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CHG: finally, the ticks timer does what it is supposed to do. 32bits and working.
[proxmark3-svn] / armsrc / legicrf.c
1 //-----------------------------------------------------------------------------
2 // (c) 2009 Henryk Plötz <henryk@ploetzli.ch>
3 //
4 // This code is licensed to you under the terms of the GNU GPL, version 2 or,
5 // at your option, any later version. See the LICENSE.txt file for the text of
6 // the license.
7 //-----------------------------------------------------------------------------
8 // LEGIC RF simulation code
9 //-----------------------------------------------------------------------------
10 #include "legicrf.h"
11
12 static struct legic_frame {
13 uint8_t bits;
14 uint32_t data;
15 } current_frame;
16
17 static enum {
18 STATE_DISCON,
19 STATE_IV,
20 STATE_CON,
21 } legic_state;
22
23 static crc_t legic_crc;
24 static int legic_read_count;
25 static uint32_t legic_prng_bc;
26 static uint32_t legic_prng_iv;
27
28 static int legic_phase_drift;
29 static int legic_frame_drift;
30 static int legic_reqresp_drift;
31
32 AT91PS_TC timer;
33 AT91PS_TC prng_timer;
34
35 /*
36 static void setup_timer(void) {
37 // Set up Timer 1 to use for measuring time between pulses. Since we're bit-banging
38 // this it won't be terribly accurate but should be good enough.
39 //
40 AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_TC1);
41 timer = AT91C_BASE_TC1;
42 timer->TC_CCR = AT91C_TC_CLKDIS;
43 timer->TC_CMR = AT91C_TC_CLKS_TIMER_DIV3_CLOCK;
44 timer->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;
45
46 //
47 // Set up Timer 2 to use for measuring time between frames in
48 // tag simulation mode. Runs 4x faster as Timer 1
49 //
50 AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_TC2);
51 prng_timer = AT91C_BASE_TC2;
52 prng_timer->TC_CCR = AT91C_TC_CLKDIS;
53 prng_timer->TC_CMR = AT91C_TC_CLKS_TIMER_DIV2_CLOCK;
54 prng_timer->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;
55 }
56
57 AT91C_BASE_PMC->PMC_PCER |= (0x1 << 12) | (0x1 << 13) | (0x1 << 14);
58 AT91C_BASE_TCB->TCB_BMR = AT91C_TCB_TC0XC0S_NONE | AT91C_TCB_TC1XC1S_TIOA0 | AT91C_TCB_TC2XC2S_NONE;
59
60 // fast clock
61 AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS; // timer disable
62 AT91C_BASE_TC0->TC_CMR = AT91C_TC_CLKS_TIMER_DIV3_CLOCK | // MCK(48MHz)/32 -- tick=1.5mks
63 AT91C_TC_WAVE | AT91C_TC_WAVESEL_UP_AUTO | AT91C_TC_ACPA_CLEAR |
64 AT91C_TC_ACPC_SET | AT91C_TC_ASWTRG_SET;
65 AT91C_BASE_TC0->TC_RA = 1;
66 AT91C_BASE_TC0->TC_RC = 0xBFFF + 1; // 0xC000
67
68 */
69
70 // At TIMER_CLOCK3 (MCK/32)
71 // testing calculating in (us) microseconds.
72 #define RWD_TIME_1 120 // READER_TIME_PAUSE 20us off, 80us on = 100us 80 * 1.5 == 120ticks
73 #define RWD_TIME_0 60 // READER_TIME_PAUSE 20us off, 40us on = 60us 40 * 1.5 == 60ticks
74 #define RWD_TIME_PAUSE 30 // 20us == 20 * 1.5 == 30ticks */
75 #define TAG_BIT_PERIOD 142 // 100us == 100 * 1.5 == 150ticks
76 #define TAG_FRAME_WAIT 495 // 330us from READER frame end to TAG frame start. 330 * 1.5 == 495
77
78 #define RWD_TIME_FUZZ 20 // rather generous 13us, since the peak detector + hysteresis fuzz quite a bit
79
80 #define SIM_DIVISOR 586 /* prng_time/SIM_DIVISOR count prng needs to be forwared */
81 #define SIM_SHIFT 900 /* prng_time+SIM_SHIFT shift of delayed start */
82
83 #define OFFSET_LOG 1024
84
85 #define FUZZ_EQUAL(value, target, fuzz) ((value) > ((target)-(fuzz)) && (value) < ((target)+(fuzz)))
86
87 #ifndef SHORT_COIL
88 # define SHORT_COIL LOW(GPIO_SSC_DOUT);
89 #endif
90 #ifndef OPEN_COIL
91 # define OPEN_COIL HIGH(GPIO_SSC_DOUT);
92 #endif
93
94 // Pause pulse, off in 20us / 30ticks,
95 // ONE / ZERO bit pulse,
96 // one == 80us / 120ticks
97 // zero == 40us / 60ticks
98 #ifndef COIL_PULSE
99 # define COIL_PULSE(x) \
100 do { \
101 SHORT_COIL; \
102 WaitTicks( (RWD_TIME_PAUSE) ); \
103 OPEN_COIL; \
104 WaitTicks((x)); \
105 } while (0)
106 #endif
107
108 // ToDo: define a meaningful maximum size for auth_table. The bigger this is, the lower will be the available memory for traces.
109 // Historically it used to be FREE_BUFFER_SIZE, which was 2744.
110 #define LEGIC_CARD_MEMSIZE 1024
111 static uint8_t* cardmem;
112
113 static void frame_append_bit(struct legic_frame * const f, uint8_t bit) {
114 // Overflow, won't happen
115 if (f->bits >= 31) return;
116
117 f->data |= (bit << f->bits);
118 f->bits++;
119 }
120
121 static void frame_clean(struct legic_frame * const f) {
122 f->data = 0;
123 f->bits = 0;
124 }
125
126 // Prng works when waiting in 99.1us cycles.
127 // and while sending/receiving in bit frames (100, 60)
128 /*static void CalibratePrng( uint32_t time){
129 // Calculate Cycles based on timer 100us
130 uint32_t i = (time - sendFrameStop) / 100 ;
131
132 // substract cycles of finished frames
133 int k = i - legic_prng_count()+1;
134
135 // substract current frame length, rewind to beginning
136 if ( k > 0 )
137 legic_prng_forward(k);
138 }
139 */
140
141 /* Generate Keystream */
142 uint32_t get_key_stream(int skip, int count) {
143 uint32_t key = 0;
144 int i;
145
146 // Use int to enlarge timer tc to 32bit
147 legic_prng_bc += prng_timer->TC_CV;
148
149 // reset the prng timer.
