X-Git-Url: http://cvs.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/5e174a511b37e17cd3fcaedad608ce605ba34ce9..c528cf39896943c2c3738c7b8a54e9be153eb2ca:/armsrc/legicrf.c diff --git a/armsrc/legicrf.c b/armsrc/legicrf.c index a804ded2..f58cb442 100644 --- a/armsrc/legicrf.c +++ b/armsrc/legicrf.c @@ -1,305 +1,1622 @@ -/* - * LEGIC RF simulation code - * - * (c) 2009 Henryk Plötz - */ - -#include - -#include "apps.h" +//----------------------------------------------------------------------------- +// (c) 2009 Henryk Plötz +// 2016 Iceman +// +// This code is licensed to you under the terms of the GNU GPL, version 2 or, +// at your option, any later version. See the LICENSE.txt file for the text of +// the license. +//----------------------------------------------------------------------------- +// LEGIC RF simulation code +//----------------------------------------------------------------------------- #include "legicrf.h" -#include - -#include "legic_prng.h" -#include "crc.h" static struct legic_frame { - int bits; + uint8_t bits; uint32_t data; } current_frame; -static crc_t legic_crc; +static enum { + STATE_DISCON, + STATE_IV, + STATE_CON, +} legic_state; + +static crc_t legic_crc; +static int legic_read_count; +static uint32_t legic_prng_bc; +static uint32_t legic_prng_iv; + +static int legic_phase_drift; +static int legic_frame_drift; +static int legic_reqresp_drift; AT91PS_TC timer; +AT91PS_TC prng_timer; -static void setup_timer(void) -{ - /* Set up Timer 1 to use for measuring time between pulses. Since we're bit-banging - * this it won't be terribly accurate but should be good enough. - */ +/* +static void setup_timer(void) { + // Set up Timer 1 to use for measuring time between pulses. Since we're bit-banging + // this it won't be terribly accurate but should be good enough. + // AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_TC1); timer = AT91C_BASE_TC1; timer->TC_CCR = AT91C_TC_CLKDIS; - timer->TC_CMR = TC_CMR_TCCLKS_TIMER_CLOCK3; + timer->TC_CMR = AT91C_TC_CLKS_TIMER_DIV3_CLOCK; timer->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG; -/* At TIMER_CLOCK3 (MCK/32) */ -#define RWD_TIME_1 150 /* RWD_TIME_PAUSE off, 80us on = 100us */ -#define RWD_TIME_0 90 /* RWD_TIME_PAUSE off, 40us on = 60us */ -#define RWD_TIME_PAUSE 30 /* 20us */ -#define RWD_TIME_FUZZ 20 /* rather generous 13us, since the peak detector + hysteresis fuzz quite a bit */ -#define TAG_TIME_BIT 150 /* 100us for every bit */ -#define TAG_TIME_WAIT 490 /* time from RWD frame end to tag frame start, experimentally determined */ - + // + // Set up Timer 2 to use for measuring time between frames in + // tag simulation mode. Runs 4x faster as Timer 1 + // + AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_TC2); + prng_timer = AT91C_BASE_TC2; + prng_timer->TC_CCR = AT91C_TC_CLKDIS; + prng_timer->TC_CMR = AT91C_TC_CLKS_TIMER_DIV2_CLOCK; + prng_timer->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG; } + AT91C_BASE_PMC->PMC_PCER |= (0x1 << 12) | (0x1 << 13) | (0x1 << 14); + AT91C_BASE_TCB->TCB_BMR = AT91C_TCB_TC0XC0S_NONE | AT91C_TCB_TC1XC1S_TIOA0 | AT91C_TCB_TC2XC2S_NONE; + + // fast clock + AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS; // timer disable + AT91C_BASE_TC0->TC_CMR = AT91C_TC_CLKS_TIMER_DIV3_CLOCK | // MCK(48MHz)/32 -- tick=1.5mks + AT91C_TC_WAVE | AT91C_TC_WAVESEL_UP_AUTO | AT91C_TC_ACPA_CLEAR | + AT91C_TC_ACPC_SET | AT91C_TC_ASWTRG_SET; + AT91C_BASE_TC0->TC_RA = 1; + AT91C_BASE_TC0->TC_RC = 0xBFFF + 1; // 0xC000 + +*/ + +// At TIMER_CLOCK3 (MCK/32) +// testing calculating in ticks. 1.5ticks = 1us +#define RWD_TIME_1 120 // READER_TIME_PAUSE 20us off, 80us on = 100us 80 * 1.5 == 120ticks +#define RWD_TIME_0 60 // READER_TIME_PAUSE 20us off, 40us on = 60us 40 * 1.5 == 60ticks +#define RWD_TIME_PAUSE 30 // 20us == 20 * 1.5 == 30ticks */ +#define TAG_BIT_PERIOD 142 // 100us == 100 * 1.5 == 150ticks +#define TAG_FRAME_WAIT 495 // 330us from READER frame end to TAG frame start. 330 * 1.5 == 495 + +#define RWD_TIME_FUZZ 20 // rather generous 13us, since the peak detector + hysteresis fuzz quite a bit + +#define SIM_DIVISOR 586 /* prng_time/SIM_DIVISOR count prng needs to be forwared */ +#define SIM_SHIFT 900 /* prng_time+SIM_SHIFT shift of delayed start */ + +#define OFFSET_LOG 1024 + #define FUZZ_EQUAL(value, target, fuzz) ((value) > ((target)-(fuzz)) && (value) < ((target)+(fuzz))) +#ifndef SHORT_COIL +# define SHORT_COIL LOW(GPIO_SSC_DOUT); +#endif +#ifndef OPEN_COIL +# define OPEN_COIL HIGH(GPIO_SSC_DOUT); +#endif +#ifndef LINE_IN +# define LINE_IN AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DIN; +#endif +// Pause pulse, off in 20us / 30ticks, +// ONE / ZERO bit pulse, +// one == 80us / 120ticks +// zero == 40us / 60ticks +#ifndef COIL_PULSE +# define COIL_PULSE(x) \ + do { \ + SHORT_COIL; \ + WaitTicks( (RWD_TIME_PAUSE) ); \ + OPEN_COIL; \ + WaitTicks((x)); \ + } while (0); +#endif + +// ToDo: define a meaningful maximum size for auth_table. The bigger this is, the lower will be the available memory for traces. +// Historically it used to be FREE_BUFFER_SIZE, which was 2744. +#define LEGIC_CARD_MEMSIZE 1024 +static uint8_t* cardmem; + +static void frame_append_bit(struct legic_frame * const f, uint8_t bit) { + // Overflow, won't happen + if (f->bits >= 31) return; + + f->data |= (bit << f->bits); + f->bits++; +} + +static void frame_clean(struct legic_frame * const f) { + f->data = 0; + f->bits = 0; +} + +// Prng works when waiting in 99.1us cycles. +// and while sending/receiving in bit frames (100, 60) +/*static void CalibratePrng( uint32_t time){ + // Calculate Cycles based on timer 100us + uint32_t i = (time - sendFrameStop) / 100 ; + + // substract cycles of finished frames + int k = i - legic_prng_count()+1; + + // substract current frame length, rewind to beginning + if ( k > 0 ) + legic_prng_forward(k); +} +*/ + +/* Generate Keystream */ +uint32_t