#include "iso14443crc.h"
#define RECEIVE_SAMPLES_TIMEOUT 2000
+#define ISO14443B_DMA_BUFFER_SIZE 256
//=============================================================================
// An ISO 14443 Type B tag. We listen for commands from the reader, using
STATE_UNSYNCD,
STATE_GOT_FALLING_EDGE_OF_SOF,
STATE_AWAITING_START_BIT,
- STATE_RECEIVING_DATA,
- STATE_ERROR_WAIT
+ STATE_RECEIVING_DATA
} state;
uint16_t shiftReg;
int bitCnt;
* Returns: true if we received a EOF
* false if we are still waiting for some more
*/
-static int Handle14443bUartBit(int bit)
+static RAMFUNC int Handle14443bUartBit(uint8_t bit)
{
switch(Uart.state) {
case STATE_UNSYNCD:
} else {
// didn't stay down long enough
// before going high, error
- Uart.state = STATE_ERROR_WAIT;
+ Uart.state = STATE_UNSYNCD;
}
} else {
// do nothing, keep waiting
if(Uart.bitCnt > 12) {
// Give up if we see too many zeros without
// a one, too.
- Uart.state = STATE_ERROR_WAIT;
+ LED_A_OFF();
+ Uart.state = STATE_UNSYNCD;
}
break;
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_ERROR_WAIT;
+ Uart.state = STATE_UNSYNCD;
}
} else {
// falling edge, this starts the data byte
if(Uart.byteCnt >= Uart.byteCntMax) {
// Buffer overflowed, give up
- Uart.posCnt = 0;
- Uart.state = STATE_ERROR_WAIT;
+ 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) {
+ } 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;
}
- Uart.posCnt = 0;
- Uart.state = STATE_ERROR_WAIT;
} else {
// this is an error
- Uart.posCnt = 0;
- Uart.state = STATE_ERROR_WAIT;
+ LED_A_OFF();
+ Uart.state = STATE_UNSYNCD;
}
}
break;
- case STATE_ERROR_WAIT:
- // We're all screwed up, so wait a little while
- // for whatever went wrong to finish, and then
- // start over.
- Uart.posCnt++;
- if(Uart.posCnt > 10) {
- Uart.state = STATE_UNSYNCD;
- LED_A_OFF();
- }
- 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;
+}
+
+
+static void UartInit(uint8_t *data)
+{
+ Uart.output = data;
+ UartReset();
+}
+
+
//-----------------------------------------------------------------------------
// 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
// Assume that we're called with the SSC (to the FPGA) and ADC path set
// correctly.
//-----------------------------------------------------------------------------
-static int GetIso14443bCommandFromReader(uint8_t *received, int *len, int maxLen)
+static int GetIso14443bCommandFromReader(uint8_t *received, uint16_t *len)
{
- uint8_t mask;
- int i, bit;
-
// Set FPGA mode to "simulated ISO 14443B tag", no modulation (listen
// only, since we are receiving, not transmitting).
// Signal field is off with the appropriate LED
LED_D_OFF();
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_SIMULATOR | FPGA_HF_SIMULATOR_NO_MODULATION);
-
// Now run a `software UART' on the stream of incoming samples.