150 ResetTimer(prng_timer);
151
152 /* If skip == -1, forward prng time based */
153 if(skip == -1) {
154 i = (legic_prng_bc + SIM_SHIFT)/SIM_DIVISOR; /* Calculate Cycles based on timer */
155 i -= legic_prng_count(); /* substract cycles of finished frames */
156 i -= count; /* substract current frame length, rewind to beginning */
157 legic_prng_forward(i);
158 } else {
159 legic_prng_forward(skip);
160 }
161
162 i = (count == 6) ? -1 : legic_read_count;
163
164 /* Write Time Data into LOG */
165 // uint8_t *BigBuf = BigBuf_get_addr();
166 // BigBuf[OFFSET_LOG+128+i] = legic_prng_count();
167 // BigBuf[OFFSET_LOG+256+i*4] = (legic_prng_bc >> 0) & 0xff;
168 // BigBuf[OFFSET_LOG+256+i*4+1] = (legic_prng_bc >> 8) & 0xff;
169 // BigBuf[OFFSET_LOG+256+i*4+2] = (legic_prng_bc >>16) & 0xff;
170 // BigBuf[OFFSET_LOG+256+i*4+3] = (legic_prng_bc >>24) & 0xff;
171 // BigBuf[OFFSET_LOG+384+i] = count;
172
173 /* Generate KeyStream */
174 for(i=0; i<count; i++) {
175 key |= legic_prng_get_bit() << i;
176 legic_prng_forward(1);
177 }
178 return key;
179 }
180
181 /* Send a frame in tag mode, the FPGA must have been set up by
182 * LegicRfSimulate
183 */
184 void frame_send_tag(uint16_t response, uint8_t bits, uint8_t crypt) {
185 /* Bitbang the response */
186 LOW(GPIO_SSC_DOUT);
187 AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT;
188 AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT;
189
190 /* Use time to crypt frame */
191 if(crypt) {
192 legic_prng_forward(2); /* TAG_FRAME_WAIT -> shift by 2 */
193 response ^= legic_prng_get_bits(bits);
194 }
195
196 /* Wait for the frame start */
197 WaitUS( TAG_FRAME_WAIT );
198
199 uint8_t bit = 0;
200 for(int i = 0; i < bits; i++) {
201
202 bit = response & 1;
203 response >>= 1;
204
205 if (bit)
206 HIGH(GPIO_SSC_DOUT);
207 else
208 LOW(GPIO_SSC_DOUT);
209
210 WaitUS(100);
211 }
212 LOW(GPIO_SSC_DOUT);
213 }
214
215 /* Send a frame in reader mode, the FPGA must have been set up by
216 * LegicRfReader
217 */
218 void frame_sendAsReader(uint32_t data, uint8_t bits){
219
220 uint32_t starttime = GET_TICKS, send = 0;
221 uint16_t mask = 1;
222
223 // xor lsfr onto data.
224 send = data ^ legic_prng_get_bits(bits);
225
226 for (; mask < BITMASK(bits); mask <<= 1) {
227 if (send & mask)
228 COIL_PULSE(RWD_TIME_1);
229 else
230 COIL_PULSE(RWD_TIME_0);
231 }
232
233 // Final pause to mark the end of the frame
234 COIL_PULSE(0);
235
236 // log
237 uint8_t cmdbytes[] = {bits, BYTEx(data, 0), BYTEx(data, 1), BYTEx(send, 0), BYTEx(send, 1)};
238 LogTrace(cmdbytes, sizeof(cmdbytes), starttime, GET_TICKS, NULL, TRUE);
239 }
240
241 /* Receive a frame from the card in reader emulation mode, the FPGA and
242 * timer must have been set up by LegicRfReader and frame_sendAsReader.
243 *
244 * The LEGIC RF protocol from card to reader does not include explicit
245 * frame start/stop information or length information. The reader must
246 * know beforehand how many bits it wants to receive. (Notably: a card
247 * sending a stream of 0-bits is indistinguishable from no card present.)
248 *
249 * Receive methodology: There is a fancy correlator in hi_read_rx_xcorr, but
250 * I'm not smart enough to use it. Instead I have patched hi_read_tx to output
251 * the ADC signal with hysteresis on SSP_DIN. Bit-bang that signal and look
252 * for edges. Count the edges in each bit interval. If they are approximately
253 * 0 this was a 0-bit, if they are approximately equal to the number of edges
254 * expected for a 212kHz subcarrier, this was a 1-bit. For timing we use the
255 * timer that's still running from frame_sendAsReader in order to get a synchronization
256 * with the frame that we just sent.
257 *
258 * FIXME: Because we're relying on the hysteresis to just do the right thing
259 * the range is severely reduced (and you'll probably also need a good antenna).
260 * So this should be fixed some time in the future for a proper receiver.
261 */
262 static void frame_receiveAsReader(struct legic_frame * const f, uint8_t bits) {
263
264 if ( bits > 32 ) return;
265
266 uint8_t i = bits, edges = 0;
267 uint32_t the_bit = 1, next_bit_at = 0, data = 0;
268 uint32_t old_level = 0;
269 volatile uint32_t level = 0;
270
271 frame_clean(f);
272
273 AT91C_BASE_PIOA->PIO_ODR = GPIO_SSC_DIN;
274 AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DIN;
275
276 // calibrate the prng.
277 legic_prng_forward(2);
278 data = legic_prng_get_bits(bits);
279
280 //FIXED time between sending frame and now listening frame. 330us
281 uint32_t starttime = GET_TICKS;
282 //if ( bits == 6 || bits == 7) {
283 // its about 9+9 ticks delay from end-send to here.
284 //WaitTicks( 495 - 9 - 9 );
285 WaitTicks( 477 );
286 //} else {
287 // WaitTicks( 477 );
288 // }
289
290 next_bit_at = GET_TICKS + TAG_BIT_PERIOD;
291
292 while ( i-- ){
293 edges = 0;
294 while ( GET_TICKS < next_bit_at) {
295
296 level = (AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_DIN);
297
298 if (level != old_level)
299 ++edges;
300
301 old_level = level;
302 }
303
304 next_bit_at += TAG_BIT_PERIOD;
305
306 // We expect 42 edges (ONE)
307 if ( edges > 20 )
308 data ^= the_bit;
309
310 the_bit <<= 1;
311 }
312
313 // output
314 f->data = data;
315 f->bits = bits;
316
317 // log
318 uint8_t cmdbytes[] = {bits, BYTEx(data, 0), BYTEx(data, 1)};
319 LogTrace(cmdbytes, sizeof(cmdbytes), starttime, GET_TICKS, NULL, FALSE);
320 }
321
322 // Setup pm3 as a Legic Reader
323 static uint32_t setup_phase_reader(uint8_t iv) {
324
325 // Switch on carrier and let the tag charge for 1ms
326 HIGH(GPIO_SSC_DOUT);
327 WaitUS(1000);
328
329 ResetTicks();
330
331 // no keystream yet
332 legic_prng_init(0);
333
334 // send IV handshake
335 frame_sendAsReader(iv, 7);
336
337 // Now both tag and reader has same IV. Prng can start.
338 legic_prng_init(iv);
339
340 frame_receiveAsReader(&current_frame, 6);
341
342 // 292us (438t) - fixed delay before sending ack.
343 // minus log and stuff 100tick?
344 WaitTicks(338);
345 legic_prng_forward(3);
346
347 // Send obsfuscated acknowledgment frame.
348 // 0x19 = 0x18 MIM22, 0x01 LSB READCMD
349 // 0x39 = 0x38 MIM256, MIM1024 0x01 LSB READCMD
350 switch ( current_frame.data ) {
351 case 0x0D: frame_sendAsReader(0x19, 6); break;
352 case 0x1D:
353 case 0x3D: frame_sendAsReader(0x39, 6); break;
354 default: break;
355 }
356
357 legic_prng_forward(2);
358 return current_frame.data;
359 }
360
361 static void LegicCommonInit(void) {
362
363 FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
364 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX);
365 SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
366
367 /* Bitbang the transmitter */
368 LOW(GPIO_SSC_DOUT);
369 AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT;
370 AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT;
371
372 // reserve a cardmem, meaning we can use the tracelog function in bigbuff easier.
