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15c4dc5a | 1 | //----------------------------------------------------------------------------- |
bd20f8f4 | 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 | //----------------------------------------------------------------------------- | |
15c4dc5a | 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. | |
15c4dc5a | 11 | //----------------------------------------------------------------------------- |
bd20f8f4 | 12 | |
e30c654b | 13 | #include "proxmark3.h" |
15c4dc5a | 14 | #include "apps.h" |
f7e3ed82 | 15 | #include "util.h" |
9ab7a6c7 | 16 | #include "string.h" |
15c4dc5a | 17 | |
f7e3ed82 | 18 | #include "iso14443crc.h" |
15c4dc5a | 19 | |
f7e3ed82 | 20 | //static void GetSamplesFor14443(int weTx, int n); |
15c4dc5a | 21 | |
22 | #define DEMOD_TRACE_SIZE 4096 | |
23 | #define READER_TAG_BUFFER_SIZE 2048 | |
24 | #define TAG_READER_BUFFER_SIZE 2048 | |
81cd0474 | 25 | #define DEMOD_DMA_BUFFER_SIZE 1024 |
15c4dc5a | 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 | //----------------------------------------------------------------------------- | |
f7e3ed82 | 40 | static void CodeIso14443bAsTag(const uint8_t *cmd, int len) |
15c4dc5a | 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; | |
f7e3ed82 | 73 | uint8_t b = cmd[i]; |
15c4dc5a | 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; | |
f7e3ed82 | 137 | uint16_t shiftReg; |
15c4dc5a | 138 | int bitCnt; |
139 | int byteCnt; | |
140 | int byteCntMax; | |
141 | int posCnt; | |
f7e3ed82 | 142 | uint8_t *output; |
15c4dc5a | 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 | */ | |
f7e3ed82 | 154 | static int Handle14443UartBit(int bit) |
15c4dc5a | 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 | if (Uart.state == STATE_ERROR_WAIT) LED_A_OFF(); // Error | |
273 | ||
274 | return FALSE; | |
275 | } | |
276 | ||
277 | //----------------------------------------------------------------------------- | |
278 | // Receive a command (from the reader to us, where we are the simulated tag), | |
279 | // and store it in the given buffer, up to the given maximum length. Keeps | |
280 | // spinning, waiting for a well-framed command, until either we get one | |
281 | // (returns TRUE) or someone presses the pushbutton on the board (FALSE). | |
282 | // | |
283 | // Assume that we're called with the SSC (to the FPGA) and ADC path set | |
284 | // correctly. | |
285 | //----------------------------------------------------------------------------- | |
f7e3ed82 | 286 | static int GetIso14443CommandFromReader(uint8_t *received, int *len, int maxLen) |
15c4dc5a | 287 | { |
f7e3ed82 | 288 | uint8_t mask; |
15c4dc5a | 289 | int i, bit; |
290 | ||
291 | // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen | |
292 | // only, since we are receiving, not transmitting). | |
293 | // Signal field is off with the appropriate LED | |
294 | LED_D_OFF(); | |
295 | FpgaWriteConfWord( | |
296 | FPGA_MAJOR_MODE_HF_SIMULATOR | FPGA_HF_SIMULATOR_NO_MODULATION); | |
297 | ||
298 | ||
299 | // Now run a `software UART' on the stream of incoming samples. | |
300 | Uart.output = received; | |
301 | Uart.byteCntMax = maxLen; | |
302 | Uart.state = STATE_UNSYNCD; | |
303 | ||
304 | for(;;) { | |
305 | WDT_HIT(); | |
306 | ||
307 | if(BUTTON_PRESS()) return FALSE; | |
308 | ||
309 | if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { | |
310 | AT91C_BASE_SSC->SSC_THR = 0x00; | |
311 | } | |
312 | if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { | |
f7e3ed82 | 313 | uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR; |
15c4dc5a | 314 | |
315 | mask = 0x80; | |
316 | for(i = 0; i < 8; i++, mask >>= 1) { | |
317 | bit = (b & mask); | |
318 | if(Handle14443UartBit(bit)) { | |
319 | *len = Uart.byteCnt; | |
320 | return TRUE; | |
321 | } | |
322 | } | |
323 | } | |
324 | } | |
325 | } | |
326 | ||
327 | //----------------------------------------------------------------------------- | |
328 | // Main loop of simulated tag: receive commands from reader, decide what | |
329 | // response to send, and send it. | |
330 | //----------------------------------------------------------------------------- | |
331 | void SimulateIso14443Tag(void) | |
332 | { | |
f7e3ed82 | 333 | static const uint8_t cmd1[] = { 0x05, 0x00, 0x08, 0x39, 0x73 }; |
334 | static const uint8_t response1[] = { | |
15c4dc5a | 335 | 0x50, 0x82, 0x0d, 0xe1, 0x74, 0x20, 0x38, 0x19, 0x22, |
336 | 0x00, 0x21, 0x85, 0x5e, 0xd7 | |
337 | }; | |
338 | ||
f7e3ed82 | 339 | uint8_t *resp; |
