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1 //-----------------------------------------------------------------------------
2 // (c) 2009 Henryk Plötz <henryk@ploetzli.ch>
3 // 2016 Iceman
4 //
5 // This code is licensed to you under the terms of the GNU GPL, version 2 or,
6 // at your option, any later version. See the LICENSE.txt file for the text of
7 // the license.
8 //-----------------------------------------------------------------------------
9 // LEGIC RF simulation code
10 //-----------------------------------------------------------------------------
11 #include "legicrf.h"
12
13 static struct legic_frame {
14 uint8_t bits;
15 uint32_t data;
16 } current_frame;
17
18 static enum {
19 STATE_DISCON,
20 STATE_IV,
21 STATE_CON,
22 } legic_state;
23
24 static crc_t legic_crc;
25 static int legic_read_count;
26 static uint32_t legic_prng_bc;
27 static uint32_t legic_prng_iv;
28
29 static int legic_phase_drift;
30 static int legic_frame_drift;
31 static int legic_reqresp_drift;
32
33 AT91PS_TC timer;
34 AT91PS_TC prng_timer;
35
36 /*
37 static void setup_timer(void) {
38 // Set up Timer 1 to use for measuring time between pulses. Since we're bit-banging
39 // this it won't be terribly accurate but should be good enough.
40 //
41 AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_TC1);
42 timer = AT91C_BASE_TC1;
43 timer->TC_CCR = AT91C_TC_CLKDIS;
44 timer->TC_CMR = AT91C_TC_CLKS_TIMER_DIV3_CLOCK;
45 timer->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;
46
47 //
48 // Set up Timer 2 to use for measuring time between frames in
49 // tag simulation mode. Runs 4x faster as Timer 1
50 //
51 AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_TC2);
52 prng_timer = AT91C_BASE_TC2;
53 prng_timer->TC_CCR = AT91C_TC_CLKDIS;
54 prng_timer->TC_CMR = AT91C_TC_CLKS_TIMER_DIV2_CLOCK;
55 prng_timer->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;
56 }
57
58 AT91C_BASE_PMC->PMC_PCER |= (0x1 << 12) | (0x1 << 13) | (0x1 << 14);
59 AT91C_BASE_TCB->TCB_BMR = AT91C_TCB_TC0XC0S_NONE | AT91C_TCB_TC1XC1S_TIOA0 | AT91C_TCB_TC2XC2S_NONE;
60
61 // fast clock
62 AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS; // timer disable
63 AT91C_BASE_TC0->TC_CMR = AT91C_TC_CLKS_TIMER_DIV3_CLOCK | // MCK(48MHz)/32 -- tick=1.5mks
64 AT91C_TC_WAVE | AT91C_TC_WAVESEL_UP_AUTO | AT91C_TC_ACPA_CLEAR |
65 AT91C_TC_ACPC_SET | AT91C_TC_ASWTRG_SET;
66 AT91C_BASE_TC0->TC_RA = 1;
67 AT91C_BASE_TC0->TC_RC = 0xBFFF + 1; // 0xC000
68
69 */
70
71 // At TIMER_CLOCK3 (MCK/32)
72 // testing calculating in (us) microseconds.
73 #define RWD_TIME_1 120 // READER_TIME_PAUSE 20us off, 80us on = 100us 80 * 1.5 == 120ticks
74 #define RWD_TIME_0 60 // READER_TIME_PAUSE 20us off, 40us on = 60us 40 * 1.5 == 60ticks
75 #define RWD_TIME_PAUSE 30 // 20us == 20 * 1.5 == 30ticks */
76 #define TAG_BIT_PERIOD 142 // 100us == 100 * 1.5 == 150ticks
77 #define TAG_FRAME_WAIT 495 // 330us from READER frame end to TAG frame start. 330 * 1.5 == 495
78
79 #define RWD_TIME_FUZZ 20 // rather generous 13us, since the peak detector + hysteresis fuzz quite a bit
80
81 #define SIM_DIVISOR 586 /* prng_time/SIM_DIVISOR count prng needs to be forwared */
82 #define SIM_SHIFT 900 /* prng_time+SIM_SHIFT shift of delayed start */
83
84 #define OFFSET_LOG 1024
85
86 #define FUZZ_EQUAL(value, target, fuzz) ((value) > ((target)-(fuzz)) && (value) < ((target)+(fuzz)))
87
88 #ifndef SHORT_COIL
89 # define SHORT_COIL LOW(GPIO_SSC_DOUT);
90 #endif
91 #ifndef OPEN_COIL
92 # define OPEN_COIL HIGH(GPIO_SSC_DOUT);
93 #endif
94 #ifndef LINE_IN
95 # define LINE_IN AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DIN;
96 #endif
97 // Pause pulse, off in 20us / 30ticks,
98 // ONE / ZERO bit pulse,
99 // one == 80us / 120ticks
100 // zero == 40us / 60ticks
101 #ifndef COIL_PULSE
102 # define COIL_PULSE(x) \
103 do { \
104 SHORT_COIL; \
105 WaitTicks( (RWD_TIME_PAUSE) ); \
106 OPEN_COIL; \
107 WaitTicks((x)); \
108 } while (0);
109 #endif
110
111 // ToDo: define a meaningful maximum size for auth_table. The bigger this is, the lower will be the available memory for traces.
112 // Historically it used to be FREE_BUFFER_SIZE, which was 2744.
113 #define LEGIC_CARD_MEMSIZE 1024
114 static uint8_t* cardmem;
115
116 static void frame_append_bit(struct legic_frame * const f, uint8_t bit) {
117 // Overflow, won't happen
118 if (f->bits >= 31) return;
119
120 f->data |= (bit << f->bits);
121 f->bits++;
122 }
123
124 static void frame_clean(struct legic_frame * const f) {
125 f->data = 0;
126 f->bits = 0;
127 }
128
129 // Prng works when waiting in 99.1us cycles.
130 // and while sending/receiving in bit frames (100, 60)
131 /*static void CalibratePrng( uint32_t time){
132 // Calculate Cycles based on timer 100us
133 uint32_t i = (time - sendFrameStop) / 100 ;
134
135 // substract cycles of finished frames
136 int k = i - legic_prng_count()+1;
137
138 // substract current frame length, rewind to beginning
139 if ( k > 0 )
140 legic_prng_forward(k);
141 }
142 */
143
144 /* Generate Keystream */
145 uint32_t get_key_stream(int skip, int count) {
146
147 int i;
148
149 // Use int to enlarge timer tc to 32bit
150 legic_prng_bc += prng_timer->TC_CV;
151
152 // reset the prng timer.