373 cardmem = BigBuf_malloc(LEGIC_CARD_MEMSIZE);
374 memset(cardmem, 0x00, LEGIC_CARD_MEMSIZE);
375
376 clear_trace();
377 set_tracing(TRUE);
378 crc_init(&legic_crc, 4, 0x19 >> 1, 0x5, 0);
379
380 StartTicks();
381 }
382
383 // Switch off carrier, make sure tag is reset
384 static void switch_off_tag_rwd(void) {
385 LOW(GPIO_SSC_DOUT);
386 WaitUS(20);
387 WDT_HIT();
388 }
389
390 // calculate crc4 for a legic READ command
391 static uint32_t legic4Crc(uint8_t cmd, uint16_t byte_index, uint8_t value, uint8_t cmd_sz) {
392 crc_clear(&legic_crc);
393 uint32_t temp = (value << cmd_sz) | (byte_index << 1) | cmd;
394 crc_update(&legic_crc, temp, cmd_sz + 8 );
395 return crc_finish(&legic_crc);
396 }
397
398 int legic_read_byte( uint16_t index, uint8_t cmd_sz) {
399
400 uint8_t byte, crc, calcCrc = 0;
401 uint32_t cmd = (index << 1) | LEGIC_READ;
402
403 //WaitTicks(366);
404 WaitTicks(330);
405 //WaitTicks(50);
406
407 frame_sendAsReader(cmd, cmd_sz);
408 frame_receiveAsReader(&current_frame, 12);
409
410 // CRC check.
411 byte = BYTEx(current_frame.data, 0);
412 crc = BYTEx(current_frame.data, 1);
413 calcCrc = legic4Crc(LEGIC_READ, index, byte, cmd_sz);
414
415 if( calcCrc != crc ) {
416 Dbprintf("!!! crc mismatch: expected %x but got %x !!!", calcCrc, crc);
417 return -1;
418 }
419
420 legic_prng_forward(4);
421 return byte;
422 }
423
424 /*
425 * - assemble a write_cmd_frame with crc and send it
426 * - wait until the tag sends back an ACK ('1' bit unencrypted)
427 * - forward the prng based on the timing
428 */
429 //int legic_write_byte(int byte, int addr, int addr_sz, int PrngCorrection) {
430 int legic_write_byte(uint8_t byte, uint16_t addr, uint8_t addr_sz) {
431
432 //do not write UID, CRC at offset 0-4.
433 if (addr <= 4) return 0;
434
435 // crc
436 crc_clear(&legic_crc);
437 crc_update(&legic_crc, 0, 1); /* CMD_WRITE */
438 crc_update(&legic_crc, addr, addr_sz);
439 crc_update(&legic_crc, byte, 8);
440 uint32_t crc = crc_finish(&legic_crc);
441
442 uint32_t crc2 = legic4Crc(LEGIC_WRITE, addr, byte, addr_sz+1);
443 if ( crc != crc2 )
444 Dbprintf("crc is missmatch");
445
446 // send write command
447 uint32_t cmd = ((crc <<(addr_sz+1+8)) //CRC
448 |(byte <<(addr_sz+1)) //Data
449 |(addr <<1) //Address
450 | LEGIC_WRITE); //CMD = Write
451
452 uint32_t cmd_sz = addr_sz+1+8+4; //crc+data+cmd
453
454 legic_prng_forward(2); /* we wait anyways */
455
456 WaitUS(TAG_FRAME_WAIT);
457
458 frame_sendAsReader(cmd, cmd_sz);
459
460 // wllm-rbnt doesnt have these
461 AT91C_BASE_PIOA->PIO_ODR = GPIO_SSC_DIN;
462 AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DIN;
463
464 // wait for ack
465 int t, old_level = 0, edges = 0;
466 int next_bit_at = 0;
467
468 WaitUS(TAG_FRAME_WAIT);
469
470 for( t = 0; t < 80; ++t) {
471 edges = 0;
472 next_bit_at += TAG_BIT_PERIOD;
473 while(timer->TC_CV < next_bit_at) {
474 int level = (AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_DIN);
475 if(level != old_level)
476 edges++;
477
478 old_level = level;
479 }
480 if(edges > 20 && edges < 60) { /* expected are 42 edges */
481 int t = timer->TC_CV;
482 int c = t / TAG_BIT_PERIOD;
483
484 ResetTimer(timer);
485 legic_prng_forward(c);
486 return 0;
487 }
488 }
489
490 ResetTimer(timer);
491 return -1;
492 }
493
494 int LegicRfReader(uint16_t offset, uint16_t len, uint8_t iv) {
495
496 len &= 0x3FF;
497
498 uint16_t i = 0;
499 uint8_t isOK = 1;
500 legic_card_select_t card;
501
502 LegicCommonInit();
503
504 if ( legic_select_card_iv(&card, iv) ) {
505 isOK = 0;
506 goto OUT;
507 }
508
509 switch_off_tag_rwd();
510
511 if (len + offset >= card.cardsize)
512 len = card.cardsize - offset;
513
514 setup_phase_reader(iv);
515
516 LED_B_ON();
517 while (i < len) {
518 int r = legic_read_byte(offset + i, card.cmdsize);
519
520 if (r == -1 || BUTTON_PRESS()) {
521 if ( MF_DBGLEVEL >= 2) DbpString("operation aborted");
522 isOK = 0;
523 goto OUT;
524 }
525 cardmem[i++] = r;
526 WDT_HIT();
527 }
528
529 OUT:
530 WDT_HIT();
531 switch_off_tag_rwd();
532 LEDsoff();
533 cmd_send(CMD_ACK,isOK,len,0,cardmem,len);
534 return 0;
535 }
536
537 /*int _LegicRfWriter(int offset, int bytes, int addr_sz, uint8_t *BigBuf, int RoundBruteforceValue) {
538 int byte_index=0;
539
540 LED_B_ON();
541 setup_phase_reader(iv);
542 //legic_prng_forward(2);
543 while(byte_index < bytes) {
544 int r;
545
546 //check if the DCF should be changed
547 if ( (offset == 0x05) && (bytes == 0x02) ) {
548 //write DCF in reverse order (addr 0x06 before 0x05)
549 r = legic_write_byte(BigBuf[(0x06-byte_index)], (0x06-byte_index), addr_sz, RoundBruteforceValue);
550 //legic_prng_forward(1);
551 if(r == 0) {
552 byte_index++;
553 r = legic_write_byte(BigBuf[(0x06-byte_index)], (0x06-byte_index), addr_sz, RoundBruteforceValue);
554 }
555 //legic_prng_forward(1);
556 }
557 else {
558 r = legic_write_byte(BigBuf[byte_index+offset], byte_index+offset, addr_sz, RoundBruteforceValue);
559 }
560 if((r != 0) || BUTTON_PRESS()) {
561 Dbprintf("operation aborted @ 0x%03.3x", byte_index);
562 switch_off_tag_rwd();
563 LED_B_OFF();
564 LED_C_OFF();
565 return -1;
566 }
567
568 WDT_HIT();
569 byte_index++;
570 if(byte_index & 0x10) LED_C_ON(); else LED_C_OFF();
571 }
572 LED_B_OFF();
573 LED_C_OFF();
574 DbpString("write successful");