15c4dc5a | 340 | int respLen; |
341 | ||
f7e3ed82 | 342 | uint8_t *resp1 = (((uint8_t *)BigBuf) + 800); |
15c4dc5a | 343 | int resp1Len; |
344 | ||
f7e3ed82 | 345 | uint8_t *receivedCmd = (uint8_t *)BigBuf; |
15c4dc5a | 346 | int len; |
347 | ||
348 | int i; | |
349 | ||
350 | int cmdsRecvd = 0; | |
351 | ||
352 | memset(receivedCmd, 0x44, 400); | |
353 | ||
354 | CodeIso14443bAsTag(response1, sizeof(response1)); | |
355 | memcpy(resp1, ToSend, ToSendMax); resp1Len = ToSendMax; | |
356 | ||
357 | // We need to listen to the high-frequency, peak-detected path. | |
358 | SetAdcMuxFor(GPIO_MUXSEL_HIPKD); | |
359 | FpgaSetupSsc(); | |
360 | ||
361 | cmdsRecvd = 0; | |
362 | ||
363 | for(;;) { | |
f7e3ed82 | 364 | uint8_t b1, b2; |
15c4dc5a | 365 | |
366 | if(!GetIso14443CommandFromReader(receivedCmd, &len, 100)) { | |
367 | Dbprintf("button pressed, received %d commands", cmdsRecvd); | |
368 | break; | |
369 | } | |
370 | ||
371 | // Good, look at the command now. | |
372 | ||
373 | if(len == sizeof(cmd1) && memcmp(receivedCmd, cmd1, len)==0) { | |
374 | resp = resp1; respLen = resp1Len; | |
375 | } else { | |
376 | Dbprintf("new cmd from reader: len=%d, cmdsRecvd=%d", len, cmdsRecvd); | |
377 | // And print whether the CRC fails, just for good measure | |
378 | ComputeCrc14443(CRC_14443_B, receivedCmd, len-2, &b1, &b2); | |
379 | if(b1 != receivedCmd[len-2] || b2 != receivedCmd[len-1]) { | |
380 | // Not so good, try again. | |
381 | DbpString("+++CRC fail"); | |
382 | } else { | |
383 | DbpString("CRC passes"); | |
384 | } | |
385 | break; | |
386 | } | |
387 | ||
388 | memset(receivedCmd, 0x44, 32); | |
389 | ||
390 | cmdsRecvd++; | |
391 | ||
392 | if(cmdsRecvd > 0x30) { | |
393 | DbpString("many commands later..."); | |
394 | break; | |
395 | } | |
396 | ||
397 | if(respLen <= 0) continue; | |
398 | ||
399 | // Modulate BPSK | |
400 | // Signal field is off with the appropriate LED | |
401 | LED_D_OFF(); | |
402 | FpgaWriteConfWord( | |
403 | FPGA_MAJOR_MODE_HF_SIMULATOR | FPGA_HF_SIMULATOR_MODULATE_BPSK); | |
404 | AT91C_BASE_SSC->SSC_THR = 0xff; | |
405 | FpgaSetupSsc(); | |
406 | ||
407 | // Transmit the response. | |
408 | i = 0; | |
409 | for(;;) { | |
410 | if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { | |
f7e3ed82 | 411 | uint8_t b = resp[i]; |
15c4dc5a | 412 | |
413 | AT91C_BASE_SSC->SSC_THR = b; | |
414 | ||
415 | i++; | |
416 | if(i > respLen) { | |
417 | break; | |
418 | } | |
419 | } | |
420 | if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { | |
f7e3ed82 | 421 | volatile uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR; |
15c4dc5a | 422 | (void)b; |
423 | } | |
424 | } | |
425 | } | |
426 | } | |
427 | ||
428 | //============================================================================= | |
429 | // An ISO 14443 Type B reader. We take layer two commands, code them | |
430 | // appropriately, and then send them to the tag. We then listen for the | |
431 | // tag's response, which we leave in the buffer to be demodulated on the | |
432 | // PC side. | |
433 | //============================================================================= | |
434 | ||
435 | static struct { | |
436 | enum { | |
437 | DEMOD_UNSYNCD, | |
438 | DEMOD_PHASE_REF_TRAINING, | |
439 | DEMOD_AWAITING_FALLING_EDGE_OF_SOF, | |
440 | DEMOD_GOT_FALLING_EDGE_OF_SOF, | |
441 | DEMOD_AWAITING_START_BIT, | |
442 | DEMOD_RECEIVING_DATA, | |
443 | DEMOD_ERROR_WAIT | |
444 | } state; | |
445 | int bitCount; | |
446 | int posCount; | |
447 | int thisBit; | |
448 | int metric; | |
449 | int metricN; | |
f7e3ed82 | 450 | uint16_t shiftReg; |
451 | uint8_t *output; | |
15c4dc5a | 452 | int len; |
453 | int sumI; | |
454 | int sumQ; | |
455 | } Demod; | |
456 | ||
457 | /* | |
458 | * Handles reception of a bit from the tag | |
459 | * | |
460 | * LED handling: | |
461 | * LED C -> ON once we have received the SOF and are expecting the rest. | |
462 | * LED C -> OFF once we have received EOF or are unsynced | |
463 | * | |
464 | * Returns: true if we received a EOF | |
465 | * false if we are still waiting for some more | |
466 | * | |
467 | */ | |
0f7f9edc | 468 | static RAMFUNC int Handle14443SamplesDemod(int ci, int cq) |
15c4dc5a | 469 | { |
470 | int v; | |
471 | ||
472 | // The soft decision on the bit uses an estimate of just the | |
473 | // quadrant of the reference angle, not the exact angle. | |
474 | #define MAKE_SOFT_DECISION() { \ | |
475 | if(Demod.sumI > 0) { \ | |
476 | v = ci; \ | |
477 | } else { \ | |
478 | v = -ci; \ | |
479 | } \ | |
480 | if(Demod.sumQ > 0) { \ | |
