1 //-----------------------------------------------------------------------------
2 // (c) 2009 Henryk Plötz <henryk@ploetzli.ch>
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
7 //-----------------------------------------------------------------------------
8 // LEGIC RF simulation code
9 //-----------------------------------------------------------------------------
12 static struct legic_frame
{
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
;
28 static int legic_phase_drift
;
29 static int legic_frame_drift
;
30 static int legic_reqresp_drift
;
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.
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;
47 // Set up Timer 2 to use for measuring time between frames in
48 // tag simulation mode. Runs 4x faster as Timer 1
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;
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;
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
70 // At TIMER_CLOCK3 (MCK/32)
71 //#define RWD_TIME_1 150 /* RWD_TIME_PAUSE off, 80us on = 100us */
72 //#define RWD_TIME_0 90 /* RWD_TIME_PAUSE off, 40us on = 60us */
73 //#define RWD_TIME_PAUSE 30 /* 20us */
75 // testing calculating in (us) microseconds.
76 #define RWD_TIME_1 120 // READER_TIME_PAUSE 20us off, 80us on = 100us 80 * 1.5 == 120ticks
77 #define RWD_TIME_0 60 // READER_TIME_PAUSE 20us off, 40us on = 60us 40 * 1.5 == 60ticks
78 #define RWD_TIME_PAUSE 30 // 20us == 20 * 1.5 == 30ticks */
79 #define TAG_BIT_PERIOD 150 // 100us == 100 * 1.5 == 150ticks
80 #define TAG_FRAME_WAIT 495 // 330us from READER frame end to TAG frame start. 330 * 1.5 == 495
82 #define RWD_TIME_FUZZ 20 // rather generous 13us, since the peak detector + hysteresis fuzz quite a bit
84 #define SIM_DIVISOR 586 /* prng_time/SIM_DIVISOR count prng needs to be forwared */
85 #define SIM_SHIFT 900 /* prng_time+SIM_SHIFT shift of delayed start */
87 #define OFFSET_LOG 1024
89 #define FUZZ_EQUAL(value, target, fuzz) ((value) > ((target)-(fuzz)) && (value) < ((target)+(fuzz)))
92 # define SHORT_COIL LOW(GPIO_SSC_DOUT);
95 # define OPEN_COIL HIGH(GPIO_SSC_DOUT);
98 uint32_t sendFrameStop
= 0;
100 // Pause pulse, off in 20us / 30ticks,
101 // ONE / ZERO bit pulse,
102 // one == 80us / 120ticks
103 // zero == 40us / 60ticks
105 # define COIL_PULSE(x) \
108 WaitTicks( (RWD_TIME_PAUSE) ); \
114 // ToDo: define a meaningful maximum size for auth_table. The bigger this is, the lower will be the available memory for traces.
115 // Historically it used to be FREE_BUFFER_SIZE, which was 2744.
116 #define LEGIC_CARD_MEMSIZE 1024
117 static uint8_t* cardmem
;
119 static void frame_append_bit(struct legic_frame
* const f
, uint8_t bit
) {
120 // Overflow, won't happen
121 if (f
->bits
>= 31) return;
123 f
->data
|= (bit
<< f
->bits
);
127 static void frame_clean(struct legic_frame
* const f
) {
132 // Prng works when waiting in 99.1us cycles.
133 // and while sending/receiving in bit frames (100, 60)
134 /*static void CalibratePrng( uint32_t time){
135 // Calculate Cycles based on timer 100us
136 uint32_t i = (time - sendFrameStop) / 100 ;
138 // substract cycles of finished frames
139 int k = i - legic_prng_count()+1;
141 // substract current frame length, rewind to beginning
143 legic_prng_forward(k);
147 /* Generate Keystream */
148 uint32_t get_key_stream(int skip
, int count
) {
152 // Use int to enlarge timer tc to 32bit
153 legic_prng_bc
+= prng_timer
->TC_CV
;
155 // reset the prng timer.
156 ResetTimer(prng_timer
);
158 /* If skip == -1, forward prng time based */
160 i
= (legic_prng_bc
+ SIM_SHIFT
)/SIM_DIVISOR
; /* Calculate Cycles based on timer */
161 i
-= legic_prng_count(); /* substract cycles of finished frames */
162 i
-= count
; /* substract current frame length, rewind to beginning */
163 legic_prng_forward(i
);
165 legic_prng_forward(skip
);
168 i
= (count
== 6) ? -1 : legic_read_count
;
170 /* Write Time Data into LOG */
171 // uint8_t *BigBuf = BigBuf_get_addr();
172 // BigBuf[OFFSET_LOG+128+i] = legic_prng_count();
173 // BigBuf[OFFSET_LOG+256+i*4] = (legic_prng_bc >> 0) & 0xff;
174 // BigBuf[OFFSET_LOG+256+i*4+1] = (legic_prng_bc >> 8) & 0xff;
175 // BigBuf[OFFSET_LOG+256+i*4+2] = (legic_prng_bc >>16) & 0xff;
176 // BigBuf[OFFSET_LOG+256+i*4+3] = (legic_prng_bc >>24) & 0xff;
177 // BigBuf[OFFSET_LOG+384+i] = count;
179 /* Generate KeyStream */
180 for(i
=0; i
<count
; i
++) {
181 key
|= legic_prng_get_bit() << i
;
182 legic_prng_forward(1);
187 /* Send a frame in tag mode, the FPGA must have been set up by
190 void frame_send_tag(uint16_t response
, uint8_t bits
, uint8_t crypt
) {
191 /* Bitbang the response */
193 AT91C_BASE_PIOA
->PIO_OER
= GPIO_SSC_DOUT
;
194 AT91C_BASE_PIOA
->PIO_PER
= GPIO_SSC_DOUT
;
196 /* Use time to crypt frame */
198 legic_prng_forward(2); /* TAG_FRAME_WAIT -> shift by 2 */
199 response
^= legic_prng_get_bits(bits
);
202 /* Wait for the frame start */
203 WaitUS( TAG_FRAME_WAIT
);
206 for(int i
= 0; i
< bits
; i
++) {
221 /* Send a frame in reader mode, the FPGA must have been set up by
224 void frame_sendAsReader(uint32_t data
, uint8_t bits
){
226 uint32_t starttime
= GET_TICKS
, send
= 0;
228 uint8_t prngstart
= legic_prng_count() ;
230 // xor lsfr onto data.