575 return 0;
576 }*/
577
578 void LegicRfWriter(uint16_t offset, uint16_t bytes, uint8_t iv) {
579
580 int byte_index = 0;
581 uint8_t isOK = 1;
582 legic_card_select_t card;
583
584 LegicCommonInit();
585
586 if ( legic_select_card_iv(&card, iv) ) {
587 isOK = 0;
588 goto OUT;
589 }
590
591 switch_off_tag_rwd();
592
593 switch(card.tagtype) {
594 case 0x0d:
595 if(offset+bytes > 22) {
596 Dbprintf("Error: can not write to 0x%03.3x on MIM22", offset + bytes);
597 return;
598 }
599 if ( MF_DBGLEVEL >= 2) Dbprintf("MIM22 card found, writing 0x%02.2x - 0x%02.2x ...", offset, offset + bytes);
600 break;
601 case 0x1d:
602 if(offset+bytes > 0x100) {
603 Dbprintf("Error: can not write to 0x%03.3x on MIM256", offset + bytes);
604 return;
605 }
606 if ( MF_DBGLEVEL >= 2) Dbprintf("MIM256 card found, writing 0x%02.2x - 0x%02.2x ...", offset, offset + bytes);
607 break;
608 case 0x3d:
609 if(offset+bytes > 0x400) {
610 Dbprintf("Error: can not write to 0x%03.3x on MIM1024", offset + bytes);
611 return;
612 }
613 if ( MF_DBGLEVEL >= 2) Dbprintf("MIM1024 card found, writing 0x%03.3x - 0x%03.3x ...", offset, offset + bytes);
614 break;
615 default:
616 return;
617 }
618
619 LED_B_ON();
620 setup_phase_reader(iv);
621 int r = 0;
622 while(byte_index < bytes) {
623
624 //check if the DCF should be changed
625 if ( ((byte_index+offset) == 0x05) && (bytes >= 0x02) ) {
626 //write DCF in reverse order (addr 0x06 before 0x05)
627 r = legic_write_byte(cardmem[(0x06-byte_index)], (0x06-byte_index), card.addrsize);
628
629 // write second byte on success
630 if(r == 0) {
631 byte_index++;
632 r = legic_write_byte(cardmem[(0x06-byte_index)], (0x06-byte_index), card.addrsize);
633 }
634 }
635 else {
636 r = legic_write_byte(cardmem[byte_index+offset], byte_index+offset, card.addrsize);
637 }
638
639 if ((r != 0) || BUTTON_PRESS()) {
640 Dbprintf("operation aborted @ 0x%03.3x", byte_index);
641 isOK = 0;
642 goto OUT;
643 }
644
645 WDT_HIT();
646 byte_index++;
647 }
648
649 OUT:
650 cmd_send(CMD_ACK, isOK, 0,0,0,0);
651 switch_off_tag_rwd();
652 LEDsoff();
653 }
654
655 void LegicRfRawWriter(int address, int byte, uint8_t iv) {
656
657 int byte_index = 0, addr_sz = 0;
658
659 LegicCommonInit();
660
661 if ( MF_DBGLEVEL >= 2) DbpString("setting up legic card");
662
663 uint32_t tag_type = setup_phase_reader(iv);
664
665 switch_off_tag_rwd();
666
667 switch(tag_type) {
668 case 0x0d:
669 if(address > 22) {
670 Dbprintf("Error: can not write to 0x%03.3x on MIM22", address);
671 return;
672 }
673 addr_sz = 5;
674 if ( MF_DBGLEVEL >= 2) Dbprintf("MIM22 card found, writing at addr 0x%02.2x - value 0x%02.2x ...", address, byte);
675 break;
676 case 0x1d:
677 if(address > 0x100) {
678 Dbprintf("Error: can not write to 0x%03.3x on MIM256", address);
679 return;
680 }
681 addr_sz = 8;
682 if ( MF_DBGLEVEL >= 2) Dbprintf("MIM256 card found, writing at addr 0x%02.2x - value 0x%02.2x ...", address, byte);
683 break;
684 case 0x3d:
685 if(address > 0x400) {
686 Dbprintf("Error: can not write to 0x%03.3x on MIM1024", address);
687 return;
688 }
689 addr_sz = 10;
690 if ( MF_DBGLEVEL >= 2) Dbprintf("MIM1024 card found, writing at addr 0x%03.3x - value 0x%03.3x ...", address, byte);
691 break;
692 default:
693 Dbprintf("No or unknown card found, aborting");
694 return;
695 }
696
697 Dbprintf("integer value: %d address: %d addr_sz: %d", byte, address, addr_sz);
698 LED_B_ON();
699
700 setup_phase_reader(iv);
701
702 int r = legic_write_byte(byte, address, addr_sz);
703
704 if((r != 0) || BUTTON_PRESS()) {
705 Dbprintf("operation aborted @ 0x%03.3x (%1d)", byte_index, r);
706 switch_off_tag_rwd();
707 LEDsoff();
708 return;
709 }
710
711 LEDsoff();
712 if ( MF_DBGLEVEL >= 1) DbpString("write successful");
713 }
714
715 int legic_select_card_iv(legic_card_select_t *p_card, uint8_t iv){
716
717 if ( p_card == NULL ) return 1;
718
719 p_card->tagtype = setup_phase_reader(iv);
720
721 switch(p_card->tagtype) {
722 case 0x0d:
723 p_card->cmdsize = 6;
724 p_card->addrsize = 5;
725 p_card->cardsize = 22;
726 break;
727 case 0x1d:
728 p_card->cmdsize = 9;
729 p_card->addrsize = 8;
730 p_card->cardsize = 256;
731 break;
732 case 0x3d:
733 p_card->cmdsize = 11;
734 p_card->addrsize = 10;
735 p_card->cardsize = 1024;
736 break;
737 default:
738 p_card->cmdsize = 0;
739 p_card->addrsize = 0;
740 p_card->cardsize = 0;
741 return 2;
742 }
743 return 0;
744 }
745 int legic_select_card(legic_card_select_t *p_card){
746 return legic_select_card_iv(p_card, 0x01);
747 }
748
749 void LegicRfInfo(void){
750
751 uint8_t buf[sizeof(legic_card_select_t)] = {0x00};
752 legic_card_select_t *card = (legic_card_select_t*) buf;
753
754 LegicCommonInit();
755
756 if ( legic_select_card(card) ) {
757 cmd_send(CMD_ACK,0,0,0,0,0);
758 goto OUT;
759 }
760
761 // read UID bytes
762 for ( uint8_t i = 0; i < sizeof(card->uid); ++i) {
763 int r = legic_read_byte(i, card->cmdsize);
764 if ( r == -1 ) {
765 cmd_send(CMD_ACK,0,0,0,0,0);
766 goto OUT;
767 }
768 card->uid[i] = r & 0xFF;
769 }
770
771 cmd_send(CMD_ACK, 1, 0, 0, buf, sizeof(legic_card_select_t));
772
773 OUT:
774 switch_off_tag_rwd();
775 LEDsoff();
776 }
777
778 /* Handle (whether to respond) a frame in tag mode
779 * Only called when simulating a tag.