153
154 /* If skip == -1, forward prng time based */
155 if(skip == -1) {
156 i = (legic_prng_bc + SIM_SHIFT)/SIM_DIVISOR; /* Calculate Cycles based on timer */
157 i -= legic_prng_count(); /* substract cycles of finished frames */
158 i -= count; /* substract current frame length, rewind to beginning */
159 legic_prng_forward(i);
160 } else {
161 legic_prng_forward(skip);
162 }
163
164 i = (count == 6) ? -1 : legic_read_count;
165
166 /* Generate KeyStream */
167 return legic_prng_get_bits(count);
168 }
169
170 /* Send a frame in tag mode, the FPGA must have been set up by
171 * LegicRfSimulate
172 */
173 void frame_send_tag(uint16_t response, uint8_t bits) {
174
175 uint16_t mask = 1;
176
177 /* Bitbang the response */
178 SHORT_COIL;
179 AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT;
180 AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT;
181
182 /* TAG_FRAME_WAIT -> shift by 2 */
183 legic_prng_forward(3);
184 response ^= legic_prng_get_bits(bits);
185
186 /* Wait for the frame start */
187 WaitTicks( TAG_FRAME_WAIT );
188
189 for (; mask < BITMASK(bits); mask <<= 1) {
190 if (response & mask)
191 OPEN_COIL
192 else
193 SHORT_COIL
194 WaitTicks(TAG_BIT_PERIOD);
195 }
196 SHORT_COIL;
197 }
198
199 /* Send a frame in reader mode, the FPGA must have been set up by
200 * LegicRfReader
201 */
202 void frame_sendAsReader(uint32_t data, uint8_t bits){
203
204 uint32_t starttime = GET_TICKS, send = 0, mask = 1;
205
206 // xor lsfr onto data.
207 send = data ^ legic_prng_get_bits(bits);
208
209 for (; mask < BITMASK(bits); mask <<= 1) {
210 if (send & mask)
211 COIL_PULSE(RWD_TIME_1)
212 else
213 COIL_PULSE(RWD_TIME_0)
214 }
215
216 // Final pause to mark the end of the frame
217 COIL_PULSE(0);
218
219 // log
220 uint8_t cmdbytes[] = {bits, BYTEx(data,0), BYTEx(data,1), BYTEx(data,2), BYTEx(send,0), BYTEx(send,1), BYTEx(send,2)};
221 LogTrace(cmdbytes, sizeof(cmdbytes), starttime, GET_TICKS, NULL, TRUE);
222 }
223
224 /* Receive a frame from the card in reader emulation mode, the FPGA and
225 * timer must have been set up by LegicRfReader and frame_sendAsReader.
226 *
227 * The LEGIC RF protocol from card to reader does not include explicit
228 * frame start/stop information or length information. The reader must
229 * know beforehand how many bits it wants to receive. (Notably: a card
230 * sending a stream of 0-bits is indistinguishable from no card present.)
231 *
232 * Receive methodology: There is a fancy correlator in hi_read_rx_xcorr, but
233 * I'm not smart enough to use it. Instead I have patched hi_read_tx to output
234 * the ADC signal with hysteresis on SSP_DIN. Bit-bang that signal and look
235 * for edges. Count the edges in each bit interval. If they are approximately
236 * 0 this was a 0-bit, if they are approximately equal to the number of edges
237 * expected for a 212kHz subcarrier, this was a 1-bit. For timing we use the
238 * timer that's still running from frame_sendAsReader in order to get a synchronization
239 * with the frame that we just sent.
240 *
241 * FIXME: Because we're relying on the hysteresis to just do the right thing
242 * the range is severely reduced (and you'll probably also need a good antenna).
243 * So this should be fixed some time in the future for a proper receiver.
244 */
245 static void frame_receiveAsReader(struct legic_frame * const f, uint8_t bits) {
246
247 if ( bits > 32 ) return;
248
249 uint8_t i = bits, edges = 0;
250 uint32_t the_bit = 1, next_bit_at = 0, data = 0;
251 uint32_t old_level = 0;
252 volatile uint32_t level = 0;
253
254 frame_clean(f);
255
256 // calibrate the prng.
257 legic_prng_forward(2);
258 data = legic_prng_get_bits(bits);
259
260 //FIXED time between sending frame and now listening frame. 330us
261 uint32_t starttime = GET_TICKS;
262 // its about 9+9 ticks delay from end-send to here.
263 WaitTicks( 477 );
264
265 next_bit_at = GET_TICKS + TAG_BIT_PERIOD;
266
267 while ( i-- ){
268 edges = 0;
269 while ( GET_TICKS < next_bit_at) {
270
271 level = (AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_DIN);
272
273 if (level != old_level)
274 ++edges;
275
276 old_level = level;
277 }
278
279 next_bit_at += TAG_BIT_PERIOD;
280
281 // We expect 42 edges (ONE)
282 if ( edges > 20 )
283 data ^= the_bit;
284
285 the_bit <<= 1;
286 }
287
288 // output
289 f->data = data;
290 f->bits = bits;
291
292 // log
293 uint8_t cmdbytes[] = {bits, BYTEx(data, 0), BYTEx(data, 1)};
294 LogTrace(cmdbytes, sizeof(cmdbytes), starttime, GET_TICKS, NULL, FALSE);
295 }
296
297 // Setup pm3 as a Legic Reader
298 static uint32_t setup_phase_reader(uint8_t iv) {
299
300 // Switch on carrier and let the tag charge for 1ms
301 HIGH(GPIO_SSC_DOUT);
302 WaitUS(5000);
303
304 ResetTicks();
305
306 // no keystream yet
307 legic_prng_init(0);
308
309 // send IV handshake
310 frame_sendAsReader(iv, 7);
311
312 // Now both tag and reader has same IV. Prng can start.
313 legic_prng_init(iv);
314
315 frame_receiveAsReader(&current_frame, 6);
316
317 // 292us (438t) - fixed delay before sending ack.
318 // minus log and stuff 100tick?
319 WaitTicks(338);
320 legic_prng_forward(3);
321
322 // Send obsfuscated acknowledgment frame.
323 // 0x19 = 0x18 MIM22, 0x01 LSB READCMD
324 // 0x39 = 0x38 MIM256, MIM1024 0x01 LSB READCMD
325 switch ( current_frame.data ) {
326 case 0x0D: frame_sendAsReader(0x19, 6); break;
327 case 0x1D:
328 case 0x3D: frame_sendAsReader(0x39, 6); break;
329 default: break;
330 }
331
332 legic_prng_forward(2);
333 return current_frame.data;
334 }
335
336 void LegicCommonInit(bool clear_mem) {
337
338 FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
339 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX);
340 SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
341
342 /* Bitbang the transmitter */
343 SHORT_COIL;
344 AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT;
345 AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT;
346 AT91C_BASE_PIOA->PIO_ODR = GPIO_SSC_DIN;
347
348 // reserve a cardmem, meaning we can use the tracelog function in bigbuff easier.
