fix 'hf iclass snoop'
authorpwpiwi <pwpiwi@users.noreply.github.com>
Fri, 8 Nov 2019 06:47:14 +0000 (07:47 +0100)
committerpwpiwi <pwpiwi@users.noreply.github.com>
Wed, 13 Nov 2019 17:03:37 +0000 (18:03 +0100)
* 'hf 15 snoop': determine and write meaningful times into trace

armsrc/iso15693.c

index bb5bdfe273385d8428ea9689d1c933d8dcb9eab3..761340e92c74aa2109353cb205176e96660c413c 100644 (file)
 #define DELAY_READER_TO_ARM               8
 #define DELAY_ARM_TO_READER               0
 //SSP_CLK runs at 13.56MHz / 4 = 3,39MHz when acting as reader. All values should be multiples of 16
-#define DELAY_TAG_TO_ARM                 32
 #define DELAY_ARM_TO_TAG                 16
+#define DELAY_TAG_TO_ARM                 32
+//SSP_CLK runs at 13.56MHz / 4 = 3,39MHz when snooping. All values should be multiples of 16
+#define DELAY_TAG_TO_ARM_SNOOP           32
+#define DELAY_READER_TO_ARM_SNOOP        32
 
 static int DEBUG = 0;
 
@@ -383,14 +386,13 @@ typedef struct DecodeTag {
 } DecodeTag_t;
 
 
-static int inline __attribute__((always_inline)) Handle15693SamplesFromTag(uint16_t amplitude, DecodeTag_t *DecodeTag)
-{
+static int inline __attribute__((always_inline)) Handle15693SamplesFromTag(uint16_t amplitude, DecodeTag_t *DecodeTag) {
        switch(DecodeTag->state) {
                case STATE_TAG_SOF_LOW:
                        // waiting for a rising edge
                        if (amplitude > NOISE_THRESHOLD + DecodeTag->previous_amplitude) {
                                if (DecodeTag->posCount > 10) {
-                                       DecodeTag->threshold_sof = amplitude - DecodeTag->previous_amplitude;
+                                       DecodeTag->threshold_sof = amplitude - DecodeTag->previous_amplitude; // to be divided by 2
                                        DecodeTag->threshold_half = 0;
                                        DecodeTag->state = STATE_TAG_SOF_RISING_EDGE;
                                } else {
@@ -403,8 +405,8 @@ static int inline __attribute__((always_inline)) Handle15693SamplesFromTag(uint1
                        break;
 
                case STATE_TAG_SOF_RISING_EDGE:
-                       if (amplitude - DecodeTag->previous_amplitude > DecodeTag->threshold_sof) { // edge still rising
-                               if (amplitude - DecodeTag->threshold_sof > DecodeTag->threshold_sof) { // steeper edge, take this as time reference
+                       if (amplitude > DecodeTag->threshold_sof + DecodeTag->previous_amplitude) { // edge still rising
+                               if (amplitude > DecodeTag->threshold_sof + DecodeTag->threshold_sof) { // steeper edge, take this as time reference
                                        DecodeTag->posCount = 1;
                                } else {
                                        DecodeTag->posCount = 2;
@@ -447,7 +449,7 @@ static int inline __attribute__((always_inline)) Handle15693SamplesFromTag(uint1
                                DecodeTag->sum2 = 0;
                                DecodeTag->posCount = 2;
                                DecodeTag->state = STATE_TAG_RECEIVING_DATA;
-                               FpgaDisableTracing(); // DEBUGGING
+                               // FpgaDisableTracing(); // DEBUGGING
                                // Dbprintf("amplitude = %d, threshold_sof = %d, threshold_half/4 = %d, previous_amplitude = %d",
                                        // amplitude,
                                        // DecodeTag->threshold_sof,
@@ -466,6 +468,12 @@ static int inline __attribute__((always_inline)) Handle15693SamplesFromTag(uint1
                        break;
 
                case STATE_TAG_RECEIVING_DATA:
+                               // FpgaDisableTracing(); // DEBUGGING
+                               // Dbprintf("amplitude = %d, threshold_sof = %d, threshold_half/4 = %d, previous_amplitude = %d",
+                                       // amplitude,
+                                       // DecodeTag->threshold_sof,
+                                       // DecodeTag->threshold_half/4,
+                                       // DecodeTag->previous_amplitude); // DEBUGGING
                        if (DecodeTag->posCount == 1) {
                                DecodeTag->sum1 = 0;
                                DecodeTag->sum2 = 0;
@@ -658,7 +666,7 @@ int GetIso15693AnswerFromTag(uint8_t* response, uint16_t max_len, uint16_t timeo
 
                if(upTo >= dmaBuf + ISO15693_DMA_BUFFER_SIZE) {                // we have read all of the DMA buffer content.
                        upTo = dmaBuf;                                             // start reading the circular buffer from the beginning
-                       if(behindBy > (9*ISO15693_DMA_BUFFER_SIZE/10)) {
+                       if (behindBy > (9*ISO15693_DMA_BUFFER_SIZE/10)) {
                                Dbprintf("About to blow circular buffer - aborted! behindBy=%d", behindBy);
                                ret = -1;
                                break;
@@ -1126,19 +1134,17 @@ void AcquireRawAdcSamplesIso15693(void)
 }
 