780 */
781 static void frame_handle_tag(struct legic_frame const * const f)
782 {
783 uint8_t *BigBuf = BigBuf_get_addr();
784
785 /* First Part of Handshake (IV) */
786 if(f->bits == 7) {
787
788 LED_C_ON();
789
790 // Reset prng timer
791 ResetTimer(prng_timer);
792
793 legic_prng_init(f->data);
794 frame_send_tag(0x3d, 6, 1); /* 0x3d^0x26 = 0x1B */
795 legic_state = STATE_IV;
796 legic_read_count = 0;
797 legic_prng_bc = 0;
798 legic_prng_iv = f->data;
799
800
801 ResetTimer(timer);
802 WaitUS(280);
803 return;
804 }
805
806 /* 0x19==??? */
807 if(legic_state == STATE_IV) {
808 int local_key = get_key_stream(3, 6);
809 int xored = 0x39 ^ local_key;
810 if((f->bits == 6) && (f->data == xored)) {
811 legic_state = STATE_CON;
812
813 ResetTimer(timer);
814 WaitUS(200);
815 return;
816
817 } else {
818 legic_state = STATE_DISCON;
819 LED_C_OFF();
820 Dbprintf("iv: %02x frame: %02x key: %02x xored: %02x", legic_prng_iv, f->data, local_key, xored);
821 return;
822 }
823 }
824
825 /* Read */
826 if(f->bits == 11) {
827 if(legic_state == STATE_CON) {
828 int key = get_key_stream(2, 11); //legic_phase_drift, 11);
829 int addr = f->data ^ key; addr = addr >> 1;
830 int data = BigBuf[addr];
831 int hash = legic4Crc(LEGIC_READ, addr, data, 11) << 8;
832 BigBuf[OFFSET_LOG+legic_read_count] = (uint8_t)addr;
833 legic_read_count++;
834
835 //Dbprintf("Data:%03.3x, key:%03.3x, addr: %03.3x, read_c:%u", f->data, key, addr, read_c);
836 legic_prng_forward(legic_reqresp_drift);
837
838 frame_send_tag(hash | data, 12, 1);
839
840 ResetTimer(timer);
841 legic_prng_forward(2);
842 WaitUS(180);
843 return;
844 }
845 }
846
847 /* Write */
848 if(f->bits == 23) {
849 int key = get_key_stream(-1, 23); //legic_frame_drift, 23);
850 int addr = f->data ^ key; addr = addr >> 1; addr = addr & 0x3ff;
851 int data = f->data ^ key; data = data >> 11; data = data & 0xff;
852
853 /* write command */
854 legic_state = STATE_DISCON;
855 LED_C_OFF();
856 Dbprintf("write - addr: %x, data: %x", addr, data);
857 return;
858 }
859
860 if(legic_state != STATE_DISCON) {
861 Dbprintf("Unexpected: sz:%u, Data:%03.3x, State:%u, Count:%u", f->bits, f->data, legic_state, legic_read_count);
862 int i;
863 Dbprintf("IV: %03.3x", legic_prng_iv);
864 for(i = 0; i<legic_read_count; i++) {
865 Dbprintf("Read Nb: %u, Addr: %u", i, BigBuf[OFFSET_LOG+i]);
866 }
867
868 for(i = -1; i<legic_read_count; i++) {
869 uint32_t t;
870 t = BigBuf[OFFSET_LOG+256+i*4];
871 t |= BigBuf[OFFSET_LOG+256+i*4+1] << 8;
872 t |= BigBuf[OFFSET_LOG+256+i*4+2] <<16;
873 t |= BigBuf[OFFSET_LOG+256+i*4+3] <<24;
874
875 Dbprintf("Cycles: %u, Frame Length: %u, Time: %u",
876 BigBuf[OFFSET_LOG+128+i],
877 BigBuf[OFFSET_LOG+384+i],
878 t);
879 }
880 }
881 legic_state = STATE_DISCON;
882 legic_read_count = 0;
883 SpinDelay(10);
884 LED_C_OFF();
885 return;
886 }
887
888 /* Read bit by bit untill full frame is received
889 * Call to process frame end answer
890 */
891 static void emit(int bit) {
892
893 switch (bit) {
894 case 1:
895 frame_append_bit(&current_frame, 1);
896 break;
897 case 0:
898 frame_append_bit(&current_frame, 0);
899 break;
900 default:
901 if(current_frame.bits <= 4) {
902 frame_clean(&current_frame);
903 } else {
904 frame_handle_tag(&current_frame);
905 frame_clean(&current_frame);
906 }
907 WDT_HIT();
908 break;
909 }
910 }
911
912 void LegicRfSimulate(int phase, int frame, int reqresp)
913 {
914 /* ADC path high-frequency peak detector, FPGA in high-frequency simulator mode,
915 * modulation mode set to 212kHz subcarrier. We are getting the incoming raw
916 * envelope waveform on DIN and should send our response on DOUT.
917 *
918 * The LEGIC RF protocol is pulse-pause-encoding from reader to card, so we'll
919 * measure the time between two rising edges on DIN, and no encoding on the
920 * subcarrier from card to reader, so we'll just shift out our verbatim data
921 * on DOUT, 1 bit is 100us. The time from reader to card frame is still unclear,
922 * seems to be 300us-ish.
923 */
924
925 legic_phase_drift = phase;
926 legic_frame_drift = frame;
927 legic_reqresp_drift = reqresp;
928
929 FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
930 SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
931 FpgaSetupSsc();
932 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_SIMULATOR | FPGA_HF_SIMULATOR_MODULATE_212K);
933
934 /* Bitbang the receiver */
935 AT91C_BASE_PIOA->PIO_ODR = GPIO_SSC_DIN;
936 AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DIN;
937
938 //setup_timer();
939 crc_init(&legic_crc, 4, 0x19 >> 1, 0x5, 0);
940
941 int old_level = 0;
942 int active = 0;
943 legic_state = STATE_DISCON;
944
945 LED_B_ON();
946 DbpString("Starting Legic emulator, press button to end");
947
948 while(!BUTTON_PRESS() && !usb_poll_validate_length()) {
949 int level = !!(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_DIN);
950 int time = timer->TC_CV;
951
952 if(level != old_level) {
953 if(level == 1) {
954 timer->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;
955
956 if (FUZZ_EQUAL(time, RWD_TIME_1, RWD_TIME_FUZZ)) {
957 /* 1 bit */
958 emit(1);
959 active = 1;
960 LED_A_ON();
961 } else if (FUZZ_EQUAL(time, RWD_TIME_0, RWD_TIME_FUZZ)) {
962 /* 0 bit */
963 emit(0);
964 active = 1;
965 LED_A_ON();
966 } else if (active) {
967 /* invalid */
968 emit(-1);
969 active = 0;
970 LED_A_OFF();
971 }
972 }
973 }
974
975 /* Frame end */
976 if(time >= (RWD_TIME_1+RWD_TIME_FUZZ) && active) {
977 emit(-1);
978 active = 0;
979 LED_A_OFF();
980 }
981
982 if(time >= (20*RWD_TIME_1) && (timer->TC_SR & AT91C_TC_CLKSTA)) {
983 timer->TC_CCR = AT91C_TC_CLKDIS;
984 }
985
986 old_level = level;
987 WDT_HIT();
988 }
989 if ( MF_DBGLEVEL >= 1) DbpString("Stopped");
990 LEDsoff();
991 }
992
993 //-----------------------------------------------------------------------------
994 // Code up a string of octets at layer 2 (including CRC, we don't generate
995 // that here) so that they can be transmitted to the reader. Doesn't transmit
996 // them yet, just leaves them ready to send in ToSend[].
997 //-----------------------------------------------------------------------------
998 // static void CodeLegicAsTag(const uint8_t *cmd, int len)
999 // {
1000 // int i;
1001
1002 // ToSendReset();
1003
1004 // // Transmit a burst of ones, as the initial thing that lets the
1005 // // reader get phase sync. This (TR1) must be > 80/fs, per spec,
1006 // // but tag that I've tried (a Paypass) exceeds that by a fair bit,
1007 // // so I will too.
1008 // for(i = 0; i < 20; i++) {
1009 // ToSendStuffBit(1);
1010 // ToSendStuffBit(1);
1011 // ToSendStuffBit(1);
1012 // ToSendStuffBit(1);
1013 // }
1014
1015 // // Send SOF.