349 cardmem = BigBuf_get_EM_addr();
350 if ( clear_mem )
351 memset(cardmem, 0x00, LEGIC_CARD_MEMSIZE);
352
353 clear_trace();
354 set_tracing(TRUE);
355 crc_init(&legic_crc, 4, 0x19 >> 1, 0x5, 0);
356
357 StartTicks();
358 }
359
360 // Switch off carrier, make sure tag is reset
361 static void switch_off_tag_rwd(void) {
362 SHORT_COIL;
363 WaitUS(20);
364 WDT_HIT();
365 }
366
367 // calculate crc4 for a legic READ command
368 static uint32_t legic4Crc(uint8_t cmd, uint16_t byte_index, uint8_t value, uint8_t cmd_sz) {
369 crc_clear(&legic_crc);
370 uint32_t temp = (value << cmd_sz) | (byte_index << 1) | cmd;
371 crc_update(&legic_crc, temp, cmd_sz + 8 );
372 return crc_finish(&legic_crc);
373 }
374
375 int legic_read_byte( uint16_t index, uint8_t cmd_sz) {
376
377 uint8_t byte, crc, calcCrc = 0;
378 uint32_t cmd = (index << 1) | LEGIC_READ;
379
380 // 90ticks = 60us (should be 100us but crc calc takes time.)
381 //WaitTicks(330); // 330ticks prng(4) - works
382 WaitTicks(240); // 240ticks prng(3) - works
383
384 frame_sendAsReader(cmd, cmd_sz);
385 frame_receiveAsReader(&current_frame, 12);
386
387 // CRC check.
388 byte = BYTEx(current_frame.data, 0);
389 crc = BYTEx(current_frame.data, 1);
390 calcCrc = legic4Crc(LEGIC_READ, index, byte, cmd_sz);
391
392 if( calcCrc != crc ) {
393 Dbprintf("!!! crc mismatch: %x != %x !!!", calcCrc, crc);
394 return -1;
395 }
396
397 legic_prng_forward(3);
398 return byte;
399 }
400
401 /*
402 * - assemble a write_cmd_frame with crc and send it
403 * - wait until the tag sends back an ACK ('1' bit unencrypted)
404 * - forward the prng based on the timing
405 */
406 bool legic_write_byte(uint16_t index, uint8_t byte, uint8_t addr_sz) {
407
408 bool isOK = false;
409 int8_t i = 40;
410 uint8_t edges = 0;
411 uint8_t cmd_sz = addr_sz+1+8+4; //crc+data+cmd;
412 uint32_t steps = 0, next_bit_at, start, crc, old_level = 0;
413
414 crc = legic4Crc(LEGIC_WRITE, index, byte, addr_sz+1);
415
416 // send write command
417 uint32_t cmd = LEGIC_WRITE;
418 cmd |= index << 1; // index
419 cmd |= byte << (addr_sz+1); // Data
420 cmd |= (crc & 0xF ) << (addr_sz+1+8); // CRC
421
422 WaitTicks(240);
423
424 frame_sendAsReader(cmd, cmd_sz);
425
426 LINE_IN;
427
428 start = GET_TICKS;
429
430 // ACK, - one single "1" bit after 3.6ms
431 // 3.6ms = 3600us * 1.5 = 5400ticks.
432 WaitTicks(5400);
433
434 next_bit_at = GET_TICKS + TAG_BIT_PERIOD;
435
436 while ( i-- ) {
437 WDT_HIT();
438 edges = 0;
439 while ( GET_TICKS < next_bit_at) {
440
441 volatile uint32_t level = (AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_DIN);
442
443 if (level != old_level)
444 ++edges;
445
446 old_level = level;
447 }
448
449 next_bit_at += TAG_BIT_PERIOD;
450
451 // We expect 42 edges (ONE)
452 if(edges > 20 ) {
453 steps = ( (GET_TICKS - start) / TAG_BIT_PERIOD);
454 legic_prng_forward(steps);
455 isOK = true;
456 goto OUT;
457 }
458 }
459
460 OUT: ;
461 legic_prng_forward(1);
462
463 uint8_t cmdbytes[] = {1, isOK, BYTEx(steps, 0), BYTEx(steps, 1) };
464 LogTrace(cmdbytes, sizeof(cmdbytes), start, GET_TICKS, NULL, FALSE);
465 return isOK;
466 }
467
468 int LegicRfReader(uint16_t offset, uint16_t len, uint8_t iv) {
469
470 uint16_t i = 0;
471 uint8_t isOK = 1;
472 legic_card_select_t card;
473
474 LegicCommonInit(TRUE);
475
476 if ( legic_select_card_iv(&card, iv) ) {
477 isOK = 0;
478 goto OUT;
479 }
480
481 if (len + offset > card.cardsize)
482 len = card.cardsize - offset;
483
484 LED_B_ON();
485 while (i < len) {
486 int r = legic_read_byte(offset + i, card.cmdsize);
487
488 if (r == -1 || BUTTON_PRESS()) {
489 if ( MF_DBGLEVEL >= 2) DbpString("operation aborted");
490 isOK = 0;
491 goto OUT;
492 }
493 cardmem[i++] = r;
494 WDT_HIT();
495 }
496
497 OUT:
498 WDT_HIT();
499 switch_off_tag_rwd();
500 LEDsoff();
501 cmd_send(CMD_ACK, isOK, len, 0, cardmem, len);
502 return 0;
503 }
504
505 void LegicRfWriter(uint16_t offset, uint16_t len, uint8_t iv, uint8_t *data) {
506
507 #define LOWERLIMIT 4
508 uint8_t isOK = 1, msg = 0;
509 legic_card_select_t card;
510
511 // uid NOT is writeable.
512 if ( offset <= LOWERLIMIT ) {
513 isOK = 0;
514 goto OUT;
515 }
516
517 LegicCommonInit(TRUE);
518
519 if ( legic_select_card_iv(&card, iv) ) {
520 isOK = 0;
521 msg = 1;
522 goto OUT;
523 }
524
525 if ( len + offset > card.cardsize)
526 len = card.cardsize - offset;
527
528 LED_B_ON();
529 while( len > 0 ) {
530 --len;
531 if ( !legic_write_byte( len + offset, data[len], card.addrsize) ) {
532 Dbprintf("operation failed | %02X | %02X | %02X", len + offset, len, data[len] );
533 isOK = 0;
534 goto OUT;
535 }
536 WDT_HIT();
537 }
538 OUT:
539 cmd_send(CMD_ACK, isOK, msg,0,0,0);
540 switch_off_tag_rwd();
541 LEDsoff();
542 }
543
544 int legic_select_card_iv(legic_card_select_t *p_card, uint8_t iv){
545
546 if ( p_card == NULL ) return 1;
547
548 p_card->tagtype = setup_phase_reader(iv);
549
550 switch(p_card->tagtype) {
551 case 0x0d:
552 p_card->cmdsize = 6;
553 p_card->addrsize = 5;
554 p_card->cardsize = 22;
555 break;
556 case 0x1d:
557 p_card->cmdsize = 9;
558 p_card->addrsize = 8;
559 p_card->cardsize = 256;
560 break;
561 case 0x3d:
562 p_card->cmdsize = 11;
563 p_card->addrsize = 10;
564 p_card->cardsize = 1024;
565 break;
566 default:
567 p_card->cmdsize = 0;
568 p_card->addrsize = 0;
569 p_card->cardsize = 0;
570 return 2;
571 }
572 return 0;
573 }
574 int legic_select_card(legic_card_select_t *p_card){
575 return legic_select_card_iv(p_card, 0x01);
576 }
577
578 //-----------------------------------------------------------------------------
579 // Work with emulator memory
580 //
581 // Note: we call FpgaDownloadAndGo(FPGA_BITSTREAM_HF) here although FPGA is not
582 // involved in dealing with emulator memory. But if it is called later, it might
583 // destroy the Emulator Memory.