231 send
= data
^ legic_prng_get_bits(bits
);
233 for (; mask
< BITMASK(bits
); mask
<<= 1) {
235 COIL_PULSE(RWD_TIME_1
);
237 COIL_PULSE(RWD_TIME_0
);
241 // Final pause to mark the end of the frame
244 sendFrameStop
= GET_TICKS
;
245 uint8_t cmdbytes
[] = {
254 LogTrace(cmdbytes
, sizeof(cmdbytes
), starttime
, sendFrameStop
, NULL
, TRUE
);
257 /* Receive a frame from the card in reader emulation mode, the FPGA and
258 * timer must have been set up by LegicRfReader and frame_sendAsReader.
260 * The LEGIC RF protocol from card to reader does not include explicit
261 * frame start/stop information or length information. The reader must
262 * know beforehand how many bits it wants to receive. (Notably: a card
263 * sending a stream of 0-bits is indistinguishable from no card present.)
265 * Receive methodology: There is a fancy correlator in hi_read_rx_xcorr, but
266 * I'm not smart enough to use it. Instead I have patched hi_read_tx to output
267 * the ADC signal with hysteresis on SSP_DIN. Bit-bang that signal and look
268 * for edges. Count the edges in each bit interval. If they are approximately
269 * 0 this was a 0-bit, if they are approximately equal to the number of edges
270 * expected for a 212kHz subcarrier, this was a 1-bit. For timing we use the
271 * timer that's still running from frame_sendAsReader in order to get a synchronization
272 * with the frame that we just sent.
274 * FIXME: Because we're relying on the hysteresis to just do the right thing
275 * the range is severely reduced (and you'll probably also need a good antenna).
276 * So this should be fixed some time in the future for a proper receiver.
278 static void frame_receiveAsReader(struct legic_frame
* const f
, uint8_t bits
) {
281 if ( bits
> 32 ) return;
283 uint8_t i
= bits
, edges
= 0;
285 uint32_t the_bit
= 1, next_bit_at
= 0, data
;
287 int old_level
= 0, level
= 0;
289 AT91C_BASE_PIOA
->PIO_ODR
= GPIO_SSC_DIN
;
290 AT91C_BASE_PIOA
->PIO_PER
= GPIO_SSC_DIN
;
292 // calibrate the prng.
294 legic_prng_forward(2);
296 // precompute the cipher
297 uint8_t prngstart
= legic_prng_count() ;
299 data
= lsfr
= legic_prng_get_bits(bits
);
301 //FIXED time between sending frame and now listening frame. 330us
302 // 387 = 0x19 0001 1001
304 // 500 = 0x1C 0001 1100
305 uint32_t starttime
= GET_TICKS
;
306 //uint16_t mywait = TAG_FRAME_WAIT - (starttime - sendFrameStop);
307 uint16_t mywait
= 495 - (starttime
- sendFrameStop
);
309 WaitTicks( 495 - 9 );
311 //Dbprintf("WAIT %d", mywait );
315 next_bit_at
= GET_TICKS
+ TAG_BIT_PERIOD
;
320 while ( GET_TICKS
< next_bit_at
) {
322 level
= (AT91C_BASE_PIOA
->PIO_PDSR
& GPIO_SSC_DIN
);
324 if (level
!= old_level
)
329 if(edges
> 20 && adjust
== 0) {
335 next_bit_at
+= TAG_BIT_PERIOD
;
337 // We expect 42 edges == ONE
338 //if (edges > 20 && edges < 64)
349 uint8_t cmdbytes
[] = {
353 BYTEx(data
, 0) ^ BYTEx(lsfr
,0),
354 BYTEx(data
, 1) ^ BYTEx(lsfr
,1),
358 LogTrace(cmdbytes
, sizeof(cmdbytes
), starttime
, GET_TICKS
, NULL
, FALSE
);
361 // Setup pm3 as a Legic Reader
362 static uint32_t setup_phase_reader(uint8_t iv
) {
364 // Switch on carrier and let the tag charge for 1ms
374 frame_sendAsReader(iv
, 7);
376 // Now both tag and reader has same IV. Prng can start.
379 frame_receiveAsReader(¤t_frame
, 6);
381 // fixed delay before sending ack.
382 WaitTicks(366); // 244us
383 legic_prng_forward(1); //240us / 100 == 2.4 iterations
385 // Send obsfuscated acknowledgment frame.
386 // 0x19 = 0x18 MIM22, 0x01 LSB READCMD
387 // 0x39 = 0x38 MIM256, MIM1024 0x01 LSB READCMD
388 switch ( current_frame
.data
) {
389 case 0x0D: frame_sendAsReader(0x19, 6); break;
391 case 0x3D: frame_sendAsReader(0x39, 6); break;
394 return current_frame
.data
;
397 static void LegicCommonInit(void) {
399 FpgaDownloadAndGo(FPGA_BITSTREAM_HF
);
400 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX
);
401 SetAdcMuxFor(GPIO_MUXSEL_HIPKD
);
403 /* Bitbang the transmitter */
405 AT91C_BASE_PIOA
->PIO_OER
= GPIO_SSC_DOUT
;
406 AT91C_BASE_PIOA
->PIO_PER
= GPIO_SSC_DOUT
;
408 // reserve a cardmem, meaning we can use the tracelog function in bigbuff easier.