1016 // for(i = 0; i < 10; i++) {
1017 // ToSendStuffBit(0);
1018 // ToSendStuffBit(0);
1019 // ToSendStuffBit(0);
1020 // ToSendStuffBit(0);
1021 // }
1022 // for(i = 0; i < 2; i++) {
1023 // ToSendStuffBit(1);
1024 // ToSendStuffBit(1);
1025 // ToSendStuffBit(1);
1026 // ToSendStuffBit(1);
1027 // }
1028
1029 // for(i = 0; i < len; i++) {
1030 // int j;
1031 // uint8_t b = cmd[i];
1032
1033 // // Start bit
1034 // ToSendStuffBit(0);
1035 // ToSendStuffBit(0);
1036 // ToSendStuffBit(0);
1037 // ToSendStuffBit(0);
1038
1039 // // Data bits
1040 // for(j = 0; j < 8; j++) {
1041 // if(b & 1) {
1042 // ToSendStuffBit(1);
1043 // ToSendStuffBit(1);
1044 // ToSendStuffBit(1);
1045 // ToSendStuffBit(1);
1046 // } else {
1047 // ToSendStuffBit(0);
1048 // ToSendStuffBit(0);
1049 // ToSendStuffBit(0);
1050 // ToSendStuffBit(0);
1051 // }
1052 // b >>= 1;
1053 // }
1054
1055 // // Stop bit
1056 // ToSendStuffBit(1);
1057 // ToSendStuffBit(1);
1058 // ToSendStuffBit(1);
1059 // ToSendStuffBit(1);
1060 // }
1061
1062 // // Send EOF.
1063 // for(i = 0; i < 10; i++) {
1064 // ToSendStuffBit(0);
1065 // ToSendStuffBit(0);
1066 // ToSendStuffBit(0);
1067 // ToSendStuffBit(0);
1068 // }
1069 // for(i = 0; i < 2; i++) {
1070 // ToSendStuffBit(1);
1071 // ToSendStuffBit(1);
1072 // ToSendStuffBit(1);
1073 // ToSendStuffBit(1);
1074 // }
1075
1076 // // Convert from last byte pos to length
1077 // ToSendMax++;
1078 // }
1079
1080 //-----------------------------------------------------------------------------
1081 // The software UART that receives commands from the reader, and its state
1082 // variables.
1083 //-----------------------------------------------------------------------------
1084 /*
1085 static struct {
1086 enum {
1087 STATE_UNSYNCD,
1088 STATE_GOT_FALLING_EDGE_OF_SOF,
1089 STATE_AWAITING_START_BIT,
1090 STATE_RECEIVING_DATA
1091 } state;
1092 uint16_t shiftReg;
1093 int bitCnt;
1094 int byteCnt;
1095 int byteCntMax;
1096 int posCnt;
1097 uint8_t *output;
1098 } Uart;
1099 */
1100 /* Receive & handle a bit coming from the reader.
1101 *
1102 * This function is called 4 times per bit (every 2 subcarrier cycles).
1103 * Subcarrier frequency fs is 212kHz, 1/fs = 4,72us, i.e. function is called every 9,44us
1104 *
1105 * LED handling:
1106 * LED A -> ON once we have received the SOF and are expecting the rest.
1107 * LED A -> OFF once we have received EOF or are in error state or unsynced
1108 *
1109 * Returns: true if we received a EOF
1110 * false if we are still waiting for some more
1111 */
1112 // static RAMFUNC int HandleLegicUartBit(uint8_t bit)
1113 // {
1114 // switch(Uart.state) {
1115 // case STATE_UNSYNCD:
1116 // if(!bit) {
1117 // // we went low, so this could be the beginning of an SOF
1118 // Uart.state = STATE_GOT_FALLING_EDGE_OF_SOF;
1119 // Uart.posCnt = 0;
1120 // Uart.bitCnt = 0;
1121 // }
1122 // break;
1123
1124 // case STATE_GOT_FALLING_EDGE_OF_SOF:
1125 // Uart.posCnt++;
1126 // if(Uart.posCnt == 2) { // sample every 4 1/fs in the middle of a bit
1127 // if(bit) {
1128 // if(Uart.bitCnt > 9) {
1129 // // we've seen enough consecutive
1130 // // zeros that it's a valid SOF
1131 // Uart.posCnt = 0;
1132 // Uart.byteCnt = 0;
1133 // Uart.state = STATE_AWAITING_START_BIT;
1134 // LED_A_ON(); // Indicate we got a valid SOF
1135 // } else {
1136 // // didn't stay down long enough
1137 // // before going high, error
1138 // Uart.state = STATE_UNSYNCD;
1139 // }
1140 // } else {
1141 // // do nothing, keep waiting
1142 // }
1143 // Uart.bitCnt++;
1144 // }
1145 // if(Uart.posCnt >= 4) Uart.posCnt = 0;
1146 // if(Uart.bitCnt > 12) {
1147 // // Give up if we see too many zeros without
1148 // // a one, too.
1149 // LED_A_OFF();
1150 // Uart.state = STATE_UNSYNCD;
1151 // }
1152 // break;
1153
1154 // case STATE_AWAITING_START_BIT:
1155 // Uart.posCnt++;
1156 // if(bit) {
1157 // if(Uart.posCnt > 50/2) { // max 57us between characters = 49 1/fs, max 3 etus after low phase of SOF = 24 1/fs
1158 // // stayed high for too long between
1159 // // characters, error
1160 // Uart.state = STATE_UNSYNCD;
1161 // }
1162 // } else {
1163 // // falling edge, this starts the data byte
1164 // Uart.posCnt = 0;
1165 // Uart.bitCnt = 0;
1166 // Uart.shiftReg = 0;
1167 // Uart.state = STATE_RECEIVING_DATA;
1168 // }
1169 // break;
1170
1171 // case STATE_RECEIVING_DATA:
1172 // Uart.posCnt++;
1173 // if(Uart.posCnt == 2) {
1174 // // time to sample a bit
1175 // Uart.shiftReg >>= 1;
1176 // if(bit) {
1177 // Uart.shiftReg |= 0x200;
1178 // }
1179 // Uart.bitCnt++;
1180 // }
1181 // if(Uart.posCnt >= 4) {
1182 // Uart.posCnt = 0;
1183 // }
1184 // if(Uart.bitCnt == 10) {
1185 // if((Uart.shiftReg & 0x200) && !(Uart.shiftReg & 0x001))
1186 // {
1187 // // this is a data byte, with correct
1188 // // start and stop bits
1189 // Uart.output[Uart.byteCnt] = (Uart.shiftReg >> 1) & 0xff;
1190 // Uart.byteCnt++;
1191
1192 // if(Uart.byteCnt >= Uart.byteCntMax) {
1193 // // Buffer overflowed, give up
1194 // LED_A_OFF();
1195 // Uart.state = STATE_UNSYNCD;
1196 // } else {
1197 // // so get the next byte now
1198 // Uart.posCnt = 0;
1199 // Uart.state = STATE_AWAITING_START_BIT;
1200 // }
1201 // } else if (Uart.shiftReg == 0x000) {
1202 // // this is an EOF byte
1203 // LED_A_OFF(); // Finished receiving
1204 // Uart.state = STATE_UNSYNCD;
1205 // if (Uart.byteCnt != 0) {
1206 // return TRUE;
1207 // }
1208 // } else {
1209 // // this is an error
1210 // LED_A_OFF();
1211 // Uart.state = STATE_UNSYNCD;
1212 // }
1213 // }
1214 // break;
1215
1216 // default:
1217 // LED_A_OFF();
1218 // Uart.state = STATE_UNSYNCD;
1219 // break;
1220 // }
1221
1222 // return FALSE;
1223 // }
1224 /*
1225
1226 static void UartReset() {
1227 Uart.byteCntMax = 3;
1228 Uart.state = STATE_UNSYNCD;
1229 Uart.byteCnt = 0;
1230 Uart.bitCnt = 0;
1231 Uart.posCnt = 0;
1232 memset(Uart.output, 0x00, 3);
1233 }
1234 */
1235 // static void UartInit(uint8_t *data) {
1236 // Uart.output = data;
1237 // UartReset();
1238 // }
1239
1240 //=============================================================================
1241 // An LEGIC reader. We take layer two commands, code them
1242 // appropriately, and then send them to the tag. We then listen for the
1243 // tag's response, which we leave in the buffer to be demodulated on the
1244 // PC side.