584 //-----------------------------------------------------------------------------
585 // arg0 = offset
586 // arg1 = num of bytes
587 void LegicEMemSet(uint32_t arg0, uint32_t arg1, uint8_t *data) {
588 FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
589 legic_emlset_mem(data, arg0, arg1);
590 }
591 // arg0 = offset
592 // arg1 = num of bytes
593 void LegicEMemGet(uint32_t arg0, uint32_t arg1) {
594 FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
595 uint8_t buf[USB_CMD_DATA_SIZE] = {0x00};
596 legic_emlget_mem(buf, arg0, arg1);
597 LED_B_ON();
598 cmd_send(CMD_ACK, arg0, arg1, 0, buf, USB_CMD_DATA_SIZE);
599 LED_B_OFF();
600 }
601 void legic_emlset_mem(uint8_t *data, int offset, int numofbytes) {
602 cardmem = BigBuf_get_EM_addr();
603 memcpy(cardmem + offset, data, numofbytes);
604 }
605 void legic_emlget_mem(uint8_t *data, int offset, int numofbytes) {
606 cardmem = BigBuf_get_EM_addr();
607 memcpy(data, cardmem + offset, numofbytes);
608 }
609
610 void LegicRfInfo(void){
611
612 int r;
613
614 uint8_t buf[sizeof(legic_card_select_t)] = {0x00};
615 legic_card_select_t *card = (legic_card_select_t*) buf;
616
617 LegicCommonInit(FALSE);
618
619 if ( legic_select_card(card) ) {
620 cmd_send(CMD_ACK,0,0,0,0,0);
621 goto OUT;
622 }
623
624 // read UID bytes
625 for ( uint8_t i = 0; i < sizeof(card->uid); ++i) {
626 r = legic_read_byte(i, card->cmdsize);
627 if ( r == -1 ) {
628 cmd_send(CMD_ACK,0,0,0,0,0);
629 goto OUT;
630 }
631 card->uid[i] = r & 0xFF;
632 }
633
634 // MCC byte.
635 r = legic_read_byte(4, card->cmdsize);
636 uint32_t calc_mcc = CRC8Legic(card->uid, 4);;
637 if ( r != calc_mcc) {
638 cmd_send(CMD_ACK,0,0,0,0,0);
639 goto OUT;
640 }
641
642 // OK
643 cmd_send(CMD_ACK, 1, 0, 0, buf, sizeof(legic_card_select_t));
644
645 OUT:
646 switch_off_tag_rwd();
647 LEDsoff();
648 }
649
650 /* Handle (whether to respond) a frame in tag mode
651 * Only called when simulating a tag.
652 */
653 static void frame_handle_tag(struct legic_frame const * const f)
654 {
655 // log
656 //uint8_t cmdbytes[] = {bits, BYTEx(data, 0), BYTEx(data, 1)};
657 //LogTrace(cmdbytes, sizeof(cmdbytes), starttime, GET_TICKS, NULL, FALSE);
658 Dbprintf("ICE: enter frame_handle_tag: %02x ", f->bits);
659
660 /* First Part of Handshake (IV) */
661 if(f->bits == 7) {
662
663 LED_C_ON();
664
665 // Reset prng timer
666 //ResetTimer(prng_timer);
667 ResetTicks();
668
669 // IV from reader.
670 legic_prng_init(f->data);
671
672 Dbprintf("ICE: IV: %02x ", f->data);
673
674 // We should have three tagtypes with three different answers.
675 legic_prng_forward(2);
676 //frame_send_tag(0x3d, 6); /* MIM1024 0x3d^0x26 = 0x1B */
677 frame_send_tag(0x1d, 6); // MIM256
678
679 legic_state = STATE_IV;
680 legic_read_count = 0;
681 legic_prng_bc = 0;
682 legic_prng_iv = f->data;
683
684 //ResetTimer(timer);
685 //WaitUS(280);
686 WaitTicks(388);
687 return;
688 }
689
690 /* 0x19==??? */
691 if(legic_state == STATE_IV) {
692 uint32_t local_key = get_key_stream(3, 6);
693 int xored = 0x39 ^ local_key;
694 if((f->bits == 6) && (f->data == xored)) {
695 legic_state = STATE_CON;
696
697 //ResetTimer(timer);
698
699 //WaitUS(200);
700 WaitTicks(300);
701 return;
702
703 } else {
704 legic_state = STATE_DISCON;
705 LED_C_OFF();
706 Dbprintf("iv: %02x frame: %02x key: %02x xored: %02x", legic_prng_iv, f->data, local_key, xored);
707 return;
708 }
709 }
710
711 /* Read */
712 if(f->bits == 11) {
713 if(legic_state == STATE_CON) {
714 uint32_t key = get_key_stream(2, 11); //legic_phase_drift, 11);
715 uint16_t addr = f->data ^ key;
716 addr >>= 1;
717 uint8_t data = cardmem[addr];
718
719 uint32_t crc = legic4Crc(LEGIC_READ, addr, data, 11) << 8;
720
721 //legic_read_count++;
722 //legic_prng_forward(legic_reqresp_drift);
723
724 frame_send_tag(crc | data, 12);
725 //ResetTimer(timer);
726 legic_prng_forward(2);
727 WaitTicks(330);
728 return;
729 }
730 }
731
732 /* Write */
733 if (f->bits == 23 || f->bits == 21 ) {
734 uint32_t key = get_key_stream(-1, 23); //legic_frame_drift, 23);
735 uint16_t addr = f->data ^ key;
736 addr >>= 1;
737 addr &= 0x3ff;
738 uint32_t data = f->data ^ key;
739 data >>= 11;
740 data &= 0xff;
741
742 cardmem[addr] = data;
743 /* write command */
744 legic_state = STATE_DISCON;
745 LED_C_OFF();
746 Dbprintf("write - addr: %x, data: %x", addr, data);
747 // should send a ACK after 3.6ms
748 return;
749 }
750
751 if(legic_state != STATE_DISCON) {
752 Dbprintf("Unexpected: sz:%u, Data:%03.3x, State:%u, Count:%u", f->bits, f->data, legic_state, legic_read_count);
753 Dbprintf("IV: %03.3x", legic_prng_iv);
754 }
755
756 legic_state = STATE_DISCON;
757 legic_read_count = 0;
758 WaitMS(10);
759 LED_C_OFF();
760 return;
761 }
762
763 /* Read bit by bit untill full frame is received
764 * Call to process frame end answer
765 */
766 static void emit(int bit) {
767
768 Dbprintf("ICE: enter emit:");
769 switch (bit) {
770 case 1:
771 frame_append_bit(&current_frame, 1);
772 break;
773 case 0:
774 frame_append_bit(&current_frame, 0);
775 break;
776 default:
777 if(current_frame.bits <= 4) {
778 frame_clean(&current_frame);
779 } else {
780 frame_handle_tag(&current_frame);
781 frame_clean(&current_frame);
782 }
783 WDT_HIT();
784 break;
785 }
786 }
787
788 void LegicRfSimulate(int phase, int frame, int reqresp)
789 {
790 /* ADC path high-frequency peak detector, FPGA in high-frequency simulator mode,
791 * modulation mode set to 212kHz subcarrier. We are getting the incoming raw
792 * envelope waveform on DIN and should send our response on DOUT.
