60aa12984a
This uses "GPL-2.0-or-later" header for files identified using scancode license scanner with 100% score as GPL 2.0 or later. Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
139 lines
2.9 KiB
C
139 lines
2.9 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/* **************************************************************************
|
|
|
|
This program creates a CRC checksum and encodes the file that is named
|
|
in the command line.
|
|
|
|
Compile with: gcc encode_crc.c -Wall -o encode_crc
|
|
|
|
Author: Michael Margraf (michael.margraf@freecom.com)
|
|
Copyright: Freecom Technology GmbH, Berlin, 2004
|
|
www.freecom.com
|
|
|
|
************************************************************************* */
|
|
|
|
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <sys/stat.h>
|
|
|
|
// *******************************************************************
|
|
// CCITT polynom G(x)=x^16+x^12+x^5+1
|
|
#define POLYNOM 0x1021
|
|
|
|
// CRC algorithm with MSB first
|
|
int make_crc16(int crc, char new)
|
|
{
|
|
int i;
|
|
crc = crc ^ (((int)new) << 8);
|
|
|
|
for(i=0; i<8; i++) { // work on 8 bits in "new"
|
|
crc <<= 1; // MSBs first
|
|
if(crc & 0x10000) crc ^= POLYNOM;
|
|
}
|
|
return crc & 0xFFFF;
|
|
}
|
|
|
|
// *******************************************************************
|
|
// Reads the file "filename" into memory and returns pointer to the buffer.
|
|
static char *readfile(char *filename, int *size)
|
|
{
|
|
FILE *fp;
|
|
char *buffer;
|
|
struct stat info;
|
|
|
|
if (stat(filename,&info)!=0)
|
|
return NULL;
|
|
|
|
if ((fp=fopen(filename,"r"))==NULL)
|
|
return NULL;
|
|
|
|
buffer=NULL;
|
|
for (;;)
|
|
{
|
|
if ((buffer=(char *)malloc(info.st_size+1))==NULL)
|
|
break;
|
|
|
|
if (fread(buffer,1,info.st_size,fp)!=info.st_size)
|
|
{
|
|
free(buffer);
|
|
buffer=NULL;
|
|
break;
|
|
}
|
|
|
|
buffer[info.st_size]='\0';
|
|
if(size) *size = info.st_size;
|
|
|
|
break;
|
|
}
|
|
|
|
(void)fclose(fp);
|
|
|
|
return buffer;
|
|
}
|
|
|
|
|
|
// *******************************************************************
|
|
int main(int argc, char** argv)
|
|
{
|
|
if(argc < 3) {
|
|
printf("ERROR: Argument missing!\n\n");
|
|
return 1;
|
|
}
|
|
|
|
int count; // size of file in bytes
|
|
char *p, *master = readfile(argv[1], &count);
|
|
if(!master) {
|
|
printf("ERROR: File not found!\n");
|
|
return 1;
|
|
}
|
|
|
|
int crc = 0xFFFF, z;
|
|
|
|
p = master;
|
|
for(z=0; z<count; z++)
|
|
crc = make_crc16(crc, *(p++)); // calculate CRC
|
|
short crc16 = (short)crc;
|
|
|
|
/*
|
|
if(argc > 2) { // with flag for device recognition ?
|
|
p = argv[2];
|
|
for(z=strlen(p); z>0; z--) {
|
|
crc ^= (int)(*p);
|
|
*(p++) = (char)crc; // encode device flag
|
|
}
|
|
}
|
|
*/
|
|
|
|
p = master;
|
|
for(z=0; z<count; z++) {
|
|
crc ^= (int)(*p);
|
|
*(p++) = (char)crc; // encode file
|
|
}
|
|
|
|
|
|
// write encoded file...
|
|
FILE *fp = fopen(argv[2], "w");
|
|
if(!fp) {
|
|
printf("ERROR: File not writeable!\n");
|
|
return 1;
|
|
}
|
|
|
|
if(argc > 3) { // add flag for device recognition ?
|
|
fwrite(argv[3], strlen(argv[3]), sizeof(char), fp);
|
|
}
|
|
else {
|
|
// Device is an FSG, so byte swap (IXP4xx is big endian)
|
|
crc16 = ((crc16 >> 8) & 0xFF) | ((crc16 << 8) & 0xFF00);
|
|
}
|
|
|
|
fwrite(&crc16, 1, sizeof(short), fp); // first write CRC
|
|
|
|
fwrite(master, count, sizeof(char), fp); // write content
|
|
fclose(fp);
|
|
|
|
free(master);
|
|
return 0;
|
|
}
|