#include <stdlib.h>
#include <stdint.h> 

#include "crc.h"
#include "uart.h"

extern FILE uart_stdout;

uint16_t crc_xmodem_update (uint16_t crc, uint8_t data)
{
    int i;
    crc = crc ^ ((uint16_t)data << 8);
    for (i=0; i<8; i++)
    {
        if (crc & 0x8000)
            crc = (crc << 1) ^ 0x1021;
        else
            crc <<= 1;
    }

    return crc;
}

uint16_t do_crc(uint8_t * data,uint16_t size)
{
	uint16_t crc =0;
	uint16_t i;
	for (i=0; i<size; i++){
		crc = crc_xmodem_update(crc,data[i]);
		//printf("%x : %x\n",crc,data[i]);	
	}
  	return crc;
}


uint16_t do_crc_update(uint16_t crc,uint8_t * data,uint16_t size)
{
  uint16_t i;
  for (i=0; i<size; i++)
	crc = crc_xmodem_update(crc,data[i]);
  return crc;
}