- Uart.output = received;
- Uart.byteCntMax = maxLen;
- Uart.state = STATE_UNSYNCD;
+ UartInit(received);
for(;;) {
WDT_HIT();
if(BUTTON_PRESS()) return FALSE;
- if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
- AT91C_BASE_SSC->SSC_THR = 0x00;
- }
if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
-
- mask = 0x80;
- for(i = 0; i < 8; i++, mask >>= 1) {
- bit = (b & mask);
- if(Handle14443bUartBit(bit)) {
+ for(uint8_t mask = 0x80; mask != 0x00; mask >>= 1) {
+ if(Handle14443bUartBit(b & mask)) {
*len = Uart.byteCnt;
return TRUE;
}
}
}
}
+
+ return FALSE;
}
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
void SimulateIso14443bTag(void)
{
- // the only command we understand is REQB, AFI=0, Select All, N=0:
+ // the only commands we understand is REQB, AFI=0, Select All, N=0:
static const uint8_t cmd1[] = { 0x05, 0x00, 0x08, 0x39, 0x73 };
- // ... and we respond with ATQB, PUPI = 820de174, Application Data = 0x20381922,
+ // ... and REQB, AFI=0, Normal Request, N=0:
+ static const uint8_t cmd2[] = { 0x05, 0x00, 0x00, 0x71, 0xFF };
+
+ // ... and we always respond with ATQB, PUPI = 820de174, Application Data = 0x20381922,
// supports only 106kBit/s in both directions, max frame size = 32Bytes,
// supports ISO14443-4, FWI=8 (77ms), NAD supported, CID not supported:
static const uint8_t response1[] = {
0x00, 0x21, 0x85, 0x5e, 0xd7
};
- uint8_t *resp;
- int respLen;
+ clear_trace();
+ set_tracing(TRUE);
+
+ const uint8_t *resp;
+ uint8_t *respCode;
+ uint16_t respLen, respCodeLen;
// allocate command receive buffer
BigBuf_free();
uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE);
- int len;
- int i;
-
- int cmdsRecvd = 0;
+ uint16_t len;
+ uint16_t cmdsRecvd = 0;
FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
// prepare the (only one) tag answer:
CodeIso14443bAsTag(response1, sizeof(response1));
- uint8_t *resp1 = BigBuf_malloc(ToSendMax);
- memcpy(resp1, ToSend, ToSendMax);
- uint16_t resp1Len = ToSendMax;
+ uint8_t *resp1Code = BigBuf_malloc(ToSendMax);
+ memcpy(resp1Code, ToSend, ToSendMax);
+ uint16_t resp1CodeLen = ToSendMax;
// We need to listen to the high-frequency, peak-detected path.
SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
cmdsRecvd = 0;
for(;;) {
- uint8_t b1, b2;
- if(!GetIso14443bCommandFromReader(receivedCmd, &len, 100)) {
+ if(!GetIso14443bCommandFromReader(receivedCmd, &len)) {
Dbprintf("button pressed, received %d commands", cmdsRecvd);
break;
- }
+ }
- // Good, look at the command now.
+ if (tracing) {
+ uint8_t parity[MAX_PARITY_SIZE];
+ LogTrace(receivedCmd, len, 0, 0, parity, TRUE);
+ }
- if(len == sizeof(cmd1) && memcmp(receivedCmd, cmd1, len) == 0) {
- resp = resp1; respLen = resp1Len;
+ // Good, look at the command now.
+ if ( (len == sizeof(cmd1) && memcmp(receivedCmd, cmd1, len) == 0)
+ || (len == sizeof(cmd2) && memcmp(receivedCmd, cmd2, len) == 0) ) {
+ resp = response1;
+ respLen = sizeof(response1);
+ respCode = resp1Code;
+ respCodeLen = resp1CodeLen;
} else {
Dbprintf("new cmd from reader: len=%d, cmdsRecvd=%d", len, cmdsRecvd);
// And print whether the CRC fails, just for good measure
+ uint8_t b1, b2;
ComputeCrc14443(CRC_14443_B, receivedCmd, len-2, &b1, &b2);
if(b1 != receivedCmd[len-2] || b2 != receivedCmd[len-1]) {
// Not so good, try again.
break;
}
- if(respLen <= 0) continue;
+ if(respCodeLen <= 0) continue;
// Modulate BPSK
// Signal field is off with the appropriate LED
FpgaSetupSsc();
// Transmit the response.
- i = 0;
+ uint16_t i = 0;
for(;;) {
if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
- uint8_t b = resp[i];
+ uint8_t b = respCode[i];
AT91C_BASE_SSC->SSC_THR = b;
i++;
- if(i > respLen) {
+ if(i > respCodeLen) {
break;
}
}
(void)b;
}
}
+
+ // trace the response:
+ if (tracing) {
+ uint8_t parity[MAX_PARITY_SIZE];
+ LogTrace(resp, respLen, 0, 0, parity, FALSE);
+ }
+
}
}
DEMOD_AWAITING_FALLING_EDGE_OF_SOF,
DEMOD_GOT_FALLING_EDGE_OF_SOF,
DEMOD_AWAITING_START_BIT,
- DEMOD_RECEIVING_DATA,
- DEMOD_ERROR_WAIT
+ DEMOD_RECEIVING_DATA
} state;
int bitCount;
int posCount;
}
-static void UartReset()
-{
- Uart.byteCntMax = MAX_FRAME_SIZE;
- Uart.state = STATE_UNSYNCD;
- Uart.byteCnt = 0;
- Uart.bitCnt = 0;
-}
-
-
-static void UartInit(uint8_t *data)
-{
- Uart.output = data;
- UartReset();
-}
-
-
/*
* Demodulate the samples we received from the tag, also log to tracebuffer
* quiet: set to 'TRUE' to disable debug output
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(DMA_BUFFER_SIZE);
+ int8_t *dmaBuf = (int8_t*) BigBuf_malloc(ISO14443B_DMA_BUFFER_SIZE);
// Set up the demodulator for tag -> reader responses.