481 | v += cq; \ | |
482 | } else { \ | |
483 | v -= cq; \ | |
484 | } \ | |
485 | } | |
486 | ||
487 | switch(Demod.state) { | |
488 | case DEMOD_UNSYNCD: | |
489 | v = ci; | |
490 | if(v < 0) v = -v; | |
491 | if(cq > 0) { | |
492 | v += cq; | |
493 | } else { | |
494 | v -= cq; | |
495 | } | |
496 | if(v > 40) { | |
497 | Demod.posCount = 0; | |
498 | Demod.state = DEMOD_PHASE_REF_TRAINING; | |
499 | Demod.sumI = 0; | |
500 | Demod.sumQ = 0; | |
501 | } | |
502 | break; | |
503 | ||
504 | case DEMOD_PHASE_REF_TRAINING: | |
505 | if(Demod.posCount < 8) { | |
506 | Demod.sumI += ci; | |
507 | Demod.sumQ += cq; | |
508 | } else if(Demod.posCount > 100) { | |
509 | // error, waited too long | |
510 | Demod.state = DEMOD_UNSYNCD; | |
511 | } else { | |
512 | MAKE_SOFT_DECISION(); | |
513 | if(v < 0) { | |
514 | Demod.state = DEMOD_AWAITING_FALLING_EDGE_OF_SOF; | |
515 | Demod.posCount = 0; | |
516 | } | |
517 | } | |
518 | Demod.posCount++; | |
519 | break; | |
520 | ||
521 | case DEMOD_AWAITING_FALLING_EDGE_OF_SOF: | |
522 | MAKE_SOFT_DECISION(); | |
523 | if(v < 0) { | |
524 | Demod.state = DEMOD_GOT_FALLING_EDGE_OF_SOF; | |
525 | Demod.posCount = 0; | |
526 | } else { | |
527 | if(Demod.posCount > 100) { | |
528 | Demod.state = DEMOD_UNSYNCD; | |
529 | } | |
530 | } | |
531 | Demod.posCount++; | |
532 | break; | |
533 | ||
534 | case DEMOD_GOT_FALLING_EDGE_OF_SOF: | |
535 | MAKE_SOFT_DECISION(); | |
536 | if(v > 0) { | |
537 | if(Demod.posCount < 12) { | |
538 | Demod.state = DEMOD_UNSYNCD; | |
539 | } else { | |
540 | LED_C_ON(); // Got SOF | |
541 | Demod.state = DEMOD_AWAITING_START_BIT; | |
542 | Demod.posCount = 0; | |
543 | Demod.len = 0; | |
544 | Demod.metricN = 0; | |
545 | Demod.metric = 0; | |
546 | } | |
547 | } else { | |
548 | if(Demod.posCount > 100) { | |
549 | Demod.state = DEMOD_UNSYNCD; | |
550 | } | |
551 | } | |
552 | Demod.posCount++; | |
553 | break; | |
554 | ||
555 | case DEMOD_AWAITING_START_BIT: | |
556 | MAKE_SOFT_DECISION(); | |
557 | if(v > 0) { | |
558 | if(Demod.posCount > 10) { | |
559 | Demod.state = DEMOD_UNSYNCD; | |
560 | } | |
561 | } else { | |
562 | Demod.bitCount = 0; | |
563 | Demod.posCount = 1; | |
564 | Demod.thisBit = v; | |
565 | Demod.shiftReg = 0; | |
566 | Demod.state = DEMOD_RECEIVING_DATA; | |
567 | } | |
568 | break; | |
569 | ||
570 | case DEMOD_RECEIVING_DATA: | |
571 | MAKE_SOFT_DECISION(); | |
572 | if(Demod.posCount == 0) { | |
573 | Demod.thisBit = v; | |
574 | Demod.posCount = 1; | |
575 | } else { | |
576 | Demod.thisBit += v; | |
577 | ||
578 | if(Demod.thisBit > 0) { | |
579 | Demod.metric += Demod.thisBit; | |
580 | } else { | |
581 | Demod.metric -= Demod.thisBit; | |
582 | } | |
583 | (Demod.metricN)++; | |
584 | ||
585 | Demod.shiftReg >>= 1; | |
586 | if(Demod.thisBit > 0) { | |
587 | Demod.shiftReg |= 0x200; | |
588 | } | |
589 | ||
590 | Demod.bitCount++; | |
591 | if(Demod.bitCount == 10) { | |
f7e3ed82 | 592 | uint16_t s = Demod.shiftReg; |
15c4dc5a | 593 | if((s & 0x200) && !(s & 0x001)) { |
f7e3ed82 | 594 | uint8_t b = (s >> 1); |
15c4dc5a | 595 | Demod.output[Demod.len] = b; |
596 | Demod.len++; | |
597 | Demod.state = DEMOD_AWAITING_START_BIT; | |
598 | } else if(s == 0x000) { | |
599 | // This is EOF | |
600 | LED_C_OFF(); | |
601 | return TRUE; | |
602 | Demod.state = DEMOD_UNSYNCD; | |
603 | } else { | |
604 | Demod.state = DEMOD_UNSYNCD; | |
605 | } | |
606 | } | |
607 | Demod.posCount = 0; | |
608 | } | |
609 | break; | |
610 | ||
611 | default: | |
612 | Demod.state = DEMOD_UNSYNCD; | |
613 | break; | |
614 | } | |
615 | ||
616 | if (Demod.state == DEMOD_UNSYNCD) LED_C_OFF(); // Not synchronized... | |
617 | return FALSE; | |
618 | } | |
619 | ||
620 | /* | |
621 | * Demodulate the samples we received from the tag | |
622 | * weTx: set to 'TRUE' if we behave like a reader | |
623 | * set to 'FALSE' if we behave like a snooper | |
624 | * quiet: set to 'TRUE' to disable debug output | |
625 | */ | |
f7e3ed82 | 626 | static void GetSamplesFor14443Demod(int weTx, int n, int quiet) |
15c4dc5a | 627 | { |
628 | int max = 0; | |
f7e3ed82 | 629 | int gotFrame = FALSE; |
15c4dc5a | 630 | |
631 | //# define DMA_BUFFER_SIZE 8 | |
f7e3ed82 | 632 | int8_t *dmaBuf; |
15c4dc5a | 633 | |
634 | int lastRxCounter; | |
f7e3ed82 | 635 | int8_t *upTo; |
15c4dc5a | 636 | |
637 | int ci, cq; | |
638 | ||
639 | int samples = 0; | |
640 | ||
641 | // Clear out the state of the "UART" that receives from the tag. | |
642 | memset(BigBuf, 0x44, 400); | |
f7e3ed82 | 643 | Demod.output = (uint8_t *)BigBuf; |
15c4dc5a | 644 | Demod.len = 0; |
