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 = -1, fdboot = -1, fdout = -1;
 100     int n;
 101     int inlength,bootlength;
 102     uint32_t ldr;
 103     unsigned char* image;
 104     int origoffset;
 105     int ret = 0;
 106
 107     if(argc < 3) {
 108         usage();
 109     }
 110
 111     infile = argv[1];
 112     bootfile = argv[2];
 113     outfile = argv[3];
 114
 115     fdin = open(infile, O_RDONLY|O_BINARY);
 116     if (fdin < 0)
 117     {
 118         perror(infile);
 119         ret = 1;
 120         goto error_exit;
 121     }
 122
 123     fdboot = open(bootfile, O_RDONLY|O_BINARY);
 124     if (fdboot < 0)
 125     {
 126         perror(bootfile);
 127         ret = 2;
 128         goto error_exit;
 129     }
 130
 131     inlength = filesize(fdin);
 132     bootlength = filesize(fdboot);
 133
 134     image = malloc(inlength + bootlength);
 135
 136     if (image==NULL)
 137     {
 138         printf("[ERR]  Could not allocate memory, aborting\n");
 139         ret = 3;
 140         goto error_exit;
 141     }
 142
 143     n = read(fdin, image, inlength);
 144     if (n != inlength)
 145     {
 146         printf("[ERR] Could not read from %s\n",infile);
 147         ret = 4;
 148         goto error_exit;
 149     }
 150
 151     n = read(fdboot, image + inlength, bootlength);
 152     if (n != bootlength)
 153     {
 154         printf("[ERR] Could not read from %s\n",bootfile);
 155         ret = 5;
 156         goto error_exit;
 157     }
 158
 159     ldr = get_uint32le(image);
 160
 161     /* TODO: Verify it's a LDR instruction */
 162     origoffset = (ldr&0xfff) + 8;
 163
 164     printf("original firmware entry point: 0x%08x\n",
 165            (unsigned int) get_uint32le(image + origoffset));
 166     printf("New entry point: 0x%08x\n",0x20000000 + inlength + 8);
 167
 168     /* Save the original firmware entry point at the start of the bootloader image */
 169     put_uint32le(get_uint32le(image + origoffset),image+inlength);
 170     put_uint32le(0x20000000 + inlength,image + inlength + 4);
 171
 172     /* Change the original firmware entry point to the third word in our bootloader */
 173     put_uint32le(0x20000000 + inlength + 8,image+origoffset);
 174
 175
 176     telechips_encode_crc(image, inlength + bootlength);
 177
 178     fdout = open(outfile, O_WRONLY|O_CREAT|O_TRUNC|O_BINARY, 0644);
 179     if (fdout < 0)
 180     {
 181         perror(bootfile);
 182         ret = 6;
 183         goto error_exit;
 184     }
 185
 186     n = write(fdout, image, inlength + bootlength);
 187     if (n != inlength + bootlength)
 188     {
 189         printf("[ERR] Could not write output file %s\n",outfile);
 190         ret = 7;
 191         goto error_exit;
 192     }
 193
 194 error_exit:
 195
 196     if (fdin >= 0)
 197         close(fdin);
 198
 199     if (fdboot >= 0)
 200         close(fdboot);
 201
 202     if (fdout >= 0)
 203         close(fdout);
 204
 205     return ret;
 206 }