409 cardmem
= BigBuf_malloc(LEGIC_CARD_MEMSIZE
);
410 memset(cardmem
, 0x00, LEGIC_CARD_MEMSIZE
);
414 crc_init(&legic_crc
, 4, 0x19 >> 1, 0x5, 0);
419 // Switch off carrier, make sure tag is reset
420 static void switch_off_tag_rwd(void) {
424 Dbprintf("Exit Switch_off_tag_rwd");
427 // calculate crc4 for a legic READ command
428 // 5,8,10 address size.
429 static uint32_t legic4Crc(uint8_t legicCmd
, uint16_t byte_index
, uint8_t value
, uint8_t cmd_sz
) {
430 crc_clear(&legic_crc
);
431 //uint32_t temp = (value << cmd_sz) | (byte_index << 1) | legicCmd;
432 //crc_update(&legic_crc, temp, cmd_sz + 8 );
433 crc_update(&legic_crc
, 1, 1); /* CMD_READ */
434 crc_update(&legic_crc
, byte_index
, cmd_sz
-1);
435 crc_update(&legic_crc
, value
, 8);
436 return crc_finish(&legic_crc
);
439 int legic_read_byte(int byte_index
, int cmd_sz
) {
448 legic_prng_forward(4); // 460 / 100 = 4.6 iterations
450 uint8_t byte
= 0, crc
= 0, calcCrc
= 0;
451 uint32_t cmd
= (byte_index
<< 1) | LEGIC_READ
;
453 frame_sendAsReader(cmd
, cmd_sz
);
454 frame_receiveAsReader(¤t_frame
, 12);
456 byte
= BYTEx(current_frame
.data
, 0);
457 calcCrc
= legic4Crc(LEGIC_READ
, byte_index
, byte
, cmd_sz
);
458 crc
= BYTEx(current_frame
.data
, 1);
460 if( calcCrc
!= crc
) {
461 Dbprintf("!!! crc mismatch: expected %x but got %x !!!", calcCrc
, crc
);
468 * - assemble a write_cmd_frame with crc and send it
469 * - wait until the tag sends back an ACK ('1' bit unencrypted)
470 * - forward the prng based on the timing
472 //int legic_write_byte(int byte, int addr, int addr_sz, int PrngCorrection) {
473 int legic_write_byte(uint8_t byte
, uint16_t addr
, uint8_t addr_sz
) {
475 //do not write UID, CRC at offset 0-4.
476 if (addr
<= 4) return 0;
479 crc_clear(&legic_crc
);
480 crc_update(&legic_crc
, 0, 1); /* CMD_WRITE */
481 crc_update(&legic_crc
, addr
, addr_sz
);
482 crc_update(&legic_crc
, byte
, 8);
483 uint32_t crc
= crc_finish(&legic_crc
);
485 uint32_t crc2
= legic4Crc(LEGIC_WRITE
, addr
, byte
, addr_sz
+1);
487 Dbprintf("crc is missmatch");
489 // send write command
490 uint32_t cmd
= ((crc
<<(addr_sz
+1+8)) //CRC
491 |(byte
<<(addr_sz
+1)) //Data
492 |(addr
<<1) //Address
493 | LEGIC_WRITE
); //CMD = Write
495 uint32_t cmd_sz
= addr_sz
+1+8+4; //crc+data+cmd
497 legic_prng_forward(2); /* we wait anyways */
499 WaitUS(TAG_FRAME_WAIT
);
501 frame_sendAsReader(cmd
, cmd_sz
);
503 // wllm-rbnt doesnt have these
504 AT91C_BASE_PIOA
->PIO_ODR
= GPIO_SSC_DIN
;
505 AT91C_BASE_PIOA
->PIO_PER
= GPIO_SSC_DIN
;
508 int t
, old_level
= 0, edges
= 0;
511 WaitUS(TAG_FRAME_WAIT
);
513 for( t
= 0; t
< 80; ++t
) {
515 next_bit_at
+= TAG_BIT_PERIOD
;
516 while(timer
->TC_CV
< next_bit_at
) {
517 int level
= (AT91C_BASE_PIOA
->PIO_PDSR
& GPIO_SSC_DIN
);
518 if(level
!= old_level
)
523 if(edges
> 20 && edges
< 60) { /* expected are 42 edges */
524 int t
= timer
->TC_CV
;
525 int c
= t
/ TAG_BIT_PERIOD
;
528 legic_prng_forward(c
);
537 int LegicRfReader(int offset
, int bytes
, int iv
) {
539 uint16_t byte_index
= 0;
540 uint8_t cmd_sz
= 0, isOK
= 1;
545 uint32_t tag_type
= setup_phase_reader(iv
);
547 switch_off_tag_rwd();
551 if ( MF_DBGLEVEL
>= 2) DbpString("MIM22 card found, reading card");
556 if ( MF_DBGLEVEL
>= 2) DbpString("MIM256 card found, reading card");
561 if ( MF_DBGLEVEL
>= 2) DbpString("MIM1024 card found, reading card");
566 if ( MF_DBGLEVEL
>= 1) Dbprintf("Unknown card format: %x", tag_type
);
574 if (bytes
+ offset
>= card_sz
)
575 bytes
= card_sz
- offset
;
577 // Start setup and read bytes.
