And the reader -> tag commands | |
1063 | memset(&Uart, 0, sizeof(Uart)); | |
1064 | Uart.output = receivedCmd; | |
1065 | Uart.byteCntMax = 100; | |
1066 | Uart.state = STATE_UNSYNCD; | |
1067 | ||
1068 | // Print some debug information about the buffer sizes | |
1069 | Dbprintf("Snooping buffers initialized:"); | |
1070 | Dbprintf(" Trace: %i bytes", DEMOD_TRACE_SIZE); | |
1071 | Dbprintf(" Reader -> tag: %i bytes", READER_TAG_BUFFER_SIZE); | |
1072 | Dbprintf(" tag -> Reader: %i bytes", TAG_READER_BUFFER_SIZE); | |
1073 | Dbprintf(" DMA: %i bytes", DMA_BUFFER_SIZE); | |
e30c654b | 1074 | |
15c4dc5a | 1075 | // Use a counter for blinking the LED |
1076 | long ledCount=0; | |
1077 | long ledFlashAt=200000; | |
e30c654b | 1078 | |
15c4dc5a | 1079 | // And put the FPGA in the appropriate mode |
1080 | // Signal field is off with the appropriate LED | |
1081 | LED_D_OFF(); | |
1082 | FpgaWriteConfWord( | |
1083 | FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ | | |
1084 | FPGA_HF_READER_RX_XCORR_SNOOP); | |
1085 | SetAdcMuxFor(GPIO_MUXSEL_HIPKD); | |
1086 | ||
1087 | // Setup for the DMA. | |
1088 | FpgaSetupSsc(); | |
1089 | upTo = dmaBuf; | |
1090 | lastRxCounter = DMA_BUFFER_SIZE; | |
f7e3ed82 | 1091 | FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); |
15c4dc5a | 1092 | // And now we loop, receiving samples. |
1093 | for(;;) { | |
1094 | // Blink the LED while Snooping | |
1095 | ledCount++; | |
1096 | if (ledCount == ledFlashAt) { | |
1097 | LED_D_ON(); | |
1098 | } | |
1099 | if (ledCount >= 2*ledFlashAt) { | |
1100 | LED_D_OFF(); | |
1101 | ledCount=0; | |
1102 | } | |
e30c654b | 1103 | |
15c4dc5a | 1104 | int behindBy = (lastRxCounter - AT91C_BASE_PDC_SSC->PDC_RCR) & |
1105 | (DMA_BUFFER_SIZE-1); | |
1106 | if(behindBy > maxBehindBy) { | |
1107 | maxBehindBy = behindBy; | |
1108 | if(behindBy > (DMA_BUFFER_SIZE-2)) { // TODO: understand whether we can increase/decrease as we want or not? | |
1109 | Dbprintf("blew circular buffer! behindBy=%x", behindBy); | |
1110 | goto done; | |
1111 | } | |
1112 | } | |
1113 | if(behindBy < 2) continue; | |
1114 | ||
1115 | ci = upTo[0]; | |
1116 | cq = upTo[1]; | |
1117 | upTo += 2; | |
1118 | lastRxCounter -= 2; | |
1119 | if(upTo - dmaBuf > DMA_BUFFER_SIZE) { | |
1120 | upTo -= DMA_BUFFER_SIZE; | |
1121 | lastRxCounter += DMA_BUFFER_SIZE; | |
f7e3ed82 | 1122 | AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) upTo; |
15c4dc5a | 1123 | AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE; |
1124 | } | |
1125 | ||
1126 | samples += 2; | |
1127 | ||
1128 | #define HANDLE_BIT_IF_BODY \ | |
1129 | if(triggered) { \ | |
1130 | ledFlashAt=30000; \ | |
1131 | trace[traceLen++] = ((samples >> 0) & 0xff); \ | |
1132 | trace[traceLen++] = ((samples >> 8) & 0xff); \ | |
1133 | trace[traceLen++] = ((samples >> 16) & 0xff); \ | |
1134 | trace[traceLen++] = ((samples >> 24) & 0xff); \ | |
