X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/117d9ec25c7cbc88555a6a990293ca95a544b915..a28d34f407dc172f1e5b0dc257e8fc89e67706f0:/armsrc/legicrf.c diff --git a/armsrc/legicrf.c b/armsrc/legicrf.c index 074a0f78..0f886656 100644 --- a/armsrc/legicrf.c +++ b/armsrc/legicrf.c @@ -81,38 +81,39 @@ static void setup_timer(void) /* Generate Keystream */ static uint32_t get_key_stream(int skip, int count) { - uint32_t key=0; int i; - - /* Use int to enlarge timer tc to 32bit */ - legic_prng_bc += prng_timer->TC_CV; - prng_timer->TC_CCR = AT91C_TC_SWTRG; - - /* 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, rewidn to bedinning */ - legic_prng_forward(i); - } else { - legic_prng_forward(skip); - } + uint32_t key=0; int i; + + /* Use int to enlarge timer tc to 32bit */ + legic_prng_bc += prng_timer->TC_CV; + prng_timer->TC_CCR = AT91C_TC_SWTRG; + + /* 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, rewidn to bedinning */ + legic_prng_forward(i); + } else { + legic_prng_forward(skip); + } - /* Write Time Data into LOG */ - uint8_t *BigBuf = BigBuf_get_addr(); - if(count == 6) { i = -1; } else { i = legic_read_count; } - BigBuf[OFFSET_LOG+128+i] = legic_prng_count(); - BigBuf[OFFSET_LOG+256+i*4] = (legic_prng_bc >> 0) & 0xff; - BigBuf[OFFSET_LOG+256+i*4+1] = (legic_prng_bc >> 8) & 0xff; - BigBuf[OFFSET_LOG+256+i*4+2] = (legic_prng_bc >>16) & 0xff; - BigBuf[OFFSET_LOG+256+i*4+3] = (legic_prng_bc >>24) & 0xff; - BigBuf[OFFSET_LOG+384+i] = count; - - /* Generate KeyStream */ - for(i=0; i> 0) & 0xff; + BigBuf[OFFSET_LOG+256+i*4+1] = (legic_prng_bc >> 8) & 0xff; + BigBuf[OFFSET_LOG+256+i*4+2] = (legic_prng_bc >>16) & 0xff; + BigBuf[OFFSET_LOG+256+i*4+3] = (legic_prng_bc >>24) & 0xff; + BigBuf[OFFSET_LOG+384+i] = count; + + /* Generate KeyStream */ + for(i=0; iTC_CV + TAG_TIME_BIT; int bit = response & 1; response = response >> 1; - if(bit) { + if(bit) AT91C_BASE_PIOA->PIO_SODR = GPIO_SSC_DOUT; - } else { + else AT91C_BASE_PIOA->PIO_CODR = GPIO_SSC_DOUT; - } + while(timer->TC_CV < nextbit) ; } AT91C_BASE_PIOA->PIO_CODR = GPIO_SSC_DOUT; @@ -171,11 +172,11 @@ static void frame_send_rwd(uint32_t data, int bits) int bit = data & 1; data = data >> 1; - if(bit ^ legic_prng_get_bit()) { + if(bit ^ legic_prng_get_bit()) bit_end = starttime + RWD_TIME_1; - } else { + 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 */ @@ -184,16 +185,15 @@ static void frame_send_rwd(uint32_t data, int bits) 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) ; + while(timer->TC_CV < bit_end); } - { - /* 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; - } + /* 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; + /* Reset the timer, to measure time until the start of the tag frame */ timer->TC_CCR = AT91C_TC_SWTRG; @@ -239,8 +239,7 @@ static void frame_receive_rwd(struct legic_frame * const f, int bits, int crypt) * since we cannot compute it on the fly while reading */ legic_prng_forward(2); - if(crypt) - { + if(crypt) { for(i=0; ibits >= 31) { + if (f->bits >= 31) return; /* Overflow, won't happen */ - } - f->data |= (bit<bits); + + f->data |= (bit << f->bits); f->bits++; } @@ -326,12 +325,11 @@ static void LegicCommonInit(void) { crc_init(&legic_crc, 4, 0x19 >> 1, 0x5, 0); } +/* Switch off carrier, make sure tag is reset */ 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); - WDT_HIT(); } /* calculate crc for a legic command */ @@ -355,9 +353,11 @@ int legic_read_byte(int byte_index, int cmd_sz) { frame_receive_rwd(¤t_frame, 12, 1); 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); + LegicCRC(byte_index, current_frame.data & 0xff, cmd_sz), + current_frame.data >> 8); return -1; } @@ -371,12 +371,12 @@ int legic_read_byte(int byte_index, int cmd_sz) { * * wait until the tag sends back an ACK ('1' bit unencrypted) * * forward the prng based on the timing */ +//int legic_write_byte(int byte, int addr, int addr_sz, int PrngCorrection) { int legic_write_byte(int byte, int addr, int addr_sz) { - //do not write UID, CRC, DCF - if(addr <= 0x06) { + //do not write UID, CRC + if(addr <= 0x04) { return 0; - } - + } //== send write command ============================== crc_clear(&legic_crc); crc_update(&legic_crc, 0, 1); /* CMD_WRITE */ @@ -390,10 +390,13 @@ int legic_write_byte(int byte, int addr, int addr_sz) { |(0x00 <<0)); //CMD = W uint32_t cmd_sz = addr_sz+1+8+4; //crc+data+cmd - legic_prng_forward(2); /* we wait anyways */ + legic_prng_forward(4); /* we wait anyways */ while(timer->TC_CV < 387) ; /* ~ 258us */ frame_send_rwd(cmd, cmd_sz); + AT91C_BASE_PIOA->PIO_ODR = GPIO_SSC_DIN; + AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DIN; + //== wait for ack ==================================== int t, old_level=0, edges=0; int next_bit_at =0; @@ -413,7 +416,7 @@ int legic_write_byte(int byte, int addr, int addr_sz) { int c = t/TAG_TIME_BIT; timer->TC_CCR = AT91C_TC_SWTRG; while(timer->TC_CV > 1) ; /* Wait till the clock has reset */ - legic_prng_forward(c); + legic_prng_forward(c-1); return 0; } } @@ -423,6 +426,11 @@ int legic_write_byte(int byte, int addr, int addr_sz) { } int LegicRfReader(int offset, int bytes) { + + // ice_legic_setup(); + // ice_legic_select_card(); + // return 0; + int byte_index=0, cmd_sz=0, card_sz=0; LegicCommonInit(); @@ -434,13 +442,18 @@ int LegicRfReader(int offset, int bytes) { uint32_t tag_type = perform_setup_phase_rwd(SESSION_IV); switch_off_tag_rwd(); //we lose to mutch time with dprintf switch(tag_type) { + case 0x0d: + DbpString("MIM22 card found, reading card ..."); + cmd_sz = 6; + card_sz = 22; + break; case 0x1d: - DbpString("MIM 256 card found, reading card ..."); + DbpString("MIM256 card found, reading card ..."); cmd_sz = 9; card_sz = 256; break; case 0x3d: - DbpString("MIM 1024 card found, reading card ..."); + DbpString("MIM1024 card found, reading card ..."); cmd_sz = 11; card_sz = 1024; break; @@ -448,12 +461,11 @@ int LegicRfReader(int offset, int bytes) { Dbprintf("Unknown card format: %x",tag_type); return -1; } - if(bytes == -1) { + if(bytes == -1) bytes = card_sz; - } - if(bytes+offset >= card_sz) { + + if(bytes+offset >= card_sz) bytes = card_sz-offset; - } perform_setup_phase_rwd(SESSION_IV); @@ -470,7 +482,7 @@ int LegicRfReader(int offset, int bytes) { BigBuf[byte_index] = r; WDT_HIT(); byte_index++; - if(byte_index & 0x10) LED_C_ON(); else LED_C_OFF(); + if (byte_index & 0x10) LED_C_ON(); else LED_C_OFF(); } LED_B_OFF(); LED_C_OFF(); @@ -480,6 +492,47 @@ int LegicRfReader(int offset, int bytes) { return 0; } +/*int _LegicRfWriter(int bytes, int offset, int addr_sz, uint8_t *BigBuf, int RoundBruteforceValue) { + int byte_index=0; + + LED_B_ON(); + perform_setup_phase_rwd(SESSION_IV); + //legic_prng_forward(2); + while(byte_index < bytes) { + int r; + + //check if the DCF should be changed + if ( (offset == 0x05) && (bytes == 0x02) ) { + //write DCF in reverse order (addr 0x06 before 0x05) + r = legic_write_byte(BigBuf[(0x06-byte_index)], (0x06-byte_index), addr_sz, RoundBruteforceValue); + //legic_prng_forward(1); + if(r == 0) { + byte_index++; + r = legic_write_byte(BigBuf[(0x06-byte_index)], (0x06-byte_index), addr_sz, RoundBruteforceValue); + } + //legic_prng_forward(1); + } + else { + r = legic_write_byte(BigBuf[byte_index+offset], byte_index+offset, addr_sz, RoundBruteforceValue); + } + if((r != 0) || BUTTON_PRESS()) { + Dbprintf("operation