get_key_stream(int skip, int count) { + + int i; + + // Use int to enlarge timer tc to 32bit + legic_prng_bc += prng_timer->TC_CV; + + // reset the prng timer. + + /* If skip == -1, forward prng time based */ + if(skip == -1) { + i = (legic_prng_bc + SIM_SHIFT)/SIM_DIVISOR; /* Calculate Cycles based on timer */ + i -= legic_prng_count(); /* substract cycles of finished frames */ + i -= count; /* substract current frame length, rewind to beginning */ + legic_prng_forward(i); + } else { + legic_prng_forward(skip); + } + + i = (count == 6) ? -1 : legic_read_count; + + /* Generate KeyStream */ + return legic_prng_get_bits(count); +} + +/* Send a frame in tag mode, the FPGA must have been set up by + * LegicRfSimulate + */ +void frame_send_tag(uint16_t response, uint8_t bits) { + + uint16_t mask = 1; + + /* Bitbang the response */ + SHORT_COIL; + AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT; + AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT; + + /* TAG_FRAME_WAIT -> shift by 2 */ + legic_prng_forward(3); + response ^= legic_prng_get_bits(bits); + + /* Wait for the frame start */ + WaitTicks( TAG_FRAME_WAIT ); + + for (; mask < BITMASK(bits); mask <<= 1) { + if (response & mask) + OPEN_COIL + else + SHORT_COIL + WaitTicks(TAG_BIT_PERIOD); + } + SHORT_COIL; +} + /* Send a frame in reader mode, the FPGA must have been set up by * LegicRfReader */ -static void frame_send_rwd(uint32_t data, int bits) -{ - /* Start clock */ - timer->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG; - while(timer->TC_CV > 1) ; /* Wait till the clock has reset */ - - int i; - for(i=0; iTC_CV; - int pause_end = starttime + RWD_TIME_PAUSE, bit_end; - int bit = data & 1; - data = data >> 1; - - if(bit ^ legic_prng_get_bit()) { - bit_end = starttime + RWD_TIME_1; - } else { - bit_end = starttime + RWD_TIME_0; - } - - /* RWD_TIME_PAUSE time off, then some time on, so that the complete bit time is - * RWD_TIME_x, where x is the bit to be transmitted */ - AT91C_BASE_PIOA->PIO_CODR = GPIO_SSC_DOUT; - while(timer->TC_CV < pause_end) ; - AT91C_BASE_PIOA->PIO_SODR = GPIO_SSC_DOUT; - legic_prng_forward(1); /* bit duration is longest. use this time to forward the lfsr */ - - while(timer->TC_CV < bit_end) ; - } +void frame_sendAsReader(uint32_t data, uint8_t bits){ + + uint32_t starttime = GET_TICKS, send = 0, mask = 1; - { - /* One final pause to mark the end of the frame */ - int pause_end = timer->TC_CV + RWD_TIME_PAUSE; - AT91C_BASE_PIOA->PIO_CODR = GPIO_SSC_DOUT; - while(timer->TC_CV < pause_end) ; - AT91C_BASE_PIOA->PIO_SODR = GPIO_SSC_DOUT; + // xor lsfr onto data. + send = data ^ legic_prng_get_bits(bits); + + for (; mask < BITMASK(bits); mask <<= 1) { + if (send & mask) + COIL_PULSE(RWD_TIME_1) + else + COIL_PULSE(RWD_TIME_0) } + + // Final pause to mark the end of the frame + COIL_PULSE(0); - /* Reset the timer, to measure time until the start of the tag frame */ - timer->TC_CCR = AT91C_TC_SWTRG; - while(timer->TC_CV > 1) ; /* Wait till the clock has reset */ + // log + uint8_t cmdbytes[] = {bits, BYTEx(data,0), BYTEx(data,1), BYTEx(data,2), BYTEx(send,0), BYTEx(send,1), BYTEx(send,2)}; + LogTrace(cmdbytes, sizeof(cmdbytes), starttime, GET_TICKS, NULL, TRUE); } /* Receive a frame from the card in reader emulation mode, the FPGA and - * timer must have been set up by LegicRfReader and frame_send_rwd. - * + * timer must have been set up by LegicRfReader and frame_sendAsReader. + * * The LEGIC RF protocol from card to reader does not include explicit * frame start/stop information or length information. The reader must * know beforehand how many bits it wants to receive. (Notably: a card * sending a stream of 0-bits is indistinguishable from no card present.) - * + * * Receive methodology: There is a fancy correlator in hi_read_rx_xcorr, but * I'm not smart enough to use it. Instead I have patched hi_read_tx to output * the ADC signal with hysteresis on SSP_DIN. Bit-bang that signal and look * for edges. Count the edges in each bit interval. If they are approximately * 0 this was a 0-bit, if they are approximately equal to the number of edges * expected for a 212kHz subcarrier, this was a 1-bit. For timing we use the - * timer that's still running from frame_send_rwd in order to get a synchronization + * timer that's still running from frame_sendAsReader in order to get a synchronization * with the frame that we just sent. - * - * FIXME: Because we're relying on the hysteresis to just do the right thing + * + * FIXME: Because we're relying on the hysteresis to just do the right thing * the range is severely reduced (and you'll probably also need a good antenna). - * So this should be fixed some time in the future for a proper receiver. + * So this should be fixed some time in the future for a proper receiver. */ -static void frame_receive_rwd(struct legic_frame * const f, int bits, int crypt) -{ - uint32_t the_bit = 1; /* Use a bitmask to save on shifts */ - uint32_t data=0; - int i, old_level=0, edges=0; - int next_bit_at = TAG_TIME_WAIT; +static void frame_receiveAsReader(struct legic_frame * const f, uint8_t bits) { + + if ( bits > 32 ) return; + uint8_t i = bits, edges = 0; + uint32_t the_bit = 1, next_bit_at = 0, data = 0; + uint32_t old_level = 0; + volatile uint32_t level = 0; - if(bits > 16) - bits = 16; - - AT91C_BASE_PIOA->PIO_ODR = GPIO_SSC_DIN; - AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DIN; - - /* we have some time now, precompute the cipher - * since we cannot compute it on the fly while reading */ + frame_clean(f); + + // calibrate the prng. legic_prng_forward(2); + data = legic_prng_get_bits(bits); + + //FIXED time between sending frame and now listening frame. 