tools/mktccboot.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2007 by Dave Chapman
  11  *
  12  * Based on mkboot, Copyright (C) 2005 by Linus Nielsen Feltzing
  13  *
  14  * This program is free software; you can redistribute it and/or
  15  * modify it under the terms of the GNU General Public License
  16  * as published by the Free Software Foundation; either version 2
  17  * of the License, or (at your option) any later version.
  18  *
  19  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  20  * KIND, either express or implied.
  21  *
  22  ****************************************************************************/
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26 #include <unistd.h>
  27 #include <sys/types.h>
  28 #include <sys/stat.h>
  29 #include <fcntl.h>
  30 #include <inttypes.h>
  31 #include "telechips.h"
  32
  33 /*
  34
  35 Append a Rockbox bootloader to a Telechips original firmware file.
  36
  37 The first instruction in a TCC firmware file is always of the form:
  38
  39    ldr     pc, [pc, #xxx]
  40
  41 where [pc, #xxx] is the entry point of the firmware - e.g. 0x20000020
  42
  43 mktccboot appends the Rockbox bootloader to the end of the original
  44 firmware image and replaces the contents of [pc, #xxx] with the entry
  45 point of our bootloader - i.e. the length of the original firmware plus
  46 0x20000000.
  47
  48 It then stores the original entry point from [pc, #xxx] in a fixed
  49 offset in the Rockbox boootloader, which is used by the bootloader to
  50 dual-boot.
  51
  52 Finally, mktccboot corrects the length and CRCs in the main firmware
  53 header, creating a new legal firmware file which can be installed on
  54 the device.
  55
  56 */
  57
  58 /* win32 compatibility */
  59
  60 #ifndef O_BINARY
  61 #define O_BINARY 0
  62 #endif
  63
  64 static void put_uint32le(uint32_t x, unsigned char* p)
  65 {
  66     p[0] = x & 0xff;
  67     p[1] = (x >> 8) & 0xff;
  68     p[2] = (x >> 16) & 0xff;
  69     p[3] = (x >> 24) & 0xff;
  70 }
  71
  72 static uint32_t get_uint32le(unsigned char* p)
  73 {
  74     return (p[3] << 24) | (p[2] << 16) | (p[1]<<8) | p[0];
  75 }
  76
  77 void usage(void)
  78 {
  79     printf("Usage: mktccboot <firmware file> <boot file> <output file>\n");
  80
  81     exit(1);
  82 }
  83
  84 off_t filesize(int fd) {
  85     struct stat buf;
  86
  87     if (fstat(fd,&buf) < 0) {
  88         perror("[ERR]  Checking filesize of input file");
  89         return -1;
  90     } else {
  91         return(buf.st_size);
  92     }
  93 }
  94
  95
  96 int main(int argc, char *argv[])
  97 {
  98     char *infile, *bootfile, *outfile;
  99     int fdin, fdboot,fdout;
 100     int n;
 101     int inlength,bootlength;
 102     uint32_t ldr;
 103     unsigned char* image;
 104     int origoffset;
 105
 106     if(argc < 3) {
 107         usage();
 108     }
 109
 110     infile = argv[1];
 111     bootfile = argv[2];
 112     outfile = argv[3];
 113
 114     fdin = open(infile, O_RDONLY|O_BINARY);
 115     if (fdin < 0)
 116     {
 117         perror(infile);
 118     }
 119
 120     fdboot = open(bootfile, O_RDONLY|O_BINARY);
 121     if (fdboot < 0)
 122     {
 123         perror(bootfile);
 124     }
 125
 126     inlength = filesize(fdin);
 127     bootlength = filesize(fdboot);
 128
 129     image = malloc(inlength + bootlength);
 130
 131     if (image==NULL)
 132     {
 133         printf("[ERR]  Could not allocate memory, aborting\n");
 134         return 1;
 135     }
 136
 137     n = read(fdin, image, inlength);
 138     if (n != inlength)
 139     {
 140         printf("[ERR] Could not read from %s\n",infile);
 141         return 2;
 142     }
 143
 144     n = read(fdboot, image + inlength, bootlength);
 145     if (n != bootlength)
 146     {
 147         printf("[ERR] Could not read from %s\n",bootfile);
 148         return 3;
 149     }
 150
 151     ldr = get_uint32le(image);
 152
 153     /* TODO: Verify it's a LDR instruction */
 154     origoffset = (ldr&0xfff) + 8;
 155
 156     printf("original firmware entry point: 0x%08x\n",get_uint32le(image + origoffset));
 157     printf("New entry point: 0x%08x\n",0x20000000 + inlength + 8);
 158
 159     /* Save the original firmware entry point at the start of the bootloader image */
 160     put_uint32le(get_uint32le(image + origoffset),image+inlength);
 161     put_uint32le(0x20000000 + inlength,image + inlength + 4);
 162
 163     /* Change the original firmware entry point to the third word in our bootloader */
 164     put_uint32le(0x20000000 + inlength + 8,image+origoffset);
 165
 166
 167     telechips_encode_crc(image, inlength + bootlength);
 168
 169     fdout = open(outfile, O_WRONLY|O_CREAT|O_TRUNC|O_BINARY, 0644);
 170     if (fdout < 0)
 171     {
 172         perror(bootfile);
 173     }
 174
 175     n = write(fdout, image, inlength + bootlength);
 176     if (n != inlength + bootlength)
 177     {
 178         printf("[ERR] Could not write output file %s\n",outfile);
 179         return 3;
 180     }
 181
 182     close(fdin);
 183     close(fdboot);
 184     close(fdout);
 185
 186     return 0;
 187 }