[proxmark3-svn] / armsrc / pcf7931.c

#include "proxmark3.h"
#include "apps.h"
#include "lfsampling.h"
#include "pcf7931.h"
#include "string.h"

#define T0_PCF 8 //period for the pcf7931 in us
#define ALLOC 16

int DemodPCF7931(uint8_t **outBlocks) {

    uint8_t bits[256] = {0x00};
	uint8_t blocks[8][16];
    uint8_t *dest = BigBuf_get_addr();
    
	int GraphTraceLen = BigBuf_max_traceLen();
	if (  GraphTraceLen > 18000 )
		GraphTraceLen = 18000;
		
	int i, j, lastval, bitidx, half_switch;
	int clock = 64;
	int tolerance = clock / 8;
	int pmc, block_done;
	int lc, warnings = 0;
	int num_blocks = 0;
	int lmin=128, lmax=128;
	uint8_t dir;
	//clear read buffer
	BigBuf_Clear_keep_EM();

	LFSetupFPGAForADC(95, true);
	DoAcquisition_default(0, true);

	lmin = 64;
	lmax = 192;

	i = 2;

	/* Find first local max/min */
    if(dest[1] > dest[0]) {
		while(i < GraphTraceLen) {
            if( !(dest[i] > dest[i-1]) && dest[i] > lmax)
				break;
			i++;
		}
		dir = 0;
	}
	else {
		while(i < GraphTraceLen) {
            if( !(dest[i] < dest[i-1]) && dest[i] < lmin)
				break;
			i++;
		}
		dir = 1;
	}

	lastval = i++;
	half_switch = 0;
	pmc = 0;
	block_done = 0;

	for (bitidx = 0; i < GraphTraceLen; i++)
	{
        if ( (dest[i-1] > dest[i] && dir == 1 && dest[i] > lmax) || (dest[i-1] < dest[i] && dir == 0 && dest[i] < lmin))
		{
			lc = i - lastval;
			lastval = i;

			// Switch depending on lc length:
			// Tolerance is 1/8 of clock rate (arbitrary)
			if (ABS(lc-clock/4) < tolerance) {
				// 16T0
				if((i - pmc) == lc) { /* 16T0 was previous one */
					/* It's a PMC ! */
					i += (128+127+16+32+33+16)-1;
					lastval = i;
					pmc = 0;
					block_done = 1;
				}
				else {
					pmc = i;
				}
			} else if (ABS(lc-clock/2) < tolerance) {
				// 32TO
				if((i - pmc) == lc) { /* 16T0 was previous one */
					/* It's a PMC ! */
					i += (128+127+16+32+33)-1;
					lastval = i;
					pmc = 0;
					block_done = 1;
				}
				else if(half_switch == 1) {
                    bits[bitidx++] = 0;
					half_switch = 0;
				}
				else
					half_switch++;
			} else if (ABS(lc-clock) < tolerance) {
				// 64TO
                bits[bitidx++] = 1;
			} else {
				// Error
				warnings++;
				if (warnings > 10)
				{
					Dbprintf("Error: too many detection errors, aborting.");
					return 0;
				}
			}

			if(block_done == 1) {
				if(bitidx == 128) {
					for(j=0; j<16; j++) {
                        blocks[num_blocks][j] = 128*bits[j*8+7]+
                                64*bits[j*8+6]+
                                32*bits[j*8+5]+
                                16*bits[j*8+4]+
                                8*bits[j*8+3]+
                                4*bits[j*8+2]+
                                2*bits[j*8+1]+
                                bits[j*8];
						
					}
					num_blocks++;
				}
				bitidx = 0;
				block_done = 0;
				half_switch = 0;
			}
			if(i < GraphTraceLen)
                dir =(dest[i-1] > dest[i]) ? 0 : 1;
		}
		if(bitidx==255)
			bitidx=0;
		warnings = 0;
		if(num_blocks == 4) break;
	}
    memcpy(outBlocks, blocks, 16*num_blocks);
	return num_blocks;
}