330us + uint32_t starttime = GET_TICKS; + // its about 9+9 ticks delay from end-send to here. + WaitTicks( 477 ); - if(crypt) - { - for(i=0; iTC_CV < next_bit_at) ; + next_bit_at = GET_TICKS + TAG_BIT_PERIOD; - next_bit_at += TAG_TIME_BIT; - - for(i=0; iTC_CV < next_bit_at) { - int level = (AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_DIN); - if(level != old_level) - edges++; + level = (AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_DIN); + + if (level != old_level) + ++edges; + old_level = level; - } - next_bit_at += TAG_TIME_BIT; + } + + next_bit_at += TAG_BIT_PERIOD; - if(edges > 20 && edges < 60) { /* expected are 42 edges */ + // We expect 42 edges (ONE) + if ( edges > 20 ) data ^= the_bit; - } - the_bit <<= 1; + the_bit <<= 1; } - + + // output f->data = data; f->bits = bits; - /* Reset the timer, to synchronize the next frame */ - timer->TC_CCR = AT91C_TC_SWTRG; - while(timer->TC_CV > 1) ; /* Wait till the clock has reset */ + // log + uint8_t cmdbytes[] = {bits, BYTEx(data, 0), BYTEx(data, 1)}; + LogTrace(cmdbytes, sizeof(cmdbytes), starttime, GET_TICKS, NULL, FALSE); } -static void frame_clean(struct legic_frame * const f) -{ - f->data = 0; - f->bits = 0; -} - -static uint32_t perform_setup_phase_rwd(int iv) -{ +// Setup pm3 as a Legic Reader +static uint32_t setup_phase_reader(uint8_t iv) { - /* Switch on carrier and let the tag charge for 1ms */ - AT91C_BASE_PIOA->PIO_SODR = GPIO_SSC_DOUT; - SpinDelay(1); + // Switch on carrier and let the tag charge for 5ms + HIGH(GPIO_SSC_DOUT); + WaitUS(5000); - legic_prng_init(0); /* no keystream yet */ - frame_send_rwd(iv, 7); - legic_prng_init(iv); + ResetTicks(); - frame_clean(¤t_frame); - frame_receive_rwd(¤t_frame, 6, 1); - legic_prng_forward(1); /* we wait anyways */ - while(timer->TC_CV < 387) ; /* ~ 258us */ - frame_send_rwd(0x19, 6); + legic_prng_init(0); + + // send IV handshake + frame_sendAsReader(iv, 7); + + // tag and reader has same IV. + legic_prng_init(iv); + + frame_receiveAsReader(¤t_frame, 6); + // 292us (438t) - fixed delay before sending ack. + // minus log and stuff 100tick? + WaitTicks(338); + legic_prng_forward(3); + + // Send obsfuscated acknowledgment frame. + // 0x19 = 0x18 MIM22, 0x01 LSB READCMD + // 0x39 = 0x38 MIM256, MIM1024 0x01 LSB READCMD + switch ( current_frame.data ) { + case 0x0D: frame_sendAsReader(0x19, 6); break; + case 0x1D: + case 0x3D: frame_sendAsReader(0x39, 6); break; + default: break; + } + + legic_prng_forward(2); return current_frame.data; } -static void LegicCommonInit(void) { - SetAdcMuxFor(GPIO_MUXSEL_HIPKD); - FpgaSetupSsc(); +void LegicCommonInit(bool clear_mem) { + + FpgaDownloadAndGo(FPGA_BITSTREAM_HF); FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX); - + SetAdcMuxFor(GPIO_MUXSEL_HIPKD); + /* Bitbang the transmitter */ - AT91C_BASE_PIOA->PIO_CODR = GPIO_SSC_DOUT; + SHORT_COIL; AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT; AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT; + AT91C_BASE_PIOA->PIO_ODR = GPIO_SSC_DIN; - setup_timer(); - + // reserve a cardmem, meaning we can use the tracelog function in bigbuff easier. + cardmem = BigBuf_get_EM_addr(); + if ( clear_mem ) + memset(cardmem, 0x00, LEGIC_CARD_MEMSIZE); + + clear_trace(); + set_tracing(TRUE); crc_init(&legic_crc, 4, 0x19 >> 1, 0x5, 0); + + StartTicks(); } -static void switch_off_tag_rwd(void) -{ - /* Switch off carrier, make sure tag is reset */ - AT91C_BASE_PIOA->PIO_CODR = GPIO_SSC_DOUT; - SpinDelay(10); - +// Switch off carrier, make sure tag is reset +static void switch_off_tag_rwd(void) { + SHORT_COIL; + WaitUS(20); WDT_HIT(); } -/* calculate crc for a legic command */ -static int LegicCRC(int byte_index, int value, int cmd_sz) { - crc_clear(&legic_crc); - crc_update(&legic_crc, 1, 1); /* CMD_READ */ - crc_update(&legic_crc, byte_index, cmd_sz-1); - crc_update(&legic_crc, value, 8); + +// calculate crc4 for a legic READ command +static uint32_t legic4Crc(uint8_t cmd, uint16_t byte_index, uint8_t value, uint8_t cmd_sz) { + crc_clear(&legic_crc); + uint32_t temp = (value << cmd_sz) | (byte_index << 1) | cmd; + crc_update(&legic_crc, temp, cmd_sz + 8 ); return crc_finish(&legic_crc); } -int legic_read_byte(int byte_index, int cmd_sz) { - int byte; +int legic_read_byte( uint16_t index, uint8_t cmd_sz) { - legic_prng_forward(4); /* we wait anyways */ - while(timer->TC_CV < 387) ; /* ~ 258us + 100us*delay */ - - frame_send_rwd(1 | (byte_index << 1), cmd_sz); - frame_clean(¤t_frame); + uint8_t byte, crc, calcCrc = 0; + uint32_t cmd = (index << 1) | LEGIC_READ; + + // 90ticks = 60us (should be 100us but crc calc takes time.) + //WaitTicks(330); // 330ticks prng(4) - works + WaitTicks(240); // 240ticks prng(3) - works + + frame_sendAsReader(cmd, cmd_sz); + frame_receiveAsReader(¤t_frame, 12); - frame_receive_rwd(¤t_frame, 12, 1); + // CRC check. + byte = BYTEx(current_frame.data, 0); + crc = BYTEx(current_frame.data, 1); + calcCrc = legic4Crc(LEGIC_READ, index, byte, cmd_sz); - byte = current_frame.data & 0xff; - if( LegicCRC(byte_index, byte, cmd_sz) != (current_frame.data >> 8) ) { - Dbprintf("!!! crc mismatch: expected %x but got %x !!!", LegicCRC(byte_index, current_frame.data & 0xff, cmd_sz), current_frame.data >> 8); + if( calcCrc != crc ) { + Dbprintf("!!! crc mismatch: %x != %x !!!", calcCrc, crc); return -1; } + legic_prng_forward(3); return byte; } -/* legic_write_byte() is not included, however it's trivial to implement - * and here are some hints on what remains to be done: - * - * * assemble a write_cmd_frame with crc and send it - * * wait until the tag sends back an ACK ('1' bit unencrypted) - * * forward the prng based on the timing +/* + * - assemble a write_cmd_frame with crc and send it + * - wait until the tag sends back an ACK ('1' bit unencrypted) + * - forward the prng based on the timing */ +bool legic_write_byte(uint16_t index, uint8_t byte, uint8_t addr_sz) { + + bool isOK = false; + int8_t i = 40; + uint8_t edges = 0; + uint8_t cmd_sz = addr_sz+1+8+4; //crc+data+cmd; + uint32_t steps = 0, next_bit_at, start, crc, old_level = 0; + crc = legic4Crc(LEGIC_WRITE, index, byte, addr_sz+1); -void