proxmark3/armsrc/util.c

//-----------------------------------------------------------------------------
// Jonathan Westhues, Sept 2005
//
// 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.
//-----------------------------------------------------------------------------
// Utility functions used in many places, not specific to any piece of code.
//-----------------------------------------------------------------------------
#include "util.h"

size_t nbytes(size_t nbits) {
	return (nbits >> 3)+((nbits % 8) > 0);
}

/*
 ref  http://www.csm.ornl.gov/~dunigan/crc.html
 Returns the value v with the bottom b [0,32] bits reflected. 
 Example: reflect(0x3e23L,3) == 0x3e26
*/
uint32_t reflect(uint32_t v, int b) {
	uint32_t t = v;
	for ( int i = 0; i < b; ++i) {
		if (t & 1)
			v |=  BITMASK((b-1)-i);
		else
			v &= ~BITMASK((b-1)-i);
		t>>=1;
	}
	return v;
}

uint8_t reflect8(uint8_t b) {
	return ((b * 0x80200802ULL) & 0x0884422110ULL) * 0x0101010101ULL >> 32;
}
uint16_t reflect16(uint16_t b) {
    uint16_t v = 0;
    v |= (b & 0x8000) >> 15; 
    v |= (b & 0x4000) >> 13;
    v |= (b & 0x2000) >> 11;
    v |= (b & 0x1000) >> 9;
    v |= (b & 0x0800) >> 7;
    v |= (b & 0x0400) >> 5;
    v |= (b & 0x0200) >> 3;
    v |= (b & 0x0100) >> 1;

    v |= (b & 0x0080) << 1;
    v |= (b & 0x0040) << 3;
    v |= (b & 0x0020) << 5;
    v |= (b & 0x0010) << 7;
    v |= (b & 0x0008) << 9;
    v |= (b & 0x0004) << 11;
    v |= (b & 0x0002) << 13;
    v |= (b & 0x0001) << 15;
    return v;
}

void num_to_bytes(uint64_t n, size_t len, uint8_t* dest) {
	while (len--) {
		dest[len] = (uint8_t) n;
		n >>= 8;
	}
}

uint64_t bytes_to_num(uint8_t* src, size_t len) {
	uint64_t num = 0;
	while (len--) {
		num = (num << 8) | (*src);
		src++;
	}
	return num;
}

// RotateLeft - Ultralight, Desfire
void rol(uint8_t *data, const size_t len) {
    uint8_t first = data[0];
    for (size_t i = 0; i < len-1; i++) {
        data[i] = data[i+1];
    }
    data[len-1] = first;
}

void lsl (uint8_t *data, size_t len) {
    for (size_t n = 0; n < len - 1; n++) {
        data[n] = (data[n] << 1) | (data[n+1] >> 7);
    }
    data[len - 1] <<= 1;
}

int32_t le24toh (uint8_t data[3]) {
    return (data[2] << 16) | (data[1] << 8) | data[0];
}

//convert hex digit to integer
uint8_t hex2int(char hexchar){
    switch(hexchar){
        case '0': return 0; break;
        case '1': return 1; break;
        case '2': return 2; break;
        case '3': return 3; break;
        case '4': return 4; break;
        case '5': return 5; break;
        case '6': return 6; break;
        case '7': return 7; break;
        case '8': return 8; break;
        case '9': return 9; break;
        case 'a':
        case 'A': return 10; break;
        case 'b':
		case 'B': return 11; break;
        case 'c':
        case 'C': return 12; break;
        case 'd':
		case 'D': return 13; break;
        case 'e':
        case 'E': return 14; break;
        case 'f':
        case 'F': return 15; break;
        default:
            return 0;
    }
}

void LEDsoff() {
	LED_A_OFF();
	LED_B_OFF();
	LED_C_OFF();
	LED_D_OFF();
}

// LEDs: R(C) O(A) G(B) -- R(D) [1, 2, 4 and 8]
void LED(int led, int ms) {
	if (led & LED_RED)
		LED_C_ON();
	if (led & LED_ORANGE)
		LED_A_ON();
	if (led & LED_GREEN)
		LED_B_ON();
	if (led & LED_RED2)
		LED_D_ON();

	if (!ms)
		return;

	SpinDelay(ms);

	if (led & LED_RED)
		LED_C_OFF();
	if (led & LED_ORANGE)
		LED_A_OFF();
	if (led & LED_GREEN)
		LED_B_OFF();
	if (led & LED_RED2)
		LED_D_OFF();
}

// Determine if a button is double clicked, single clicked,
// not clicked, or held down (for ms || 1sec)
// In general, don't use this function unless you expect a
// double click, otherwise it will waste 500ms -- use BUTTON_HELD instead
int BUTTON_CLICKED(int ms) {
	// Up to 500ms in between clicks to mean a double click
	int ticks = (48000 * (ms ? ms : 1000)) >> 10;

