X-Git-Url: http://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/cf194819cc71d7e0121e896e71989efc6dbfc280..437035a75b2737d0b36886bc2bacaeb0219c6325:/armsrc/iso14443b.c diff --git a/armsrc/iso14443b.c b/armsrc/iso14443b.c index 22227e74..76d7a075 100644 --- a/armsrc/iso14443b.c +++ b/armsrc/iso14443b.c @@ -1,5 +1,6 @@ //----------------------------------------------------------------------------- // Jonathan Westhues, split Nov 2006 +// piwi 2018 // // 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 @@ -16,8 +17,8 @@ #include "iso14443crc.h" -#define RECEIVE_SAMPLES_TIMEOUT 2000 -#define ISO14443B_DMA_BUFFER_SIZE 256 +#define RECEIVE_SAMPLES_TIMEOUT 1000 // TR0 max is 256/fs = 256/(848kHz) = 302us or 64 samples from FPGA. 1000 seems to be much too high? +#define ISO14443B_DMA_BUFFER_SIZE 128 // PCB Block number for APDUs static uint8_t pcb_blocknum = 0; @@ -243,7 +244,7 @@ static RAMFUNC int Handle14443bUartBit(uint8_t bit) LED_A_OFF(); // Finished receiving Uart.state = STATE_UNSYNCD; if (Uart.byteCnt != 0) { - return TRUE; + return true; } } else { // this is an error @@ -259,7 +260,7 @@ static RAMFUNC int Handle14443bUartBit(uint8_t bit) break; } - return FALSE; + return false; } @@ -283,7 +284,7 @@ static void UartInit(uint8_t *data) // Receive a command (from the reader to us, where we are the simulated tag), // and store it in the given buffer, up to the given maximum length. Keeps // spinning, waiting for a well-framed command, until either we get one -// (returns TRUE) or someone presses the pushbutton on the board (FALSE). +// (returns true) or someone presses the pushbutton on the board (false). // // Assume that we're called with the SSC (to the FPGA) and ADC path set // correctly. @@ -302,20 +303,20 @@ static int GetIso14443bCommandFromReader(uint8_t *received, uint16_t *len) for(;;) { WDT_HIT(); - if(BUTTON_PRESS()) return FALSE; + if(BUTTON_PRESS()) return false; if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR; for(uint8_t mask = 0x80; mask != 0x00; mask >>= 1) { if(Handle14443bUartBit(b & mask)) { *len = Uart.byteCnt; - return TRUE; + return true; } } } } - return FALSE; + return false; } //----------------------------------------------------------------------------- @@ -347,7 +348,7 @@ void SimulateIso14443bTag(void) FpgaDownloadAndGo(FPGA_BITSTREAM_HF); clear_trace(); - set_tracing(TRUE); + set_tracing(true); const uint8_t *resp; uint8_t *respCode; @@ -374,7 +375,7 @@ void SimulateIso14443bTag(void) // We need to listen to the high-frequency, peak-detected path. SetAdcMuxFor(GPIO_MUXSEL_HIPKD); - FpgaSetupSsc(); + FpgaSetupSsc(FPGA_MAJOR_MODE_HF_SIMULATOR); cmdsRecvd = 0; @@ -385,10 +386,7 @@ void SimulateIso14443bTag(void) break; } - if (tracing) { - uint8_t parity[MAX_PARITY_SIZE]; - LogTrace(receivedCmd, len, 0, 0, parity, TRUE); - } + LogTrace(receivedCmd, len, 0, 0, NULL, true); // Good, look at the command now. if ( (len == sizeof(cmd1) && memcmp(receivedCmd, cmd1, len) == 0) @@ -440,7 +438,7 @@ void SimulateIso14443bTag(void) LED_D_OFF(); FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_SIMULATOR | FPGA_HF_SIMULATOR_MODULATE_BPSK); AT91C_BASE_SSC->SSC_THR = 0xff; - FpgaSetupSsc(); + FpgaSetupSsc(FPGA_MAJOR_MODE_HF_SIMULATOR); // Transmit the response. uint16_t i = 0; @@ -462,10 +460,7 @@ void SimulateIso14443bTag(void) } // trace the response: - if (tracing) { - uint8_t parity[MAX_PARITY_SIZE]; - LogTrace(resp, respLen, 0, 0, parity, FALSE); - } + LogTrace(resp, respLen, 0, 0, NULL, false); } } @@ -535,60 +530,11 @@ static RAMFUNC int Handle14443bSamplesDemod(int ci, int cq) #define SUBCARRIER_DETECT_THRESHOLD 8 -// Subcarrier amplitude v = sqrt(ci^2 + cq^2), approximated here by abs(ci) + abs(cq) -/* #define CHECK_FOR_SUBCARRIER() { \ - v = ci; \ - if(v < 0) v = -v; \ - if(cq > 0) { \ - v += cq; \ - } else { \ - v -= cq; \ - } \ - } - */ // Subcarrier amplitude v = sqrt(ci^2 + cq^2), approximated here by max(abs(ci),abs(cq)) + 1/2*min(abs(ci),abs(cq))) - - //note: couldn't we just use MAX(ABS(ci),ABS(cq)) + (MIN(ABS(ci),ABS(cq))/2) from common.h - marshmellow -#define CHECK_FOR_SUBCARRIER() { \ - v = MAX(ABS(ci),ABS(cq)) + (MIN(ABS(ci),ABS(cq))/2); \ - } - /* - if(ci < 0) { \ - if(cq < 0) { \ // ci < 0, cq < 0 - if (cq < ci) { \ - v = -cq - (ci >> 1); \ - } else { \ - v = -ci - (cq >> 1); \ - } \ - } else { \ // ci < 0, cq >= 0 - if (cq < -ci) { \ - v = -ci + (cq >> 1); \ - } else { \ - v = cq - (ci >> 1); \ - } \ - } \ - } else { \ - if(cq < 0) { \ // ci >= 0, cq < 0 - if (-cq < ci) { \ - v = ci - (cq >> 1); \ - } else { \ - v = -cq + (ci >> 1); \ - } \ - } else { \ // ci >= 0, cq >= 0 - if (cq < ci) { \ - v = ci + (cq >> 1); \ - } else { \ - v = cq + (ci >> 1); \ - } \ - } \ - } \ - } - */ - +#define AMPLITUDE(ci,cq) (MAX(ABS(ci),ABS(cq)) + (MIN(ABS(ci),ABS(cq))/2)) switch(Demod.state) { case DEMOD_UNSYNCD: - CHECK_FOR_SUBCARRIER(); - if(v > SUBCARRIER_DETECT_THRESHOLD) { // subcarrier detected + if(AMPLITUDE(ci,cq) > SUBCARRIER_DETECT_THRESHOLD) { // subcarrier detected Demod.state = DEMOD_PHASE_REF_TRAINING; Demod.sumI = ci; Demod.sumQ = cq; @@ -598,8 +544,7 @@ static RAMFUNC int Handle14443bSamplesDemod(int ci, int cq) case DEMOD_PHASE_REF_TRAINING: if(Demod.posCount < 8) { - CHECK_FOR_SUBCARRIER(); - if (v > SUBCARRIER_DETECT_THRESHOLD) { + if (AMPLITUDE(ci,cq) > 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; @@ -702,7 +647,7 @@ static RAMFUNC int Handle14443bSamplesDemod(int ci, int cq) LED_C_OFF(); if(s == 0x000) { // This is EOF (start, stop and all data bits == '0' - return TRUE; + return true; } } } @@ -716,7 +661,7 @@ static RAMFUNC int Handle14443bSamplesDemod(int ci, int cq) break; } - return FALSE; + return false; } @@ -739,14 +684,15 @@ static void DemodInit(uint8_t *data) /* * Demodulate the samples we received from the tag, also log to tracebuffer - * quiet: set to 'TRUE' to disable debug output + * quiet: set to 'true' to disable debug output */ static void GetSamplesFor14443bDemod(int n, bool quiet) { - int max = 0; - bool gotFrame = FALSE; - int lastRxCounter, ci, cq, samples = 0; - + int maxBehindBy = 0; + bool gotFrame = false; + int lastRxCounter, samples = 0; + int8_t ci, cq; + // Allocate memory from BigBuf for some buffers // free all previous allocations first BigBuf_free(); @@ -755,15 +701,19 @@ static void GetSamplesFor14443bDemod(int n, bool quiet) uint8_t *receivedResponse = BigBuf_malloc(MAX_FRAME_SIZE); // The DMA buffer, used to stream samples from the FPGA - int8_t *dmaBuf = (int8_t*) BigBuf_malloc(ISO14443B_DMA_BUFFER_SIZE); + uint16_t *dmaBuf = (uint16_t*) BigBuf_malloc(ISO14443B_DMA_BUFFER_SIZE * sizeof(uint16_t)); // Set up the demodulator for tag -> reader responses. DemodInit(receivedResponse); + // wait for last transfer to complete + while (!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXEMPTY)) + // Setup and start DMA. + FpgaSetupSsc(FPGA_MAJOR_MODE_HF_READER_RX_XCORR); FpgaSetupSscDma((uint8_t*) dmaBuf, ISO14443B_DMA_BUFFER_SIZE); - int8_t *upTo = dmaBuf; + uint16_t *upTo = dmaBuf; lastRxCounter = ISO14443B_DMA_BUFFER_SIZE; // Signal field is ON with the appropriate LED: @@ -772,43 +722,43 @@ static void GetSamplesFor14443bDemod(int n, bool quiet) FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ); for(;;) { - int behindBy = lastRxCounter - AT91C_BASE_PDC_SSC->PDC_RCR; - if(behindBy > max) max = behindBy; - - while(((lastRxCounter-AT91C_BASE_PDC_SSC->PDC_RCR) & (ISO14443B_DMA_BUFFER_SIZE-1)) > 2) { - ci = upTo[0]; - cq = upTo[1]; - upTo += 2; - if(upTo >= dmaBuf + ISO14443B_DMA_BUFFER_SIZE) { - upTo = dmaBuf; - AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) upTo; - AT91C_BASE_PDC_SSC->PDC_RNCR = ISO14443B_DMA_BUFFER_SIZE; - } - lastRxCounter -= 2; - if(lastRxCounter <= 0) { - lastRxCounter += ISO14443B_DMA_BUFFER_SIZE; - } + int behindBy = (lastRxCounter - AT91C_BASE_PDC_SSC->PDC_RCR) & (ISO14443B_DMA_BUFFER_SIZE-1); + if(behindBy > maxBehindBy) { + maxBehindBy = behindBy; + } - samples += 2; + if(behindBy < 1) continue; - if(Handle14443bSamplesDemod(ci, cq)) { - gotFrame = TRUE; - break; - } + ci = *upTo >> 8; + cq = *upTo; + upTo++; + lastRxCounter--; + if(upTo >= dmaBuf + ISO14443B_DMA_BUFFER_SIZE) { // we have read all of the DMA buffer content. + upTo = dmaBuf; // start reading the circular buffer from the beginning + lastRxCounter += ISO14443B_DMA_BUFFER_SIZE; + } + if (AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_ENDRX)) { // DMA Counter Register had reached 0, already rotated. + AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf; // refresh the DMA Next Buffer and + AT91C_BASE_PDC_SSC->PDC_RNCR = ISO14443B_DMA_BUFFER_SIZE; // DMA Next Counter registers + } + samples++; + + if(Handle14443bSamplesDemod(ci, cq)) { + gotFrame = true; + break; } - if(samples > n || gotFrame) { + if(samples > n) { break; } } - AT91C_BASE_PDC_SSC->PDC_PTCR = AT91C_PDC_RXTDIS; + FpgaDisableSscDma(); - if (!quiet) 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); + if (!quiet) Dbprintf("max behindby = %d, samples = %d, gotFrame = %d, Demod.len = %d, Demod.sumI = %d, Demod.sumQ = %d", maxBehindBy, samples, gotFrame, Demod.len, Demod.sumI, Demod.sumQ); //Tracing - if (tracing && Demod.len > 0) { - uint8_t parity[MAX_PARITY_SIZE]; - LogTrace(Demod.output, Demod.len, 0, 0, parity, FALSE); + if (Demod.len > 0) { + LogTrace(Demod.output, Demod.len, 