1245 //=============================================================================
1246 /*
1247 static struct {
1248 enum {
1249 DEMOD_UNSYNCD,
1250 DEMOD_PHASE_REF_TRAINING,
1251 DEMOD_AWAITING_FALLING_EDGE_OF_SOF,
1252 DEMOD_GOT_FALLING_EDGE_OF_SOF,
1253 DEMOD_AWAITING_START_BIT,
1254 DEMOD_RECEIVING_DATA
1255 } state;
1256 int bitCount;
1257 int posCount;
1258 int thisBit;
1259 uint16_t shiftReg;
1260 uint8_t *output;
1261 int len;
1262 int sumI;
1263 int sumQ;
1264 } Demod;
1265 */
1266 /*
1267 * Handles reception of a bit from the tag
1268 *
1269 * This function is called 2 times per bit (every 4 subcarrier cycles).
1270 * Subcarrier frequency fs is 212kHz, 1/fs = 4,72us, i.e. function is called every 9,44us
1271 *
1272 * LED handling:
1273 * LED C -> ON once we have received the SOF and are expecting the rest.
1274 * LED C -> OFF once we have received EOF or are unsynced
1275 *
1276 * Returns: true if we received a EOF
1277 * false if we are still waiting for some more
1278 *
1279 */
1280
1281 /*
1282 static RAMFUNC int HandleLegicSamplesDemod(int ci, int cq)
1283 {
1284 int v = 0;
1285 int ai = ABS(ci);
1286 int aq = ABS(cq);
1287 int halfci = (ai >> 1);
1288 int halfcq = (aq >> 1);
1289
1290 switch(Demod.state) {
1291 case DEMOD_UNSYNCD:
1292
1293 CHECK_FOR_SUBCARRIER()
1294
1295 if(v > SUBCARRIER_DETECT_THRESHOLD) { // subcarrier detected
1296 Demod.state = DEMOD_PHASE_REF_TRAINING;
1297 Demod.sumI = ci;
1298 Demod.sumQ = cq;
1299 Demod.posCount = 1;
1300 }
1301 break;
1302
1303 case DEMOD_PHASE_REF_TRAINING:
1304 if(Demod.posCount < 8) {
1305
1306 CHECK_FOR_SUBCARRIER()
1307
1308 if (v > SUBCARRIER_DETECT_THRESHOLD) {
1309 // set the reference phase (will code a logic '1') by averaging over 32 1/fs.
1310 // note: synchronization time > 80 1/fs
1311 Demod.sumI += ci;
1312 Demod.sumQ += cq;
1313 ++Demod.posCount;
1314 } else {
1315 // subcarrier lost
1316 Demod.state = DEMOD_UNSYNCD;
1317 }
1318 } else {
1319 Demod.state = DEMOD_AWAITING_FALLING_EDGE_OF_SOF;
1320 }
1321 break;
1322
1323 case DEMOD_AWAITING_FALLING_EDGE_OF_SOF:
1324
1325 MAKE_SOFT_DECISION()
1326
1327 //Dbprintf("ICE: %d %d %d %d %d", v, Demod.sumI, Demod.sumQ, ci, cq );
1328 // logic '0' detected
1329 if (v <= 0) {
1330
1331 Demod.state = DEMOD_GOT_FALLING_EDGE_OF_SOF;
1332
1333 // start of SOF sequence
1334 Demod.posCount = 0;
1335 } else {
1336 // maximum length of TR1 = 200 1/fs
1337 if(Demod.posCount > 25*2) Demod.state = DEMOD_UNSYNCD;
1338 }
1339 ++Demod.posCount;
1340 break;
1341
1342 case DEMOD_GOT_FALLING_EDGE_OF_SOF:
1343 ++Demod.posCount;
1344
1345 MAKE_SOFT_DECISION()
1346
1347 if(v > 0) {
1348 // low phase of SOF too short (< 9 etu). Note: spec is >= 10, but FPGA tends to "smear" edges
1349 if(Demod.posCount < 10*2) {
1350 Demod.state = DEMOD_UNSYNCD;
1351 } else {
1352 LED_C_ON(); // Got SOF
1353 Demod.state = DEMOD_AWAITING_START_BIT;
1354 Demod.posCount = 0;
1355 Demod.len = 0;
1356 }
1357 } else {
1358 // low phase of SOF too long (> 12 etu)
1359 if(Demod.posCount > 13*2) {
1360 Demod.state = DEMOD_UNSYNCD;
1361 LED_C_OFF();
1362 }
1363 }
1364 break;
1365
1366 case DEMOD_AWAITING_START_BIT:
1367 ++Demod.posCount;
1368
1369 MAKE_SOFT_DECISION()
1370
1371 if(v > 0) {
1372 // max 19us between characters = 16 1/fs, max 3 etu after low phase of SOF = 24 1/fs
1373 if(Demod.posCount > 3*2) {
1374 Demod.state = DEMOD_UNSYNCD;
1375 LED_C_OFF();
1376 }
1377 } else {
1378 // start bit detected
1379 Demod.bitCount = 0;
1380 Demod.posCount = 1; // this was the first half
1381 Demod.thisBit = v;
1382 Demod.shiftReg = 0;
1383 Demod.state = DEMOD_RECEIVING_DATA;
1384 }
1385 break;
1386
1387 case DEMOD_RECEIVING_DATA:
1388
1389 MAKE_SOFT_DECISION()
1390
1391 if(Demod.posCount == 0) {
1392 // first half of bit
1393 Demod.thisBit = v;
1394 Demod.posCount = 1;
1395 } else {
1396 // second half of bit
1397 Demod.thisBit += v;
1398 Demod.shiftReg >>= 1;
1399 // logic '1'
1400 if(Demod.thisBit > 0)
1401 Demod.shiftReg |= 0x200;
1402
1403 ++Demod.bitCount;
1404
1405 if(Demod.bitCount == 10) {
1406
1407 uint16_t s = Demod.shiftReg;
1408
1409 if((s & 0x200) && !(s & 0x001)) {
1410 // stop bit == '1', start bit == '0'
1411 uint8_t b = (s >> 1);
1412 Demod.output[Demod.len] = b;
1413 ++Demod.len;
1414 Demod.state = DEMOD_AWAITING_START_BIT;
1415 } else {
1416 Demod.state = DEMOD_UNSYNCD;
1417 LED_C_OFF();
1418
1419 if(s == 0x000) {
1420 // This is EOF (start, stop and all data bits == '0'
1421 return TRUE;
1422 }
1423 }
1424 }
1425 Demod.posCount = 0;
1426 }
1427 break;
1428
1429 default:
1430 Demod.state = DEMOD_UNSYNCD;
1431 LED_C_OFF();
1432 break;
1433 }
1434 return FALSE;
1435 }
1436 */
1437 /*
1438 // Clear out the state of the "UART" that receives from the tag.