	// If we're not even pressed, forget about it!
	if (!BUTTON_PRESS())
		return BUTTON_NO_CLICK;

	// Borrow a PWM unit for my real-time clock
	AT91C_BASE_PWMC->PWMC_ENA = PWM_CHANNEL(0);
	// 48 MHz / 1024 gives 46.875 kHz
	AT91C_BASE_PWMC_CH0->PWMC_CMR = PWM_CH_MODE_PRESCALER(10);
	AT91C_BASE_PWMC_CH0->PWMC_CDTYR = 0;
	AT91C_BASE_PWMC_CH0->PWMC_CPRDR = 0xffff;

	uint16_t start = AT91C_BASE_PWMC_CH0->PWMC_CCNTR;

	int letoff = 0;
	for(;;)
	{
		uint16_t now = AT91C_BASE_PWMC_CH0->PWMC_CCNTR;

		// We haven't let off the button yet
		if (!letoff)
		{
			// We just let it off!
			if (!BUTTON_PRESS())
			{
				letoff = 1;

				// reset our timer for 500ms
				start = AT91C_BASE_PWMC_CH0->PWMC_CCNTR;
				ticks = (48000 * (500)) >> 10;
			}

			// Still haven't let it off
			else
				// Have we held down a full second?
				if (now == (uint16_t)(start + ticks))
					return BUTTON_HOLD;
		}

		// We already let off, did we click again?
		else
			// Sweet, double click!
			if (BUTTON_PRESS())
				return BUTTON_DOUBLE_CLICK;

			// Have we ran out of time to double click?
			else
				if (now == (uint16_t)(start + ticks))
					// At least we did a single click
					return BUTTON_SINGLE_CLICK;

		WDT_HIT();
	}

	// We should never get here
	return BUTTON_ERROR;
}

// Determine if a button is held down
int BUTTON_HELD(int ms) {
	// If button is held for one second
	int ticks = (48000 * (ms ? ms : 1000)) >> 10;

	// If we're not even pressed, forget about it!
	if (!BUTTON_PRESS())
		return BUTTON_NO_CLICK;

	// Borrow a PWM unit for my real-time clock
	AT91C_BASE_PWMC->PWMC_ENA = PWM_CHANNEL(0);
	// 48 MHz / 1024 gives 46.875 kHz
	AT91C_BASE_PWMC_CH0->PWMC_CMR = PWM_CH_MODE_PRESCALER(10);
	AT91C_BASE_PWMC_CH0->PWMC_CDTYR = 0;
	AT91C_BASE_PWMC_CH0->PWMC_CPRDR = 0xffff;

	uint16_t start = AT91C_BASE_PWMC_CH0->PWMC_CCNTR;

	for(;;)
	{
		uint16_t now = AT91C_BASE_PWMC_CH0->PWMC_CCNTR;

		// As soon as our button let go, we didn't hold long enough
		if (!BUTTON_PRESS())
			return BUTTON_SINGLE_CLICK;

		// Have we waited the full second?
		else
			if (now == (uint16_t)(start + ticks))
				return BUTTON_HOLD;

		WDT_HIT();
	}

	// We should never get here
	return BUTTON_ERROR;
}

/* Similar to FpgaGatherVersion this formats stored version information
 * into a string representation. It takes a pointer to the struct version_information,
 * verifies the magic properties, then stores a formatted string, prefixed by
 * prefix in dst.
 */
void FormatVersionInformation(char *dst, int len, const char *prefix, void *version_information) {
	struct version_information *v = (struct version_information*)version_information;
	dst[0] = 0;
	strncat(dst, prefix, len-1);
	if (v->magic != VERSION_INFORMATION_MAGIC) {
		strncat(dst, "Missing/Invalid version information\n", len - strlen(dst) - 1);
		return;
	}
	if (v->versionversion != 1) {
		strncat(dst, "Version information not understood\n", len - strlen(dst) - 1);
		return;
	}
	if (!v->present) {
		strncat(dst, "Version information not available\n", len - strlen(dst) - 1);
		return;
	}

	strncat(dst, v->gitversion, len - strlen(dst) - 1);
	if (v->clean == 0) {
		strncat(dst, "-unclean", len - strlen(dst) - 1);
	} else if (v->clean == 2) {
		strncat(dst, "-suspect", len - strlen(dst) - 1);
	}

	strncat(dst, " ", len - strlen(dst) - 1);
	strncat(dst, v->buildtime, len - strlen(dst) - 1);
	strncat(dst, "\n", len - strlen(dst) - 1);
}