aborted @ 0x%03.3x", byte_index); + switch_off_tag_rwd(); + LED_B_OFF(); + LED_C_OFF(); + return -1; + } + + WDT_HIT(); + byte_index++; + if(byte_index & 0x10) LED_C_ON(); else LED_C_OFF(); + } + LED_B_OFF(); + LED_C_OFF(); + DbpString("write successful"); + return 0; +}*/ + void LegicRfWriter(int bytes, int offset) { int byte_index=0, addr_sz=0; uint8_t *BigBuf = BigBuf_get_addr(); @@ -490,32 +543,56 @@ void LegicRfWriter(int bytes, int offset) { uint32_t tag_type = perform_setup_phase_rwd(SESSION_IV); switch_off_tag_rwd(); switch(tag_type) { + case 0x0d: + if(offset+bytes > 22) { + Dbprintf("Error: can not write to 0x%03.3x on MIM22", offset+bytes); + return; + } + addr_sz = 5; + Dbprintf("MIM22 card found, writing 0x%02.2x - 0x%02.2x ...", offset, offset+bytes); + break; case 0x1d: if(offset+bytes > 0x100) { - Dbprintf("Error: can not write to 0x%03.3x on MIM 256", offset+bytes); + Dbprintf("Error: can not write to 0x%03.3x on MIM256", offset+bytes); return; } addr_sz = 8; - Dbprintf("MIM 256 card found, writing 0x%02.2x - 0x%02.2x ...", offset, offset+bytes); + Dbprintf("MIM256 card found, writing 0x%02.2x - 0x%02.2x ...", offset, offset+bytes); break; case 0x3d: if(offset+bytes > 0x400) { - Dbprintf("Error: can not write to 0x%03.3x on MIM 1024", offset+bytes); + Dbprintf("Error: can not write to 0x%03.3x on MIM1024", offset+bytes); return; } addr_sz = 10; - Dbprintf("MIM 1024 card found, writing 0x%03.3x - 0x%03.3x ...", offset, offset+bytes); + Dbprintf("MIM1024 card found, writing 0x%03.3x - 0x%03.3x ...", offset, offset+bytes); break; default: Dbprintf("No or unknown card found, aborting"); return; } +#if 1 LED_B_ON(); perform_setup_phase_rwd(SESSION_IV); - legic_prng_forward(2); + while(byte_index < bytes) { - int r = legic_write_byte(BigBuf[byte_index+offset], byte_index+offset, addr_sz); + int r; + + //check if the DCF should be changed + if ( ((byte_index+offset) == 0x05) && (bytes >= 0x02) ) { + //write DCF in reverse order (addr 0x06 before 0x05) + r = legic_write_byte(BigBuf[(0x06-byte_index)], (0x06-byte_index), addr_sz); + + // write second byte on success... + if(r == 0) { + byte_index++; + r = legic_write_byte(BigBuf[(0x06-byte_index)], (0x06-byte_index), addr_sz); + } + } + else { + r = legic_write_byte(BigBuf[byte_index+offset], byte_index+offset, addr_sz); + } if((r != 0) || BUTTON_PRESS()) { Dbprintf("operation aborted @ 0x%03.3x", byte_index); switch_off_tag_rwd(); @@ -523,6 +600,76 @@ void LegicRfWriter(int bytes, int offset) { LED_C_OFF(); return; } + + WDT_HIT(); + byte_index++; + if(byte_index & 0x10) LED_C_ON(); else LED_C_OFF(); + } + LED_B_OFF(); + LED_C_OFF(); + DbpString("write successful"); +#else + for(byte_index = -2; byte_index < 200; byte_index++) + { + Dbprintf("+ Try RndValue %d...", byte_index); + if(_LegicRfWriter(bytes, offset, addr_sz, BigBuf, byte_index) == 0) + break; + } +#endif + +} + +void LegicRfRawWriter(int offset, int byte) { + int byte_index=0, addr_sz=0; + + LegicCommonInit(); + + DbpString("setting up legic card"); + uint32_t tag_type = perform_setup_phase_rwd(SESSION_IV); + switch_off_tag_rwd(); + switch(tag_type) { + case 0x0d: + if(offset > 22) { + Dbprintf("Error: can not write to 0x%03.3x on MIM22", offset); + return; + } + addr_sz = 5; + Dbprintf("MIM22 card found, writing at addr 0x%02.2x - value 0x%02.2x ...", offset, byte); + break; + case 0x1d: + if(offset > 0x100) { + Dbprintf("Error: can not write to 0x%03.3x on MIM256", offset); + return; + } + addr_sz = 8; + Dbprintf("MIM256 card found, writing at addr 0x%02.2x - value 0x%02.2x ...", offset, byte); + break; + case 0x3d: + if(offset > 0x400) { + Dbprintf("Error: can not write to 0x%03.3x