int IsBlock0PCF7931(uint8_t *Block) {
	// Assume RFU means 0 :)
	if((memcmp(Block, "\x00\x00\x00\x00\x00\x00\x00\x01", 8) == 0) && memcmp(Block+9, "\x00\x00\x00\x00\x00\x00\x00", 7) == 0) // PAC enabled
		return 1;
	if((memcmp(Block+9, "\x00\x00\x00\x00\x00\x00\x00", 7) == 0) && Block[7] == 0) // PAC disabled, can it *really* happen ?
		return 1;
	return 0;
}

int IsBlock1PCF7931(uint8_t *Block) {
	// Assume RFU means 0 :)
	if( Block[10] == 0 && 
	    Block[11] == 0 && 
		Block[12] == 0 && 
		Block[13] == 0)
		 if ( (Block[14] & 0x7f) <= 9 && Block[15] <= 9)
			return 1;
	return 0;
}

void ReadPCF7931() {
	uint8_t Blocks[8][17];
	uint8_t tmpBlocks[4][16];
	int i, j, ind, ind2, n;
	int num_blocks = 0;
	int max_blocks = 8;
	int ident = 0;
	int error = 0;
	int tries = 0;

	memset(Blocks, 0, 8*17*sizeof(uint8_t));

	do {
		memset(tmpBlocks, 0, 4*16*sizeof(uint8_t));
		n = DemodPCF7931((uint8_t**)tmpBlocks);
		if(!n)
			error++;
		if(error==10 && num_blocks == 0) {
			Dbprintf("Error, no tag or bad tag");
			return;
		}
		else if (tries==20 || error==10) {
			Dbprintf("Error reading the tag");
			Dbprintf("Here is the partial content");
			goto end;
		}

		for(i=0; i<n; i++)
			Dbprintf("(dbg) %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x",
					 tmpBlocks[i][0], tmpBlocks[i][1], tmpBlocks[i][2], tmpBlocks[i][3], tmpBlocks[i][4], tmpBlocks[i][5], tmpBlocks[i][6], tmpBlocks[i][7],
					tmpBlocks[i][8], tmpBlocks[i][9], tmpBlocks[i][10], tmpBlocks[i][11], tmpBlocks[i][12], tmpBlocks[i][13], tmpBlocks[i][14], tmpBlocks[i][15]);
		if(!ident) {
			for(i=0; i<n; i++) {
				if(IsBlock0PCF7931(tmpBlocks[i])) {
					// Found block 0 ?
					if(i < n-1 && IsBlock1PCF7931(tmpBlocks[i+1])) {
						// Found block 1!
						// \o/
						ident = 1;
						memcpy(Blocks[0], tmpBlocks[i], 16);
						Blocks[0][ALLOC] = 1;
						memcpy(Blocks[1], tmpBlocks[i+1], 16);
						Blocks[1][ALLOC] = 1;
						max_blocks = MAX((Blocks[1][14] & 0x7f), Blocks[1][15]) + 1;
						// Debug print
						Dbprintf("(dbg) Max blocks: %d", max_blocks);
						num_blocks = 2;
						// Handle following blocks
						for(j=i+2, ind2=2; j!=i; j++, ind2++, num_blocks++) {
							if(j==n) j=0;
							if(j==i) break;
							memcpy(Blocks[ind2], tmpBlocks[j], 16);
							Blocks[ind2][ALLOC] = 1;
						}
						break;
					}
				}
			}
		}
		else {
			for(i=0; i<n; i++) { // Look for identical block in known blocks
				if(memcmp(tmpBlocks[i], "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", 16)) { // Block is not full of 00
					for(j=0; j<max_blocks; j++) {
						if(Blocks[j][ALLOC] == 1 && !memcmp(tmpBlocks[i], Blocks[j], 16)) {
							// Found an identical block
							for(ind=i-1,ind2=j-1; ind >= 0; ind--,ind2--) {
								if(ind2 < 0)
									ind2 = max_blocks;
								if(!Blocks[ind2][ALLOC]) { // Block ind2 not already found
									// Dbprintf("Tmp %d -> Block %d", ind, ind2);
									memcpy(Blocks[ind2], tmpBlocks[ind], 16);
									Blocks[ind2][ALLOC] = 1;
									num_blocks++;
									if(num_blocks == max_blocks) goto end;
								}
							}
							for(ind=i+1,ind2=j+1; ind < n; ind++,ind2++) {
								if(ind2 > max_blocks)
									ind2 = 0;
								if(!Blocks[ind2][ALLOC]) { // Block ind2 not already found
									// Dbprintf("Tmp %d -> Block %d", ind, ind2);
									memcpy(Blocks[ind2], tmpBlocks[ind], 16);
									Blocks[ind2][ALLOC] = 1;
									num_blocks++;
									if(num_blocks == max_blocks) goto end;
								}
							}
						}
					}
				}
			}
		}
		tries++;
		if (BUTTON_PRESS()) return;
	} while (num_blocks != max_blocks);
 end:
	Dbprintf("-----------------------------------------");
	Dbprintf("Memory content:");
	Dbprintf("-----------------------------------------");
	for(i=0; i<max_blocks; i++) {
		if(Blocks[i][ALLOC]==1)
			Dbprintf("%02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x",
					 Blocks[i][0], Blocks[i][1], Blocks[i][2], Blocks[i][3], Blocks[i][4], Blocks[i][5], Blocks[i][6], Blocks[i][7],
					Blocks[i][8], Blocks[i][9], Blocks[i][10], Blocks[i][11], Blocks[i][12], Blocks[i][13], Blocks[i][14], Blocks[i][15]);
		else
			Dbprintf("<missing block %d>", i);
	}
	Dbprintf("-----------------------------------------");