LegicRfReader(int offset, int bytes) { - int byte_index=0, cmd_sz=0, card_sz=0; + // send write command + uint32_t cmd = LEGIC_WRITE; + cmd |= index << 1; // index + cmd |= byte << (addr_sz+1); // Data + cmd |= (crc & 0xF ) << (addr_sz+1+8); // CRC + + WaitTicks(240); - LegicCommonInit(); + frame_sendAsReader(cmd, cmd_sz); + + LINE_IN; + + start = GET_TICKS; - memset(BigBuf, 0, 1024); + // ACK, - one single "1" bit after 3.6ms + // 3.6ms = 3600us * 1.5 = 5400ticks. + WaitTicks(5400); + + next_bit_at = GET_TICKS + TAG_BIT_PERIOD; - DbpString("setting up legic card"); - uint32_t tag_type = perform_setup_phase_rwd(0x55); - switch(tag_type) { + while ( i-- ) { + WDT_HIT(); + edges = 0; + while ( GET_TICKS < next_bit_at) { + + volatile uint32_t level = (AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_DIN); + + if (level != old_level) + ++edges; + + old_level = level; + } + + next_bit_at += TAG_BIT_PERIOD; + + // We expect 42 edges (ONE) + if(edges > 20 ) { + steps = ( (GET_TICKS - start) / TAG_BIT_PERIOD); + legic_prng_forward(steps); + isOK = true; + goto OUT; + } + } + +OUT: ; + legic_prng_forward(1); + + uint8_t cmdbytes[] = {1, isOK, BYTEx(steps, 0), BYTEx(steps, 1) }; + LogTrace(cmdbytes, sizeof(cmdbytes), start, GET_TICKS, NULL, FALSE); + return isOK; +} + +int LegicRfReader(uint16_t offset, uint16_t len, uint8_t iv) { + + uint16_t i = 0; + uint8_t isOK = 1; + legic_card_select_t card; + + LegicCommonInit(TRUE); + + if ( legic_select_card_iv(&card, iv) ) { + isOK = 0; + goto OUT; + } + + if (len + offset > card.cardsize) + len = card.cardsize - offset; + + LED_B_ON(); + while (i < len) { + int r = legic_read_byte(offset + i, card.cmdsize); + + if (r == -1 || BUTTON_PRESS()) { + if ( MF_DBGLEVEL >= 2) DbpString("operation aborted"); + isOK = 0; + goto OUT; + } + cardmem[i++] = r; + WDT_HIT(); + } + +OUT: + WDT_HIT(); + switch_off_tag_rwd(); + LEDsoff(); + cmd_send(CMD_ACK, isOK, len, 0, cardmem, len); + return 0; +} + +void LegicRfWriter(uint16_t offset, uint16_t len, uint8_t iv, uint8_t *data) { + + #define LOWERLIMIT 4 + uint8_t isOK = 1, msg = 0; + legic_card_select_t card; + + // uid NOT is writeable. + if ( offset <= LOWERLIMIT ) { + isOK = 0; + goto OUT; + } + + LegicCommonInit(TRUE); + + if ( legic_select_card_iv(&card, iv) ) { + isOK = 0; + msg = 1; + goto OUT; + } + + if ( len + offset > card.cardsize) + len = card.cardsize - offset; + + LED_B_ON(); + while( len > 0 ) { + --len; + if ( !legic_write_byte( len + offset, data[len], card.addrsize) ) { + Dbprintf("operation failed | %02X | %02X | %02X", len + offset, len, data[len] ); + isOK = 0; + goto OUT; + } + WDT_HIT(); + } +OUT: + cmd_send(CMD_ACK, isOK, msg,0,0,0); + switch_off_tag_rwd(); + LEDsoff(); +} + +int legic_select_card_iv(legic_card_select_t *p_card, uint8_t iv){ + + if ( p_card == NULL ) return 1; + + p_card->tagtype = setup_phase_reader(iv); + + switch(p_card->tagtype) { + case 0x0d: + p_card->cmdsize = 6; + p_card->addrsize = 5; + p_card->cardsize = 22; + break; case 0x1d: - DbpString("MIM 256 card found, reading card ..."); - cmd_sz = 9; - card_sz = 256; + p_card->cmdsize = 9; + p_card->addrsize = 8; + p_card->cardsize = 256; break; case 0x3d: - DbpString("MIM 1024 card found, reading card ..."); - cmd_sz = 11; - card_sz = 1024; + p_card->cmdsize = 11; + p_card->addrsize = 10; + p_card->cardsize = 1024; break; - default: - Dbprintf("Unknown card format: %x",tag_type); - switch_off_tag_rwd(); - return; + default: + p_card->cmdsize = 0; + p_card->addrsize = 0; + p_card->cardsize = 0; + return 2; + } + return 0; +} +int legic_select_card(legic_card_select_t *p_card){ + return legic_select_card_iv(p_card, 0x01); +} + +//----------------------------------------------------------------------------- +// Work with emulator memory +// +// Note: we call FpgaDownloadAndGo(FPGA_BITSTREAM_HF) here although FPGA is not +// involved in dealing with emulator memory. But if it is called later, it might +// destroy the Emulator Memory. +//----------------------------------------------------------------------------- +// arg0 = offset +// arg1 = num of bytes +void LegicEMemSet(uint32_t arg0, uint32_t arg1, uint8_t *data) { + FpgaDownloadAndGo(FPGA_BITSTREAM_HF); + legic_emlset_mem(data, arg0, arg1); +} +// arg0 = offset +// arg1 = num of bytes +void LegicEMemGet(uint32_t arg0, uint32_t arg1) { + FpgaDownloadAndGo(FPGA_BITSTREAM_HF); + uint8_t buf[USB_CMD_DATA_SIZE] = {0x00}; + legic_emlget_mem(buf, arg0, arg1); + LED_B_ON(); + cmd_send(CMD_ACK, arg0, arg1, 0, buf, USB_CMD_DATA_SIZE); + LED_B_OFF(); +} +void legic_emlset_mem(uint8_t *data, int offset, int numofbytes) { + cardmem = BigBuf_get_EM_addr(); + memcpy(cardmem + offset, data, numofbytes); +} +void legic_emlget_mem(uint8_t *data, int offset, int numofbytes) { + cardmem = BigBuf_get_EM_addr(); + memcpy(data, cardmem + offset, numofbytes); +} + +void LegicRfInfo(void){ + + int r; + + uint8_t buf[sizeof(legic_card_select_t)] = {0x00}; + legic_card_select_t *card = (legic_card_select_t*) buf; + + LegicCommonInit(FALSE); + + if ( legic_select_card(card) ) { + cmd_send(CMD_ACK,0,0,0,0,0); + goto OUT; + } + + // read UID bytes + for ( uint8_t i = 0; i < sizeof(card->uid); ++i) { + r = legic_read_byte(i, card->cmdsize); + if ( r == -1 ) { + cmd_send(CMD_ACK,0,0,0,0,0); + goto OUT; + } + card->uid[i] = r & 0xFF; } - if(bytes == -1) { - bytes = card_sz; + + // MCC byte. + r = legic_read_byte(4, card->cmdsize); + uint32_t calc_mcc = CRC8Legic(card->uid, 4);; + if ( r != calc_mcc) { + cmd_send(CMD_ACK,0,0,0,0,0); + goto OUT; } - if(bytes+offset >= card_sz) { - bytes = card_sz-offset; + + // OK + cmd_send(CMD_ACK, 1, 0, 0, buf, sizeof(legic_card_select_t)); + +OUT: + switch_off_tag_rwd(); + LEDsoff(); +} + +/* Handle (whether to respond) a frame in tag mode + * Only called when simulating a tag. + */ +static void frame_handle_tag(struct legic_frame const * const