 
-void SnoopIso15693(void)
-{
+void SnoopIso15693(void) {
+
        LED_A_ON();
        
        FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
-       BigBuf_free();
 
        clear_trace();
        set_tracing(true);
 
        // The DMA buffer, used to stream samples from the FPGA
-       uint16_t* dmaBuf = (uint16_t*)BigBuf_malloc(ISO15693_DMA_BUFFER_SIZE*sizeof(uint16_t));
-       uint16_t *upTo;
+       uint16_t dmaBuf[ISO15693_DMA_BUFFER_SIZE];
 
        // Count of samples received so far, so that we can include timing
        // information in the trace buffer.
@@ -1163,28 +1169,35 @@ void SnoopIso15693(void)
        Dbprintf("Snoop started. Press PM3 Button to stop.");
 
        FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER | FPGA_HF_READER_MODE_SNOOP_AMPLITUDE);
+       LED_D_OFF();
        SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
-
-       // Setup for the DMA.
        FpgaSetupSsc(FPGA_MAJOR_MODE_HF_READER);
-       upTo = dmaBuf;
+       StartCountSspClk();
        FpgaSetupSscDma((uint8_t*) dmaBuf, ISO15693_DMA_BUFFER_SIZE);
-
+       
        bool TagIsActive = false;
        bool ReaderIsActive = false;
        bool ExpectTagAnswer = false;
-
+       uint32_t dma_start_time = 0;
+       uint16_t *upTo = dmaBuf;
+       
        // And now we loop, receiving samples.
        for(;;) {
                uint16_t behindBy = ((uint16_t*)AT91C_BASE_PDC_SSC->PDC_RPR - upTo) & (ISO15693_DMA_BUFFER_SIZE-1);
 
                if (behindBy == 0) continue;
 
+               samples++;
+               if (samples == 1) {
+                       // DMA has transferred the very first data
+                       dma_start_time = GetCountSspClk() & 0xfffffff0;
+               }
+               
                uint16_t snoopdata = *upTo++;
 
-               if(upTo >= dmaBuf + ISO15693_DMA_BUFFER_SIZE) {                    // we have read all of the DMA buffer content.
+               if (upTo >= dmaBuf + ISO15693_DMA_BUFFER_SIZE) {                   // we have read all of the DMA buffer content.
                        upTo = dmaBuf;                                                 // start reading the circular buffer from the beginning
-                       if(behindBy > (9*ISO15693_DMA_BUFFER_SIZE/10)) {
+                       if (behindBy > (9*ISO15693_DMA_BUFFER_SIZE/10)) {
                                Dbprintf("About to blow circular buffer - aborted! behindBy=%d, samples=%d", behindBy, samples);
                                break;
                        }
@@ -1192,61 +1205,90 @@ void SnoopIso15693(void)
                                AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;          // refresh the DMA Next Buffer and
                                AT91C_BASE_PDC_SSC->PDC_RNCR = ISO15693_DMA_BUFFER_SIZE;   // DMA Next Counter registers
                                WDT_HIT();
-                               if(BUTTON_PRESS()) {
+                               if (BUTTON_PRESS()) {
                                        DbpString("Snoop stopped.");
                                        break;
                                }
                        }
                }
-               samples++;
 