	cmd_send(CMD_ACK,0,0,0,0,0);
}


/* Write on a byte of a PCF7931 tag
 * @param address : address of the block to write
   @param byte : address of the byte to write
    @param data : data to write
 */
void WritePCF7931(uint8_t pass1, uint8_t pass2, uint8_t pass3, uint8_t pass4, uint8_t pass5, uint8_t pass6, uint8_t pass7, uint16_t init_delay, int32_t l, int32_t p, uint8_t address, uint8_t byte, uint8_t data)
{
	uint32_t tab[1024] = {0}; // data times frame
	uint32_t u = 0;
	uint8_t parity = 0;
	bool comp = 0;

	//BUILD OF THE DATA FRAME

	//alimentation of the tag (time for initializing)
	AddPatternPCF7931(init_delay, 0, 8192/2*T0_PCF, tab);

	//PMC
	Dbprintf("Initialization delay : %d us", init_delay);
	AddPatternPCF7931(8192/2*T0_PCF + 319*T0_PCF+70, 3*T0_PCF, 29*T0_PCF, tab);

	Dbprintf("Offsets : %d us on the low pulses width, %d us on the low pulses positions", l, p);

	//password indication bit
	AddBitPCF7931(1, tab, l, p);

	//password (on 56 bits)
	Dbprintf("Password (LSB first on each byte) : %02x %02x %02x %02x %02x %02x %02x", pass1,pass2,pass3,pass4,pass5,pass6,pass7);
	AddBytePCF7931(pass1, tab, l, p);
	AddBytePCF7931(pass2, tab, l, p);
	AddBytePCF7931(pass3, tab, l, p);
	AddBytePCF7931(pass4, tab, l, p);
	AddBytePCF7931(pass5, tab, l, p);
	AddBytePCF7931(pass6, tab, l, p);
	AddBytePCF7931(pass7, tab, l, p);


	//programming mode (0 or 1)
	AddBitPCF7931(0, tab, l, p);

	//block adress on 6 bits
	Dbprintf("Block address : %02x", address);
	for (u=0; u<6; u++)
	{
		if (address&(1<<u)) {	// bit 1
			 parity++;
			 AddBitPCF7931(1, tab, l, p);
		} else{					// bit 0
			 AddBitPCF7931(0, tab, l, p);
		}
	}

	//byte address on 4 bits
	Dbprintf("Byte address : %02x", byte);
	for (u=0; u<4; u++)
	{
		if (byte&(1<<u)) {	// bit 1
			 parity++;
			 AddBitPCF7931(1, tab, l, p);
		} else{				// bit 0
			 AddBitPCF7931(0, tab, l, p);
		}
	}

	//data on 8 bits
	Dbprintf("Data : %02x", data);
	for (u=0; u<8; u++)
	{
		if (data&(1<<u)) {	// bit 1
			 parity++;
			 AddBitPCF7931(1, tab, l, p);
		} else{				//bit 0
			 AddBitPCF7931(0, tab, l, p);
		}
	}