793 *
794 * The LEGIC RF protocol is pulse-pause-encoding from reader to card, so we'll
795 * measure the time between two rising edges on DIN, and no encoding on the
796 * subcarrier from card to reader, so we'll just shift out our verbatim data
797 * on DOUT, 1 bit is 100us. The time from reader to card frame is still unclear,
798 * seems to be 330us.
799 */
800
801 int old_level = 0, active = 0;
802 volatile uint32_t level = 0;
803
804 legic_state = STATE_DISCON;
805 legic_phase_drift = phase;
806 legic_frame_drift = frame;
807 legic_reqresp_drift = reqresp;
808
809 FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
810
811 /* to get the stream of bits from FPGA in sim mode.*/
812 SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
813 FpgaSetupSsc();
814 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_SIMULATOR | FPGA_HF_SIMULATOR_MODULATE_212K);
815
816 /* Bitbang the receiver */
817 // LINE_IN;
818 AT91C_BASE_PIOA->PIO_ODR = GPIO_SSC_DIN;
819 AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DIN;
820
821 // need a way to determine which tagtype we are simulating
822
823 // hook up emulator memory
824 cardmem = BigBuf_get_EM_addr();
825
826 clear_trace();
827 set_tracing(TRUE);
828
829 crc_init(&legic_crc, 4, 0x19 >> 1, 0x5, 0);
830
831 StartTicks();
832
833 LED_B_ON();
834 DbpString("Starting Legic emulator, press button to end");
835
836 while(!BUTTON_PRESS() && !usb_poll_validate_length()) {
837
838 level = !!(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_DIN);
839
840 uint32_t time = GET_TICKS;
841
842 if (level != old_level) {
843
844 if (level) {
845
846 ResetTicks();
847
848 if (FUZZ_EQUAL(time, RWD_TIME_1, RWD_TIME_FUZZ)) {
849 /* 1 bit */
850 emit(1);
851 active = 1;
852 LED_A_ON();
853 } else if (FUZZ_EQUAL(time, RWD_TIME_0, RWD_TIME_FUZZ)) {
854 /* 0 bit */
855 emit(0);
856 active = 1;
857 LED_A_ON();
858 } else if (active) {
859 /* invalid */
860 emit(-1);
861 active = 0;
862 LED_A_OFF();
863 }
864 }
865 }
866
867 /* Frame end */
868 if(time >= (RWD_TIME_1 + RWD_TIME_FUZZ) && active) {
869 emit(-1);
870 active = 0;
871 LED_A_OFF();
872 }
873
874 /*
875 * Disable the counter, Then wait for the clock to acknowledge the
876 * shutdown in its status register. Reading the SR has the
877 * side-effect of clearing any pending state in there.
878 */
879 //if(time >= (20*RWD_TIME_1) && (timer->TC_SR & AT91C_TC_CLKSTA))
880 //if(time >= (20 * RWD_TIME_1) )
881 //StopTicks();
882
883 old_level = level;
884 WDT_HIT();
885 }
886
887 WDT_HIT();
888 DbpString("LEGIC Prime emulator stopped");
889 switch_off_tag_rwd();
890 LEDsoff();
891 cmd_send(CMD_ACK, 1, 0, 0, 0, 0);
892 }
893
894 //-----------------------------------------------------------------------------
895 // Code up a string of octets at layer 2 (including CRC, we don't generate
896 // that here) so that they can be transmitted to the reader. Doesn't transmit
897 // them yet, just leaves them ready to send in ToSend[].
898 //-----------------------------------------------------------------------------
899 // static void CodeLegicAsTag(const uint8_t *cmd, int len)
900 // {
901 // int i;
902
903 // ToSendReset();
904
905 // // Transmit a burst of ones, as the initial thing that lets the
906 // // reader get phase sync. This (TR1) must be > 80/fs, per spec,
907 // // but tag that I've tried (a Paypass) exceeds that by a fair bit,
908 // // so I will too.
909 // for(i = 0; i < 20; i++) {
910 // ToSendStuffBit(1);
911 // ToSendStuffBit(1);
912 // ToSendStuffBit(1);
913 // ToSendStuffBit(1);
914 // }
915
916 // // Send SOF.
917 // for(i = 0; i < 10; i++) {
918 // ToSendStuffBit(0);
919 // ToSendStuffBit(0);
920 // ToSendStuffBit(0);
921 // ToSendStuffBit(0);
922 // }
923 // for(i = 0; i < 2; i++) {
924 // ToSendStuffBit(1);
925 // ToSendStuffBit(1);
926 // ToSendStuffBit(1);
927 // ToSendStuffBit(1);
928 // }
929
930 // for(i = 0; i < len; i++) {
931 // int j;
932 // uint8_t b = cmd[i];
933
934 // // Start bit
935 // ToSendStuffBit(0);
936 // ToSendStuffBit(0);
937 // ToSendStuffBit(0);
938 // ToSendStuffBit(0);
939
940 // // Data bits
941 // for(j = 0; j < 8; j++) {
942 // if(b & 1) {
943 // ToSendStuffBit(1);
944 // ToSendStuffBit(1);
945 // ToSendStuffBit(1);
946 // ToSendStuffBit(1);
947 // } else {
948 // ToSendStuffBit(0);
949 // ToSendStuffBit(0);
950 // ToSendStuffBit(0);
951 // ToSendStuffBit(0);
952 // }
953 // b >>= 1;
954 // }
955
956 // // Stop bit
957 // ToSendStuffBit(1);
958 // ToSendStuffBit(1);
959 // ToSendStuffBit(1);
960 // ToSendStuffBit(1);
961 // }
962
963 // // Send EOF.
964 // for(i = 0; i < 10; i++) {
965 // ToSendStuffBit(0);
966 // ToSendStuffBit(0);
967 // ToSendStuffBit(0);
968 // ToSendStuffBit(0);
969 // }
970 // for(i = 0; i < 2; i++) {
971 // ToSendStuffBit(1);
972 // ToSendStuffBit(1);
973 // ToSendStuffBit(1);
974 // ToSendStuffBit(1);
975 // }
976
977 // // Convert from last byte pos to length
978 // ToSendMax++;
979 // }
980
981 //-----------------------------------------------------------------------------
982 // The software UART that receives commands from the reader, and its state
983 // variables.