f) +{ + // log + //uint8_t cmdbytes[] = {bits, BYTEx(data, 0), BYTEx(data, 1)}; + //LogTrace(cmdbytes, sizeof(cmdbytes), starttime, GET_TICKS, NULL, FALSE); + //Dbprintf("ICE: enter frame_handle_tag: %02x ", f->bits); + + /* First Part of Handshake (IV) */ + if(f->bits == 7) { + + LED_C_ON(); + + // Reset prng timer + //ResetTimer(prng_timer); + ResetTicks(); + + // IV from reader. + legic_prng_init(f->data); + + Dbprintf("ICE: IV: %02x ", f->data); + + // We should have three tagtypes with three different answers. + legic_prng_forward(2); + //frame_send_tag(0x3d, 6); /* MIM1024 0x3d^0x26 = 0x1B */ + frame_send_tag(0x1d, 6); // MIM256 + + legic_state = STATE_IV; + legic_read_count = 0; + legic_prng_bc = 0; + legic_prng_iv = f->data; + + //ResetTimer(timer); + //WaitUS(280); + WaitTicks(388); + return; + } + + /* 0x19==??? */ + if(legic_state == STATE_IV) { + uint32_t local_key = get_key_stream(3, 6); + int xored = 0x39 ^ local_key; + if((f->bits == 6) && (f->data == xored)) { + legic_state = STATE_CON; + + ResetTimer(timer); + WaitTicks(300); + return; + + } else { + legic_state = STATE_DISCON; + LED_C_OFF(); + Dbprintf("iv: %02x frame: %02x key: %02x xored: %02x", legic_prng_iv, f->data, local_key, xored); + return; + } + } + + /* Read */ + if(f->bits == 11) { + if(legic_state == STATE_CON) { + uint32_t key = get_key_stream(2, 11); //legic_phase_drift, 11); + uint16_t addr = f->data ^ key; + addr >>= 1; + uint8_t data = cardmem[addr]; + + uint32_t crc = legic4Crc(LEGIC_READ, addr, data, 11) << 8; + + //legic_read_count++; + //legic_prng_forward(legic_reqresp_drift); + + frame_send_tag(crc | data, 12); + //ResetTimer(timer); + legic_prng_forward(2); + WaitTicks(330); + return; + } + } + + /* Write */ + if (f->bits == 23 || f->bits == 21 ) { + uint32_t key = get_key_stream(-1, 23); //legic_frame_drift, 23); + uint16_t addr = f->data ^ key; + addr >>= 1; + addr &= 0x3ff; + uint32_t data = f->data ^ key; + data >>= 11; + data &= 0xff; + + cardmem[addr] = data; + /* write command */ + legic_state = STATE_DISCON; + LED_C_OFF(); + Dbprintf("write - addr: %x, data: %x", addr, data); + // should send a ACK after 3.6ms + return; + } + + if(legic_state != STATE_DISCON) { + Dbprintf("Unexpected: sz:%u, Data:%03.3x, State:%u, Count:%u", f->bits, f->data, legic_state, legic_read_count); + Dbprintf("IV: %03.3x", legic_prng_iv); + } + + legic_state = STATE_DISCON; + legic_read_count = 0; + WaitMS(10); + LED_C_OFF(); + return; +} + +/* Read bit by bit untill full frame is received + * Call to process frame end answer + */ +static void emit(int bit) { + + switch (bit) { + case 1: + frame_append_bit(¤t_frame, 1); + break; + case 0: + frame_append_bit(¤t_frame, 0); + break; + default: + if(current_frame.bits <= 4) { + frame_clean(¤t_frame); + } else { + frame_handle_tag(¤t_frame); + frame_clean(¤t_frame); + } + WDT_HIT(); + break; + } +} + +void LegicRfSimulate(int phase, int frame, int reqresp) +{ + /* ADC path high-frequency peak detector, FPGA in high-frequency simulator mode, + * modulation mode set to 212kHz subcarrier. We are getting the incoming raw + * envelope waveform on DIN and should send our response on DOUT. + * + * The LEGIC RF protocol is pulse-pause-encoding from reader to card, so we'll + * measure the time between two rising edges on DIN, and no encoding on the + * subcarrier from card to reader, so we'll just shift out our verbatim data + * on DOUT, 1 bit is 100us. The time from reader to card frame is still unclear, + * seems to be 330us. + */ + + int old_level = 0, active = 0; + volatile int32_t level = 0; + + legic_state = STATE_DISCON; + legic_phase_drift = phase; + legic_frame_drift = frame; + legic_reqresp_drift = reqresp; + + + /* to get the stream of bits from FPGA in sim mode.*/ + FpgaDownloadAndGo(FPGA_BITSTREAM_HF); + // Set up the synchronous serial port + //FpgaSetupSsc(); + // connect Demodulated Signal to ADC: + SetAdcMuxFor(GPIO_MUXSEL_HIPKD); + FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_SIMULATOR | FPGA_HF_SIMULATOR_MODULATE_212K); + //FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_SIMULATOR | FPGA_HF_SIMULATOR_NO_MODULATION); + + #define LEGIC_DMA_BUFFER 256 + // The DMA buffer, used to stream samples from the FPGA + //uint8_t *dmaBuf = BigBuf_malloc(LEGIC_DMA_BUFFER); + //uint8_t *data = dmaBuf; + // Setup and start DMA. + // if ( !FpgaSetupSscDma((uint8_t*) dmaBuf, LEGIC_DMA_BUFFER) ){ + // if (MF_DBGLEVEL > 1) Dbprintf("FpgaSetupSscDma failed. Exiting"); + // return; + // } + + //StartCountSspClk(); + /* Bitbang the receiver */ + AT91C_BASE_PIOA->PIO_ODR = GPIO_SSC_DIN; + AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DIN; + + // need a way to determine which tagtype we are simulating + + // hook up emulator memory + cardmem = BigBuf_get_EM_addr(); + + clear_trace(); + set_tracing(TRUE); + + crc_init(&legic_crc, 4, 0x19 >> 1, 0x5, 0); + + StartTicks(); + + LED_B_ON(); + DbpString("Starting Legic emulator, press button to end"); + + /* + * The mode FPGA_HF_SIMULATOR_MODULATE_212K works like this. + * - A 1-bit input to the FPGA becomes 8 pulses on 212kHz (fc/64) (18.88us). + * - A 0-bit input to the FPGA becomes an unmodulated time of 18.88us + * + * In this mode the SOF can be written as 00011101 = 0x1D + * The EOF can be written as 10111000 = 0xb8 + * A logic 1 is 01 + * A logic 0 is 10 + volatile uint8_t b; + uint8_t i = 0; + while( !BUTTON_PRESS() ) { + WDT_HIT(); + + // not sending anything. + if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { + AT91C_BASE_SSC->SSC_THR = 0x00; } - switch_off_tag_rwd(); //we lost to mutch time with dprintf - perform_setup_phase_rwd(0x55); + // receive + if ( AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY ) { + b = (uint8_t) AT91C_BASE_SSC->SSC_RHR; + bd[i] = b; + ++i; + // if(OutOfNDecoding(b & 0x0f)) + // *len = Uart.byteCnt; + } + + } + */ - while(byte_index < bytes) { - int r = legic_read_byte(byte_index+offset, cmd_sz); - if(r == -1) { - Dbprintf("aborting"); - switch_off_tag_rwd(); - return; + while(!BUTTON_PRESS() && !usb_poll_validate_length()) { + + level = !!