RfidResearchGroup/proxmark3
1
1
Fork 0
mirror of https://github.com/RfidResearchGroup/proxmark3.git synced 2024-12-28 03:14:53 +08:00
Code Issues Projects Releases Packages Wiki Activity

hitag rework - WIP

Browse source
This commit is contained in:
iceman1001 2019-12-24 10:20:07 +01:00
parent d2330aa393
commit 094c9905b0
2 changed files with 273 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

241
armsrc/lfadc.c Normal file
View file

@ -0,0 +1,241 @@
//-----------------------------------------------------------------------------
// 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
// the license.
//-----------------------------------------------------------------------------
// LF ADC read/write implementation
//-----------------------------------------------------------------------------
#include "lfadc.h"
#include "lfsampling.h"
#include "fpgaloader.h"
#include "ticks.h"
// Sam7s has several timers, we will use the source TIMER_CLOCK1 (aka AT91C_TC_CLKS_TIMER_DIV1_CLOCK)
// TIMER_CLOCK1 = MCK/2, MCK is running at 48 MHz, Timer is running at 48/2 = 24 MHz
// Carrier periods (T0) have duration of 8 microseconds (us), which is 1/125000 per second
// T0 = TIMER_CLOCK1 / 125000 = 192
//#define T0 192
// Sam7s has three counters, we will use the first TIMER_COUNTER_0 (aka TC0)
// using TIMER_CLOCK3 (aka AT91C_TC_CLKS_TIMER_DIV3_CLOCK)
// as a counting signal. TIMER_CLOCK3 = MCK/32, MCK is running at 48 MHz, so the timer is running at 48/32 = 1500 kHz
// Carrier period (T0) have duration of 8 microseconds (us), which is 1/125000 per second (125 kHz frequency)
// T0 = timer/carrier = 1500kHz/125kHz = 1500000/125000 = 6
#define T0 3
//////////////////////////////////////////////////////////////////////////////
// Global variables
//////////////////////////////////////////////////////////////////////////////
bool rising_edge = false;
bool logging = true;
bool reader_mode = false;
//////////////////////////////////////////////////////////////////////////////
// Auxiliary functions
//////////////////////////////////////////////////////////////////////////////
bool lf_test_periods(size_t expected, size_t count) {
// Compute 10% deviation (integer operation, so rounded down)
size_t diviation = expected / 10;
return ((count > (expected - diviation)) && (count < (expected + diviation)));
}
//////////////////////////////////////////////////////////////////////////////
// Low frequency (LF) adc passthrough functionality
//////////////////////////////////////////////////////////////////////////////
uint8_t previous_adc_val = 0;
size_t lf_count_edge_periods_ex(size_t max, bool wait, bool detect_gap) {
size_t periods = 0;
volatile uint8_t adc_val;
//uint8_t avg_peak = 140, avg_through = 96;
uint8_t avg_peak = 130, avg_through = 106;
while (!BUTTON_PRESS()) {
// Watchdog hit
WDT_HIT();
if (AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
adc_val = AT91C_BASE_SSC->SSC_RHR;
periods++;
if (logging) logSample(adc_val, 1, 8, 0, 0);
// Only test field changes if state of adc values matter
if (!wait) {
// Test if we are locating a field modulation (100% ASK = complete field drop)
if (detect_gap) {
// Only return when the field completely dissapeared
if (adc_val == 0) {
return periods;
}
} else {
// Trigger on a modulation swap by observing an edge change
if (rising_edge) {
if ((previous_adc_val > avg_peak) && (adc_val <= previous_adc_val)) {
rising_edge = false;
return periods;
}
} else {
if ((previous_adc_val < avg_through) && (adc_val >= previous_adc_val)) {
rising_edge = true;
return periods;
}
}
}
}
previous_adc_val = adc_val;
if (periods == max) return 0;
}
}
if (logging) logSample(255, 1, 8, 0, 0);
return 0;
}
size_t lf_count_edge_periods(size_t max) {
return lf_count_edge_periods_ex(max, false, false);
}
size_t lf_detect_gap(size_t max) {
return lf_count_edge_periods_ex(max, false, true);
}
void lf_reset_counter() {
// TODO: find out the correct reset settings for tag and reader mode
if (reader_mode) {
// Reset values for reader mode