984 //-----------------------------------------------------------------------------
985 /*
986 static struct {
987 enum {
988 STATE_UNSYNCD,
989 STATE_GOT_FALLING_EDGE_OF_SOF,
990 STATE_AWAITING_START_BIT,
991 STATE_RECEIVING_DATA
992 } state;
993 uint16_t shiftReg;
994 int bitCnt;
995 int byteCnt;
996 int byteCntMax;
997 int posCnt;
998 uint8_t *output;
999 } Uart;
1000 */
1001 /* Receive & handle a bit coming from the reader.
1002 *
1003 * This function is called 4 times per bit (every 2 subcarrier cycles).
1004 * Subcarrier frequency fs is 212kHz, 1/fs = 4,72us, i.e. function is called every 9,44us
1005 *
1006 * LED handling:
1007 * LED A -> ON once we have received the SOF and are expecting the rest.
1008 * LED A -> OFF once we have received EOF or are in error state or unsynced
1009 *
1010 * Returns: true if we received a EOF
1011 * false if we are still waiting for some more
1012 */
1013 // static RAMFUNC int HandleLegicUartBit(uint8_t bit)
1014 // {
1015 // switch(Uart.state) {
1016 // case STATE_UNSYNCD:
1017 // if(!bit) {
1018 // // we went low, so this could be the beginning of an SOF
1019 // Uart.state = STATE_GOT_FALLING_EDGE_OF_SOF;
1020 // Uart.posCnt = 0;
1021 // Uart.bitCnt = 0;
1022 // }
1023 // break;
1024
1025 // case STATE_GOT_FALLING_EDGE_OF_SOF:
1026 // Uart.posCnt++;
1027 // if(Uart.posCnt == 2) { // sample every 4 1/fs in the middle of a bit
1028 // if(bit) {
1029 // if(Uart.bitCnt > 9) {
1030 // // we've seen enough consecutive
1031 // // zeros that it's a valid SOF
1032 // Uart.posCnt = 0;
1033 // Uart.byteCnt = 0;
1034 // Uart.state = STATE_AWAITING_START_BIT;
1035 // LED_A_ON(); // Indicate we got a valid SOF
1036 // } else {
1037 // // didn't stay down long enough
1038 // // before going high, error
1039 // Uart.state = STATE_UNSYNCD;
1040 // }
1041 // } else {
1042 // // do nothing, keep waiting
1043 // }
1044 // Uart.bitCnt++;
1045 // }
1046 // if(Uart.posCnt >= 4) Uart.posCnt = 0;
1047 // if(Uart.bitCnt > 12) {
1048 // // Give up if we see too many zeros without
1049 // // a one, too.
1050 // LED_A_OFF();
1051 // Uart.state = STATE_UNSYNCD;
1052 // }
1053 // break;
1054
1055 // case STATE_AWAITING_START_BIT:
1056 // Uart.posCnt++;
1057 // if(bit) {
1058 // if(Uart.posCnt > 50/2) { // max 57us between characters = 49 1/fs, max 3 etus after low phase of SOF = 24 1/fs
1059 // // stayed high for too long between
1060 // // characters, error
1061 // Uart.state = STATE_UNSYNCD;
1062 // }
1063 // } else {
1064 // // falling edge, this starts the data byte
1065 // Uart.posCnt = 0;
1066 // Uart.bitCnt = 0;
1067 // Uart.shiftReg = 0;
1068 // Uart.state = STATE_RECEIVING_DATA;
1069 // }
1070 // break;
1071
1072 // case STATE_RECEIVING_DATA:
1073 // Uart.posCnt++;
1074 // if(Uart.posCnt == 2) {
1075 // // time to sample a bit
1076 // Uart.shiftReg >>= 1;
1077 // if(bit) {
1078 // Uart.shiftReg |= 0x200;
1079 // }
1080 // Uart.bitCnt++;
1081 // }
1082 // if(Uart.posCnt >= 4) {
1083 // Uart.posCnt = 0;
1084 // }
1085 // if(Uart.bitCnt == 10) {
1086 // if((Uart.shiftReg & 0x200) && !(Uart.shiftReg & 0x001))
1087 // {
1088 // // this is a data byte, with correct
1089 // // start and stop bits
1090 // Uart.output[Uart.byteCnt] = (Uart.shiftReg >> 1) & 0xff;
1091 // Uart.byteCnt++;
1092
1093 // if(Uart.byteCnt >= Uart.byteCntMax) {
1094 // // Buffer overflowed, give up
1095 // LED_A_OFF();
1096 // Uart.state = STATE_UNSYNCD;
1097 // } else {
1098 // // so get the next byte now
1099 // Uart.posCnt = 0;
1100 // Uart.state = STATE_AWAITING_START_BIT;
1101 // }
1102 // } else if (Uart.shiftReg == 0x000) {
1103 // // this is an EOF byte
1104 // LED_A_OFF(); // Finished receiving
1105 // Uart.state = STATE_UNSYNCD;
1106 // if (Uart.byteCnt != 0) {
1107 // return TRUE;
1108 // }
1109 // } else {
1110 // // this is an error
1111 // LED_A_OFF();
1112 // Uart.state = STATE_UNSYNCD;
1113 // }
1114 // }
1115 // break;
1116
1117 // default:
1118 // LED_A_OFF();
1119 // Uart.state = STATE_UNSYNCD;
1120 // break;
1121 // }
1122
1123 // return FALSE;
1124 // }
1125 /*
1126
1127 static void UartReset() {
1128 Uart.byteCntMax = 3;
1129 Uart.state = STATE_UNSYNCD;
1130 Uart.byteCnt = 0;
1131 Uart.bitCnt = 0;
1132 Uart.posCnt = 0;
1133 memset(Uart.output, 0x00, 3);
1134 }
1135 */
1136 // static void UartInit(uint8_t *data) {
1137 // Uart.output = data;
1138 // UartReset();
1139 // }
1140
1141 //=============================================================================
1142 // An LEGIC reader. We take layer two commands, code them
1143 // appropriately, and then send them to the tag. We then listen for the
1144 // tag's response, which we leave in the buffer to be demodulated on the
1145 // PC side.
1146 //=============================================================================
1147 /*
1148 static struct {
1149 enum {
1150 DEMOD_UNSYNCD,
1151 DEMOD_PHASE_REF_TRAINING,
1152 DEMOD_AWAITING_FALLING_EDGE_OF_SOF,
1153 DEMOD_GOT_FALLING_EDGE_OF_SOF,
1154 DEMOD_AWAITING_START_BIT,
1155 DEMOD_RECEIVING_DATA
1156 } state;
1157 int bitCount;
1158 int posCount;
1159 int thisBit;
1160 uint16_t shiftReg;
1161 uint8_t *output;
1162 int len;
1163 int sumI;
1164 int sumQ;
1165 } Demod;
1166 */
1167 /*
1168 * Handles reception of a bit from the tag
1169 *
1170 * This function is called 2 times per bit (every 4 subcarrier cycles).
1171 * Subcarrier frequency fs is 212kHz, 1/fs = 4,72us, i.e. function is called every 9,44us
1172 *
1173 * LED handling:
1174 * LED C -> ON once we have received the SOF and are expecting the rest.