578 setup_phase_reader(iv
);
581 while (byte_index
< bytes
) {
582 int r
= legic_read_byte(byte_index
+ offset
, cmd_sz
);
584 if (r
== -1 || BUTTON_PRESS()) {
585 if ( MF_DBGLEVEL
>= 3) DbpString("operation aborted");
589 cardmem
[++byte_index
] = r
;
595 switch_off_tag_rwd();
597 uint8_t len
= (bytes
& 0x3FF);
598 cmd_send(CMD_ACK
,isOK
,len
,0,cardmem
,len
);
602 /*int _LegicRfWriter(int offset, int bytes, int addr_sz, uint8_t *BigBuf, int RoundBruteforceValue) {
606 setup_phase_reader(iv);
607 //legic_prng_forward(2);
608 while(byte_index < bytes) {
611 //check if the DCF should be changed
612 if ( (offset == 0x05) && (bytes == 0x02) ) {
613 //write DCF in reverse order (addr 0x06 before 0x05)
614 r = legic_write_byte(BigBuf[(0x06-byte_index)], (0x06-byte_index), addr_sz, RoundBruteforceValue);
615 //legic_prng_forward(1);
618 r = legic_write_byte(BigBuf[(0x06-byte_index)], (0x06-byte_index), addr_sz, RoundBruteforceValue);
620 //legic_prng_forward(1);
623 r = legic_write_byte(BigBuf[byte_index+offset], byte_index+offset, addr_sz, RoundBruteforceValue);
625 if((r != 0) || BUTTON_PRESS()) {
626 Dbprintf("operation aborted @ 0x%03.3x", byte_index);
627 switch_off_tag_rwd();
635 if(byte_index & 0x10) LED_C_ON(); else LED_C_OFF();
639 DbpString("write successful");
643 void LegicRfWriter(int offset
, int bytes
, int iv
) {
645 int byte_index
= 0, addr_sz
= 0;
649 if ( MF_DBGLEVEL
>= 2) DbpString("setting up legic card");
651 uint32_t tag_type
= setup_phase_reader(iv
);
653 switch_off_tag_rwd();
657 if(offset
+bytes
> 22) {
658 Dbprintf("Error: can not write to 0x%03.3x on MIM22", offset
+ bytes
);
662 if ( MF_DBGLEVEL
>= 2) Dbprintf("MIM22 card found, writing 0x%02.2x - 0x%02.2x ...", offset
, offset
+ bytes
);
665 if(offset
+bytes
> 0x100) {
666 Dbprintf("Error: can not write to 0x%03.3x on MIM256", offset
+ bytes
);
670 if ( MF_DBGLEVEL
>= 2) Dbprintf("MIM256 card found, writing 0x%02.2x - 0x%02.2x ...", offset
, offset
+ bytes
);
673 if(offset
+bytes
> 0x400) {
674 Dbprintf("Error: can not write to 0x%03.3x on MIM1024", offset
+ bytes
);
678 if ( MF_DBGLEVEL
>= 2) Dbprintf("MIM1024 card found, writing 0x%03.3x - 0x%03.3x ...", offset
, offset
+ bytes
);
681 Dbprintf("No or unknown card found, aborting");
686 setup_phase_reader(iv
);
688 while(byte_index
< bytes
) {
690 //check if the DCF should be changed
691 if ( ((byte_index
+offset
) == 0x05) && (bytes
>= 0x02) ) {
692 //write DCF in reverse order (addr 0x06 before 0x05)
693 r
= legic_write_byte(cardmem
[(0x06-byte_index
)], (0x06-byte_index
), addr_sz
);
695 // write second byte on success...
698 r
= legic_write_byte(cardmem
[(0x06-byte_index
)], (0x06-byte_index
), addr_sz
);
702 r
= legic_write_byte(cardmem
[byte_index
+offset
], byte_index
+offset
, addr_sz
);
705 if ((r
!= 0) || BUTTON_PRESS()) {
706 Dbprintf("operation aborted @ 0x%03.3x", byte_index
);
707 switch_off_tag_rwd();
716 if ( MF_DBGLEVEL
>= 1) DbpString("write successful");
719 void LegicRfRawWriter(int address
, int byte
, int iv
) {
721 int byte_index
= 0, addr_sz
= 0;
725 if ( MF_DBGLEVEL
>= 2) DbpString("setting up legic card");
727 uint32_t tag_type
= setup_phase_reader(iv
);
729 switch_off_tag_rwd();
734 Dbprintf("Error: can not write to 0x%03.3x on MIM22", address
);
738 if ( MF_DBGLEVEL
>= 2) Dbprintf("MIM22 card found, writing at addr 0x%02.2x - value 0x%02.2x ...", address
, byte
);
741 if(address
> 0x100) {
742 Dbprintf("Error: can not write to 0x%03.3x on MIM256", address
);
746 if ( MF_DBGLEVEL
>= 2) Dbprintf("MIM256 card found, writing at addr 0x%02.2x - value 0x%02.2x ...", address
, byte
);
749 if(address
> 0x400) {
750 Dbprintf("Error: can not write to 0x%03.3x on MIM1024", address
);
754 if ( MF_DBGLEVEL
>= 2) Dbprintf("MIM1024 card found, writing at addr 0x%03.3x - value 0x%03.3x ...", address
, byte
);
757 Dbprintf("No or unknown card found, aborting");
761 Dbprintf("integer value: %d address: %d addr_sz: %d", byte
, address
, addr_sz
);
764 setup_phase_reader(iv
);
766 int r
= legic_write_byte(byte
, address
, addr_sz
);
768 if((r
!= 0) || BUTTON_PRESS()) {
769 Dbprintf("operation aborted @ 0x%03.3x (%1d)", byte_index
, r
);
770 switch_off_tag_rwd();
776 if ( MF_DBGLEVEL
>= 1) DbpString("write successful");
779 /* Handle (whether to respond) a frame in tag mode
780 * Only called when simulating a tag.
