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  * 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 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <sys/types.h>
  25 #include <sys/stat.h>
  26 #include <fcntl.h>
  27 #include <inttypes.h>
  28 #include "telechips.h"
  29
  30 /*
  31
  32 Append a Rockbox bootloader to a Telechips original firmware file.
  33
  34 The first instruction in a TCC firmware file is always of the form:
  35
  36    ldr     pc, [pc, #xxx]
  37
  38 where [pc, #xxx] is the entry point of the firmware - e.g. 0x20000020
  39
  40 mktccboot appends the Rockbox bootloader to the end of the original
  41 firmware image and replaces the contents of [pc, #xxx] with the entry
  42 point of our bootloader - i.e. the length of the original firmware plus
  43 0x20000000.
  44
  45 It then stores the original entry point from [pc, #xxx] in a fixed
  46 offset in the Rockbox boootloader, which is used by the bootloader to
  47 dual-boot.
  48
  49 Finally, mktccboot corrects the length and CRCs in the main firmware
  50 header, creating a new legal firmware file which can be installed on
  51 the device.
  52
  53 */
  54
  55 /* win32 compatibility */
  56
  57 #ifndef O_BINARY
  58 #define O_BINARY 0
  59 #endif
  60
  61 static void put_uint32le(uint32_t x, unsigned char* p)
  62 {
  63     p[0] = x & 0xff;
  64     p[1] = (x >> 8) & 0xff;
  65     p[2] = (x >> 16) & 0xff;
  66     p[3] = (x >> 24) & 0xff;
  67 }
  68
  69 static uint32_t get_uint32le(unsigned char* p)
  70 {
  71     return (p[3] << 24) | (p[2] << 16) | (p[1]<<8) | p[0];
  72 }
  73
  74 void usage(void)
  75 {
  76     printf("Usage: mktccboot <firmware file> <boot file> <output file>\n");
  77
  78     exit(1);
  79 }
  80
  81 off_t filesize(int fd) {
  82     struct stat buf;
  83
  84     if (fstat(fd,&buf) < 0) {
  85         perror("[ERR]  Checking filesize of input file");
  86         return -1;
  87     } else {
  88         return(buf.st_size);
  89     }
  90 }
  91
  92
  93 int main(int argc, char *argv[])
  94 {
  95     char *infile, *bootfile, *outfile;
  96     int fdin, fdboot,fdout;
  97     int i,n;
  98     int inlength,bootlength;
  99     uint32_t ldr;
 100     unsigned char* image;
 101     int origoffset;
 102
 103     if(argc < 3) {
 104         usage();
 105     }
 106
 107     infile = argv[1];
 108     bootfile = argv[2];
 109     outfile = argv[3];
 110
 111     fdin = open(infile, O_RDONLY|O_BINARY);
 112     if (fdin < 0)
 113     {
 114         perror(infile);
 115     }
 116
 117     fdboot = open(bootfile, O_RDONLY|O_BINARY);
 118     if (fdboot < 0)
 119     {
 120         perror(bootfile);
 121     }
 122
 123     inlength = filesize(fdin);
 124     bootlength = filesize(fdboot);
 125
 126     image = malloc(inlength + bootlength);
 127
 128     if (image==NULL)
 129     {
 130         printf("[ERR]  Could not allocate memory, aborting\n");
 131         return 1;
 132     }
 133
 134     n = read(fdin, image, inlength);
 135     if (n != inlength)
 136     {
 137         printf("[ERR] Could not read from %s\n",infile);
 138         return 2;
 139     }
 140
 141     n = read(fdboot, image + inlength, bootlength);
 142     if (n != bootlength)
 143     {
 144         printf("[ERR] Could not read from %s\n",bootfile);
 145         return 3;
 146     }
 147
 148     ldr = get_uint32le(image);
 149
 150     /* TODO: Verify it's a LDR instruction */
 151     origoffset = (ldr&0xfff) + 8;
 152
 153     printf("original firmware entry point: 0x%08x\n",get_uint32le(image + origoffset));
 154     printf("New entry point: 0x%08x\n",0x20000000 + inlength + 8);
 155
 156     /* Save the original firmware entry point at the start of the bootloader image */
 157     put_uint32le(get_uint32le(image + origoffset),image+inlength);
 158     put_uint32le(0x20000000 + inlength,image + inlength + 4);
 159
 160     /* Change the original firmware entry point to the third word in our bootloader */
 161     put_uint32le(0x20000000 + inlength + 8,image+origoffset);
 162
 163
 164     telechips_encode_crc(image, inlength + bootlength);
 165
 166     fdout = open(outfile, O_WRONLY|O_CREAT|O_TRUNC|O_BINARY, 0644);
 167     if (fdout < 0)
 168     {
 169         perror(bootfile);
 170     }
 171
 172     n = write(fdout, image, inlength + bootlength);
 173     if (n != inlength + bootlength)
 174     {
 175         printf("[ERR] Could not write output file %s\n",outfile);
 176         return 3;
 177     }
 178
 179     close(fdin);
 180     close(fdboot);
 181     close(fdout);
 182
 183     return 0;
 184 }