1175 * LED C -> OFF once we have received EOF or are unsynced
1176 *
1177 * Returns: true if we received a EOF
1178 * false if we are still waiting for some more
1179 *
1180 */
1181
1182 /*
1183 static RAMFUNC int HandleLegicSamplesDemod(int ci, int cq)
1184 {
1185 int v = 0;
1186 int ai = ABS(ci);
1187 int aq = ABS(cq);
1188 int halfci = (ai >> 1);
1189 int halfcq = (aq >> 1);
1190
1191 switch(Demod.state) {
1192 case DEMOD_UNSYNCD:
1193
1194 CHECK_FOR_SUBCARRIER()
1195
1196 if(v > SUBCARRIER_DETECT_THRESHOLD) { // subcarrier detected
1197 Demod.state = DEMOD_PHASE_REF_TRAINING;
1198 Demod.sumI = ci;
1199 Demod.sumQ = cq;
1200 Demod.posCount = 1;
1201 }
1202 break;
1203
1204 case DEMOD_PHASE_REF_TRAINING:
1205 if(Demod.posCount < 8) {
1206
1207 CHECK_FOR_SUBCARRIER()
1208
1209 if (v > SUBCARRIER_DETECT_THRESHOLD) {
1210 // set the reference phase (will code a logic '1') by averaging over 32 1/fs.
1211 // note: synchronization time > 80 1/fs
1212 Demod.sumI += ci;
1213 Demod.sumQ += cq;
1214 ++Demod.posCount;
1215 } else {
1216 // subcarrier lost
1217 Demod.state = DEMOD_UNSYNCD;
1218 }
1219 } else {
1220 Demod.state = DEMOD_AWAITING_FALLING_EDGE_OF_SOF;
1221 }
1222 break;
1223
1224 case DEMOD_AWAITING_FALLING_EDGE_OF_SOF:
1225
1226 MAKE_SOFT_DECISION()
1227
1228 //Dbprintf("ICE: %d %d %d %d %d", v, Demod.sumI, Demod.sumQ, ci, cq );
1229 // logic '0' detected
1230 if (v <= 0) {
1231
1232 Demod.state = DEMOD_GOT_FALLING_EDGE_OF_SOF;
1233
1234 // start of SOF sequence
1235 Demod.posCount = 0;
1236 } else {
1237 // maximum length of TR1 = 200 1/fs
1238 if(Demod.posCount > 25*2) Demod.state = DEMOD_UNSYNCD;
1239 }
1240 ++Demod.posCount;
1241 break;
1242
1243 case DEMOD_GOT_FALLING_EDGE_OF_SOF:
1244 ++Demod.posCount;
1245
1246 MAKE_SOFT_DECISION()
1247
1248 if(v > 0) {
1249 // low phase of SOF too short (< 9 etu). Note: spec is >= 10, but FPGA tends to "smear" edges
1250 if(Demod.posCount < 10*2) {
1251 Demod.state = DEMOD_UNSYNCD;
1252 } else {
1253 LED_C_ON(); // Got SOF
1254 Demod.state = DEMOD_AWAITING_START_BIT;
1255 Demod.posCount = 0;
1256 Demod.len = 0;
1257 }
1258 } else {
1259 // low phase of SOF too long (> 12 etu)
1260 if(Demod.posCount > 13*2) {
1261 Demod.state = DEMOD_UNSYNCD;
1262 LED_C_OFF();
1263 }
1264 }
1265 break;
1266
1267 case DEMOD_AWAITING_START_BIT:
1268 ++Demod.posCount;
1269
1270 MAKE_SOFT_DECISION()
1271
1272 if(v > 0) {
1273 // max 19us between characters = 16 1/fs, max 3 etu after low phase of SOF = 24 1/fs
1274 if(Demod.posCount > 3*2) {
1275 Demod.state = DEMOD_UNSYNCD;
1276 LED_C_OFF();
1277 }
1278 } else {
1279 // start bit detected
1280 Demod.bitCount = 0;
1281 Demod.posCount = 1; // this was the first half
1282 Demod.thisBit = v;
1283 Demod.shiftReg = 0;
1284 Demod.state = DEMOD_RECEIVING_DATA;
1285 }
1286 break;
1287
1288 case DEMOD_RECEIVING_DATA:
1289
1290 MAKE_SOFT_DECISION()
1291
1292 if(Demod.posCount == 0) {
1293 // first half of bit
1294 Demod.thisBit = v;
1295 Demod.posCount = 1;
1296 } else {
1297 // second half of bit
1298 Demod.thisBit += v;
1299 Demod.shiftReg >>= 1;
1300 // logic '1'
1301 if(Demod.thisBit > 0)
1302 Demod.shiftReg |= 0x200;
1303
1304 ++Demod.bitCount;
1305
1306 if(Demod.bitCount == 10) {
1307
1308 uint16_t s = Demod.shiftReg;
1309
1310 if((s & 0x200) && !(s & 0x001)) {
1311 // stop bit == '1', start bit == '0'
1312 uint8_t b = (s >> 1);
1313 Demod.output[Demod.len] = b;
1314 ++Demod.len;
1315 Demod.state = DEMOD_AWAITING_START_BIT;
1316 } else {
1317 Demod.state = DEMOD_UNSYNCD;
1318 LED_C_OFF();
1319
1320 if(s == 0x000) {
1321 // This is EOF (start, stop and all data bits == '0'
1322 return TRUE;
1323 }
1324 }
1325 }
1326 Demod.posCount = 0;
1327 }
1328 break;
1329
1330 default:
1331 Demod.state = DEMOD_UNSYNCD;
1332 LED_C_OFF();
1333 break;
1334 }
1335 return FALSE;
1336 }
1337 */
1338 /*
1339 // Clear out the state of the "UART" that receives from the tag.
1340 static void DemodReset() {
1341 Demod.len = 0;
1342 Demod.state = DEMOD_UNSYNCD;
1343 Demod.posCount = 0;
1344 Demod.sumI = 0;
1345 Demod.sumQ = 0;
1346 Demod.bitCount = 0;
1347 Demod.thisBit = 0;
1348 Demod.shiftReg = 0;
1349 memset(Demod.output, 0x00, 3);
1350 }
1351
1352 static void DemodInit(uint8_t *data) {
1353 Demod.output = data;
1354 DemodReset();
1355 }
1356 */
1357
1358 /*
1359 * Demodulate the samples we received from the tag, also log to tracebuffer
1360 * quiet: set to 'TRUE' to disable debug output
1361 */
1362
1363 /*
1364 #define LEGIC_DMA_BUFFER_SIZE 256
1365
1366 static void GetSamplesForLegicDemod(int n, bool quiet)
1367 {
1368 int max = 0;
1369 bool gotFrame = FALSE;
1370 int lastRxCounter = LEGIC_DMA_BUFFER_SIZE;
1371 int ci, cq, samples = 0;
1372
1373 BigBuf_free();
1374
1375 // And put the FPGA in the appropriate mode
1376 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_QUARTER_FREQ);
1377
1378 // The response (tag -> reader) that we're receiving.