782 static void frame_handle_tag(struct legic_frame
const * const f
)
784 uint8_t *BigBuf
= BigBuf_get_addr();
786 /* First Part of Handshake (IV) */
792 ResetTimer(prng_timer
);
794 legic_prng_init(f
->data
);
795 frame_send_tag(0x3d, 6, 1); /* 0x3d^0x26 = 0x1B */
796 legic_state
= STATE_IV
;
797 legic_read_count
= 0;
799 legic_prng_iv
= f
->data
;
808 if(legic_state
== STATE_IV
) {
809 int local_key
= get_key_stream(3, 6);
810 int xored
= 0x39 ^ local_key
;
811 if((f
->bits
== 6) && (f
->data
== xored
)) {
812 legic_state
= STATE_CON
;
819 legic_state
= STATE_DISCON
;
821 Dbprintf("iv: %02x frame: %02x key: %02x xored: %02x", legic_prng_iv
, f
->data
, local_key
, xored
);
828 if(legic_state
== STATE_CON
) {
829 int key
= get_key_stream(2, 11); //legic_phase_drift, 11);
830 int addr
= f
->data
^ key
; addr
= addr
>> 1;
831 int data
= BigBuf
[addr
];
832 int hash
= legic4Crc(LEGIC_READ
, addr
, data
, 11) << 8;
833 BigBuf
[OFFSET_LOG
+legic_read_count
] = (uint8_t)addr
;
836 //Dbprintf("Data:%03.3x, key:%03.3x, addr: %03.3x, read_c:%u", f->data, key, addr, read_c);
837 legic_prng_forward(legic_reqresp_drift
);
839 frame_send_tag(hash
| data
, 12, 1);
842 legic_prng_forward(2);
850 int key
= get_key_stream(-1, 23); //legic_frame_drift, 23);
851 int addr
= f
->data
^ key
; addr
= addr
>> 1; addr
= addr
& 0x3ff;
852 int data
= f
->data
^ key
; data
= data
>> 11; data
= data
& 0xff;
855 legic_state
= STATE_DISCON
;
857 Dbprintf("write - addr: %x, data: %x", addr
, data
);
861 if(legic_state
!= STATE_DISCON
) {
862 Dbprintf("Unexpected: sz:%u, Data:%03.3x, State:%u, Count:%u", f
->bits
, f
->data
, legic_state
, legic_read_count
);
864 Dbprintf("IV: %03.3x", legic_prng_iv
);
865 for(i
= 0; i
<legic_read_count
; i
++) {
866 Dbprintf("Read Nb: %u, Addr: %u", i
, BigBuf
[OFFSET_LOG
+i
]);
869 for(i
= -1; i
<legic_read_count
; i
++) {
871 t
= BigBuf
[OFFSET_LOG
+256+i
*4];
872 t
|= BigBuf
[OFFSET_LOG
+256+i
*4+1] << 8;
873 t
|= BigBuf
[OFFSET_LOG
+256+i
*4+2] <<16;
874 t
|= BigBuf
[OFFSET_LOG
+256+i
*4+3] <<24;
876 Dbprintf("Cycles: %u, Frame Length: %u, Time: %u",
877 BigBuf
[OFFSET_LOG
+128+i
],
878 BigBuf
[OFFSET_LOG
+384+i
],
882 legic_state
= STATE_DISCON
;
883 legic_read_count
= 0;
889 /* Read bit by bit untill full frame is received
890 * Call to process frame end answer
892 static void emit(int bit
) {
896 frame_append_bit(¤t_frame
, 1);
899 frame_append_bit(¤t_frame
, 0);
902 if(current_frame
.bits
<= 4) {
903 frame_clean(¤t_frame
);
905 frame_handle_tag(¤t_frame
);
906 frame_clean(¤t_frame
);
913 void LegicRfSimulate(int phase
, int frame
, int reqresp
)
915 /* ADC path high-frequency peak detector, FPGA in high-frequency simulator mode,
916 * modulation mode set to 212kHz subcarrier. We are getting the incoming raw
917 * envelope waveform on DIN and should send our response on DOUT.
919 * The LEGIC RF protocol is pulse-pause-encoding from reader to card, so we'll
920 * measure the time between two rising edges on DIN, and no encoding on the
921 * subcarrier from card to reader, so we'll just shift out our verbatim data
922 * on DOUT, 1 bit is 100us. The time from reader to card frame is still unclear,
923 * seems to be 300us-ish.
926 legic_phase_drift
= phase
;
927 legic_frame_drift
= frame
;
928 legic_reqresp_drift
= reqresp
;
930 FpgaDownloadAndGo(FPGA_BITSTREAM_HF
);
931 SetAdcMuxFor(GPIO_MUXSEL_HIPKD
);
933 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_SIMULATOR
| FPGA_HF_SIMULATOR_MODULATE_212K
);
935 /* Bitbang the receiver */
936 AT91C_BASE_PIOA
->PIO_ODR
= GPIO_SSC_DIN
;
937 AT91C_BASE_PIOA
->PIO_PER
= GPIO_SSC_DIN
;
940 crc_init(&legic_crc
, 4, 0x19 >> 1, 0x5, 0);
944 legic_state
= STATE_DISCON
;
947 DbpString("Starting Legic emulator, press button to end");
949 while(!BUTTON_PRESS() && !usb_poll_validate_length()) {
950 int level
= !!(AT91C_BASE_PIOA
->PIO_PDSR
& GPIO_SSC_DIN
);
951 int time
= timer
->TC_CV
;
953 if(level
!= old_level
) {
955 timer
->TC_CCR
= AT91C_TC_CLKEN
| AT91C_TC_SWTRG
;
957 if (FUZZ_EQUAL(time
, RWD_TIME_1
, RWD_TIME_FUZZ
)) {
962 } else if (FUZZ_EQUAL(time
, RWD_TIME_0
, RWD_TIME_FUZZ
)) {
977 if(time
>= (RWD_TIME_1
+RWD_TIME_FUZZ
) && active
) {
983 if(time
>= (20*RWD_TIME_1
) && (timer
->TC_SR
& AT91C_TC_CLKSTA
)) {
984 timer
->TC_CCR
= AT91C_TC_CLKDIS
;
990 if ( MF_DBGLEVEL
>= 1) DbpString("Stopped");
994 //-----------------------------------------------------------------------------
995 // Code up a string of octets at layer 2 (including CRC, we don't generate
996 // that here) so that they can be transmitted to the reader. Doesn't transmit
997 // them yet, just leaves them ready to send in ToSend[].
998 //-----------------------------------------------------------------------------
999 // static void CodeLegicAsTag(const uint8_t *cmd, int len)
1005 // // Transmit a burst of ones, as the initial thing that lets the
1006 // // reader get phase sync. This (TR1) must be > 80/fs, per spec,
1007 // // but tag that I've tried (a Paypass) exceeds that by a fair bit,
1008 // // so I will too.