(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_DIN); + + uint32_t time = GET_TICKS; + + if (level != old_level) { + if (level == 1) { + + //Dbprintf("start, %u ", time); + StartTicks(); + // did we get a signal + if (FUZZ_EQUAL(time, RWD_TIME_1, RWD_TIME_FUZZ)) { + // 1 bit + emit(1); + active = 1; + LED_A_ON(); + } else if (FUZZ_EQUAL(time, RWD_TIME_0, RWD_TIME_FUZZ)) { + // 0 bit + emit(0); + active = 1; + LED_A_ON(); + } else if (active) { + // invalid + emit(-1); + active = 0; + LED_A_OFF(); + } + } } - ((uint8_t*)BigBuf)[byte_index] = r; - byte_index++; - } + + + /* Frame end */ + if(time >= (RWD_TIME_1 + RWD_TIME_FUZZ) && active) { + emit(-1); + active = 0; + LED_A_OFF(); + } + + /* + * Disable the counter, Then wait for the clock to acknowledge the + * shutdown in its status register. Reading the SR has the + * side-effect of clearing any pending state in there. + */ + //if(time >= (20*RWD_TIME_1) && (timer->TC_SR & AT91C_TC_CLKSTA)) + if(time >= (20 * RWD_TIME_1) ) + StopTicks(); + + old_level = level; + WDT_HIT(); +} + + WDT_HIT(); + DbpString("LEGIC Prime emulator stopped"); switch_off_tag_rwd(); - Dbprintf("Card read, use 'hf legic decode' or 'data hexsamples %d' to view results", (bytes+7) & ~7); + FpgaDisableSscDma(); + LEDsoff(); + cmd_send(CMD_ACK, 1, 0, 0, 0, 0); +} + + +//----------------------------------------------------------------------------- +// Code up a string of octets at layer 2 (including CRC, we don't generate +// that here) so that they can be transmitted to the reader. Doesn't transmit +// them yet, just leaves them ready to send in ToSend[]. +//----------------------------------------------------------------------------- +// static void CodeLegicAsTag(const uint8_t *cmd, int len) +// { + // int i; + + // ToSendReset(); + + // // Transmit a burst of ones, as the initial thing that lets the + // // reader get phase sync. This (TR1) must be > 80/fs, per spec, + // // but tag that I've tried (a Paypass) exceeds that by a fair bit, + // // so I will too. + // for(i = 0; i < 20; i++) { + // ToSendStuffBit(1); + // ToSendStuffBit(1); + // ToSendStuffBit(1); + // ToSendStuffBit(1); + // } + + // // Send SOF. + // for(i = 0; i < 10; i++) { + // ToSendStuffBit(0); + // ToSendStuffBit(0); + // ToSendStuffBit(0); + // ToSendStuffBit(0); + // } + // for(i = 0; i < 2; i++) { + // ToSendStuffBit(1); + // ToSendStuffBit(1); + // ToSendStuffBit(1); + // ToSendStuffBit(1); + // } + + // for(i = 0; i < len; i++) { + // int j; + // uint8_t b = cmd[i]; + + // // Start bit + // ToSendStuffBit(0); + // ToSendStuffBit(0); + // ToSendStuffBit(0); + // ToSendStuffBit(0); + + // // Data bits + // for(j = 0; j < 8; j++) { + // if(b & 1) { + // ToSendStuffBit(1); + // ToSendStuffBit(1); + // ToSendStuffBit(1); + // ToSendStuffBit(1); + // } else { + // ToSendStuffBit(0); + // ToSendStuffBit(0); + // ToSendStuffBit(0); + // ToSendStuffBit(0); + // } + // b >>= 1; + // } + + // // Stop bit + // ToSendStuffBit(1); + // ToSendStuffBit(1); + // ToSendStuffBit(1); + // ToSendStuffBit(1); + // } + + // // Send EOF. + // for(i = 0; i < 10; i++) { + // ToSendStuffBit(0); + // ToSendStuffBit(0); + // ToSendStuffBit(0); + // ToSendStuffBit(0); + // } + // for(i = 0; i < 2; i++) { + // ToSendStuffBit(1); + // ToSendStuffBit(1); + // ToSendStuffBit(1); + // ToSendStuffBit(1); + // } + + // // Convert from last byte pos to length + // ToSendMax++; +// } + +//----------------------------------------------------------------------------- +// The software UART that receives commands from the reader, and its state +// variables. +//----------------------------------------------------------------------------- +/* +static struct { + enum { + STATE_UNSYNCD, + STATE_GOT_FALLING_EDGE_OF_SOF, + STATE_AWAITING_START_BIT, + STATE_RECEIVING_DATA + } state; + uint16_t shiftReg; + int bitCnt; + int byteCnt; + int byteCntMax; + int posCnt; + uint8_t *output; +} Uart; +*/ +/* Receive & handle a bit coming from the reader. + * + * This function is called 4 times per bit (every 2 subcarrier cycles). + * Subcarrier frequency fs is 212kHz, 1/fs = 4,72us, i.e. function is called every 9,44us + * + * LED handling: + * LED A -> ON once we have received the SOF and are expecting the rest. + * LED A -> OFF once we have received EOF or are in error state or unsynced + * + * Returns: true if we received a EOF + * false if we are still waiting for some more + */ +// static RAMFUNC int HandleLegicUartBit(uint8_t bit) +// { + // switch(Uart.state) { + // case STATE_UNSYNCD: + // if(!bit) { + // // we went low, so this could be the beginning of an SOF + // Uart.state = STATE_GOT_FALLING_EDGE_OF_SOF; + // Uart.posCnt = 0; + // Uart.bitCnt = 0; + // } + // break; + + // case STATE_GOT_FALLING_EDGE_OF_SOF: + // Uart.posCnt++; + // if(Uart.posCnt == 2) { // sample every 4 1/fs in the middle of a bit + // if(bit) { + // if(Uart.bitCnt > 9) { + // // we've seen enough consecutive + // // zeros that it's a valid SOF + // Uart.posCnt = 0; + // Uart.byteCnt = 0; + // Uart.state = STATE_AWAITING_START_BIT; + // LED_A_ON(); // Indicate we got a valid SOF + // } else { + // // didn't stay down long enough + // // before going high, error + // Uart.state = STATE_UNSYNCD; + // } + // } else { + // // do nothing, keep waiting + // } + // Uart.bitCnt++; + // } + // if(Uart.posCnt >= 4) Uart.posCnt = 0; + // if(Uart.bitCnt > 12) { + // // Give up if we see too many zeros without + // // a one, too. + // LED_A_OFF(); + // Uart.state = STATE_UNSYNCD; + // } + // break; + + // case STATE_AWAITING_START_BIT: + // Uart.posCnt++; + // if(bit) { + // if(Uart.posCnt > 50/2) { // max 57us between characters = 49 1/fs, max 3 etus after low phase of SOF = 24 1/fs + // // stayed high for too long between + // // characters, error + // Uart.state = STATE_UNSYNCD; + // } + // } else { + // // falling edge, this starts the data byte + // Uart.posCnt = 0; + // Uart.bitCnt = 0; + // Uart.shiftReg = 0; + // Uart.state = STATE_RECEIVING_DATA; + // } + // break; + + // case STATE_RECEIVING_DATA: + // Uart.posCnt++; + // if(Uart.posCnt == 2) { + // // time to sample a bit + // Uart.shiftReg >>= 1; + // if(bit) { + // Uart.shiftReg |= 0x200; + // } + // Uart.bitCnt++; + // } + // if(Uart.posCnt >= 4) { + // Uart.posCnt = 0; + // } + // if(Uart.bitCnt == 10) { + // if((Uart.shiftReg & 0x200) && !