IDEA_microblaze

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/*
 * helloworld.c: simple test application
 *
 * This application configures UART 16550 to baud rate 9600.
 * PS7 UART (Zynq) is not initialized by this application, since
 * bootrom/bsp configures it to baud rate 115200
 *
 * ------------------------------------------------
 * | UART TYPE   BAUD RATE                        |
 * ------------------------------------------------
 *   uartns550   9600
 *   uartlite    Configurable only in HW design
 *   ps7_uart    115200 (configured by bootrom/bsp)
 */

#include <stdio.h>
#include <string.h>
#include "platform.h"
#include "xil_printf.h"

//int modInverse(int a, int m)
//{
//  int m0 = m, t, q;
//  int x0 = 0, x1 = 1;
//
//  if (m == 1)
//      return 0;
//
//  while (a > 1) {
//      q = a / m;
//      t = m;
//      m = a % m;
//      a = t;
//      t = x0;
//      x0 = x1 - q * x0;
//      x1 = t;
//  }
//
//  return x1;
//}

unsigned short int modInverse(unsigned short int a, unsigned short int m)
{
    a = a%m;
    for (unsigned short int x=1; x<m; x++)
       if ((a*x) % m == 1)
          return x;
}

int main()
{
    init_platform();

    unsigned short int Keys[60];
    unsigned short int inversedKeys[60];
    int i;
    char c;
    const int MOD = 65537;
    char *str = "RWoM6zqNvL3J+nZVJhRgI0RvV2Q/k618MCQcsWVgbmI=";

    memset(Keys, 0, sizeof(unsigned short int) * 60);
    memset(inversedKeys, 0, sizeof(unsigned short int) * 60);

    memcpy(Keys, str, strlen(str));

    inversedKeys[1] = modInverse(Keys[49], MOD);
    inversedKeys[2] = - Keys[50];
    inversedKeys[3] = - Keys[51];
    inversedKeys[4] = modInverse(Keys[52], MOD);

    for (i = 5; i <= 52; i ++) {
        inversedKeys[i] = Keys[52 - i];
        inversedKeys[i + 1] = Keys[52 -i + 1];

        inversedKeys[i + 2] = modInverse(Keys[52 - i - 4], MOD);
        inversedKeys[i + 3] = - Keys[52 - i - 2];
        inversedKeys[i + 4] = - Keys[52 - i - 3];
        inversedKeys[i + 5] = modInverse(Keys[52 - i - 1], MOD);
    }

    str = &Keys;

    for (i = 0; i < sizeof(Keys); i ++) {
            xil_printf("%c", str[i]);
        }
        xil_printf("\n");

    str = &inversedKeys;
    for (i = 0; i < sizeof(inversedKeys); i ++) {
        xil_printf("%c", str[i]);
    }
    xil_printf("\n");

    xil_printf("%d\n", modInverse(100, 7));

    cleanup_platform();
    return 0;
}