1439 static void DemodReset() {
1440 Demod.len = 0;
1441 Demod.state = DEMOD_UNSYNCD;
1442 Demod.posCount = 0;
1443 Demod.sumI = 0;
1444 Demod.sumQ = 0;
1445 Demod.bitCount = 0;
1446 Demod.thisBit = 0;
1447 Demod.shiftReg = 0;
1448 memset(Demod.output, 0x00, 3);
1449 }
1450
1451 static void DemodInit(uint8_t *data) {
1452 Demod.output = data;
1453 DemodReset();
1454 }
1455 */
1456
1457 /*
1458 * Demodulate the samples we received from the tag, also log to tracebuffer
1459 * quiet: set to 'TRUE' to disable debug output
1460 */
1461
1462 /*
1463 #define LEGIC_DMA_BUFFER_SIZE 256
1464
1465 static void GetSamplesForLegicDemod(int n, bool quiet)
1466 {
1467 int max = 0;
1468 bool gotFrame = FALSE;
1469 int lastRxCounter = LEGIC_DMA_BUFFER_SIZE;
1470 int ci, cq, samples = 0;
1471
1472 BigBuf_free();
1473
1474 // And put the FPGA in the appropriate mode
1475 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_QUARTER_FREQ);
1476
1477 // The response (tag -> reader) that we're receiving.
1478 // Set up the demodulator for tag -> reader responses.
1479 DemodInit(BigBuf_malloc(MAX_FRAME_SIZE));
1480
1481 // The DMA buffer, used to stream samples from the FPGA
1482 int8_t *dmaBuf = (int8_t*) BigBuf_malloc(LEGIC_DMA_BUFFER_SIZE);
1483 int8_t *upTo = dmaBuf;
1484
1485 // Setup and start DMA.
1486 if ( !FpgaSetupSscDma((uint8_t*) dmaBuf, LEGIC_DMA_BUFFER_SIZE) ){
1487 if (MF_DBGLEVEL > 1) Dbprintf("FpgaSetupSscDma failed. Exiting");
1488 return;
1489 }
1490
1491 // Signal field is ON with the appropriate LED:
1492 LED_D_ON();
1493 for(;;) {
1494 int behindBy = lastRxCounter - AT91C_BASE_PDC_SSC->PDC_RCR;
1495 if(behindBy > max) max = behindBy;
1496
1497 while(((lastRxCounter-AT91C_BASE_PDC_SSC->PDC_RCR) & (LEGIC_DMA_BUFFER_SIZE-1)) > 2) {
1498 ci = upTo[0];
1499 cq = upTo[1];
1500 upTo += 2;
1501 if(upTo >= dmaBuf + LEGIC_DMA_BUFFER_SIZE) {
1502 upTo = dmaBuf;
1503 AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) upTo;
1504 AT91C_BASE_PDC_SSC->PDC_RNCR = LEGIC_DMA_BUFFER_SIZE;
1505 }
1506 lastRxCounter -= 2;
1507 if(lastRxCounter <= 0)
1508 lastRxCounter = LEGIC_DMA_BUFFER_SIZE;
1509
1510 samples += 2;
1511
1512 gotFrame = HandleLegicSamplesDemod(ci , cq );
1513 if ( gotFrame )
1514 break;
1515 }
1516
1517 if(samples > n || gotFrame)
1518 break;
1519 }
1520
1521 FpgaDisableSscDma();
1522
1523 if (!quiet && Demod.len == 0) {
1524 Dbprintf("max behindby = %d, samples = %d, gotFrame = %d, Demod.len = %d, Demod.sumI = %d, Demod.sumQ = %d",
1525 max,
1526 samples,
1527 gotFrame,
1528 Demod.len,
1529 Demod.sumI,
1530 Demod.sumQ
1531 );
1532 }
1533
1534 //Tracing
1535 if (Demod.len > 0) {
1536 uint8_t parity[MAX_PARITY_SIZE] = {0x00};
1537 LogTrace(Demod.output, Demod.len, 0, 0, parity, FALSE);
1538 }
1539 }
1540
1541 */
1542
1543 //-----------------------------------------------------------------------------
1544 // Transmit the command (to the tag) that was placed in ToSend[].
1545 //-----------------------------------------------------------------------------
1546 /*
1547 static void TransmitForLegic(void)
1548 {
1549 int c;
1550
1551 FpgaSetupSsc();
1552
1553 while(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY))
1554 AT91C_BASE_SSC->SSC_THR = 0xff;
1555
1556 // Signal field is ON with the appropriate Red LED
1557 LED_D_ON();
1558
1559 // Signal we are transmitting with the Green LED
1560 LED_B_ON();
1561 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX | FPGA_HF_READER_TX_SHALLOW_MOD);
1562
1563 for(c = 0; c < 10;) {
1564 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1565 AT91C_BASE_SSC->SSC_THR = 0xff;
1566 c++;
1567 }
1568 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
1569 volatile uint32_t r = AT91C_BASE_SSC->SSC_RHR;
1570 (void)r;
1571 }
1572 WDT_HIT();
1573 }
1574
1575 c = 0;
1576 for(;;) {
1577 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1578 AT91C_BASE_SSC->SSC_THR = ToSend[c];
1579 legic_prng_forward(1); // forward the lfsr
1580 c++;
1581 if(c >= ToSendMax) {
1582 break;
1583 }
1584 }
1585 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
1586 volatile uint32_t r = AT91C_BASE_SSC->SSC_RHR;
1587 (void)r;
1588 }
1589 WDT_HIT();
1590 }
1591 LED_B_OFF();
1592 }
1593 */
1594
1595 //-----------------------------------------------------------------------------
1596 // Code a layer 2 command (string of octets, including CRC) into ToSend[],
1597 // so that it is ready to transmit to the tag using TransmitForLegic().
1598 //-----------------------------------------------------------------------------
1599 /*
1600 static void CodeLegicBitsAsReader(const uint8_t *cmd, uint8_t cmdlen, int bits)
1601 {
1602 int i, j;
1603 uint8_t b;
1604
1605 ToSendReset();
1606
1607 // Send SOF
1608 for(i = 0; i < 7; i++)
1609 ToSendStuffBit(1);
1610
1611
1612 for(i = 0; i < cmdlen; i++) {
1613 // Start bit
1614 ToSendStuffBit(0);
1615
1616 // Data bits
1617 b = cmd[i];
1618 for(j = 0; j < bits; j++) {
1619 if(b & 1) {
1620 ToSendStuffBit(1);
1621 } else {
1622 ToSendStuffBit(0);
1623 }
1624 b >>= 1;
1625 }
1626 }
1627
1628 // Convert from last character reference to length
1629 ++ToSendMax;
1630 }
1631 */
1632 /**
1633 Convenience function to encode, transmit and trace Legic comms
1634 **/
1635 /*
1636 static void CodeAndTransmitLegicAsReader(const uint8_t *cmd, uint8_t cmdlen, int bits)
1637 {
1638 CodeLegicBitsAsReader(cmd, cmdlen, bits);
1639 TransmitForLegic();
1640 if (tracing) {
1641 uint8_t parity[1] = {0x00};
1642 LogTrace(cmd, cmdlen, 0, 0, parity, TRUE);
1643 }
1644 }
1645
1646 */
1647 // Set up LEGIC communication
1648 /*
1649 void ice_legic_setup() {
1650
1651 // standard things.
1652 FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
1653 BigBuf_free(); BigBuf_Clear_ext(false);
1654 clear_trace();
1655 set_tracing(TRUE);
1656 DemodReset();
1657 UartReset();
1658
1659 // Set up the synchronous serial port
1660 FpgaSetupSsc();
1661
1662 // connect Demodulated Signal to ADC:
1663 SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
1664
1665 // Signal field is on with the appropriate LED
1666 LED_D_ON();
1667 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX | FPGA_HF_READER_TX_SHALLOW_MOD);
1668 SpinDelay(20);
1669 // Start the timer
1670 //StartCountSspClk();
1671
1672 // initalize CRC
1673 crc_init(&legic_crc, 4, 0x19 >> 1, 0x5, 0);
1674
1675 // initalize prng
1676 legic_prng_init(0);
1677 }
1678 */
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