(Uart.shiftReg & 0x001)) + // { + // // this is a data byte, with correct + // // start and stop bits + // Uart.output[Uart.byteCnt] = (Uart.shiftReg >> 1) & 0xff; + // Uart.byteCnt++; + + // if(Uart.byteCnt >= Uart.byteCntMax) { + // // Buffer overflowed, give up + // LED_A_OFF(); + // Uart.state = STATE_UNSYNCD; + // } else { + // // so get the next byte now + // Uart.posCnt = 0; + // Uart.state = STATE_AWAITING_START_BIT; + // } + // } else if (Uart.shiftReg == 0x000) { + // // this is an EOF byte + // LED_A_OFF(); // Finished receiving + // Uart.state = STATE_UNSYNCD; + // if (Uart.byteCnt != 0) { + // return TRUE; + // } + // } else { + // // this is an error + // LED_A_OFF(); + // Uart.state = STATE_UNSYNCD; + // } + // } + // break; + + // default: + // LED_A_OFF(); + // Uart.state = STATE_UNSYNCD; + // break; + // } + + // return FALSE; +// } +/* + +static void UartReset() { + Uart.byteCntMax = 3; + Uart.state = STATE_UNSYNCD; + Uart.byteCnt = 0; + Uart.bitCnt = 0; + Uart.posCnt = 0; + memset(Uart.output, 0x00, 3); +} +*/ +// static void UartInit(uint8_t *data) { + // Uart.output = data; + // UartReset(); +// } + +//============================================================================= +// An LEGIC reader. We take layer two commands, code them +// appropriately, and then send them to the tag. We then listen for the +// tag's response, which we leave in the buffer to be demodulated on the +// PC side. +//============================================================================= +/* +static struct { + enum { + DEMOD_UNSYNCD, + DEMOD_PHASE_REF_TRAINING, + DEMOD_AWAITING_FALLING_EDGE_OF_SOF, + DEMOD_GOT_FALLING_EDGE_OF_SOF, + DEMOD_AWAITING_START_BIT, + DEMOD_RECEIVING_DATA + } state; + int bitCount; + int posCount; + int thisBit; + uint16_t shiftReg; + uint8_t *output; + int len; + int sumI; + int sumQ; +} Demod; +*/ +/* + * Handles reception of a bit from the tag + * + * This function is called 2 times per bit (every 4 subcarrier cycles). + * Subcarrier frequency fs is 212kHz, 1/fs = 4,72us, i.e. function is called every 9,44us + * + * LED handling: + * LED C -> ON once we have received the SOF and are expecting the rest. + * LED C -> OFF once we have received EOF or are unsynced + * + * Returns: true if we received a EOF + * false if we are still waiting for some more + * + */ + +/* +static RAMFUNC int HandleLegicSamplesDemod(int ci, int cq) +{ + int v = 0; + int ai = ABS(ci); + int aq = ABS(cq); + int halfci = (ai >> 1); + int halfcq = (aq >> 1); + + switch(Demod.state) { + case DEMOD_UNSYNCD: + + CHECK_FOR_SUBCARRIER() + + if(v > SUBCARRIER_DETECT_THRESHOLD) { // subcarrier detected + Demod.state = DEMOD_PHASE_REF_TRAINING; + Demod.sumI = ci; + Demod.sumQ = cq; + Demod.posCount = 1; + } + break; + + case DEMOD_PHASE_REF_TRAINING: + if(Demod.posCount < 8) { + + CHECK_FOR_SUBCARRIER() + + if (v > SUBCARRIER_DETECT_THRESHOLD) { + // set the reference phase (will code a logic '1') by averaging over 32 1/fs. + // note: synchronization time > 80 1/fs + Demod.sumI += ci; + Demod.sumQ += cq; + ++Demod.posCount; + } else { + // subcarrier lost + Demod.state = DEMOD_UNSYNCD; + } + } else { + Demod.state = DEMOD_AWAITING_FALLING_EDGE_OF_SOF; + } + break; + + case DEMOD_AWAITING_FALLING_EDGE_OF_SOF: + + MAKE_SOFT_DECISION() + + //Dbprintf("ICE: %d %d %d %d %d", v, Demod.sumI, Demod.sumQ, ci, cq ); + // logic '0' detected + if (v <= 0) { + + Demod.state = DEMOD_GOT_FALLING_EDGE_OF_SOF; + + // start of SOF sequence + Demod.posCount = 0; + } else { + // maximum length of TR1 = 200 1/fs + if(Demod.posCount > 25*2) Demod.state = DEMOD_UNSYNCD; + } + ++Demod.posCount; + break; + + case DEMOD_GOT_FALLING_EDGE_OF_SOF: + ++Demod.posCount; + + MAKE_SOFT_DECISION() + + if(v > 0) { + // low phase of SOF too short (< 9 etu). Note: spec is >= 10, but FPGA tends to "smear" edges + if(Demod.posCount < 10*2) { + Demod.state = DEMOD_UNSYNCD; + } else { + LED_C_ON(); // Got SOF + Demod.state = DEMOD_AWAITING_START_BIT; + Demod.posCount = 0; + Demod.len = 0; + } + } else { + // low phase of SOF too long (> 12 etu) + if(Demod.posCount > 13*2) { + Demod.state = DEMOD_UNSYNCD; + LED_C_OFF(); + } + } + break; + + case DEMOD_AWAITING_START_BIT: + ++Demod.posCount; + + MAKE_SOFT_DECISION() + + if(v > 0) { + // max 19us between characters = 16 1/fs, max 3 etu after low phase of SOF = 24 1/fs + if(Demod.posCount > 3*2) { + Demod.state = DEMOD_UNSYNCD; + LED_C_OFF(); + } + } else { + // start bit detected + Demod.bitCount = 0; + Demod.posCount = 1; // this was the first half + Demod.thisBit = v; + Demod.shiftReg = 0; + Demod.state = DEMOD_RECEIVING_DATA; + } + break; + + case DEMOD_RECEIVING_DATA: + + MAKE_SOFT_DECISION() + + if(Demod.posCount == 0) { + // first half of bit + Demod.thisBit = v; + Demod.posCount = 1; + } else { + // second half of bit + Demod.thisBit += v; + Demod.shiftReg >>= 1; + // logic '1' + if(Demod.thisBit > 0) + Demod.shiftReg |= 0x200; + + ++Demod.bitCount; + + if(Demod.bitCount == 10) { + + uint16_t s = Demod.shiftReg; + + if((s & 0x200) && !