645 | Demod.state = DEMOD_UNSYNCD; | |
646 | ||
647 | // And the UART that receives from the reader | |
f7e3ed82 | 648 | Uart.output = (((uint8_t *)BigBuf) + 1024); |
15c4dc5a | 649 | Uart.byteCntMax = 100; |
650 | Uart.state = STATE_UNSYNCD; | |
651 | ||
652 | // Setup for the DMA. | |
f7e3ed82 | 653 | dmaBuf = (int8_t *)(BigBuf + 32); |
15c4dc5a | 654 | upTo = dmaBuf; |
81cd0474 | 655 | lastRxCounter = DEMOD_DMA_BUFFER_SIZE; |
656 | FpgaSetupSscDma((uint8_t *)dmaBuf, DEMOD_DMA_BUFFER_SIZE); | |
15c4dc5a | 657 | |
658 | // Signal field is ON with the appropriate LED: | |
659 | if (weTx) LED_D_ON(); else LED_D_OFF(); | |
660 | // And put the FPGA in the appropriate mode | |
661 | FpgaWriteConfWord( | |
662 | FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ | | |
663 | (weTx ? 0 : FPGA_HF_READER_RX_XCORR_SNOOP)); | |
664 | ||
665 | for(;;) { | |
666 | int behindBy = lastRxCounter - AT91C_BASE_PDC_SSC->PDC_RCR; | |
667 | if(behindBy > max) max = behindBy; | |
668 | ||
81cd0474 | 669 | while(((lastRxCounter-AT91C_BASE_PDC_SSC->PDC_RCR) & (DEMOD_DMA_BUFFER_SIZE-1)) |
15c4dc5a | 670 | > 2) |
671 | { | |
672 | ci = upTo[0]; | |
673 | cq = upTo[1]; | |
674 | upTo += 2; | |
81cd0474 | 675 | if(upTo - dmaBuf > DEMOD_DMA_BUFFER_SIZE) { |
676 | upTo -= DEMOD_DMA_BUFFER_SIZE; | |
f7e3ed82 | 677 | AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) upTo; |
81cd0474 | 678 | AT91C_BASE_PDC_SSC->PDC_RNCR = DEMOD_DMA_BUFFER_SIZE; |
15c4dc5a | 679 | } |
680 | lastRxCounter -= 2; | |
681 | if(lastRxCounter <= 0) { | |
81cd0474 | 682 | lastRxCounter += DEMOD_DMA_BUFFER_SIZE; |
15c4dc5a | 683 | } |
684 | ||
685 | samples += 2; | |
686 | ||
687 | Handle14443UartBit(1); | |
688 | Handle14443UartBit(1); | |
689 | ||
690 | if(Handle14443SamplesDemod(ci, cq)) { | |
691 | gotFrame = 1; | |
692 | } | |
693 | } | |
694 | ||
695 | if(samples > 2000) { | |
696 | break; | |
697 | } | |
698 | } | |
699 | AT91C_BASE_PDC_SSC->PDC_PTCR = AT91C_PDC_RXTDIS; | |
700 | if (!quiet) Dbprintf("%x %x %x", max, gotFrame, Demod.len); | |
701 | } | |
702 | ||
703 | //----------------------------------------------------------------------------- | |
704 | // Read the tag's response. We just receive a stream of slightly-processed | |
705 | // samples from the FPGA, which we will later do some signal processing on, | |
706 | // to get the bits. | |
707 | //----------------------------------------------------------------------------- | |
f7e3ed82 | 708 | /*static void GetSamplesFor14443(int weTx, int n) |
15c4dc5a | 709 | { |
f7e3ed82 | 710 | uint8_t *dest = (uint8_t *)BigBuf; |
15c4dc5a | 711 | int c; |
712 | ||
713 | FpgaWriteConfWord( | |
714 | FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ | | |
715 | (weTx ? 0 : FPGA_HF_READER_RX_XCORR_SNOOP)); | |
716 | ||
717 | c = 0; | |
718 | for(;;) { | |
719 | if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { | |
720 | AT91C_BASE_SSC->SSC_THR = 0x43; | |
721 | } | |
722 | if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { | |
f7e3ed82 | 723 | int8_t b; |
724 | b = (int8_t)AT91C_BASE_SSC->SSC_RHR; | |
15c4dc5a | 725 | |
f7e3ed82 | 726 | dest[c++] = (uint8_t)b; |
15c4dc5a | 727 | |
728 | if(c >= n) { | |
729 | break; | |
730 | } | |
731 | } | |
732 | } | |
733 | }*/ | |
734 | ||
735 | //----------------------------------------------------------------------------- | |
736 | // Transmit the command (to the tag) that was placed in ToSend[]. | |
737 | //----------------------------------------------------------------------------- | |
738 | static void TransmitFor14443(void) | |
739 | { | |
740 | int c; | |
741 | ||
742 | FpgaSetupSsc(); | |
743 | ||
744 | while(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { | |
745 | AT91C_BASE_SSC->SSC_THR = 0xff; | |
746 | } | |
747 | ||
748 | // Signal field is ON with the appropriate Red LED | |
749 | LED_D_ON(); | |
750 | // Signal we are transmitting with the Green LED | |
751 | LED_B_ON(); | |
752 | FpgaWriteConfWord( | |
753 | FPGA_MAJOR_MODE_HF_READER_TX | FPGA_HF_READER_TX_SHALLOW_MOD); | |
754 | ||
755 | for(c = 0; c < 10;) { | |
756 | if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { | |
757 | AT91C_BASE_SSC->SSC_THR = 0xff; | |
758 | c++; | |
759 | } | |
760 | if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { | |
f7e3ed82 | 761 | volatile uint32_t r = AT91C_BASE_SSC->SSC_RHR; |
15c4dc5a | 762 | (void)r; |
763 | } | |
764 | WDT_HIT(); | |
765 | } | |
766 | ||
767 | c = 0; | |
768 | for(;;) { | |
769 | if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { | |
770 | AT91C_BASE_SSC->SSC_THR = ToSend[c]; | |
771 | c++; | |
772 | if(c >= ToSendMax) { | |
773 | break; | |
774 | } | |
775 | } | |
776 | if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { | |
f7e3ed82 | 777 | volatile uint32_t r = AT91C_BASE_SSC->SSC_RHR; |
15c4dc5a | 778 | (void)r; |
779 | } | |
780 | WDT_HIT(); | |
781 | } | |
782 | LED_B_OFF(); // Finished sending | |
783 | } | |
784 | ||
785 | //----------------------------------------------------------------------------- | |
786 | // Code a layer 2 command (string of octets, including CRC) into ToSend[], | |
787 | // so that it is ready to transmit to the tag using TransmitFor14443(). | |
788 | //----------------------------------------------------------------------------- | |
f7e3ed82 | 789 | void CodeIso14443bAsReader(const uint8_t *cmd, int len) |
15c4dc5a | 790 | { |
791 | int i, j; | |
f7e3ed82 | 792 | uint8_t b; |
15c4dc5a | 793 | |
794 | ToSendReset(); | |
795 | ||
796 | // Establish initial reference level | |
797 | for(i = 0; i < 40; i++) { | |
798 | ToSendStuffBit(1); | |
799 | } | |
800 | // Send SOF | |
801 | for(i = 0; i < 10; i++) { | |
802 | ToSendStuffBit(0); | |
803 | } | |
804 | ||
805 | for(i = 0; i < len; i++) { | |
806 | // Stop bits/EGT | |
807 | ToSendStuffBit(1); | |
808 | ToSendStuffBit(1); | |
809 | // Start bit | |
810 | ToSendStuffBit(0); | |
811 | // Data bits | |
812 | b = cmd[i]; | |
813 | for(j = 0; j < 8; j++) { | |
814 | if(b & 1) { | |
815 | ToSendStuffBit(1); | |
816 | } else { | |
817 | ToSendStuffBit(0); | |
818 | } | |
819 | b >>= 1; | |
820 | } | |
821 | } | |
822 | // Send EOF | |
823 | ToSendStuffBit(1); | |
824 | for(i = 0; i < 10; i++) { | |
825 | ToSendStuffBit(0); | |
826 | } | |
827 | for(i = 0; i < 8; i++) { | |
828 | ToSendStuffBit(1); | |
829 | } | |
830 | ||
831 | // And then a little more, to make sure that the last character makes | |
832 | // it out before we switch to rx mode. | |
833 | for(i = 0; i < 24; i++) { | |
834 | ToSendStuffBit(1); | |
835 | } | |
836 | ||
837 | // Convert from last character reference to length | |
838 | ToSendMax++; | |
839 | } | |
840 | ||
841 | //----------------------------------------------------------------------------- | |
842 | // Read an ISO 14443 tag. We send it some set of commands, and record the | |
843 | // responses. | |
844 | // The command name is misleading, it actually decodes the reponse in HEX | |
845 | // into the output buffer (read the result using hexsamples, not hisamples) | |
846 | //----------------------------------------------------------------------------- | |
f7e3ed82 | 847 | void AcquireRawAdcSamplesIso14443(uint32_t parameter) |
15c4dc5a | 848 | { |
f7e3ed82 | 849 | uint8_t cmd1[] = { 0x05, 0x00, 0x08, 0x39, 0x73 }; |
15c4dc5a | 850 | |
851 | // Make sure that we start from off, since the tags are stateful; | |
852 | // confusing things will happen if we don't reset them between reads. | |
853 | FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); | |
854 | LED_D_OFF(); | |
855 | SpinDelay(200); | |
856 | ||
857 | SetAdcMuxFor(GPIO_MUXSEL_HIPKD); | |
858 | FpgaSetupSsc(); | |
859 | ||
860 | // Now give it time to spin up. | |
861 | // Signal field is on with the appropriate LED | |
862 | LED_D_ON(); | |
863 | FpgaWriteConfWord( | |
864 | FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ); | |
865 | SpinDelay(200); | |
866 | ||
867 | CodeIso14443bAsReader(cmd1, sizeof(cmd1)); | |
868 | TransmitFor14443(); | |
869 | // LED_A_ON(); | |
870 | GetSamplesFor14443Demod(TRUE, 2000, FALSE); | |
871 | // LED_A_OFF(); | |
872 | } | |
873 | ||
874 | //----------------------------------------------------------------------------- | |
875 | // Read a SRI512 ISO 14443 tag. | |
876 | // | |
877 | // SRI512 tags are just simple memory tags, here we're looking at making a dump | |
878 | // of the contents of the memory. No anticollision algorithm is done, we assume | |
879 | // we have a single tag in the field. | |
880 | // | |
881 | // I tried to be systematic and check every answer of the tag, every CRC, etc... | |
882 | //----------------------------------------------------------------------------- | |
f7e3ed82 | 883 | void ReadSRI512Iso14443(uint32_t parameter) |
15c4dc5a | 884 | { |
885 | ReadSTMemoryIso14443(parameter,0x0F); | |
886 | } | |
f7e3ed82 | 887 | void ReadSRIX4KIso14443(uint32_t parameter) |
15c4dc5a | 888 | { |
889 | ReadSTMemoryIso14443(parameter,0x7F); | |
890 | } | |
891 | ||
f7e3ed82 | 892 | void ReadSTMemoryIso14443(uint32_t parameter,uint32_t dwLast) |
15c4dc5a | 893 | { |
f7e3ed82 | 894 | uint8_t i = 0x00; |