DemodInit(receivedResponse);
// Setup and start DMA.
- FpgaSetupSscDma((uint8_t*) dmaBuf, DMA_BUFFER_SIZE);
+ FpgaSetupSscDma((uint8_t*) dmaBuf, ISO14443B_DMA_BUFFER_SIZE);
int8_t *upTo = dmaBuf;
- lastRxCounter = DMA_BUFFER_SIZE;
+ lastRxCounter = ISO14443B_DMA_BUFFER_SIZE;
// Signal field is ON with the appropriate LED:
LED_D_ON();
int behindBy = lastRxCounter - AT91C_BASE_PDC_SSC->PDC_RCR;
if(behindBy > max) max = behindBy;
- while(((lastRxCounter-AT91C_BASE_PDC_SSC->PDC_RCR) & (DMA_BUFFER_SIZE-1)) > 2) {
+ 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 + DMA_BUFFER_SIZE) {
+ if(upTo >= dmaBuf + ISO14443B_DMA_BUFFER_SIZE) {
upTo = dmaBuf;
AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) upTo;
- AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
+ AT91C_BASE_PDC_SSC->PDC_RNCR = ISO14443B_DMA_BUFFER_SIZE;
}
lastRxCounter -= 2;
if(lastRxCounter <= 0) {
- lastRxCounter += DMA_BUFFER_SIZE;
+ lastRxCounter += ISO14443B_DMA_BUFFER_SIZE;
}
samples += 2;
//Tracing
if (tracing && Demod.len > 0) {
uint8_t parity[MAX_PARITY_SIZE];
- //GetParity(Demod.output, Demod.len, parity);
LogTrace(Demod.output, Demod.len, 0, 0, parity, FALSE);
}
}
TransmitFor14443b();
if (tracing) {
uint8_t parity[MAX_PARITY_SIZE];
- GetParity(cmd, len, parity);
LogTrace(cmd,len, 0, 0, parity, TRUE);
}
}
// Now give it time to spin up.
// Signal field is on with the appropriate LED
LED_D_ON();
- FpgaWriteConfWord(
- FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ);
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ);
SpinDelay(200);
// First command: wake up the tag using the INITIATE command
uint8_t cmd1[] = {0x06, 0x00, 0x97, 0x5b};
-
CodeAndTransmit14443bAsReader(cmd1, sizeof(cmd1));
-// LED_A_ON();
GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT, TRUE);
-// LED_A_OFF();
if (Demod.len == 0) {
- DbpString("No response from tag");
- return;
+ DbpString("No response from tag");
+ return;
} else {
- Dbprintf("Randomly generated UID from tag (+ 2 byte CRC): %02x %02x %02x",
- Demod.output[0], Demod.output[1], Demod.output[2]);
+ Dbprintf("Randomly generated Chip ID (+ 2 byte CRC): %02x %02x %02x",
+ Demod.output[0], Demod.output[1], Demod.output[2]);
}
+
// There is a response, SELECT the uid
DbpString("Now SELECT tag:");
cmd1[0] = 0x0E; // 0x0E is SELECT
cmd1[1] = Demod.output[0];
ComputeCrc14443(CRC_14443_B, cmd1, 2, &cmd1[2], &cmd1[3]);
CodeAndTransmit14443bAsReader(cmd1, sizeof(cmd1));
-
-// LED_A_ON();
GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT, TRUE);
-// LED_A_OFF();
if (Demod.len != 3) {
Dbprintf("Expected 3 bytes from tag, got %d", Demod.len);
return;
Dbprintf("Bad response to SELECT from Tag, aborting: %02x %02x", cmd1[1], Demod.output[0]);
return;
}
+
// Tag is now selected,
// First get the tag's UID:
cmd1[0] = 0x0B;
ComputeCrc14443(CRC_14443_B, cmd1, 1 , &cmd1[1], &cmd1[2]);
CodeAndTransmit14443bAsReader(cmd1, 3); // Only first three bytes for this one
-
-// LED_A_ON();
GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT, TRUE);
-// LED_A_OFF();