1135 | trace[traceLen++] = 0; \ | |
1136 | trace[traceLen++] = 0; \ | |
1137 | trace[traceLen++] = 0; \ | |
1138 | trace[traceLen++] = 0; \ | |
1139 | trace[traceLen++] = Uart.byteCnt; \ | |
1140 | memcpy(trace+traceLen, receivedCmd, Uart.byteCnt); \ | |
1141 | traceLen += Uart.byteCnt; \ | |
1142 | if(traceLen > 1000) break; \ | |
1143 | } \ | |
1144 | /* And ready to receive another command. */ \ | |
1145 | memset(&Uart, 0, sizeof(Uart)); \ | |
1146 | Uart.output = receivedCmd; \ | |
1147 | Uart.byteCntMax = 100; \ | |
1148 | Uart.state = STATE_UNSYNCD; \ | |
1149 | /* And also reset the demod code, which might have been */ \ | |
1150 | /* false-triggered by the commands from the reader. */ \ | |
1151 | memset(&Demod, 0, sizeof(Demod)); \ | |
1152 | Demod.output = receivedResponse; \ | |
1153 | Demod.state = DEMOD_UNSYNCD; \ | |
1154 | ||
1155 | if(Handle14443UartBit(ci & 1)) { | |
1156 | HANDLE_BIT_IF_BODY | |
1157 | } | |
1158 | if(Handle14443UartBit(cq & 1)) { | |
1159 | HANDLE_BIT_IF_BODY | |
1160 | } | |
1161 | ||
1162 | if(Handle14443SamplesDemod(ci, cq)) { | |
1163 | // timestamp, as a count of samples | |
1164 | trace[traceLen++] = ((samples >> 0) & 0xff); | |
1165 | trace[traceLen++] = ((samples >> 8) & 0xff); | |
1166 | trace[traceLen++] = ((samples >> 16) & 0xff); | |
1167 | trace[traceLen++] = 0x80 | ((samples >> 24) & 0xff); | |
1168 | // correlation metric (~signal strength estimate) | |
1169 | if(Demod.metricN != 0) { | |
1170 | Demod.metric /= Demod.metricN; | |
1171 | } | |
1172 | trace[traceLen++] = ((Demod.metric >> 0) & 0xff); | |
1173 | trace[traceLen++] = ((Demod.metric >> 8) & 0xff); | |
1174 | trace[traceLen++] = ((Demod.metric >> 16) & 0xff); | |
1175 | trace[traceLen++] = ((Demod.metric >> 24) & 0xff); | |
1176 | // length | |
1177 | trace[traceLen++] = Demod.len; | |
1178 | memcpy(trace+traceLen, receivedResponse, Demod.len); | |
1179 | traceLen += Demod.len; | |
e30c654b | 1180 | if(traceLen > DEMOD_TRACE_SIZE) { |
15c4dc5a | 1181 | DbpString("Reached trace limit"); |
1182 | goto done; | |
1183 | } | |
1184 | ||
1185 | triggered = TRUE; | |
1186 | ||
1187 | // And ready to receive another response. | |
1188 | memset(&Demod, 0, sizeof(Demod)); | |
1189 | Demod.output = receivedResponse; | |
1190 | Demod.state = DEMOD_UNSYNCD; | |
1191 | } | |
1192 | WDT_HIT(); | |
1193 | ||
1194 | if(BUTTON_PRESS()) { | |
1195 | DbpString("cancelled"); | |
1196 | goto done; | |
1197 | } | |
1198 | } | |
1199 | ||
1200 | done: | |
1201 | LED_D_OFF(); | |
1202 | AT91C_BASE_PDC_SSC->PDC_PTCR = AT91C_PDC_RXTDIS; | |
1203 | DbpString("Snoop statistics:"); | |
1204 | Dbprintf(" Max behind by: %i", maxBehindBy); | |
1205 | Dbprintf(" Uart State: %x", Uart.state); | |
1206 | Dbprintf(" Uart ByteCnt: %i", Uart.byteCnt); | |
1207 | Dbprintf(" Uart ByteCntMax: %i", Uart.byteCntMax); | |
1208 | Dbprintf(" Trace length: %i", traceLen); | |
1209 | } |