1009 // for(i = 0; i < 20; i++) {
1010 // ToSendStuffBit(1);
1011 // ToSendStuffBit(1);
1012 // ToSendStuffBit(1);
1013 // ToSendStuffBit(1);
1017 // for(i = 0; i < 10; i++) {
1018 // ToSendStuffBit(0);
1019 // ToSendStuffBit(0);
1020 // ToSendStuffBit(0);
1021 // ToSendStuffBit(0);
1023 // for(i = 0; i < 2; i++) {
1024 // ToSendStuffBit(1);
1025 // ToSendStuffBit(1);
1026 // ToSendStuffBit(1);
1027 // ToSendStuffBit(1);
1030 // for(i = 0; i < len; i++) {
1032 // uint8_t b = cmd[i];
1035 // ToSendStuffBit(0);
1036 // ToSendStuffBit(0);
1037 // ToSendStuffBit(0);
1038 // ToSendStuffBit(0);
1041 // for(j = 0; j < 8; j++) {
1043 // ToSendStuffBit(1);
1044 // ToSendStuffBit(1);
1045 // ToSendStuffBit(1);
1046 // ToSendStuffBit(1);
1048 // ToSendStuffBit(0);
1049 // ToSendStuffBit(0);
1050 // ToSendStuffBit(0);
1051 // ToSendStuffBit(0);
1057 // ToSendStuffBit(1);
1058 // ToSendStuffBit(1);
1059 // ToSendStuffBit(1);
1060 // ToSendStuffBit(1);
1064 // for(i = 0; i < 10; i++) {
1065 // ToSendStuffBit(0);
1066 // ToSendStuffBit(0);
1067 // ToSendStuffBit(0);
1068 // ToSendStuffBit(0);
1070 // for(i = 0; i < 2; i++) {
1071 // ToSendStuffBit(1);
1072 // ToSendStuffBit(1);
1073 // ToSendStuffBit(1);
1074 // ToSendStuffBit(1);
1077 // // Convert from last byte pos to length
1081 //-----------------------------------------------------------------------------
1082 // The software UART that receives commands from the reader, and its state
1084 //-----------------------------------------------------------------------------
1088 STATE_GOT_FALLING_EDGE_OF_SOF
,
1089 STATE_AWAITING_START_BIT
,
1090 STATE_RECEIVING_DATA
1100 /* Receive & handle a bit coming from the reader.
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
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
1109 * Returns: true if we received a EOF
1110 * false if we are still waiting for some more
1112 // static RAMFUNC int HandleLegicUartBit(uint8_t bit)
1114 // switch(Uart.state) {
1115 // case STATE_UNSYNCD:
1117 // // we went low, so this could be the beginning of an SOF
1118 // Uart.state = STATE_GOT_FALLING_EDGE_OF_SOF;
1124 // case STATE_GOT_FALLING_EDGE_OF_SOF:
1126 // if(Uart.posCnt == 2) { // sample every 4 1/fs in the middle of a bit
1128 // if(Uart.bitCnt > 9) {
1129 // // we've seen enough consecutive
1130 // // zeros that it's a valid SOF
1132 // Uart.byteCnt = 0;
1133 // Uart.state = STATE_AWAITING_START_BIT;
1134 // LED_A_ON(); // Indicate we got a valid SOF
1136 // // didn't stay down long enough
1137 // // before going high, error
1138 // Uart.state = STATE_UNSYNCD;
1141 // // do nothing, keep waiting
1145 // if(Uart.posCnt >= 4) Uart.posCnt = 0;
1146 // if(Uart.bitCnt > 12) {
1147 // // Give up if we see too many zeros without
1150 // Uart.state = STATE_UNSYNCD;
1154 // case STATE_AWAITING_START_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;
1163 // // falling edge, this starts the data byte
1166 // Uart.shiftReg = 0;
1167 // Uart.state = STATE_RECEIVING_DATA;
1171 // case STATE_RECEIVING_DATA:
1173 // if(Uart.posCnt == 2) {
1174 // // time to sample a bit
1175 // Uart.shiftReg >>= 1;
1177 // Uart.shiftReg |= 0x200;
1181 // if(Uart.posCnt >= 4) {
1184 // if(Uart.bitCnt == 10) {
1185 // if((Uart.shiftReg & 0x200) && !(Uart.shiftReg & 0x001))
1187 // // this is a data byte, with correct
1188 // // start and stop bits
1189 // Uart.output[Uart.byteCnt] = (Uart.shiftReg >> 1) & 0xff;
1192 // if(Uart.byteCnt >= Uart.byteCntMax) {
1193 // // Buffer overflowed, give up
1195 // Uart.state = STATE_UNSYNCD;
1197 // // so get the next byte now
1199 // Uart.state = STATE_AWAITING_START_BIT;
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) {
1209 // // this is an error
1211 // Uart.state = STATE_UNSYNCD;
1218 // Uart.state = STATE_UNSYNCD;
1226 static void UartReset() {
1227 Uart
.byteCntMax
= 3;
1228 Uart
.state
= STATE_UNSYNCD
;
1232 memset(Uart
.output
, 0x00, 3);
1235 // static void UartInit(uint8_t *data) {
1236 // Uart.output = data;
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
1245 //=============================================================================
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
1267 * Handles reception of a bit from the tag
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
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
1276 * Returns: true if we received a EOF
1277 * false if we are still waiting for some more
1281 #ifndef SUBCARRIER_DETECT_THRESHOLD
1282 # define SUBCARRIER_DETECT_THRESHOLD 8
1285 // Subcarrier amplitude v = sqrt(ci^2 + cq^2), approximated here by max(abs(ci),abs(cq)) + 1/2*min(abs(ci),abs(cq)))
1286 #ifndef CHECK_FOR_SUBCARRIER
1287 # define CHECK_FOR_SUBCARRIER() { v = MAX(ai, aq) + MIN(halfci, halfcq); }
1290 // The soft decision on the bit uses an estimate of just the
1291 // quadrant of the reference angle, not the exact angle.