	//parity bit
	if((parity%2)==0){
	 	AddBitPCF7931(0, tab, l, p); //even parity
	}else{
		AddBitPCF7931(1, tab, l, p);//odd parity
	}

	//time access memory
	AddPatternPCF7931(5120+2680, 0, 0, tab);

	//conversion of the scale time
	for(u=0;u<500;u++){
		tab[u]=(tab[u] * 3)/2;
	}

	//compensation of the counter reload
	while (!comp){
		comp = 1;
		for(u=0;tab[u]!=0;u++){
			if(tab[u] > 0xFFFF){
			  tab[u] -= 0xFFFF;
			  comp = 0;
			}
		}
	}

	SendCmdPCF7931(tab);
}


/* Send a trame to a PCF7931 tags
 * @param tab : array of the data frame
 */

void SendCmdPCF7931(uint32_t * tab){
	uint16_t u=0, tempo=0;

	Dbprintf("Sending data frame...");

	FpgaDownloadAndGo(FPGA_BITSTREAM_LF);

	FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz

	FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_PASSTHRU );

	LED_A_ON();

	// steal this pin from the SSP and use it to control the modulation
	AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT;
	AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT;

	//initialization of the timer
	AT91C_BASE_PMC->PMC_PCER |= (0x1 << 12) | (0x1 << 13) | (0x1 << 14);
	AT91C_BASE_TCB->TCB_BMR = AT91C_TCB_TC0XC0S_NONE | AT91C_TCB_TC1XC1S_TIOA0 | AT91C_TCB_TC2XC2S_NONE;
	AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS; // timer disable
	AT91C_BASE_TC0->TC_CMR = AT91C_TC_CLKS_TIMER_DIV3_CLOCK;  //clock at 48/32 MHz
	AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN;
	AT91C_BASE_TCB->TCB_BCR = 1;


	tempo = AT91C_BASE_TC0->TC_CV;
	for( u = 0; tab[u] != 0; u += 3){

		// modulate antenna
		HIGH(GPIO_SSC_DOUT);
		while(tempo != tab[u]) tempo = AT91C_BASE_TC0->TC_CV;		

		// stop modulating antenna
		LOW(GPIO_SSC_DOUT);
		while(tempo != tab[u+1]) tempo = AT91C_BASE_TC0->TC_CV;

		// modulate antenna
		HIGH(GPIO_SSC_DOUT);
		while(tempo != tab[u+2]) tempo = AT91C_BASE_TC0->TC_CV;		
	}

	LED_A_OFF();
	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
	SpinDelay(200);

	AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS; // timer disable
	LED(0xFFFF, 1000);
}


/* Add a byte for building the data frame of PCF7931 tags 
 * @param b : byte to add
 * @param tab : array of the data frame
 * @param l : offset on low pulse width
 * @param p : offset on low pulse positioning
 */