if (Demod.len != 10) {
Dbprintf("Expected 10 bytes from tag, got %d", Demod.len);
return;
ComputeCrc14443(CRC_14443_B, Demod.output, 8, &cmd1[2], &cmd1[3]);
if(cmd1[2] != Demod.output[8] || cmd1[3] != Demod.output[9]) {
Dbprintf("CRC Error reading block! Expected: %04x got: %04x",
- (cmd1[2]<<8)+cmd1[3], (Demod.output[8]<<8)+Demod.output[9]);
+ (cmd1[2]<<8)+cmd1[3], (Demod.output[8]<<8)+Demod.output[9]);
// Do not return;, let's go on... (we should retry, maybe ?)
}
Dbprintf("Tag UID (64 bits): %08x %08x",
- (Demod.output[7]<<24) + (Demod.output[6]<<16) + (Demod.output[5]<<8) + Demod.output[4],
- (Demod.output[3]<<24) + (Demod.output[2]<<16) + (Demod.output[1]<<8) + Demod.output[0]);
+ (Demod.output[7]<<24) + (Demod.output[6]<<16) + (Demod.output[5]<<8) + Demod.output[4],
+ (Demod.output[3]<<24) + (Demod.output[2]<<16) + (Demod.output[1]<<8) + Demod.output[0]);
// Now loop to read all 16 blocks, address from 0 to last block
Dbprintf("Tag memory dump, block 0 to %d", dwLast);
cmd1[1] = i;
ComputeCrc14443(CRC_14443_B, cmd1, 2, &cmd1[2], &cmd1[3]);
CodeAndTransmit14443bAsReader(cmd1, sizeof(cmd1));
-
-// LED_A_ON();
GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT, TRUE);
-// LED_A_OFF();
if (Demod.len != 6) { // Check if we got an answer from the tag
DbpString("Expected 6 bytes from tag, got less...");
return;
ComputeCrc14443(CRC_14443_B, Demod.output, 4, &cmd1[2], &cmd1[3]);
if(cmd1[2] != Demod.output[4] || cmd1[3] != Demod.output[5]) {
Dbprintf("CRC Error reading block! Expected: %04x got: %04x",
- (cmd1[2]<<8)+cmd1[3], (Demod.output[4]<<8)+Demod.output[5]);
+ (cmd1[2]<<8)+cmd1[3], (Demod.output[4]<<8)+Demod.output[5]);
// Do not return;, let's go on... (we should retry, maybe ?)
}
// Now print out the memory location:
Dbprintf("Address=%02x, Contents=%08x, CRC=%04x", i,
- (Demod.output[3]<<24) + (Demod.output[2]<<16) + (Demod.output[1]<<8) + Demod.output[0],
- (Demod.output[4]<<8)+Demod.output[5]);
+ (Demod.output[3]<<24) + (Demod.output[2]<<16) + (Demod.output[1]<<8) + Demod.output[0],
+ (Demod.output[4]<<8)+Demod.output[5]);
if (i == 0xff) {
break;
}
* Memory usage for this function, (within BigBuf)
* Last Received command (reader->tag) - MAX_FRAME_SIZE
* Last Received command (tag->reader) - MAX_FRAME_SIZE
- * DMA Buffer - DMA_BUFFER_SIZE
+ * DMA Buffer - ISO14443B_DMA_BUFFER_SIZE
* Demodulated samples received - all the rest
*/
void RAMFUNC SnoopIso14443b(void)
set_tracing(TRUE);
// The DMA buffer, used to stream samples from the FPGA
- int8_t *dmaBuf = (int8_t*) BigBuf_malloc(DMA_BUFFER_SIZE);
+ int8_t *dmaBuf = (int8_t*) BigBuf_malloc(ISO14443B_DMA_BUFFER_SIZE);
int lastRxCounter;
int8_t *upTo;
int ci, cq;
Dbprintf(" Trace: %i bytes", BigBuf_max_traceLen());
Dbprintf(" Reader -> tag: %i bytes", MAX_FRAME_SIZE);
Dbprintf(" tag -> Reader: %i bytes", MAX_FRAME_SIZE);
- Dbprintf(" DMA: %i bytes", DMA_BUFFER_SIZE);
+ Dbprintf(" DMA: %i bytes", ISO14443B_DMA_BUFFER_SIZE);
// Signal field is off, no reader signal, no tag signal
LEDsoff();
// Setup for the DMA.