1292 // Subcarrier amplitude v = sqrt(ci^2 + cq^2), approximated here by max(abs(ci),abs(cq)) + 1/2*min(abs(ci),abs(cq)))
1293 #define MAKE_SOFT_DECISION() { \
1294 if(Demod.sumI > 0) \
1299 if(Demod.sumQ > 0) \
1306 static RAMFUNC
int HandleLegicSamplesDemod(int ci
, int cq
)
1311 int halfci
= (ai
>> 1);
1312 int halfcq
= (aq
>> 1);
1314 switch(Demod
.state
) {
1317 CHECK_FOR_SUBCARRIER()
1319 if(v
> SUBCARRIER_DETECT_THRESHOLD
) { // subcarrier detected
1320 Demod
.state
= DEMOD_PHASE_REF_TRAINING
;
1327 case DEMOD_PHASE_REF_TRAINING
:
1328 if(Demod
.posCount
< 8) {
1330 CHECK_FOR_SUBCARRIER()
1332 if (v
> SUBCARRIER_DETECT_THRESHOLD
) {
1333 // set the reference phase (will code a logic '1') by averaging over 32 1/fs.
1334 // note: synchronization time > 80 1/fs
1340 Demod
.state
= DEMOD_UNSYNCD
;
1343 Demod
.state
= DEMOD_AWAITING_FALLING_EDGE_OF_SOF
;
1347 case DEMOD_AWAITING_FALLING_EDGE_OF_SOF
:
1349 MAKE_SOFT_DECISION()
1351 //Dbprintf("ICE: %d %d %d %d %d", v, Demod.sumI, Demod.sumQ, ci, cq );
1352 // logic '0' detected
1355 Demod
.state
= DEMOD_GOT_FALLING_EDGE_OF_SOF
;
1357 // start of SOF sequence
1360 // maximum length of TR1 = 200 1/fs
1361 if(Demod
.posCount
> 25*2) Demod
.state
= DEMOD_UNSYNCD
;
1366 case DEMOD_GOT_FALLING_EDGE_OF_SOF
:
1369 MAKE_SOFT_DECISION()
1372 // low phase of SOF too short (< 9 etu). Note: spec is >= 10, but FPGA tends to "smear" edges
1373 if(Demod
.posCount
< 10*2) {
1374 Demod
.state
= DEMOD_UNSYNCD
;
1376 LED_C_ON(); // Got SOF
1377 Demod
.state
= DEMOD_AWAITING_START_BIT
;
1382 // low phase of SOF too long (> 12 etu)
1383 if(Demod
.posCount
> 13*2) {
1384 Demod
.state
= DEMOD_UNSYNCD
;
1390 case DEMOD_AWAITING_START_BIT
:
1393 MAKE_SOFT_DECISION()
1396 // max 19us between characters = 16 1/fs, max 3 etu after low phase of SOF = 24 1/fs
1397 if(Demod
.posCount
> 3*2) {
1398 Demod
.state
= DEMOD_UNSYNCD
;
1402 // start bit detected
1404 Demod
.posCount
= 1; // this was the first half
1407 Demod
.state
= DEMOD_RECEIVING_DATA
;
1411 case DEMOD_RECEIVING_DATA
:
1413 MAKE_SOFT_DECISION()
1415 if(Demod
.posCount
== 0) {
1416 // first half of bit
1420 // second half of bit
1422 Demod
.shiftReg
>>= 1;
1424 if(Demod
.thisBit
> 0)
1425 Demod
.shiftReg
|= 0x200;
1429 if(Demod
.bitCount
== 10) {
1431 uint16_t s
= Demod
.shiftReg
;
1433 if((s
& 0x200) && !(s
& 0x001)) {
1434 // stop bit == '1', start bit == '0'
1435 uint8_t b
= (s
>> 1);
1436 Demod
.output
[Demod
.len
] = b
;
1438 Demod
.state
= DEMOD_AWAITING_START_BIT
;
1440 Demod
.state
= DEMOD_UNSYNCD
;
1444 // This is EOF (start, stop and all data bits == '0'
1454 Demod
.state
= DEMOD_UNSYNCD
;
1461 // Clear out the state of the "UART" that receives from the tag.
1462 static void DemodReset() {
1464 Demod
.state
= DEMOD_UNSYNCD
;
1471 memset(Demod
.output
, 0x00, 3);
1474 static void DemodInit(uint8_t *data
) {
1475 Demod
.output
= data
;
1480 * Demodulate the samples we received from the tag, also log to tracebuffer
1481 * quiet: set to 'TRUE' to disable debug output
1483 #define LEGIC_DMA_BUFFER_SIZE 256
1484 static void GetSamplesForLegicDemod(int n
, bool quiet
)
1487 bool gotFrame
= FALSE
;
1488 int lastRxCounter
= LEGIC_DMA_BUFFER_SIZE
;
1489 int ci
, cq
, samples
= 0;
1493 // And put the FPGA in the appropriate mode
1494 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR
| FPGA_HF_READER_RX_XCORR_QUARTER_FREQ
);
1496 // The response (tag -> reader) that we're receiving.
1497 // Set up the demodulator for tag -> reader responses.
1498 DemodInit(BigBuf_malloc(MAX_FRAME_SIZE
));
1500 // The DMA buffer, used to stream samples from the FPGA
1501 int8_t *dmaBuf
= (int8_t*) BigBuf_malloc(LEGIC_DMA_BUFFER_SIZE
);
1502 int8_t *upTo
= dmaBuf
;
1504 // Setup and start DMA.
