view ostc4pack/src/checksum_final_add_fletcher.cpp @ 261:cc2406b835ff bm-3

Bugfix: do not reset saturation on surfacing Commit 822416168585 introduced a subtle bug. On surfacing, the value of saturation was reset to 0. This is prefect proof why global data is a dangerous thing, and subtle changes can introduce seemingly unrelated bugs. While it would be much better to factor out as much as possible global data, the fix here does not do that. Simply, the bug is fixed without touching the rather complex gTissue_nitrogen_bar/gTissue_helium_bar handling. Signed-off-by: Jan Mulder <jlmulder@xs4all.nl>
author Jan Mulder <jlmulder@xs4all.nl>
date Tue, 23 Apr 2019 13:05:20 +0200
parents 1e707b34667e
children 01f40cb1057e
line wrap: on
line source

#include <iostream>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <time.h>

void fletcher16(unsigned char *result1, unsigned char *result2, unsigned char const *data, size_t bytes )
{
        unsigned short sum1 = 0xff, sum2 = 0xff;
        size_t tlen;
 
        while (bytes) {
                tlen = bytes >= 20 ? 20 : bytes;
                bytes -= tlen;
                do {
                        sum2 += sum1 += *data++;
                } while (--tlen);
                sum1 = (sum1 & 0xff) + (sum1 >> 8);
                sum2 = (sum2 & 0xff) + (sum2 >> 8);
        }
        /* Second reduction step to reduce sums to 8 bits */
        sum1 = (sum1 & 0xff) + (sum1 >> 8);
        sum2 = (sum2 & 0xff) + (sum2 >> 8);
        *result2 = (sum2 & 0xff);
        *result1 = (sum1 & 0xff);
//        return sum2 << 8 | sum1;
}


// This is a variant of fletcher16 with a 16 bit sum instead of an 8 bit sum,
// and modulo 2^16 instead of 2^16-1
void
hw_ostc3_firmware_checksum (unsigned char *result1, unsigned char *result2, unsigned char *result3, unsigned char *result4, unsigned char const *data, size_t bytes )
{
	unsigned short low = 0;
	unsigned short high = 0;
	for (unsigned int i = 0; i < bytes; i++) {
		low  += data[i];
		high += low;
	}
        *result1 = (low & 0xff);
        *result2 = (low/256 & 0xff);
        *result3 = (unsigned char)(high & 0xff);
        *result4 = (unsigned char)((high/256) & 0xff);
//	return (((unsigned int)high) << 16) + low;
}


int main(int argc, char** argv) {
	
	
	FILE *fp, * fpout;
	size_t lenTotal,lenTemp;
	unsigned char buf[2000000];
	char *file = argv[1];
	char *file2 =  argv[2];
	char *file3 =  argv[3];
	unsigned int pruefsumme;
	unsigned char buf2[4];

   	printf("1: %s\n",  file);
   	printf("2: %s\n",  file2);
   	printf("3: %s\n",  file3);
   	printf("\n");
     
	
		//write File with length and cheksum
	char filename[500], filenameout[510] ;
	sprintf(filename,"%s",file);
	int filelength = strlen(filename);
	filename[filelength -4] = 0;
	
	lenTotal = 0;
	if (NULL == (fp = fopen(file, "rb")))
	{
	    printf("Unable to open %s for reading\n", file);
	    return -1;
	}
	lenTemp = fread(&buf[lenTotal], sizeof(char), sizeof(buf), fp);
//	lenTemp = fread(buf, sizeof(char), sizeof(buf), fp);
	lenTotal = lenTemp;
	printf("%d bytes read (hex: %#x )\n", lenTemp,lenTemp);
	fclose(fp);

	if(file2)
	{
		if (NULL == (fp = fopen(file2, "rb")))
		{
		    printf("Unable to open %s for reading\n", file2);
		    return -1;
		}
		lenTemp = fread(&buf[lenTotal], sizeof(char), sizeof(buf)-lenTotal, fp);
		lenTotal += lenTemp;
		printf("%d bytes read (hex: %#x )\n", lenTemp,lenTemp);
		fclose(fp);
	}
	if(file3)
	{
		if (NULL == (fp = fopen(file3, "rb")))
		{
		    printf("Unable to open %s for reading\n", file3);
		    return -1;
		}
		lenTemp = fread(&buf[lenTotal], sizeof(char), sizeof(buf)-lenTotal, fp);
		lenTotal += lenTemp;
		printf("%d bytes read (hex: %#x )\n", lenTemp,lenTemp);
		fclose(fp);
	}

   	printf("\n");
	printf("%d bytes read (hex: %#x ) total \n", lenTotal,lenTotal);

	time_t rawtime;
	time (&rawtime);
	struct tm *timeinfo;
	timeinfo = localtime(&rawtime);
	
//	sprintf(filenameout,"fwupdate_%s.bin",ctime(&rawtime));
	sprintf(filenameout,"OSTC4update_%02u%02u%02u.bin",timeinfo->tm_year-100,timeinfo->tm_mon+1,timeinfo->tm_mday);

    fpout = fopen(filenameout, "wb");     
    for(int i = 0;i <lenTotal;i++)
    {
    	if(fwrite(&buf[i],1,1,fpout) != 1)
     	printf("error writing\n");
	}
	
	hw_ostc3_firmware_checksum(&buf2[0],&buf2[1],&buf2[2],&buf2[3],buf,lenTotal);
	printf("checksum  %#x %#x %#x %#x\n", buf2[0],buf2[1], buf2[2], buf2[3]);
   	if(fwrite(&buf2[0],1,4,fpout) != 4)
    	printf("error writing checksum\n");
    ;
	fclose(fpout);
}