15c4dc5a | 895 | |
896 | // Make sure that we start from off, since the tags are stateful; | |
897 | // confusing things will happen if we don't reset them between reads. | |
898 | LED_D_OFF(); | |
899 | FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); | |
900 | SpinDelay(200); | |
901 | ||
902 | SetAdcMuxFor(GPIO_MUXSEL_HIPKD); | |
903 | FpgaSetupSsc(); | |
904 | ||
905 | // Now give it time to spin up. | |
906 | // Signal field is on with the appropriate LED | |
907 | LED_D_ON(); | |
908 | FpgaWriteConfWord( | |
909 | FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ); | |
910 | SpinDelay(200); | |
911 | ||
912 | // First command: wake up the tag using the INITIATE command | |
f7e3ed82 | 913 | uint8_t cmd1[] = { 0x06, 0x00, 0x97, 0x5b}; |
15c4dc5a | 914 | CodeIso14443bAsReader(cmd1, sizeof(cmd1)); |
915 | TransmitFor14443(); | |
916 | // LED_A_ON(); | |
917 | GetSamplesFor14443Demod(TRUE, 2000,TRUE); | |
918 | // LED_A_OFF(); | |
919 | ||
920 | if (Demod.len == 0) { | |
921 | DbpString("No response from tag"); | |
922 | return; | |
923 | } else { | |
924 | Dbprintf("Randomly generated UID from tag (+ 2 byte CRC): %x %x %x", | |
925 | Demod.output[0], Demod.output[1],Demod.output[2]); | |
926 | } | |
927 | // There is a response, SELECT the uid | |
928 | DbpString("Now SELECT tag:"); | |
929 | cmd1[0] = 0x0E; // 0x0E is SELECT | |
930 | cmd1[1] = Demod.output[0]; | |
931 | ComputeCrc14443(CRC_14443_B, cmd1, 2, &cmd1[2], &cmd1[3]); | |
932 | CodeIso14443bAsReader(cmd1, sizeof(cmd1)); | |
933 | TransmitFor14443(); | |
934 | // LED_A_ON(); | |
935 | GetSamplesFor14443Demod(TRUE, 2000,TRUE); | |
936 | // LED_A_OFF(); | |
937 | if (Demod.len != 3) { | |
938 | Dbprintf("Expected 3 bytes from tag, got %d", Demod.len); | |
939 | return; | |
940 | } | |
941 | // Check the CRC of the answer: | |
942 | ComputeCrc14443(CRC_14443_B, Demod.output, 1 , &cmd1[2], &cmd1[3]); | |
943 | if(cmd1[2] != Demod.output[1] || cmd1[3] != Demod.output[2]) { | |
944 | DbpString("CRC Error reading select response."); | |
945 | return; | |
946 | } | |
947 | // Check response from the tag: should be the same UID as the command we just sent: | |
948 | if (cmd1[1] != Demod.output[0]) { | |
949 | Dbprintf("Bad response to SELECT from Tag, aborting: %x %x", cmd1[1], Demod.output[0]); | |
950 | return; | |
951 | } | |
952 | // Tag is now selected, | |
953 | // First get the tag's UID: | |
954 | cmd1[0] = 0x0B; | |
955 | ComputeCrc14443(CRC_14443_B, cmd1, 1 , &cmd1[1], &cmd1[2]); | |
956 | CodeIso14443bAsReader(cmd1, 3); // Only first three bytes for this one | |
957 | TransmitFor14443(); | |
958 | // LED_A_ON(); | |
959 | GetSamplesFor14443Demod(TRUE, 2000,TRUE); | |
960 | // LED_A_OFF(); | |
961 | if (Demod.len != 10) { | |
962 | Dbprintf("Expected 10 bytes from tag, got %d", Demod.len); | |
963 | return; | |
964 | } | |
965 | // The check the CRC of the answer (use cmd1 as temporary variable): | |
966 | ComputeCrc14443(CRC_14443_B, Demod.output, 8, &cmd1[2], &cmd1[3]); | |
967 | if(cmd1[2] != Demod.output[8] || cmd1[3] != Demod.output[9]) { | |
968 | Dbprintf("CRC Error reading block! - Below: expected, got %x %x", | |
969 | (cmd1[2]<<8)+cmd1[3], (Demod.output[8]<<8)+Demod.output[9]); | |
970 | // Do not return;, let's go on... (we should retry, maybe ?) | |
971 | } | |
972 | Dbprintf("Tag UID (64 bits): %08x %08x", | |
973 | (Demod.output[7]<<24) + (Demod.output[6]<<16) + (Demod.output[5]<<8) + Demod.output[4], | |
974 | (Demod.output[3]<<24) + (Demod.output[2]<<16) + (Demod.output[1]<<8) + Demod.output[0]); | |
975 | ||
976 | // Now loop to read all 16 blocks, address from 0 to 15 | |
977 | DbpString("Tag memory dump, block 0 to 15"); | |
978 | cmd1[0] = 0x08; | |
979 | i = 0x00; | |
980 | dwLast++; | |
981 | for (;;) { | |
982 | if (i == dwLast) { | |
983 | DbpString("System area block (0xff):"); | |
984 | i = 0xff; | |
985 | } | |
986 | cmd1[1] = i; | |
987 | ComputeCrc14443(CRC_14443_B, cmd1, 2, &cmd1[2], &cmd1[3]); | |
988 | CodeIso14443bAsReader(cmd1, sizeof(cmd1)); | |
989 | TransmitFor14443(); | |
990 | // LED_A_ON(); | |
991 | GetSamplesFor14443Demod(TRUE, 2000,TRUE); | |
992 | // LED_A_OFF(); | |
993 | if (Demod.len != 6) { // Check if we got an answer from the tag | |
994 | DbpString("Expected 6 bytes from tag, got less..."); | |
995 | return; | |
996 | } | |
997 | // The check the CRC of the answer (use cmd1 as temporary variable): | |
998 | ComputeCrc14443(CRC_14443_B, Demod.output, 4, &cmd1[2], &cmd1[3]); | |
999 | if(cmd1[2] != Demod.output[4] || cmd1[3] != Demod.output[5]) { | |