(s & 0x001)) { + // stop bit == '1', start bit == '0' + uint8_t b = (s >> 1); + Demod.output[Demod.len] = b; + ++Demod.len; + Demod.state = DEMOD_AWAITING_START_BIT; + } else { + Demod.state = DEMOD_UNSYNCD; + LED_C_OFF(); + + if(s == 0x000) { + // This is EOF (start, stop and all data bits == '0' + return TRUE; + } + } + } + Demod.posCount = 0; + } + break; + + default: + Demod.state = DEMOD_UNSYNCD; + LED_C_OFF(); + break; + } + return FALSE; +} +*/ +/* +// Clear out the state of the "UART" that receives from the tag. +static void DemodReset() { + Demod.len = 0; + Demod.state = DEMOD_UNSYNCD; + Demod.posCount = 0; + Demod.sumI = 0; + Demod.sumQ = 0; + Demod.bitCount = 0; + Demod.thisBit = 0; + Demod.shiftReg = 0; + memset(Demod.output, 0x00, 3); +} + +static void DemodInit(uint8_t *data) { + Demod.output = data; + DemodReset(); } +*/ +/* + * Demodulate the samples we received from the tag, also log to tracebuffer + * quiet: set to 'TRUE' to disable debug output + */ + + /* + #define LEGIC_DMA_BUFFER_SIZE 256 + + static void GetSamplesForLegicDemod(int n, bool quiet) +{ + int max = 0; + bool gotFrame = FALSE; + int lastRxCounter = LEGIC_DMA_BUFFER_SIZE; + int ci, cq, samples = 0; + + BigBuf_free(); + + // And put the FPGA in the appropriate mode + FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_QUARTER_FREQ); + + // The response (tag -> reader) that we're receiving. + // Set up the demodulator for tag -> reader responses. + DemodInit(BigBuf_malloc(MAX_FRAME_SIZE)); + + // The DMA buffer, used to stream samples from the FPGA + int8_t *dmaBuf = (int8_t*) BigBuf_malloc(LEGIC_DMA_BUFFER_SIZE); + int8_t *upTo = dmaBuf; + + // Setup and start DMA. + if ( !FpgaSetupSscDma((uint8_t*) dmaBuf, LEGIC_DMA_BUFFER_SIZE) ){ + if (MF_DBGLEVEL > 1) Dbprintf("FpgaSetupSscDma failed. Exiting"); + return; + } + + // Signal field is ON with the appropriate LED: + LED_D_ON(); + for(;;) { + int behindBy = lastRxCounter - AT91C_BASE_PDC_SSC->PDC_RCR; + if(behindBy > max) max = behindBy; + + while(((lastRxCounter-AT91C_BASE_PDC_SSC->PDC_RCR) & (LEGIC_DMA_BUFFER_SIZE-1)) > 2) { + ci = upTo[0]; + cq = upTo[1]; + upTo += 2; + if(upTo >= dmaBuf + LEGIC_DMA_BUFFER_SIZE) { + upTo = dmaBuf; + AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) upTo; + AT91C_BASE_PDC_SSC->PDC_RNCR = LEGIC_DMA_BUFFER_SIZE; + } + lastRxCounter -= 2; + if(lastRxCounter <= 0) + lastRxCounter = LEGIC_DMA_BUFFER_SIZE; + + samples += 2; + + gotFrame = HandleLegicSamplesDemod(ci , cq ); + if ( gotFrame ) + break; + } + + if(samples > n || gotFrame) + break; + } + + FpgaDisableSscDma(); + + if (!quiet && Demod.len == 0) { + Dbprintf("max behindby = %d, samples = %d, gotFrame = %d, Demod.len = %d, Demod.sumI = %d, Demod.sumQ = %d", + max, + samples, + gotFrame, + Demod.len, + Demod.sumI, + Demod.sumQ + ); + } + + //Tracing + if (Demod.len > 0) { + uint8_t parity[MAX_PARITY_SIZE] = {0x00}; + LogTrace(Demod.output, Demod.len, 0, 0, parity, FALSE); + } +} + +*/ + +//----------------------------------------------------------------------------- +// Transmit the command (to the tag) that was placed in ToSend[]. +//----------------------------------------------------------------------------- +/* +static void TransmitForLegic(void) +{ + int c; + + FpgaSetupSsc(); + + while(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) + AT91C_BASE_SSC->SSC_THR = 0xff; + + // Signal field is ON with the appropriate Red LED + LED_D_ON(); + + // Signal we are transmitting with the Green LED + LED_B_ON(); + FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX | FPGA_HF_READER_TX_SHALLOW_MOD); + + for(c = 0; c < 10;) { + if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { + AT91C_BASE_SSC->SSC_THR = 0xff; + c++; + } + if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { + volatile uint32_t r = AT91C_BASE_SSC->SSC_RHR; + (void)r; + } + WDT_HIT(); + } + + c = 0; + for(;;) { + if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { + AT91C_BASE_SSC->SSC_THR = ToSend[c]; + legic_prng_forward(1); // forward the lfsr + c++; + if(c >= ToSendMax) { + break; + } + } + if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { + volatile uint32_t r = AT91C_BASE_SSC->SSC_RHR; + (void)r; + } + WDT_HIT(); + } + LED_B_OFF(); +} +*/ + +//----------------------------------------------------------------------------- +// Code a layer 2 command (string of octets, including CRC) into ToSend[], +// so that it is ready to transmit to the tag using TransmitForLegic(). +//----------------------------------------------------------------------------- +/* +static void CodeLegicBitsAsReader(const uint8_t *cmd, uint8_t cmdlen, int bits) +{ + int i, j; + uint8_t b; + + ToSendReset(); + + // Send SOF + for(i = 0; i < 7; i++) + ToSendStuffBit(1); + + + for(i = 0; i < cmdlen; i++) { + // Start bit + ToSendStuffBit(0); + + // Data bits + b = cmd[i]; + for(j = 0; j < bits; j++) { + if(b & 1) { + ToSendStuffBit(1); + } else { + ToSendStuffBit(0); + } + b >>= 1; + } + } + + // Convert from last character reference to length + ++ToSendMax; +} +*/ +/** + Convenience function to encode, transmit and trace Legic comms + **/ +/* + static void CodeAndTransmitLegicAsReader(const uint8_t *cmd, uint8_t cmdlen, int bits) +{ + CodeLegicBitsAsReader(cmd, cmdlen, bits); + TransmitForLegic(); + if (tracing) { + uint8_t parity[1] = {0x00}; + LogTrace(cmd, cmdlen, 0, 0, parity, TRUE); + } +} + +*/ +// Set up LEGIC communication +/* +void ice_legic_setup() { + + // standard things. + FpgaDownloadAndGo(FPGA_BITSTREAM_HF); + BigBuf_free(); BigBuf_Clear_ext(false); + clear_trace(); + set_tracing(TRUE); + DemodReset(); + UartReset(); + + // Set up the synchronous serial port + FpgaSetupSsc(); + + // connect Demodulated Signal to ADC: + SetAdcMuxFor(GPIO_MUXSEL_HIPKD); + + // Signal field is on with the appropriate LED + LED_D_ON(); + FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX | FPGA_HF_READER_TX_SHALLOW_MOD); + SpinDelay(20); + // Start the timer + //StartCountSspClk(); + + // initalize CRC + crc_init(&legic_crc, 4, 0x19 >> 1, 0x5, 0); + + // initalize prng + legic_prng_init(0); +} +*/ \ No newline at end of file