0, 0, NULL, false); } } @@ -820,11 +770,7 @@ static void TransmitFor14443b(void) { int c; - FpgaSetupSsc(); - - while(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { - AT91C_BASE_SSC->SSC_THR = 0xff; - } + FpgaSetupSsc(FPGA_MAJOR_MODE_HF_READER_TX); // Signal field is ON with the appropriate Red LED LED_D_ON(); @@ -832,31 +778,15 @@ static void TransmitFor14443b(void) 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]; + AT91C_BASE_SSC->SSC_THR = ~ToSend[c]; 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(); // Finished sending @@ -874,19 +804,14 @@ static void CodeIso14443bAsReader(const uint8_t *cmd, int len) ToSendReset(); - // Establish initial reference level - for(i = 0; i < 40; i++) { - ToSendStuffBit(1); - } // Send SOF for(i = 0; i < 10; i++) { ToSendStuffBit(0); } + ToSendStuffBit(1); + ToSendStuffBit(1); for(i = 0; i < len; i++) { - // Stop bits/EGT - ToSendStuffBit(1); - ToSendStuffBit(1); // Start bit ToSendStuffBit(0); // Data bits @@ -899,19 +824,18 @@ static void CodeIso14443bAsReader(const uint8_t *cmd, int len) } b >>= 1; } + // Stop bit + ToSendStuffBit(1); } + // Send EOF - ToSendStuffBit(1); for(i = 0; i < 10; i++) { ToSendStuffBit(0); } - for(i = 0; i < 8; i++) { - ToSendStuffBit(1); - } + ToSendStuffBit(1); - // And then a little more, to make sure that the last character makes - // it out before we switch to rx mode. - for(i = 0; i < 24; i++) { + // ensure that last byte is filled up + for(i = 0; i < 8; i++) { ToSendStuffBit(1); } @@ -927,10 +851,7 @@ static void CodeAndTransmit14443bAsReader(const uint8_t *cmd, int len) { CodeIso14443bAsReader(cmd, len); TransmitFor14443b(); - if (tracing) { - uint8_t parity[MAX_PARITY_SIZE]; - LogTrace(cmd,len, 0, 0, parity, TRUE); - } + LogTrace(cmd,len, 0, 0, NULL, true); } /* Sends an APDU to the tag @@ -951,7 +872,7 @@ int iso14443b_apdu(uint8_t const *message, size_t message_length, uint8_t *respo // send CodeAndTransmit14443bAsReader(message_frame, message_length + 4); // get response - GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT*100, TRUE); + GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT, true); if(Demod.len < 3) { return 0; @@ -981,7 +902,7 @@ int iso14443b_select_card() // first, wake up the tag CodeAndTransmit14443bAsReader(wupb, sizeof(wupb)); - GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT, TRUE); + GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT, true); // ATQB too short? if (Demod.len < 14) { @@ -996,7 +917,7 @@ int iso14443b_select_card() attrib[7] = Demod.output[10] & 0x0F; ComputeCrc14443(CRC_14443_B, attrib, 9, attrib + 9, attrib + 10); CodeAndTransmit14443bAsReader(attrib, sizeof(attrib)); - GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT, TRUE); + GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT, true); // Answer to ATTRIB too short? if(Demod.len < 3) { @@ -1011,7 +932,7 @@ int iso14443b_select_card() void iso14443b_setup() { FpgaDownloadAndGo(FPGA_BITSTREAM_HF); // Set up the synchronous serial port - FpgaSetupSsc(); + FpgaSetupSsc(FPGA_MAJOR_MODE_HF_READER_TX); // connect Demodulated Signal to ADC: SetAdcMuxFor(GPIO_MUXSEL_HIPKD); @@ -1019,9 +940,6 @@ void iso14443b_setup() { LED_D_ON(); FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX | FPGA_HF_READER_TX_SHALLOW_MOD); - // Start the timer - StartCountSspClk(); - DemodReset(); UartReset(); } @@ -1047,7 +965,7 @@ void ReadSTMemoryIso14443b(uint32_t dwLast) SpinDelay(200); SetAdcMuxFor(GPIO_MUXSEL_HIPKD); - FpgaSetupSsc(); + FpgaSetupSsc(FPGA_MAJOR_MODE_HF_READER_RX_XCORR); // Now give it time to spin up. // Signal field is on with the appropriate LED @@ -1056,15 +974,17 @@ void ReadSTMemoryIso14443b(uint32_t dwLast) SpinDelay(200); clear_trace(); - set_tracing(TRUE); + set_tracing(true); // First command: wake up the tag using the INITIATE command uint8_t cmd1[] = {0x06, 0x00, 0x97, 0x5b}; CodeAndTransmit14443bAsReader(cmd1, sizeof(cmd1)); - GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT, TRUE); + GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT, true); if (Demod.len == 0) { DbpString("No response from tag"); + LED_D_OFF(); + FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); return; } else { Dbprintf("Randomly generated Chip ID (+ 2 byte CRC): %02x %02x %02x", @@ -1077,20 +997,26 @@ void ReadSTMemoryIso14443b(uint32_t dwLast) cmd1[1] = Demod.output[0]; ComputeCrc14443(CRC_14443_B, cmd1, 2, &cmd1[2], &cmd1[3]); CodeAndTransmit14443bAsReader(cmd1, sizeof(cmd1)); - GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT, TRUE); + GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT, true); if (Demod.len != 3) { Dbprintf("Expected 3 bytes from tag, got %d", Demod.len); + LED_D_OFF(); + FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); return; } // Check the CRC of the answer: ComputeCrc14443(CRC_14443_B, Demod.output, 1 , &cmd1[2], &cmd1[3]); if(cmd1[2] != Demod.output[1] || cmd1[3] != Demod.output[2]) { DbpString("CRC Error reading select response."); + LED_D_OFF(); + FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); return; } // Check response from the tag: should be the same UID as the command we just sent: if (cmd1[1] != Demod.output[0]) { Dbprintf("Bad response to SELECT from Tag, aborting: %02x %02x", cmd1[1], Demod.output[0]); + LED_D_OFF(); + FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); return; } @@ -1099,9 +1025,11 @@ void ReadSTMemoryIso14443b(uint32_t dwLast) cmd1[0] = 0x0B; ComputeCrc14443(CRC_14443_B, cmd1, 1 , &cmd1[1], &cmd1[2]); CodeAndTransmit14443bAsReader(cmd1, 3); // Only first three bytes for this one - GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT, TRUE); + GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT, true); if (Demod.len != 10) { Dbprintf("Expected 10 bytes from tag, got %d", Demod.len); + LED_D_OFF(); + FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); return; } // The check the CRC of the answer (use cmd1 as temporary variable): @@ -1128,9 +1056,11 @@ void ReadSTMemoryIso14443b(uint32_t dwLast) cmd1[1] = i; ComputeCrc14443(CRC_14443_B, cmd1, 2, &cmd1[2], &cmd1[3]); CodeAndTransmit14443bAsReader(cmd1, sizeof(cmd1)); - GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT, TRUE); + GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT, true); if (Demod.len != 6) { // Check if we got an answer from the tag DbpString("Expected 6 bytes from tag, got less..."); + LED_D_OFF(); + FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); return; } // The check the CRC of the answer (use cmd1 as temporary variable): @@ -1149,6 +1079,9 @@ void ReadSTMemoryIso14443b(uint32_t dwLast) } i++; } + + LED_D_OFF(); + FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); } @@ -1171,22 +1104,17 @@ void ReadSTMemoryIso14443b(uint32_t dwLast) */ void RAMFUNC SnoopIso14443b(void) { - // We won't start recording the frames that we acquire until we trigger; - // a good trigger condition to get started is probably when we see a - // response from the tag. - int triggered = TRUE; // TODO: set and evaluate trigger condition - FpgaDownloadAndGo(FPGA_BITSTREAM_HF); BigBuf_free(); clear_trace(); - set_tracing(TRUE); + set_tracing(true); // The DMA buffer, used to stream samples from the FPGA - int8_t *dmaBuf = (int8_t*) BigBuf_malloc(ISO14443B_DMA_BUFFER_SIZE); + uint16_t *dmaBuf = (uint16_t*) BigBuf_malloc(ISO14443B_DMA_BUFFER_SIZE * sizeof(uint16_t)); int lastRxCounter; - int8_t *upTo; - int ci, cq; + uint16_t *upTo; + int8_t ci, cq; int maxBehindBy = 0; // Count of samples received so far, so that we can include timing @@ -1211,56 +1139,55 @@ void RAMFUNC SnoopIso14443b(void) SetAdcMuxFor(GPIO_MUXSEL_HIPKD); // Setup for the DMA. - FpgaSetupSsc(); + FpgaSetupSsc(FPGA_MAJOR_MODE_HF_READER_RX_XCORR); upTo = dmaBuf; lastRxCounter = ISO14443B_DMA_BUFFER_SIZE; FpgaSetupSscDma((uint8_t*) dmaBuf, ISO14443B_DMA_BUFFER_SIZE); - uint8_t parity[MAX_PARITY_SIZE]; - bool TagIsActive = FALSE; - bool ReaderIsActive = FALSE; + bool TagIsActive = false; + bool ReaderIsActive = false; + // We won't start recording the frames that we acquire until we trigger. + // A good trigger condition to get started is probably when we see a + // reader command + bool triggered = false; // And now we loop, receiving samples. for(;;) { - int behindBy = (lastRxCounter - AT91C_BASE_PDC_SSC->PDC_RCR) & - (ISO14443B_DMA_BUFFER_SIZE-1); + int behindBy = (lastRxCounter - AT91C_BASE_PDC_SSC->PDC_RCR) & (ISO14443B_DMA_BUFFER_SIZE-1); if(behindBy > maxBehindBy) { maxBehindBy = behindBy; } - if(behindBy < 2) continue; + if(behindBy < 1) continue; - ci = upTo[0]; - cq = upTo[1]; - upTo += 2; - lastRxCounter -= 2; - if(upTo >= dmaBuf + ISO14443B_DMA_BUFFER_SIZE) { - upTo = dmaBuf; + ci = *upTo>>8; + cq = *upTo; + upTo++; + lastRxCounter--; + if(upTo >= dmaBuf + ISO14443B_DMA_BUFFER_SIZE) { // we have read all of the DMA buffer content. + upTo = dmaBuf; // start reading the circular buffer from the beginning again lastRxCounter += ISO14443B_DMA_BUFFER_SIZE; - AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf; - AT91C_BASE_PDC_SSC->PDC_RNCR = ISO14443B_DMA_BUFFER_SIZE; - WDT_HIT(); - if(behindBy > (9*ISO14443B_DMA_BUFFER_SIZE/10)) { // TODO: understand whether we can increase/decrease as we want or not? - Dbprintf("blew circular buffer! behindBy=%d", behindBy); - break; - } - if(!tracing) { - DbpString("Reached trace