bool AddBytePCF7931(uint8_t byte, uint32_t * tab, int32_t l, int32_t p){

	uint32_t u;
	for ( u=0; u<8; u++)
	{
Commit	Line	Data
ac2df346	1	#include "proxmark3.h"
	2	#include "apps.h"
	3	#include "lfsampling.h"
36804420	4	#include "pcf7931.h"
ac2df346	5	#include "string.h"
36804420	6
	7	#define T0_PCF 8 //period for the pcf7931 in us
	8	#define ALLOC 16
	9
36804420	10	int DemodPCF7931(uint8_t **outBlocks) {
	11
	12	uint8_t bits[256] = {0x00};
	13	uint8_t blocks[8][16];
	14	uint8_t *dest = BigBuf_get_addr();
	15
	16	int GraphTraceLen = BigBuf_max_traceLen();
	17	if ( GraphTraceLen > 18000 )
	18	GraphTraceLen = 18000;
2efd6394	19
36804420	20	int i, j, lastval, bitidx, half_switch;
	21	int clock = 64;
	22	int tolerance = clock / 8;
	23	int pmc, block_done;
	24	int lc, warnings = 0;
	25	int num_blocks = 0;
	26	int lmin=128, lmax=128;
	27	uint8_t dir;
c0f15a05	28	//clear read buffer
c0f15a05	29	BigBuf_Clear_keep_EM();
36804420	30
	31	LFSetupFPGAForADC(95, true);
	32	DoAcquisition_default(0, true);
	33
	34	lmin = 64;
	35	lmax = 192;
	36
	37	i = 2;
	38
	39	/* Find first local max/min */
	40	if(dest[1] > dest[0]) {
	41	while(i < GraphTraceLen) {
	42	if( !(dest[i] > dest[i-1]) && dest[i] > lmax)
	43	break;
	44	i++;
	45	}
	46	dir = 0;
	47	}
	48	else {
	49	while(i < GraphTraceLen) {
	50	if( !(dest[i] < dest[i-1]) && dest[i] < lmin)
	51	break;
	52	i++;
	53	}
	54	dir = 1;
	55	}
	56
	57	lastval = i++;
	58	half_switch = 0;
	59	pmc = 0;
	60	block_done = 0;
	61
	62	for (bitidx = 0; i < GraphTraceLen; i++)
	63	{
	64	if ( (dest[i-1] > dest[i] && dir == 1 && dest[i] > lmax) \|\| (dest[i-1] < dest[i] && dir == 0 && dest[i] < lmin))
	65	{
	66	lc = i - lastval;
	67	lastval = i;
	68
	69	// Switch depending on lc length:
	70	// Tolerance is 1/8 of clock rate (arbitrary)
f2c2b174	71	if (ABS(lc-clock/4) < tolerance) {
36804420	72	// 16T0
	73	if((i - pmc) == lc) { /* 16T0 was previous one */
	74	/* It's a PMC ! */
	75	i += (128+127+16+32+33+16)-1;
	76	lastval = i;
	77	pmc = 0;
	78	block_done = 1;
	79	}
	80	else {
	81	pmc = i;
	82	}
f2c2b174	83	} else if (ABS(lc-clock/2) < tolerance) {
36804420	84	// 32TO
	85	if((i - pmc) == lc) { /* 16T0 was previous one */
	86	/* It's a PMC ! */
	87	i += (128+127+16+32+33)-1;
	88	lastval = i;
	89	pmc = 0;
	90	block_done = 1;
	91	}
	92	else if(half_switch == 1) {
	93	bits[bitidx++] = 0;
	94	half_switch = 0;
	95	}
	96	else
	97	half_switch++;
f2c2b174	98	} else if (ABS(lc-clock) < tolerance) {
36804420	99	// 64TO
	100	bits[bitidx++] = 1;
	101	} else {
	102	// Error
	103	warnings++;
	104	if (warnings > 10)
	105	{
	106	Dbprintf("Error: too many detection errors, aborting.");
	107	return 0;
	108	}
	109	}
	110
	111	if(block_done == 1) {
	112	if(bitidx == 128) {
	113	for(j=0; j<16; j++) {
	114	blocks[num_blocks][j] = 128bits[j8+7]+
	115	64bits[j8+6]+
	116	32bits[j8+5]+
	117	16bits[j8+4]+
	118	8bits[j8+3]+
	119	4bits[j8+2]+
	120	2bits[j8+1]+
	121	bits[j*8];
	122
	123	}
	124	num_blocks++;
	125	}
	126	bitidx = 0;
	127	block_done = 0;
	128	half_switch = 0;
	129	}
	130	if(i < GraphTraceLen)
	131	dir =(dest[i-1] > dest[i]) ? 0 : 1;
	132	}
	133	if(bitidx==255)
	134	bitidx=0;
	135	warnings = 0;
	136	if(num_blocks == 4) break;
	137	}
	138	memcpy(outBlocks, blocks, 16*num_blocks);