on MIM1024", offset); + return; + } + addr_sz = 10; + Dbprintf("MIM1024 card found, writing at addr 0x%03.3x - value 0x%03.3x ...", offset, byte); + break; + default: + Dbprintf("No or unknown card found, aborting"); + return; + } + Dbprintf("integer value: %d offset: %d addr_sz: %d", byte, offset, addr_sz); + LED_B_ON(); + perform_setup_phase_rwd(SESSION_IV); + //legic_prng_forward(2); + + int r = legic_write_byte(byte, offset, addr_sz); + + if((r != 0) || BUTTON_PRESS()) { + Dbprintf("operation aborted @ 0x%03.3x (%1d)", byte_index, r); + switch_off_tag_rwd(); + LED_B_OFF(); + LED_C_OFF(); + return; + WDT_HIT(); byte_index++; if(byte_index & 0x10) LED_C_ON(); else LED_C_OFF(); @@ -711,7 +858,7 @@ void LegicRfSimulate(int phase, int frame, int reqresp) LED_B_ON(); DbpString("Starting Legic emulator, press button to end"); - while(!BUTTON_PRESS()) { + while(!BUTTON_PRESS() && !usb_poll_validate_length()) { int level = !!(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_DIN); int time = timer->TC_CV; @@ -757,3 +904,757 @@ void LegicRfSimulate(int phase, int frame, int reqresp) LED_C_OFF(); } + +//----------------------------------------------------------------------------- +//----------------------------------------------------------------------------- + + +//----------------------------------------------------------------------------- +// 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 = MAX_FRAME_SIZE; + Uart.state = STATE_UNSYNCD; + Uart.byteCnt = 0; + Uart.bitCnt = 0; + Uart.posCnt = 0; + memset(Uart.output, 0x00, MAX_FRAME_SIZE); +} + +// 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 + * + */ + + #ifndef SUBCARRIER_DETECT_THRESHOLD + # define SUBCARRIER_DETECT_THRESHOLD 8 + #endif + + // Subcarrier amplitude v = sqrt(ci^2 + cq^2), approximated here by max(abs(ci),abs(cq)) + 1/2*min(abs(ci),abs(cq))) +#ifndef CHECK_FOR_SUBCARRIER +# define CHECK_FOR_SUBCARRIER() { v = MAX(ai, aq) + MIN(halfci, halfcq); } +#endif + +// The soft decision on the bit uses an estimate of just the +// quadrant of the reference angle, not the exact angle. +// Subcarrier amplitude v = sqrt(ci^2 + cq^2), approximated here by max(abs(ci),abs(cq)) + 1/2*min(abs(ci),abs(cq))) +#define MAKE_SOFT_DECISION() { \ + if(Demod.sumI > 0) \ + v = ci; \ + else \ + v = -ci; \ + \ + if(Demod.sumQ > 0) \ + v += cq; \ + else \ + v -= cq; \ + \ + } + +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, MAX_FRAME_SIZE); +} + +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); + } +} + +int ice_legic_select_card() +{ + //int cmd_size=0, card_size=0; + uint8_t wakeup[] = { 0x7F }; + uint8_t getid[] = {0x19}; + + legic_prng_init(SESSION_IV); + + // first, wake up the tag, 7bits + CodeAndTransmitLegicAsReader(wakeup, sizeof(wakeup), 7); + + GetSamplesForLegicDemod(1000, TRUE); + + // 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); + CodeAndTransmitLegicAsReader(getid, sizeof(getid), 8); + GetSamplesForLegicDemod(1000, TRUE); + + //if (Demod.len < 14) return 2; + Dbprintf("CARD TYPE: %02x LEN: %d", Demod.output[0], Demod.len); + + switch(Demod.output[0]) { + case 0x1d: + DbpString("MIM 256 card found"); + // cmd_size = 9; + // card_size = 256; + break; + case 0x3d: + DbpString("MIM 1024 card found"); + // cmd_size = 11; + // card_size = 1024; + break; + default: + return -1; + } + + // if(bytes == -1) + // bytes = card_size; + + // if(bytes + offset >= card_size) + // bytes = card_size - offset; + + FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); + set_tracing(FALSE); + return 1; +} + +// 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(200); + // 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