1379 // Set up the demodulator for tag -> reader responses.
1380 DemodInit(BigBuf_malloc(MAX_FRAME_SIZE));
1381
1382 // The DMA buffer, used to stream samples from the FPGA
1383 int8_t *dmaBuf = (int8_t*) BigBuf_malloc(LEGIC_DMA_BUFFER_SIZE);
1384 int8_t *upTo = dmaBuf;
1385
1386 // Setup and start DMA.
1387 if ( !FpgaSetupSscDma((uint8_t*) dmaBuf, LEGIC_DMA_BUFFER_SIZE) ){
1388 if (MF_DBGLEVEL > 1) Dbprintf("FpgaSetupSscDma failed. Exiting");
1389 return;
1390 }
1391
1392 // Signal field is ON with the appropriate LED:
1393 LED_D_ON();
1394 for(;;) {
1395 int behindBy = lastRxCounter - AT91C_BASE_PDC_SSC->PDC_RCR;
1396 if(behindBy > max) max = behindBy;
1397
1398 while(((lastRxCounter-AT91C_BASE_PDC_SSC->PDC_RCR) & (LEGIC_DMA_BUFFER_SIZE-1)) > 2) {
1399 ci = upTo[0];
1400 cq = upTo[1];
1401 upTo += 2;
1402 if(upTo >= dmaBuf + LEGIC_DMA_BUFFER_SIZE) {
1403 upTo = dmaBuf;
1404 AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) upTo;
1405 AT91C_BASE_PDC_SSC->PDC_RNCR = LEGIC_DMA_BUFFER_SIZE;
1406 }
1407 lastRxCounter -= 2;
1408 if(lastRxCounter <= 0)
1409 lastRxCounter = LEGIC_DMA_BUFFER_SIZE;
1410
1411 samples += 2;
1412
1413 gotFrame = HandleLegicSamplesDemod(ci , cq );
1414 if ( gotFrame )
1415 break;
1416 }
1417
1418 if(samples > n || gotFrame)
1419 break;
1420 }
1421
1422 FpgaDisableSscDma();
1423
1424 if (!quiet && Demod.len == 0) {
1425 Dbprintf("max behindby = %d, samples = %d, gotFrame = %d, Demod.len = %d, Demod.sumI = %d, Demod.sumQ = %d",
1426 max,
1427 samples,
1428 gotFrame,
1429 Demod.len,
1430 Demod.sumI,
1431 Demod.sumQ
1432 );
1433 }
1434
1435 //Tracing
1436 if (Demod.len > 0) {
1437 uint8_t parity[MAX_PARITY_SIZE] = {0x00};
1438 LogTrace(Demod.output, Demod.len, 0, 0, parity, FALSE);
1439 }
1440 }
1441
1442 */
1443
1444 //-----------------------------------------------------------------------------
1445 // Transmit the command (to the tag) that was placed in ToSend[].
1446 //-----------------------------------------------------------------------------
1447 /*
1448 static void TransmitForLegic(void)
1449 {
1450 int c;
1451
1452 FpgaSetupSsc();
1453
1454 while(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY))
1455 AT91C_BASE_SSC->SSC_THR = 0xff;
1456
1457 // Signal field is ON with the appropriate Red LED
1458 LED_D_ON();
1459
1460 // Signal we are transmitting with the Green LED
1461 LED_B_ON();
1462 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX | FPGA_HF_READER_TX_SHALLOW_MOD);
1463
1464 for(c = 0; c < 10;) {
1465 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1466 AT91C_BASE_SSC->SSC_THR = 0xff;
1467 c++;
1468 }
1469 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
1470 volatile uint32_t r = AT91C_BASE_SSC->SSC_RHR;
1471 (void)r;
1472 }
1473 WDT_HIT();
1474 }
1475
1476 c = 0;
1477 for(;;) {
1478 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1479 AT91C_BASE_SSC->SSC_THR = ToSend[c];
1480 legic_prng_forward(1); // forward the lfsr
1481 c++;
1482 if(c >= ToSendMax) {
1483 break;
1484 }
1485 }
1486 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
1487 volatile uint32_t r = AT91C_BASE_SSC->SSC_RHR;
1488 (void)r;
1489 }
1490 WDT_HIT();
1491 }
1492 LED_B_OFF();
1493 }
1494 */
1495
1496 //-----------------------------------------------------------------------------
1497 // Code a layer 2 command (string of octets, including CRC) into ToSend[],
1498 // so that it is ready to transmit to the tag using TransmitForLegic().
1499 //-----------------------------------------------------------------------------
1500 /*
1501 static void CodeLegicBitsAsReader(const uint8_t *cmd, uint8_t cmdlen, int bits)
1502 {
1503 int i, j;
1504 uint8_t b;
1505
1506 ToSendReset();
1507
1508 // Send SOF
1509 for(i = 0; i < 7; i++)
1510 ToSendStuffBit(1);
1511
1512
1513 for(i = 0; i < cmdlen; i++) {
1514 // Start bit
1515 ToSendStuffBit(0);
1516
1517 // Data bits
1518 b = cmd[i];
1519 for(j = 0; j < bits; j++) {
1520 if(b & 1) {
1521 ToSendStuffBit(1);
1522 } else {
1523 ToSendStuffBit(0);
1524 }
1525 b >>= 1;
1526 }
1527 }
1528
1529 // Convert from last character reference to length
1530 ++ToSendMax;
1531 }
1532 */
1533 /**
1534 Convenience function to encode, transmit and trace Legic comms
1535 **/
1536 /*
1537 static void CodeAndTransmitLegicAsReader(const uint8_t *cmd, uint8_t cmdlen, int bits)
1538 {
1539 CodeLegicBitsAsReader(cmd, cmdlen, bits);
1540 TransmitForLegic();
1541 if (tracing) {
1542 uint8_t parity[1] = {0x00};
1543 LogTrace(cmd, cmdlen, 0, 0, parity, TRUE);
1544 }
1545 }
1546
1547 */
1548 // Set up LEGIC communication
1549 /*
1550 void ice_legic_setup() {
1551
1552 // standard things.
1553 FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
1554 BigBuf_free(); BigBuf_Clear_ext(false);
1555 clear_trace();
1556 set_tracing(TRUE);
1557 DemodReset();
1558 UartReset();
1559
1560 // Set up the synchronous serial port
1561 FpgaSetupSsc();
1562
1563 // connect Demodulated Signal to ADC:
1564 SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
1565
1566 // Signal field is on with the appropriate LED
1567 LED_D_ON();
1568 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX | FPGA_HF_READER_TX_SHALLOW_MOD);
1569 SpinDelay(20);
1570 // Start the timer
1571 //StartCountSspClk();
1572
1573 // initalize CRC
1574 crc_init(&legic_crc, 4, 0x19 >> 1, 0x5, 0);
1575
1576 // initalize prng
1577 legic_prng_init(0);
1578 }
1579 */
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