1000 | Dbprintf("CRC Error reading block! - Below: expected, got %x %x", | |
1001 | (cmd1[2]<<8)+cmd1[3], (Demod.output[4]<<8)+Demod.output[5]); | |
1002 | // Do not return;, let's go on... (we should retry, maybe ?) | |
1003 | } | |
1004 | // Now print out the memory location: | |
1005 | Dbprintf("Address=%x, Contents=%x, CRC=%x", i, | |
1006 | (Demod.output[3]<<24) + (Demod.output[2]<<16) + (Demod.output[1]<<8) + Demod.output[0], | |
1007 | (Demod.output[4]<<8)+Demod.output[5]); | |
1008 | if (i == 0xff) { | |
1009 | break; | |
1010 | } | |
1011 | i++; | |
1012 | } | |
1013 | } | |
1014 | ||
1015 | ||
1016 | //============================================================================= | |
1017 | // Finally, the `sniffer' combines elements from both the reader and | |
1018 | // simulated tag, to show both sides of the conversation. | |
1019 | //============================================================================= | |
1020 | ||
1021 | //----------------------------------------------------------------------------- | |
1022 | // Record the sequence of commands sent by the reader to the tag, with | |
1023 | // triggering so that we start recording at the point that the tag is moved | |
1024 | // near the reader. | |
1025 | //----------------------------------------------------------------------------- | |
1026 | /* | |
1027 | * Memory usage for this function, (within BigBuf) | |
1028 | * 0-4095 : Demodulated samples receive (4096 bytes) - DEMOD_TRACE_SIZE | |
1029 | * 4096-6143 : Last Received command, 2048 bytes (reader->tag) - READER_TAG_BUFFER_SIZE | |
1030 | * 6144-8191 : Last Received command, 2048 bytes(tag->reader) - TAG_READER_BUFFER_SIZE | |
81cd0474 | 1031 | * 8192-9215 : DMA Buffer, 1024 bytes (samples) - DEMOD_DMA_BUFFER_SIZE |
15c4dc5a | 1032 | */ |
0f7f9edc | 1033 | void RAMFUNC SnoopIso14443(void) |
15c4dc5a | 1034 | { |
1035 | // We won't start recording the frames that we acquire until we trigger; | |
1036 | // a good trigger condition to get started is probably when we see a | |
1037 | // response from the tag. | |
0f7f9edc | 1038 | int triggered = TRUE; |
15c4dc5a | 1039 | |
1040 | // The command (reader -> tag) that we're working on receiving. | |
f7e3ed82 | 1041 | uint8_t *receivedCmd = (uint8_t *)(BigBuf) + DEMOD_TRACE_SIZE; |
15c4dc5a | 1042 | // The response (tag -> reader) that we're working on receiving. |
f7e3ed82 | 1043 | uint8_t *receivedResponse = (uint8_t *)(BigBuf) + DEMOD_TRACE_SIZE + READER_TAG_BUFFER_SIZE; |
15c4dc5a | 1044 | |
1045 | // As we receive stuff, we copy it from receivedCmd or receivedResponse | |
1046 | // into trace, along with its length and other annotations. | |
f7e3ed82 | 1047 | uint8_t *trace = (uint8_t *)BigBuf; |
15c4dc5a | 1048 | int traceLen = 0; |
1049 | ||
1050 | // The DMA buffer, used to stream samples from the FPGA. | |
f7e3ed82 | 1051 | int8_t *dmaBuf = (int8_t *)(BigBuf) + DEMOD_TRACE_SIZE + READER_TAG_BUFFER_SIZE + TAG_READER_BUFFER_SIZE; |
15c4dc5a | 1052 | int lastRxCounter; |
f7e3ed82 | 1053 | int8_t *upTo; |
15c4dc5a | 1054 | int ci, cq; |
1055 | int maxBehindBy = 0; | |
1056 | ||
1057 | // Count of samples received so far, so that we can include timing | |
1058 | // information in the trace buffer. | |
1059 | int samples = 0; | |
1060 | ||
1061 | // Initialize the trace buffer | |
1062 | memset(trace, 0x44, DEMOD_TRACE_SIZE); | |
1063 | ||
1064 | // Set up the demodulator for tag -> reader responses. | |
1065 | Demod.output = receivedResponse; | |
1066 | Demod.len = 0; | |
1067 | Demod.state = DEMOD_UNSYNCD; | |
1068 | ||
1069 | // And the reader -> tag commands | |
1070 | memset(&Uart, 0, sizeof(Uart)); | |
1071 | Uart.output = receivedCmd; | |
1072 | Uart.byteCntMax = 100; | |
1073 | Uart.state = STATE_UNSYNCD; | |
1074 | ||
1075 | // Print some debug information about the buffer sizes | |
1076 | Dbprintf("Snooping buffers initialized:"); | |
1077 | Dbprintf(" Trace: %i bytes", DEMOD_TRACE_SIZE); | |
1078 | Dbprintf(" Reader -> tag: %i bytes", READER_TAG_BUFFER_SIZE); | |
1079 | Dbprintf(" tag -> Reader: %i bytes", TAG_READER_BUFFER_SIZE); | |
81cd0474 | 1080 | Dbprintf(" DMA: %i bytes", DEMOD_DMA_BUFFER_SIZE); |
e30c654b | 1081 | |
e30c654b | 1082 | |
15c4dc5a | 1083 | // And put the FPGA in the appropriate mode |
1084 | // Signal field is off with the appropriate LED | |
1085 | LED_D_OFF(); | |
1086 | FpgaWriteConfWord( | |
1087 | FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ | | |
1088 | FPGA_HF_READER_RX_XCORR_SNOOP); | |
1089 | SetAdcMuxFor(GPIO_MUXSEL_HIPKD); | |
1090 | ||