FpgaSetupSsc();
upTo = dmaBuf;
- lastRxCounter = DMA_BUFFER_SIZE;
- FpgaSetupSscDma((uint8_t*) dmaBuf, DMA_BUFFER_SIZE);
+ lastRxCounter = ISO14443B_DMA_BUFFER_SIZE;
+ FpgaSetupSscDma((uint8_t*) dmaBuf, ISO14443B_DMA_BUFFER_SIZE);
uint8_t parity[MAX_PARITY_SIZE];
bool TagIsActive = FALSE;
// And now we loop, receiving samples.
for(;;) {
int behindBy = (lastRxCounter - AT91C_BASE_PDC_SSC->PDC_RCR) &
- (DMA_BUFFER_SIZE-1);
+ (ISO14443B_DMA_BUFFER_SIZE-1);
if(behindBy > maxBehindBy) {
maxBehindBy = behindBy;
}
cq = upTo[1];
upTo += 2;
lastRxCounter -= 2;
- if(upTo >= dmaBuf + DMA_BUFFER_SIZE) {
+ if(upTo >= dmaBuf + ISO14443B_DMA_BUFFER_SIZE) {
upTo = dmaBuf;
- lastRxCounter += DMA_BUFFER_SIZE;
+ lastRxCounter += ISO14443B_DMA_BUFFER_SIZE;
AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
- AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
+ AT91C_BASE_PDC_SSC->PDC_RNCR = ISO14443B_DMA_BUFFER_SIZE;
WDT_HIT();
- if(behindBy > (9*DMA_BUFFER_SIZE/10)) { // TODO: understand whether we can increase/decrease as we want or not?
+ 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 (!TagIsActive) { // no need to try decoding reader data if the tag is sending
if(Handle14443bUartBit(ci & 0x01)) {
if(triggered && tracing) {
- //GetParity(Uart.output, Uart.byteCnt, parity);
LogTrace(Uart.output, Uart.byteCnt, samples, samples, parity, TRUE);
}
/* And ready to receive another command. */
}
if(Handle14443bUartBit(cq & 0x01)) {
if(triggered && tracing) {
- //GetParity(Uart.output, Uart.byteCnt, parity);
LogTrace(Uart.output, Uart.byteCnt, samples, samples, parity, TRUE);
}
/* And ready to receive another command. */
/* false-triggered by the commands from the reader. */
DemodReset();
}
- ReaderIsActive = (Uart.state != STATE_UNSYNCD);
+ 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 & 0xFE, cq & 0xFE)) {
+ if(Handle14443bSamplesDemod(ci | 0x01, cq | 0x01)) {
//Use samples as a time measurement
if(tracing)
{
uint8_t parity[MAX_PARITY_SIZE];
- //GetParity(Demod.output, Demod.len, parity);
LogTrace(Demod.output, Demod.len, samples, samples, parity, FALSE);
}
triggered = TRUE;
set_tracing(TRUE);
-/* if(!powerfield) {
- // Make sure that we start from off, since the tags are stateful;
- // confusing things will happen if we don't reset them between reads.
- FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
- LED_D_OFF();
- SpinDelay(200);
- }
- */
-
- // if(!GETBIT(GPIO_LED_D)) { // if field is off
- // FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ);
- // // Signal field is on with the appropriate LED
- // LED_D_ON();
- // SpinDelay(200);
- // }
-
CodeAndTransmit14443bAsReader(data, datalen);
if(recv) {