rising_edge = false;
previous_adc_val = 0xFF;
} else {
// Reset values for tag/transponder mode
rising_edge = false;
previous_adc_val = 0xFF;
}
}
bool lf_get_tag_modulation() {
return (rising_edge == false);
}
void lf_wait_periods(size_t periods) {
lf_count_edge_periods_ex(periods, true, false);
}
void lf_init(bool reader) {
reader_mode = reader;
FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
if (reader) {
FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
} else {
FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC);
}
// Connect the A/D to the peak-detected low-frequency path.
SetAdcMuxFor(GPIO_MUXSEL_LOPKD);
// Now set up the SSC to get the ADC samples that are now streaming at us.
FpgaSetupSsc();
// When in reader mode, give the field a bit of time to settle.
if (reader) SpinDelay(50);
// Steal this pin from the SSP (SPI communication channel with fpga) and use it to control the modulation
AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT;
AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT;
LOW(GPIO_SSC_DOUT);
// Enable peripheral Clock for TIMER_CLOCK0
AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_TC0);
AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS;
AT91C_BASE_TC0->TC_CMR = AT91C_TC_CLKS_TIMER_DIV4_CLOCK;
// Enable peripheral Clock for TIMER_CLOCK0
AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_TC1);
AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKDIS;
AT91C_BASE_TC1->TC_CMR = AT91C_TC_CLKS_TIMER_DIV4_CLOCK;
// Clear all leds
LEDsoff();
// Reset and enable timers
AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;
AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;
// Prepare data trace
if (logging) initSamplingBuffer();
}
void lf_finalize() {
// Disable timers
AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS;
AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKDIS;
// return stolen pin to SSP
AT91C_BASE_PIOA->PIO_PDR = GPIO_SSC_DOUT;
AT91C_BASE_PIOA->PIO_ASR = GPIO_SSC_DIN | GPIO_SSC_DOUT;
FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
LEDsoff();
}
size_t lf_detect_field_drop(size_t max) {
size_t periods = 0;
volatile uint8_t adc_val;
// usb check?
while (!BUTTON_PRESS()) {
// Watchdog hit
WDT_HIT();
if (AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
periods++;
adc_val = AT91C_BASE_SSC->SSC_RHR;
if (logging) logSample(adc_val, 1, 8, 0, 0);
if (adc_val == 0) {
rising_edge = false;
return periods;
}
if (periods == max) return 0;
}
}
return 0;
}
inline void lf_modulation(bool modulation) {
if (modulation) {
HIGH(GPIO_SSC_DOUT);
} else {
LOW(GPIO_SSC_DOUT);
}
}
inline void lf_manchester_send_bit(uint8_t bit) {
lf_modulation(bit != 0);
lf_wait_periods(16);
lf_modulation(bit == 0);
lf_wait_periods(16);
}
bool lf_manchester_send_bytes(const uint8_t *frame, size_t frame_len) {
LED_B_ON();
// Send the content of the frame
for (size_t i = 0; i < frame_len; i++) {
lf_manchester_send_bit((frame[i / 8] >> (7 - (i % 8))) & 1);
}
LED_B_OFF();
return true;
}

32
armsrc/lfadc.h Normal file
View file

@ -0,0 +1,32 @@
//-----------------------------------------------------------------------------
// 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
// the license.
//-----------------------------------------------------------------------------
// LF ADC read/write implementation
//-----------------------------------------------------------------------------
#ifndef __LFADC_H__
#define __LFADC_H__
#include "proxmark3_arm.h"
#include "common.h"
#include "cmd.h"
#include "util.h"
#include "string.h"
extern bool logging;
bool lf_test_periods(size_t expected, size_t count);
size_t lf_count_edge_periods(size_t max);
size_t lf_detect_gap(size_t max);
void lf_reset_counter();
bool lf_get_tag_modulation();
void lf_wait_periods(size_t periods);
void lf_init(bool reader);
void lf_finalize();
size_t lf_detect_field_drop(size_t max);
bool lf_manchester_send_bytes(const uint8_t *frame, size_t frame_len);
void lf_modulation(bool mod);
#endif // __LFADC_H__