	139	return num_blocks;
	140	}
	141
	142	int IsBlock0PCF7931(uint8_t *Block) {
	143	// Assume RFU means 0 :)
	144	if((memcmp(Block, "\x00\x00\x00\x00\x00\x00\x00\x01", 8) == 0) && memcmp(Block+9, "\x00\x00\x00\x00\x00\x00\x00", 7) == 0) // PAC enabled
	145	return 1;
	146	if((memcmp(Block+9, "\x00\x00\x00\x00\x00\x00\x00", 7) == 0) && Block[7] == 0) // PAC disabled, can it really happen ?
	147	return 1;
	148	return 0;
	149	}
	150
	151	int IsBlock1PCF7931(uint8_t *Block) {
	152	// Assume RFU means 0 :)
2efd6394	153	if( Block[10] == 0 &&
	154	Block[11] == 0 &&
	155	Block[12] == 0 &&
	156	Block[13] == 0)
	157	if ( (Block[14] & 0x7f) <= 9 && Block[15] <= 9)
36804420	158	return 1;
36804420	159	return 0;
	160	}
	161
	162	void ReadPCF7931() {
	163	uint8_t Blocks[8][17];
	164	uint8_t tmpBlocks[4][16];
	165	int i, j, ind, ind2, n;
	166	int num_blocks = 0;
	167	int max_blocks = 8;
	168	int ident = 0;
	169	int error = 0;
	170	int tries = 0;
	171
	172	memset(Blocks, 0, 817sizeof(uint8_t));
	173
	174	do {
	175	memset(tmpBlocks, 0, 416sizeof(uint8_t));
	176	n = DemodPCF7931((uint8_t**)tmpBlocks);
	177	if(!n)
	178	error++;
	179	if(error==10 && num_blocks == 0) {
	180	Dbprintf("Error, no tag or bad tag");
	181	return;
	182	}
	183	else if (tries==20 \|\| error==10) {
	184	Dbprintf("Error reading the tag");
	185	Dbprintf("Here is the partial content");
	186	goto end;
	187	}
	188
	189	for(i=0; i<n; i++)
	190	Dbprintf("(dbg) %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x",
	191	tmpBlocks[i][0], tmpBlocks[i][1], tmpBlocks[i][2], tmpBlocks[i][3], tmpBlocks[i][4], tmpBlocks[i][5], tmpBlocks[i][6], tmpBlocks[i][7],
	192	tmpBlocks[i][8], tmpBlocks[i][9], tmpBlocks[i][10], tmpBlocks[i][11], tmpBlocks[i][12], tmpBlocks[i][13], tmpBlocks[i][14], tmpBlocks[i][15]);
	193	if(!ident) {
	194	for(i=0; i<n; i++) {
	195	if(IsBlock0PCF7931(tmpBlocks[i])) {
	196	// Found block 0 ?
	197	if(i < n-1 && IsBlock1PCF7931(tmpBlocks[i+1])) {
	198	// Found block 1!
	199	// \o/
	200	ident = 1;
	201	memcpy(Blocks[0], tmpBlocks[i], 16);
	202	Blocks[0][ALLOC] = 1;
	203	memcpy(Blocks[1], tmpBlocks[i+1], 16);
	204	Blocks[1][ALLOC] = 1;
f2c2b174	205	max_blocks = MAX((Blocks[1][14] & 0x7f), Blocks[1][15]) + 1;
36804420	206	// Debug print
	207	Dbprintf("(dbg) Max blocks: %d", max_blocks);
	208	num_blocks = 2;
	209	// Handle following blocks
	210	for(j=i+2, ind2=2; j!=i; j++, ind2++, num_blocks++) {
	211	if(j==n) j=0;
	212	if(j==i) break;
	213	memcpy(Blocks[ind2], tmpBlocks[j], 16);
	214	Blocks[ind2][ALLOC] = 1;
	215	}
	216	break;
	217	}
	218	}
	219	}
	220	}
	221	else {
	222	for(i=0; i<n; i++) { // Look for identical block in known blocks
	223	if(memcmp(tmpBlocks[i], "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", 16)) { // Block is not full of 00
	224	for(j=0; j<max_blocks; j++) {
	225	if(Blocks[j][ALLOC] == 1 && !memcmp(tmpBlocks[i], Blocks[j], 16)) {
	226	// Found an identical block
	227	for(ind=i-1,ind2=j-1; ind >= 0; ind--,ind2--) {
	228	if(ind2 < 0)
	229	ind2 = max_blocks;
	230	if(!Blocks[ind2][ALLOC]) { // Block ind2 not already found
	231	// Dbprintf("Tmp %d -> Block %d", ind, ind2);
	232	memcpy(Blocks[ind2], tmpBlocks[ind], 16);
	233	Blocks[ind2][ALLOC] = 1;
	234	num_blocks++;
	235	if(num_blocks == max_blocks) goto end;
