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Diffstat (limited to 'tools/firmware-utils/src/encode_crc.c')
-rwxr-xr-x | tools/firmware-utils/src/encode_crc.c | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/tools/firmware-utils/src/encode_crc.c b/tools/firmware-utils/src/encode_crc.c new file mode 100755 index 0000000000..647fb92e89 --- /dev/null +++ b/tools/firmware-utils/src/encode_crc.c @@ -0,0 +1,151 @@ +/* ************************************************************************** + + 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 + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + + ************************************************************************* */ + + +#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; +} |