1505 if ( !FpgaSetupSscDma((uint8_t*) dmaBuf
, LEGIC_DMA_BUFFER_SIZE
) ){
1506 if (MF_DBGLEVEL
> 1) Dbprintf("FpgaSetupSscDma failed. Exiting");
1510 // Signal field is ON with the appropriate LED:
1513 int behindBy
= lastRxCounter
- AT91C_BASE_PDC_SSC
->PDC_RCR
;
1514 if(behindBy
> max
) max
= behindBy
;
1516 while(((lastRxCounter
-AT91C_BASE_PDC_SSC
->PDC_RCR
) & (LEGIC_DMA_BUFFER_SIZE
-1)) > 2) {
1520 if(upTo
>= dmaBuf
+ LEGIC_DMA_BUFFER_SIZE
) {
1522 AT91C_BASE_PDC_SSC
->PDC_RNPR
= (uint32_t) upTo
;
1523 AT91C_BASE_PDC_SSC
->PDC_RNCR
= LEGIC_DMA_BUFFER_SIZE
;
1526 if(lastRxCounter
<= 0)
1527 lastRxCounter
= LEGIC_DMA_BUFFER_SIZE
;
1531 gotFrame
= HandleLegicSamplesDemod(ci
, cq
);
1536 if(samples
> n
|| gotFrame
)
1540 FpgaDisableSscDma();
1542 if (!quiet
&& Demod
.len
== 0) {
1543 Dbprintf("max behindby = %d, samples = %d, gotFrame = %d, Demod.len = %d, Demod.sumI = %d, Demod.sumQ = %d",
1554 if (Demod
.len
> 0) {
1555 uint8_t parity
[MAX_PARITY_SIZE
] = {0x00};
1556 LogTrace(Demod
.output
, Demod
.len
, 0, 0, parity
, FALSE
);
1559 //-----------------------------------------------------------------------------
1560 // Transmit the command (to the tag) that was placed in ToSend[].
1561 //-----------------------------------------------------------------------------
1562 static void TransmitForLegic(void)
1568 while(AT91C_BASE_SSC
->SSC_SR
& (AT91C_SSC_TXRDY
))
1569 AT91C_BASE_SSC
->SSC_THR
= 0xff;
1571 // Signal field is ON with the appropriate Red LED
1574 // Signal we are transmitting with the Green LED
1576 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX
| FPGA_HF_READER_TX_SHALLOW_MOD
);
1578 for(c
= 0; c
< 10;) {
1579 if(AT91C_BASE_SSC
->SSC_SR
& (AT91C_SSC_TXRDY
)) {
1580 AT91C_BASE_SSC
->SSC_THR
= 0xff;
1583 if(AT91C_BASE_SSC
->SSC_SR
& (AT91C_SSC_RXRDY
)) {
1584 volatile uint32_t r
= AT91C_BASE_SSC
->SSC_RHR
;
1592 if(AT91C_BASE_SSC
->SSC_SR
& (AT91C_SSC_TXRDY
)) {
1593 AT91C_BASE_SSC
->SSC_THR
= ToSend
[c
];
1594 legic_prng_forward(1); // forward the lfsr
1596 if(c
>= ToSendMax
) {
1600 if(AT91C_BASE_SSC
->SSC_SR
& (AT91C_SSC_RXRDY
)) {
1601 volatile uint32_t r
= AT91C_BASE_SSC
->SSC_RHR
;
1610 //-----------------------------------------------------------------------------
1611 // Code a layer 2 command (string of octets, including CRC) into ToSend[],
1612 // so that it is ready to transmit to the tag using TransmitForLegic().
1613 //-----------------------------------------------------------------------------
1614 static void CodeLegicBitsAsReader(const uint8_t *cmd
, uint8_t cmdlen
, int bits
)
1622 for(i
= 0; i
< 7; i
++)
1626 for(i
= 0; i
< cmdlen
; i
++) {
1632 for(j
= 0; j
< bits
; j
++) {
1642 // Convert from last character reference to length
1647 Convenience function to encode, transmit and trace Legic comms
1649 static void CodeAndTransmitLegicAsReader(const uint8_t *cmd
, uint8_t cmdlen
, int bits
)
1651 CodeLegicBitsAsReader(cmd
, cmdlen
, bits
);
1654 uint8_t parity
[1] = {0x00};
1655 LogTrace(cmd
, cmdlen
, 0, 0, parity
, TRUE
);
1659 int ice_legic_select_card()
1661 //int cmd_size=0, card_size=0;
1662 uint8_t wakeup
[] = { 0x7F };
1663 uint8_t getid
[] = {0x19};
1665 //legic_prng_init(SESSION_IV);
1667 // first, wake up the tag, 7bits
1668 CodeAndTransmitLegicAsReader(wakeup
, sizeof(wakeup
), 7);
1670 GetSamplesForLegicDemod(1000, TRUE
);
1672 //frame_receiveAsReader(¤t_frame, 6, 1);
1674 legic_prng_forward(1); /* we wait anyways */
1676 //while(timer->TC_CV < 387) ; /* ~ 258us */
1677 //frame_sendAsReader(0x19, 6);
1678 CodeAndTransmitLegicAsReader(getid
, sizeof(getid
), 8);
1679 GetSamplesForLegicDemod(1000, TRUE
);
1681 //if (Demod.len < 14) return 2;
1682 Dbprintf("CARD TYPE: %02x LEN: %d", Demod
.output
[0], Demod
.len
);
1684 switch(Demod
.output
[0]) {
1686 DbpString("MIM 256 card found");
1691 DbpString("MIM 1024 card found");
1693 // card_size = 1024;
1700 // bytes = card_size;
1702 // if(bytes + offset >= card_size)
1703 // bytes = card_size - offset;
1705 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF
);
1710 // Set up LEGIC communication
1711 void ice_legic_setup() {
1714 FpgaDownloadAndGo(FPGA_BITSTREAM_HF
);
1715 BigBuf_free(); BigBuf_Clear_ext(false);
1721 // Set up the synchronous serial port
1724 // connect Demodulated Signal to ADC:
1725 SetAdcMuxFor(GPIO_MUXSEL_HIPKD
);
1727 // Signal field is on with the appropriate LED
1729 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX
| FPGA_HF_READER_TX_SHALLOW_MOD
);
1732 //StartCountSspClk();
1735 crc_init(&legic_crc
, 4, 0x19 >> 1, 0x5, 0);