tools/gigabeat.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2006 by Christian Hack
  11  *
  12  * All files in this archive are subject to the GNU General Public License.
  13  * See the file COPYING in the source tree root for full license agreement.
  14  *
  15  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  16  * KIND, either express or implied.
  17  *
  18  ****************************************************************************/
  19
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22
  23 extern void int2le(unsigned int val, unsigned char* addr);
  24 extern unsigned int le2int(unsigned char* buf);
  25
  26 static FILE * openinfile( const char * filename )
  27 {
  28     FILE * F = fopen( filename, "rb" );
  29     if( F == NULL )
  30     {
  31         fprintf( stderr, "Couldn't open input file %s\n", filename );
  32         perror( "Error was " );
  33         exit( -1 );
  34     };
  35     return F;
  36 }
  37
  38 static FILE * openoutfile( const char * filename )
  39 {
  40     FILE * F = fopen( filename, "wb" );
  41     if( F == NULL )
  42     {
  43         fprintf( stderr, "Couldn't open output file %s\n", filename );
  44         perror( "Error was " );
  45         exit( -1 );
  46     };
  47     return F;
  48 }
  49
  50 int gigabeat_code(char *infile, char *outfile)
  51 {
  52     FILE *in, *out;
  53     unsigned long size = 0;
  54     unsigned long bytes_read;
  55     unsigned char buf[4];
  56     unsigned long data;
  57     unsigned long key = 0x19751217;
  58
  59     in = openinfile(infile);
  60     out = openoutfile(outfile);
  61
  62     while (!feof(in)) {
  63         bytes_read = fread(buf, 1, 4, in);
  64
  65         /* Read in little-endian */
  66         data = le2int(buf);
  67
  68         data = data ^ key;
  69
  70         key = key + (key << 1);
  71         key = key + 0x19751217;
  72
  73         size += bytes_read;
  74
  75         /* Write out little-endian */
  76         int2le(data, buf);
  77
  78         fwrite(buf, 1, bytes_read, out);
  79     }
  80
  81     fprintf(stderr, "File processed successfully\n" );
  82
  83     fclose(in);
  84     fclose(out);
  85     return(0);
  86 }