                if (!TagIsActive) {                                            // no need to try decoding reader data if the tag is sending
                        if (Handle15693SampleFromReader(snoopdata & 0x02, &DecodeReader)) {
-                               FpgaDisableSscDma();
-                               ExpectTagAnswer = true;
-                               LogTrace_ISO15693(DecodeReader.output, DecodeReader.byteCount, samples*64, samples*64, NULL, true);
+                               // FpgaDisableSscDma();
+                               uint32_t eof_time = dma_start_time + samples*16 + 8 - DELAY_READER_TO_ARM_SNOOP; // end of EOF
+                               if (DecodeReader.byteCount > 0) {
+                                       uint32_t sof_time = eof_time
+                                                                       - DecodeReader.byteCount * (DecodeReader.Coding==CODING_1_OUT_OF_4?128*16:2048*16) // time for byte transfers
+                                                                       - 32*16  // time for SOF transfer
+                                                                       - 16*16; // time for EOF transfer
+                                       LogTrace_ISO15693(DecodeReader.output, DecodeReader.byteCount, sof_time*4, eof_time*4, NULL, true);
+                               }
                                /* And ready to receive another command. */
                                DecodeReaderReset(&DecodeReader);
                                /* And also reset the demod code, which might have been */
                                /* false-triggered by the commands from the reader. */
                                DecodeTagReset(&DecodeTag);
-                               upTo = dmaBuf;
-                               FpgaSetupSscDma((uint8_t*) dmaBuf, ISO15693_DMA_BUFFER_SIZE);
-                       }
-                       if (Handle15693SampleFromReader(snoopdata & 0x01, &DecodeReader)) {
-                               FpgaDisableSscDma();
+                               ReaderIsActive = false;
                                ExpectTagAnswer = true;
-                               LogTrace_ISO15693(DecodeReader.output, DecodeReader.byteCount, samples*64, samples*64, NULL, true);
+                               // upTo = dmaBuf;
+                               // samples = 0;
+                               // FpgaSetupSscDma((uint8_t*) dmaBuf, ISO15693_DMA_BUFFER_SIZE);
+                               // continue;
+                       } else if (Handle15693SampleFromReader(snoopdata & 0x01, &DecodeReader)) {
+                               // FpgaDisableSscDma();
+                               uint32_t eof_time = dma_start_time + samples*16 + 16 - DELAY_READER_TO_ARM_SNOOP; // end of EOF
+                               if (DecodeReader.byteCount > 0) {
+                                       uint32_t sof_time = eof_time
+                                                                       - DecodeReader.byteCount * (DecodeReader.Coding==CODING_1_OUT_OF_4?128*16:2048*16) // time for byte transfers
+                                                                       - 32*16  // time for SOF transfer
+                                                                       - 16*16; // time for EOF transfer
+                                       LogTrace_ISO15693(DecodeReader.output, DecodeReader.byteCount, sof_time*4, eof_time*4, NULL, true);
+                               }
                                /* And ready to receive another command. */
                                DecodeReaderReset(&DecodeReader);
                                /* And also reset the demod code, which might have been */
                                /* false-triggered by the commands from the reader. */
                                DecodeTagReset(&DecodeTag);
-                               upTo = dmaBuf;
-                               FpgaSetupSscDma((uint8_t*) dmaBuf, ISO15693_DMA_BUFFER_SIZE);
+                               ReaderIsActive = false;
+                               ExpectTagAnswer = true;
+                               // upTo = dmaBuf;
+                               // samples = 0;
+                               // FpgaSetupSscDma((uint8_t*) dmaBuf, ISO15693_DMA_BUFFER_SIZE);
+                               // continue;
+                       } else {
+                               ReaderIsActive = (DecodeReader.state >= STATE_READER_RECEIVE_DATA_1_OUT_OF_4);
                        }
-                       ReaderIsActive = (DecodeReader.state >= STATE_READER_AWAIT_2ND_RISING_EDGE_OF_SOF);
                }
 
                if (!ReaderIsActive && ExpectTagAnswer) {                       // no need to try decoding tag data if the reader is currently sending or no answer expected yet
                        if (Handle15693SamplesFromTag(snoopdata >> 2, &DecodeTag)) {
-                               FpgaDisableSscDma();
-                               //Use samples as a time measurement
-                               LogTrace_ISO15693(DecodeTag.output, DecodeTag.len, samples*64, samples*64, NULL, false);
+                               // FpgaDisableSscDma();
+                               uint32_t eof_time = dma_start_time + samples*16 - DELAY_TAG_TO_ARM_SNOOP; // end of EOF
+                               if (DecodeTag.lastBit == SOF_PART2) {
+                                       eof_time -= 8*16; // needed 8 additional samples to confirm single SOF (iCLASS)
+                               }
+                               uint32_t sof_time = eof_time
+                                                                       - DecodeTag.len * 8 * 8 * 16 // time for byte transfers
+                                                                       - 32 * 16  // time for SOF transfer
+                                                                       - (DecodeTag.lastBit != SOF_PART2?32*16:0); // time for EOF transfer
+                               LogTrace_ISO15693(DecodeTag.output, DecodeTag.len, sof_time*4, eof_time*4, NULL, false);
                                // And ready to receive another response.
                                DecodeTagReset(&DecodeTag);
                                DecodeReaderReset(&DecodeReader);
                                ExpectTagAnswer = false;
-                               upTo = dmaBuf;
-                               FpgaSetupSscDma((uint8_t*) dmaBuf, ISO15693_DMA_BUFFER_SIZE);
+                               TagIsActive = false;
+                               // upTo = dmaBuf;
+                               // samples = 0;
+                               // FpgaSetupSscDma((uint8_t*) dmaBuf, ISO15693_DMA_BUFFER_SIZE);
+                               // continue;
+                       } else {
+                               TagIsActive = (DecodeTag.state >= STATE_TAG_RECEIVING_DATA);
                        }
-                       TagIsActive = (DecodeTag.state >= STATE_TAG_RECEIVING_DATA);
                }
 
        }
 
        FpgaDisableSscDma();
-       BigBuf_free();
 
        LEDsoff();
 
Impressum, Datenschutz