X-Git-Url: http://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/db09cb3adbe715b058a64357184e4963a8b6d78e..d19929cbe8d681b60496ca6d9d9cbd806822e163:/armsrc/lfops.c diff --git a/armsrc/lfops.c b/armsrc/lfops.c index 5ef01dcf..1b5f220e 100644 --- a/armsrc/lfops.c +++ b/armsrc/lfops.c @@ -433,17 +433,17 @@ void SimulateTagLowFrequency(int period, int gap, int ledcontrol) { int i; uint8_t *tab = (uint8_t *)BigBuf; - - FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_SIMULATOR); - + + FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_EDGE_DETECT); + AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT | GPIO_SSC_CLK; - + AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT; AT91C_BASE_PIOA->PIO_ODR = GPIO_SSC_CLK; - + #define SHORT_COIL() LOW(GPIO_SSC_DOUT) #define OPEN_COIL() HIGH(GPIO_SSC_DOUT) - + i = 0; for(;;) { while(!(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_CLK)) { @@ -453,18 +453,18 @@ void SimulateTagLowFrequency(int period, int gap, int ledcontrol) } WDT_HIT(); } - + if (ledcontrol) LED_D_ON(); - + if(tab[i]) OPEN_COIL(); else SHORT_COIL(); - + if (ledcontrol) LED_D_OFF(); - + while(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_CLK) { if(BUTTON_PRESS()) { DbpString("Stopped"); @@ -472,7 +472,7 @@ void SimulateTagLowFrequency(int period, int gap, int ledcontrol) } WDT_HIT(); } - + i++; if(i == period) { i = 0; @@ -484,197 +484,9 @@ void SimulateTagLowFrequency(int period, int gap, int ledcontrol) } } -/* Provides a framework for bidirectional LF tag communication - * Encoding is currently Hitag2, but the general idea can probably - * be transferred to other encodings. - * - * The new FPGA code will, for the LF simulator mode, give on SSC_FRAME - * (PA15) a thresholded version of the signal from the ADC. Setting the - * ADC path to the low frequency peak detection signal, will enable a - * somewhat reasonable receiver for modulation on the carrier signal - * that is generated by the reader. The signal is low when the reader - * field is switched off, and high when the reader field is active. Due - * to the way that the signal looks like, mostly only the rising edge is - * useful, your mileage may vary. - * - * Neat perk: PA15 can not only be used as a bit-banging GPIO, but is also - * TIOA1, which can be used as the capture input for timer 1. This should - * make it possible to measure the exact edge-to-edge time, without processor - * intervention. - * - * Arguments: divisor is the divisor to be sent to the FPGA (e.g. 95 for 125kHz) - * t0 is the carrier frequency cycle duration in terms of MCK (384 for 125kHz) - * - * The following defines are in carrier periods: - */ -#define HITAG_T_0_MIN 15 /* T[0] should be 18..22 */ -#define HITAG_T_1_MIN 24 /* T[1] should be 26..30 */ -#define HITAG_T_EOF 40 /* T_EOF should be > 36 */ -#define HITAG_T_WRESP 208 /* T_wresp should be 204..212 */ - -static void hitag_handle_frame(int t0, int frame_len, char *frame); -//#define DEBUG_RA_VALUES 1 #define DEBUG_FRAME_CONTENTS 1 void SimulateTagLowFrequencyBidir(int divisor, int t0) { -#if DEBUG_RA_VALUES || DEBUG_FRAME_CONTENTS - int i = 0; -#endif - char frame[10]; - int frame_pos=0; - - DbpString("Starting Hitag2 emulator, press button to end"); - hitag2_init(); - - /* Set up simulator mode, frequency divisor which will drive the FPGA - * and analog mux selection. - */ - FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_SIMULATOR); - FpgaSendCommand(FPGA_CMD_SET_DIVISOR, divisor); - SetAdcMuxFor(GPIO_MUXSEL_LOPKD); - RELAY_OFF(); - - /* Set up Timer 1: - * Capture mode, timer source MCK/2 (TIMER_CLOCK1), TIOA is external trigger, - * external trigger rising edge, load RA on rising edge of TIOA, load RB on rising - * edge of TIOA. Assign PA15 to TIOA1 (peripheral B) - */ - - AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_TC1); - AT91C_BASE_PIOA->PIO_BSR = GPIO_SSC_FRAME; - AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKDIS; - AT91C_BASE_TC1->TC_CMR = AT91C_TC_CLKS_TIMER_DIV1_CLOCK | - AT91C_TC_ETRGEDG_RISING | - AT91C_TC_ABETRG | - AT91C_TC_LDRA_RISING | - AT91C_TC_LDRB_RISING; - AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKEN | - AT91C_TC_SWTRG; - - /* calculate the new value for the carrier period in terms of TC1 values */ - t0 = t0/2; - - int overflow = 0; - while(!BUTTON_PRESS()) { - WDT_HIT(); - if(AT91C_BASE_TC1->TC_SR & AT91C_TC_LDRAS) { - int ra = AT91C_BASE_TC1->TC_RA; - if((ra > t0*HITAG_T_EOF) | overflow) ra = t0*HITAG_T_EOF+1; -#if DEBUG_RA_VALUES - if(ra > 255 || overflow) ra = 255; - ((char*)BigBuf)[i] = ra; - i = (i+1) % 8000; -#endif - - if(overflow || (ra > t0*HITAG_T_EOF) || (ra < t0*HITAG_T_0_MIN)) { - /* Ignore */ - } else if(ra >= t0*HITAG_T_1_MIN ) { - /* '1' bit */ - if(frame_pos < 8*sizeof(frame)) { - frame[frame_pos / 8] |= 1<<( 7-(frame_pos%8) ); - frame_pos++; - } - } else if(ra >= t0*HITAG_T_0_MIN) { - /* '0' bit */ - if(frame_pos < 8*sizeof(frame)) { - frame[frame_pos / 8] |= 0<<( 7-(frame_pos%8) ); - frame_pos++; - } - } - - overflow = 0; - LED_D_ON(); - } else { - if(AT91C_BASE_TC1->TC_CV > t0*HITAG_T_EOF) { - /* Minor nuisance: In Capture mode, the timer can not be - * stopped by a Compare C. There's no way to stop the clock - * in software, so we'll just have to note the fact that an - * overflow happened and the next loaded timer value might - * have wrapped. Also, this marks the end of frame, and the - * still running counter can be used to determine the correct - * time for the start of the reply. - */ - overflow = 1; - - if(frame_pos > 0) { - /* Have a frame, do something with it */ -#if DEBUG_FRAME_CONTENTS - ((char*)BigBuf)[i++] = frame_pos; - memcpy( ((char*)BigBuf)+i, frame, 7); - i+=7; - i = i % sizeof(BigBuf); -#endif - hitag_handle_frame(t0, frame_pos, frame); - memset(frame, 0, sizeof(frame)); - } - frame_pos = 0; - - } - LED_D_OFF(); - } - } - DbpString("All done"); -} - -static void hitag_send_bit(int t0, int bit) { - if(bit == 1) { - /* Manchester: Loaded, then unloaded */ - LED_A_ON(); - SHORT_COIL(); - while(AT91C_BASE_TC1->TC_CV < t0*15); - OPEN_COIL(); - while(AT91C_BASE_TC1->TC_CV < t0*31); - LED_A_OFF(); - } else if(bit == 0) { - /* Manchester: Unloaded, then loaded */ - LED_B_ON(); - OPEN_COIL(); - while(AT91C_BASE_TC1->TC_CV < t0*15); - SHORT_COIL(); - while(AT91C_BASE_TC1->TC_CV < t0*31); - LED_B_OFF(); - } - AT91C_BASE_TC1->TC_CCR = AT91C_TC_SWTRG; /* Reset clock for the next bit */ - -} -static void hitag_send_frame(int t0, int frame_len, const char const * frame, int fdt) -{ - OPEN_COIL(); - AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT; - - /* Wait for HITAG_T_WRESP carrier periods after the last reader bit, - * not that since the clock counts since the rising edge, but T_wresp is - * with respect to the falling edge, we need to wait actually (T_wresp - T_g) - * periods. The gap time T_g varies (4..10). - */ - while(AT91C_BASE_TC1->TC_CV < t0*(fdt-8)); - - int saved_cmr = AT91C_BASE_TC1->TC_CMR; - AT91C_BASE_TC1->TC_CMR &= ~AT91C_TC_ETRGEDG; /* Disable external trigger for the clock */ - AT91C_BASE_TC1->TC_CCR = AT91C_TC_SWTRG; /* Reset the clock and use it for response timing */ - - int i; - for(i=0; i<5; i++) - hitag_send_bit(t0, 1); /* Start of frame */ - - for(i=0; iTC_CMR = saved_cmr; -} - -/* Callback structure to cleanly separate tag emulation code from the radio layer. */ -static int hitag_cb(const char* response_data, const int response_length, const int fdt, void *cb_cookie) -{ - hitag_send_frame(*(int*)cb_cookie, response_length, response_data, fdt); - return 0; -} -/* Frame length in bits, frame contents in MSBit first format */ -static void hitag_handle_frame(int t0, int frame_len, char *frame) -{ - hitag2_handle_command(frame, frame_len, hitag_cb, &t0); } // compose fc/8 fc/10 waveform