	236	}
	237	}
	238	for(ind=i+1,ind2=j+1; ind < n; ind++,ind2++) {
	239	if(ind2 > max_blocks)
	240	ind2 = 0;
	241	if(!Blocks[ind2][ALLOC]) { // Block ind2 not already found
	242	// Dbprintf("Tmp %d -> Block %d", ind, ind2);
	243	memcpy(Blocks[ind2], tmpBlocks[ind], 16);
	244	Blocks[ind2][ALLOC] = 1;
	245	num_blocks++;
	246	if(num_blocks == max_blocks) goto end;
	247	}
	248	}
	249	}
	250	}
	251	}
	252	}
	253	}
	254	tries++;
	255	if (BUTTON_PRESS()) return;
	256	} while (num_blocks != max_blocks);
	257	end:
	258	Dbprintf("-----------------------------------------");
	259	Dbprintf("Memory content:");
	260	Dbprintf("-----------------------------------------");
	261	for(i=0; i<max_blocks; i++) {
	262	if(Blocks[i][ALLOC]==1)
	263	Dbprintf("%02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x",
	264	Blocks[i][0], Blocks[i][1], Blocks[i][2], Blocks[i][3], Blocks[i][4], Blocks[i][5], Blocks[i][6], Blocks[i][7],
	265	Blocks[i][8], Blocks[i][9], Blocks[i][10], Blocks[i][11], Blocks[i][12], Blocks[i][13], Blocks[i][14], Blocks[i][15]);
	266	else
	267	Dbprintf("<missing block %d>", i);
	268	}
	269	Dbprintf("-----------------------------------------");
270
e16054a4	271	cmd_send(CMD_ACK,0,0,0,0,0);
36804420	272	}
	273
	274
	275	/* Write on a byte of a PCF7931 tag
	276	* @param address : address of the block to write
	277	@param byte : address of the byte to write
	278	@param data : data to write
	279	*/
	280	void WritePCF7931(uint8_t pass1, uint8_t pass2, uint8_t pass3, uint8_t pass4, uint8_t pass5, uint8_t pass6, uint8_t pass7, uint16_t init_delay, int32_t l, int32_t p, uint8_t address, uint8_t byte, uint8_t data)
	281	{
2efd6394	282	uint32_t tab[1024] = {0}; // data times frame
36804420	283	uint32_t u = 0;
	284	uint8_t parity = 0;
	285	bool comp = 0;
	286
	287	//BUILD OF THE DATA FRAME
	288
	289	//alimentation of the tag (time for initializing)
	290	AddPatternPCF7931(init_delay, 0, 8192/2*T0_PCF, tab);
	291
	292	//PMC
	293	Dbprintf("Initialization delay : %d us", init_delay);
	294	AddPatternPCF7931(8192/2T0_PCF + 319T0_PCF+70, 3T0_PCF, 29T0_PCF, tab);
	295
	296	Dbprintf("Offsets : %d us on the low pulses width, %d us on the low pulses positions", l, p);
	297
	298	//password indication bit
	299	AddBitPCF7931(1, tab, l, p);
	300
36804420	301	//password (on 56 bits)
	302	Dbprintf("Password (LSB first on each byte) : %02x %02x %02x %02x %02x %02x %02x", pass1,pass2,pass3,pass4,pass5,pass6,pass7);
	303	AddBytePCF7931(pass1, tab, l, p);
	304	AddBytePCF7931(pass2, tab, l, p);
	305	AddBytePCF7931(pass3, tab, l, p);
	306	AddBytePCF7931(pass4, tab, l, p);
	307	AddBytePCF7931(pass5, tab, l, p);
	308	AddBytePCF7931(pass6, tab, l, p);
	309	AddBytePCF7931(pass7, tab, l, p);
	310
	311
	312	//programming mode (0 or 1)
	313	AddBitPCF7931(0, tab, l, p);
	314
	315	//block adress on 6 bits
	316	Dbprintf("Block address : %02x", address);
	317	for (u=0; u<6; u++)
	318	{
	319	if (address&(1<<u)) { // bit 1
	320	parity++;
	321	AddBitPCF7931(1, tab, l, p);
	322	} else{ // bit 0
	323	AddBitPCF7931(0, tab, l, p);
	324	}
	325	}
	326
	327	//byte address on 4 bits
	328	Dbprintf("Byte address : %02x", byte);
	329	for (u=0; u<4; u++)
	330	{
	331	if (byte&(1<<u)) { // bit 1
	332	parity++;
	333	AddBitPCF7931(1, tab, l, p);
