flash/extract/extract.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2003 by Jörg Hohensohn
  11  *
  12  * Tool to extract the scrambled image out of an Archos flash ROM dump
  13  *
  14  * All files in this archive are subject to the GNU General Public License.
  15  * See the file COPYING in the source tree root for full license agreement.
  16  *
  17  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  18  * KIND, either express or implied.
  19  *
  20  ****************************************************************************/
  21
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <memory.h>
  25
  26 #define UINT8 unsigned char
  27 #define UINT16 unsigned short
  28 #define UINT32 unsigned long
  29
  30 #define IMAGE_HEADER 0x6000 // a 32 byte header in front of the software image
  31 #define IMAGE_START  0x6020     // software image position in Flash
  32
  33
  34 // place a 32 bit value into memory, big endian
  35 void Write32(UINT8* pByte, UINT32 value)
  36 {
  37         pByte[0] = (UINT8)(value >> 24);
  38         pByte[1] = (UINT8)(value >> 16);
  39         pByte[2] = (UINT8)(value >> 8);
  40         pByte[3] = (UINT8)(value);
  41 }
  42
  43
  44 // read a 32 bit value from memory, big endian
  45 UINT32 Read32(UINT8* pByte)
  46 {
  47         UINT32 value = 0;
  48
  49         value |= (UINT32)pByte[0] << 24;
  50         value |= (UINT32)pByte[1] << 16;
  51         value |= (UINT32)pByte[2] << 8;
  52         value |= (UINT32)pByte[3];
  53
  54         return value;
  55 }
  56
  57
  58 // entry point
  59 int main(int argc, char* argv[])
  60 {
  61         FILE* pInFile;
  62         FILE* pOutFile;
  63         UINT8 aHeader[6];
  64         UINT8 aImage[256*1024];
  65         UINT32 i;
  66         UINT32 uiSize, uiStart;
  67         UINT16 usChecksum = 0;
  68
  69         if (argc < 2)
  70         {
  71                 printf("Extract the software image out of an original Archos Flash ROM dump.\n");
  72                 printf("Result is a scrambled file, use the descramble tool to get the binary,\n");
  73                 printf(" always without the -fm option, even if processing an FM software.\n\n");
  74                 printf("Usage: extract <flash dump file> <output file>\n");
  75                 printf("Example: extract internal_rom_2000000-203FFFF.bin archos.ajz\n");
  76                 exit(0);
  77         }
  78
  79         pInFile = fopen(argv[1], "rb");
  80         if (pInFile == NULL)
  81         {
  82                 printf("Error opening input file %s\n", argv[1]);
  83                 exit(1);
  84         }
  85
  86         if (fread(aImage, 1, sizeof(aImage), pInFile) != sizeof(aImage))
  87         {
  88                 printf("Error reading input file %s, must be 256kB in size.\n", argv[1]);
  89                 fclose(pInFile);
  90                 exit(2);
  91         }
  92         fclose(pInFile);
  93
  94         // find out about the type
  95         uiStart = Read32(aImage + 8);
  96         uiSize = Read32(aImage + 12); // booted ROM image
  97         if (uiStart == 0x02000100 && uiSize > 20000)
  98         {       // Player has no loader, starts directly with the image
  99                 uiStart = 0x0100;
 100         }
 101         else
 102         {       // Recorder / FM / V2 Recorder
 103                 uiStart = IMAGE_START;
 104                 uiSize = Read32(aImage + IMAGE_HEADER + 4); // size record of header
 105         }
 106
 107         // sanity check
 108         if (uiSize > sizeof(aImage) - uiStart || uiSize < 40000)
 109         {
 110                 printf("Error: Impossible image size &d bytes.\n", uiSize);
 111                 exit(3);
 112         }
 113
 114         // generate checksum
 115         for (i=0; i<uiSize; i++)
 116         {
 117                 UINT8 byte;
 118                 byte = aImage[uiStart + i];
 119                 byte = ~((byte >> 1) | ((byte << 7) & 0x80)); /* poor man's ROR */
 120                 usChecksum += byte;
 121         }
 122
 123         // make header
 124         Write32(aHeader + 2, usChecksum); // checksum in 5th and 6th byte
 125         Write32(aHeader, uiSize); // size in first 4 bytes
 126
 127         pOutFile = fopen(argv[2], "wb");
 128         if (pOutFile == NULL)
 129         {
 130                 printf("Error opening output file %s\n", argv[2]);
 131                 exit(4);
 132         }
 133
 134         if (fwrite(aHeader, 1, sizeof(aHeader), pOutFile) != sizeof(aHeader)
 135          || fwrite(aImage + uiStart, 1, uiSize, pOutFile) != uiSize)
 136         {
 137                 printf("Write error\n");
 138                 fclose(pOutFile);
 139                 exit(5);
 140         }
 141
 142         fclose(pOutFile);
 143
 144         return 0;
 145 }