1091 | // Setup for the DMA. | |
1092 | FpgaSetupSsc(); | |
1093 | upTo = dmaBuf; | |
81cd0474 | 1094 | lastRxCounter = DEMOD_DMA_BUFFER_SIZE; |
1095 | FpgaSetupSscDma((uint8_t *)dmaBuf, DEMOD_DMA_BUFFER_SIZE); | |
0f7f9edc | 1096 | |
1097 | LED_A_ON(); | |
1098 | ||
15c4dc5a | 1099 | // And now we loop, receiving samples. |
1100 | for(;;) { | |
15c4dc5a | 1101 | int behindBy = (lastRxCounter - AT91C_BASE_PDC_SSC->PDC_RCR) & |
81cd0474 | 1102 | (DEMOD_DMA_BUFFER_SIZE-1); |
15c4dc5a | 1103 | if(behindBy > maxBehindBy) { |
1104 | maxBehindBy = behindBy; | |
81cd0474 | 1105 | if(behindBy > (DEMOD_DMA_BUFFER_SIZE-2)) { // TODO: understand whether we can increase/decrease as we want or not? |
7e758047 | 1106 | Dbprintf("blew circular buffer! behindBy=0x%x", behindBy); |
15c4dc5a | 1107 | goto done; |
1108 | } | |
1109 | } | |
1110 | if(behindBy < 2) continue; | |
1111 | ||
1112 | ci = upTo[0]; | |
1113 | cq = upTo[1]; | |
1114 | upTo += 2; | |
1115 | lastRxCounter -= 2; | |
81cd0474 | 1116 | if(upTo - dmaBuf > DEMOD_DMA_BUFFER_SIZE) { |
1117 | upTo -= DEMOD_DMA_BUFFER_SIZE; | |
1118 | lastRxCounter += DEMOD_DMA_BUFFER_SIZE; | |
f7e3ed82 | 1119 | AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) upTo; |
81cd0474 | 1120 | AT91C_BASE_PDC_SSC->PDC_RNCR = DEMOD_DMA_BUFFER_SIZE; |
15c4dc5a | 1121 | } |
1122 | ||
1123 | samples += 2; | |
1124 | ||
1125 | #define HANDLE_BIT_IF_BODY \ | |
1126 | if(triggered) { \ | |
15c4dc5a | 1127 | trace[traceLen++] = ((samples >> 0) & 0xff); \ |
1128 | trace[traceLen++] = ((samples >> 8) & 0xff); \ | |
1129 | trace[traceLen++] = ((samples >> 16) & 0xff); \ | |
1130 | trace[traceLen++] = ((samples >> 24) & 0xff); \ | |
1131 | trace[traceLen++] = 0; \ | |
1132 | trace[traceLen++] = 0; \ | |
1133 | trace[traceLen++] = 0; \ | |
1134 | trace[traceLen++] = 0; \ | |
1135 | trace[traceLen++] = Uart.byteCnt; \ | |
1136 | memcpy(trace+traceLen, receivedCmd, Uart.byteCnt); \ | |
1137 | traceLen += Uart.byteCnt; \ | |
1138 | if(traceLen > 1000) break; \ | |
1139 | } \ | |
1140 | /* And ready to receive another command. */ \ | |
1141 | memset(&Uart, 0, sizeof(Uart)); \ | |
1142 | Uart.output = receivedCmd; \ | |
1143 | Uart.byteCntMax = 100; \ | |
1144 | Uart.state = STATE_UNSYNCD; \ | |
1145 | /* And also reset the demod code, which might have been */ \ | |
1146 | /* false-triggered by the commands from the reader. */ \ | |
1147 | memset(&Demod, 0, sizeof(Demod)); \ | |
1148 | Demod.output = receivedResponse; \ | |
1149 | Demod.state = DEMOD_UNSYNCD; \ | |
1150 | ||
1151 | if(Handle14443UartBit(ci & 1)) { | |
1152 | HANDLE_BIT_IF_BODY | |
1153 | } | |
1154 | if(Handle14443UartBit(cq & 1)) { | |
1155 | HANDLE_BIT_IF_BODY | |
1156 | } | |
1157 | ||
1158 | if(Handle14443SamplesDemod(ci, cq)) { | |
1159 | // timestamp, as a count of samples | |
1160 | trace[traceLen++] = ((samples >> 0) & 0xff); | |
1161 | trace[traceLen++] = ((samples >> 8) & 0xff); | |
1162 | trace[traceLen++] = ((samples >> 16) & 0xff); | |
1163 | trace[traceLen++] = 0x80 | ((samples >> 24) & 0xff); | |
1164 | // correlation metric (~signal strength estimate) | |
1165 | if(Demod.metricN != 0) { | |
1166 | Demod.metric /= Demod.metricN; | |
1167 | } | |
1168 | trace[traceLen++] = ((Demod.metric >> 0) & 0xff); | |
1169 | trace[traceLen++] = ((Demod.metric >> 8) & 0xff); | |
1170 | trace[traceLen++] = ((Demod.metric >> 16) & 0xff); | |
1171 | trace[traceLen++] = ((Demod.metric >> 24) & 0xff); | |
1172 | // length | |
1173 | trace[traceLen++] = Demod.len; | |
1174 | memcpy(trace+traceLen, receivedResponse, Demod.len); | |
1175 | traceLen += Demod.len; | |
e30c654b | 1176 | if(traceLen > DEMOD_TRACE_SIZE) { |
15c4dc5a | 1177 | DbpString("Reached trace limit"); |
1178 | goto done; | |
1179 | } | |
1180 | ||
1181 | triggered = TRUE; | |
0f7f9edc | 1182 | LED_A_OFF(); |
1183 | LED_B_ON(); | |
15c4dc5a | 1184 | |
1185 | // And ready to receive another response. | |
1186 | memset(&Demod, 0, sizeof(Demod)); | |
1187 | Demod.output = receivedResponse; | |
1188 | Demod.state = DEMOD_UNSYNCD; | |
1189 | } | |
1190 | WDT_HIT(); | |
1191 | ||
1192 | if(BUTTON_PRESS()) { | |
1193 | DbpString("cancelled"); | |
1194 | goto done; | |
1195 | } | |
1196 | } | |
1197 | ||
1198 | done: | |
0f7f9edc | 1199 | LED_A_OFF(); |
1200 | LED_B_OFF(); | |
1201 | LED_C_OFF(); | |
1202 | AT91C_BASE_PDC_SSC->PDC_PTCR = AT91C_PDC_RXTDIS; | |
15c4dc5a | 1203 | DbpString("Snoop statistics:"); |
0f7f9edc | 1204 | Dbprintf(" Max behind by: %i", maxBehindBy); |
15c4dc5a | 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 | } |