	334	} else{ // bit 0
	335	AddBitPCF7931(0, tab, l, p);
	336	}
	337	}
	338
	339	//data on 8 bits
	340	Dbprintf("Data : %02x", data);
	341	for (u=0; u<8; u++)
	342	{
	343	if (data&(1<<u)) { // bit 1
	344	parity++;
	345	AddBitPCF7931(1, tab, l, p);
	346	} else{ //bit 0
	347	AddBitPCF7931(0, tab, l, p);
	348	}
	349	}
	350
	351
	352	//parity bit
	353	if((parity%2)==0){
	354	AddBitPCF7931(0, tab, l, p); //even parity
	355	}else{
	356	AddBitPCF7931(1, tab, l, p);//odd parity
	357	}
	358
	359	//time access memory
	360	AddPatternPCF7931(5120+2680, 0, 0, tab);
	361
	362	//conversion of the scale time
	363	for(u=0;u<500;u++){
	364	tab[u]=(tab[u] * 3)/2;
365	}
366
2efd6394	367	//compensation of the counter reload
36804420	368	while (!comp){
	369	comp = 1;
	370	for(u=0;tab[u]!=0;u++){
	371	if(tab[u] > 0xFFFF){
	372	tab[u] -= 0xFFFF;
	373	comp = 0;
	374	}
	375	}
	376	}
	377
	378	SendCmdPCF7931(tab);
	379	}
	380
	381
	382
	383	/* Send a trame to a PCF7931 tags
	384	* @param tab : array of the data frame
	385	*/
	386
	387	void SendCmdPCF7931(uint32_t * tab){
614da335	388	uint16_t u=0, tempo=0;
36804420	389
614da335	390	Dbprintf("Sending data frame...");
36804420	391
	392	FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
	393
	394	FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
	395
	396	FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_PASSTHRU );
	397
	398	LED_A_ON();
	399
	400	// steal this pin from the SSP and use it to control the modulation
	401	AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT;
	402	AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT;
	403
	404	//initialization of the timer
	405	AT91C_BASE_PMC->PMC_PCER \|= (0x1 << 12) \| (0x1 << 13) \| (0x1 << 14);
	406	AT91C_BASE_TCB->TCB_BMR = AT91C_TCB_TC0XC0S_NONE \| AT91C_TCB_TC1XC1S_TIOA0 \| AT91C_TCB_TC2XC2S_NONE;
	407	AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS; // timer disable
	408	AT91C_BASE_TC0->TC_CMR = AT91C_TC_CLKS_TIMER_DIV3_CLOCK; //clock at 48/32 MHz
	409	AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN;
	410	AT91C_BASE_TCB->TCB_BCR = 1;
	411
	412
	413	tempo = AT91C_BASE_TC0->TC_CV;
614da335	414	for( u = 0; tab[u] != 0; u += 3){
36804420	415
	416	// modulate antenna
	417	HIGH(GPIO_SSC_DOUT);
614da335	418	while(tempo != tab[u]) tempo = AT91C_BASE_TC0->TC_CV;
36804420	419
	420	// stop modulating antenna
	421	LOW(GPIO_SSC_DOUT);
614da335	422	while(tempo != tab[u+1]) tempo = AT91C_BASE_TC0->TC_CV;
36804420	423
	424	// modulate antenna
	425	HIGH(GPIO_SSC_DOUT);
614da335	426	while(tempo != tab[u+2]) tempo = AT91C_BASE_TC0->TC_CV;
36804420	427	}
	428
	429	LED_A_OFF();
	430	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
	431	SpinDelay(200);
	432
36804420	433	AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS; // timer disable
36804420	434	LED(0xFFFF, 1000);
	435	}
	436
	437
	438	/* Add a byte for building the data frame of PCF7931 tags
	439	* @param b : byte to add
	440	* @param tab : array of the data frame
	441	* @param l : offset on low pulse width
	442	* @param p : offset on low pulse positioning
	443	*/
	444
	445	bool AddBytePCF7931(uint8_t byte, uint32_t * tab, int32_t l, int32_t p){
	446
	447	uint32_t u;
614da335	448	for ( u=0; u<8; u++)
36804420	449	{
36804420	450