limit"); + if(behindBy > (9*ISO14443B_DMA_BUFFER_SIZE/10)) { + Dbprintf("About to blow circular buffer - aborted! behindBy=%d", behindBy); break; } + } + if (AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_ENDRX)) { // DMA Counter Register had reached 0, already rotated. + AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf; // refresh the DMA Next Buffer and + AT91C_BASE_PDC_SSC->PDC_RNCR = ISO14443B_DMA_BUFFER_SIZE; // DMA Next Counter registers + WDT_HIT(); if(BUTTON_PRESS()) { DbpString("cancelled"); break; } } - samples += 2; + samples++; if (!TagIsActive) { // no need to try decoding reader data if the tag is sending if(Handle14443bUartBit(ci & 0x01)) { - if(triggered && tracing) { - LogTrace(Uart.output, Uart.byteCnt, samples, samples, parity, TRUE); - } + triggered = true; + LogTrace(Uart.output, Uart.byteCnt, samples, samples, NULL, true); /* And ready to receive another command. */ UartReset(); /* And also reset the demod code, which might have been */ @@ -1268,9 +1195,8 @@ void RAMFUNC SnoopIso14443b(void) DemodReset(); } if(Handle14443bUartBit(cq & 0x01)) { - if(triggered && tracing) { - LogTrace(Uart.output, Uart.byteCnt, samples, samples, parity, TRUE); - } + triggered = true; + LogTrace(Uart.output, Uart.byteCnt, samples, samples, NULL, true); /* And ready to receive another command. */ UartReset(); /* And also reset the demod code, which might have been */ @@ -1280,17 +1206,10 @@ void RAMFUNC SnoopIso14443b(void) ReaderIsActive = (Uart.state > STATE_GOT_FALLING_EDGE_OF_SOF); } - if(!ReaderIsActive) { // no need to try decoding tag data if the reader is sending - and we cannot afford the time - if(Handle14443bSamplesDemod(ci | 0x01, cq | 0x01)) { - + if(!ReaderIsActive && triggered) { // no need to try decoding tag data if the reader is sending or not yet triggered + if(Handle14443bSamplesDemod(ci/2, cq/2)) { //Use samples as a time measurement - if(tracing) - { - uint8_t parity[MAX_PARITY_SIZE]; - LogTrace(Demod.output, Demod.len, samples, samples, parity, FALSE); - } - triggered = TRUE; - + LogTrace(Demod.output, Demod.len, samples, samples, NULL, false); // And ready to receive another response. DemodReset(); } @@ -1301,7 +1220,6 @@ void RAMFUNC SnoopIso14443b(void) FpgaDisableSscDma(); LEDsoff(); - AT91C_BASE_PDC_SSC->PDC_PTCR = AT91C_PDC_RXTDIS; DbpString("Snoop statistics:"); Dbprintf(" Max behind by: %i", maxBehindBy); Dbprintf(" Uart State: %x", Uart.state); @@ -1327,15 +1245,19 @@ void SendRawCommand14443B(uint32_t datalen, uint32_t recv, uint8_t powerfield, u { FpgaDownloadAndGo(FPGA_BITSTREAM_HF); SetAdcMuxFor(GPIO_MUXSEL_HIPKD); - FpgaSetupSsc(); + + // switch field on and give tag some time to power up + LED_D_ON(); + FpgaSetupSsc(FPGA_MAJOR_MODE_HF_READER_TX); + SpinDelay(10); if (datalen){ - set_tracing(TRUE); + set_tracing(true); CodeAndTransmit14443bAsReader(data, datalen); if(recv) { - GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT, TRUE); + GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT, true); uint16_t iLen = MIN(Demod.len, USB_CMD_DATA_SIZE); cmd_send(CMD_ACK, iLen, 0, 0, Demod.output, iLen); }